Alberta Electric System Operator
Long Range Significant Transmission Outages for the period of 24 months starting 2025-04-05

The table below contains the significant transmission outages submitted as tentative to the AESO.
These Outages have not yet necessarily been approved, but are listed for awareness and coordination purposes.
An Outage has been considered significant for this table if it meets any one (1) or more of the following criteria:
  1. it affects a transmission facility operating at two hundred and forty (240) kV or greater;
  2. it affects an intertie;
  3. it affects an element connecting facilities owned by two (2) or more different legal owners of transmission facilities;
  4. it affects an element that connects a generating unit or an aggregated generating facility to the interconnected electric system;
  5. it requires the ISO to issue a dispatch or directive for generation in order to facilitate the planned outage;
  6. it affects a cutplane limit;
  7. it limits or reduces the operability of a synchronous condenser, static VAr compensator, static compensator or other similar dynamic device; or
  8. it affects high voltage direct current facilities.
Note: Where a transmission outage requires generation curtailments, the adjustments to generation will typically happen in the hours before the scheduled transmission outage and in the hour after the element is returned to service.

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Owner From To Duration Element Scheduled Activity Affected Intertie
BHE Canada 05-Oct-24 00:00 30-Apr-25 17:00 207.71 Days
Continuous
120s C1 (120s Picture Butte) forced outage  
ALTALINK 24-Jan-25 00:00 31-Dec-25 16:00 341.67 Days
Continuous
74s C3 (74s Janet) forced outage  
ENMAX, ALTALINK 28-Mar-25 09:00 30-Apr-25 14:00 33.21 Days
Continuous
240kV West Bus (SS-25), 1109L (SS-25 - SS-65), 25B240-D136 (SS-25), 25B240-D133 (SS-25), 25B240-D141 (SS-25), 25B240-D142 (SS-25), 25B240-D139 (SS-25), 25MD240-1109 (SS-25) scaffold and begin to terminate new Cables at SS-25  
EPCOR 31-Mar-25 07:00 07-Aug-25 17:00 129.42 Days
Continuous
987s T1 (987s Clover Bar), 987s CCP7213 (987s Clover Bar), 987s CCP7214 (987s Clover Bar) Cloverbar - TX1 LCR  
SUNCOR 01-Apr-25 08:00 08-Apr-25 20:00 7.5 Days
Continuous
29EDD-34 29PT-341 (29EDD-34), 29EDD-34 29-952-142 (29EDD-34), 29EDD-34 29-952-143 (29EDD-34), 29EDD-34 29PS-0375 (29EDD-34), 29EDD-34 29-652-10200T (29EDD-34), 29EDD-34 29-652-10301 (29EDD-34), 29EDD-34 29-652-10302 (29EDD-34), 29EDD-34 29-652-10303 (29EDD-34), 29EDD-34 29PS-0380 (29EDD-34), 29EDD-34 29PS-0381 (29EDD-34), 29EDD-34 29PS-0382 (29EDD-34), 29EDD-34 29PS-609 (29EDD-34), 29EDD-34 29PS-610 (29EDD-34) 10 year PM on 29EDD34;29PT-341 system and 5 year, 10 year PM on 29EDD34;29PP-103 system
 
ATCO 01-Apr-25 09:00 09-Apr-25 17:00 8.33 Days
Continuous
7L701 (757s Battle River - 7LA701 tap), 757s 707 (757s Battle River) replace overhead shield wire with OPGW cable on 7L701 from structure 1 to 11  
ALTALINK 04-Apr-25 13:00 09-Apr-25 14:00 5.04 Days
Continuous
879L (368s Burdett - 879L tap) Replace structures 719-723.  
ENMAX, ALTALINK 05-Apr-25 08:00 06-Apr-25 16:00 1.33 Days
Continuous
771L (SS-47 - SS-162), 162B138-RB82 (SS-162), 47.1TR (SS-47), 47.2TR (SS-47), 162B138-RB81 (SS-162) HV SW Maint. 162SW85, 162SW84, MD-771L. SW85 at 162 center phase does not open past 90 deg-adjust. Summer washing 47sub SW81, SW86.  
EPCOR 07-Apr-25 07:00 08-Apr-25 17:00 1.42 Days
Continuous
665s T2 (665s Dome) Dome: TX2 Tap Changer Maintenance  
ALTALINK 07-Apr-25 07:00 14-Apr-25 17:30 7.44 Days
Continuous
786L (799s Coleman - BCH Natal) NTL Station Upgrade Project. Reconfigure 1L275, remove span  
ENMAX 07-Apr-25 08:00 08-Apr-25 16:00 1.33 Days
Continuous
162B138-RB80 (SS-162), 162B138-RB81 (SS-162), 162.81L (391s Balzac - SS-162) HV SW Maint. 162SW82, 162SW83, MD-162.81L  
ALTALINK 07-Apr-25 08:00 08-Apr-25 16:30 1.35 Days
Continuous
391s 162.81 (391s Balzac) HV SW Maint. 162SW82, 162SW83, MD-162.81L.  
SUNCOR 07-Apr-25 08:00 13-Apr-25 20:00 6.5 Days
Continuous
29EDD-56 29PT-190 (29EDD-56) BP (Corey) - 29EDD-56;29PT-190 SYSTEM;PM 5y; 29EDD56;29PP-41H SYSTEM;PM 5Y/10Y  
BCH 07-Apr-25 09:00 14-Apr-25 17:00 7.33 Days
Continuous
1L275 (799s Coleman - BCH Natal) NTL Station Upgrade Project. Reconfigure 1L275, remove span BC maintenance does not affect the Alberta ATC AB-BC
ALTALINK, DOW 08-Apr-25 06:30 09-Apr-25 19:30 1.54 Days
Continuous
899L (166s Dow Chemical Fort Saskatchewan - 218s Fort Saskatchewan Co-Gen), 166s 899N (166s Dow Chemical Fort Saskatchewan) urgent replacement of 138 kV Koncar CTs associated with 166s 899N  
ALTALINK 08-Apr-25 07:30 16-Apr-25 10:30 8.13 Days
Continuous
72s T1 (72s Leismer), 72s 2 (72s Leismer) oil reclaim and leak repairs  
ATCO 08-Apr-25 09:30 08-Apr-25 17:00 7.5 Hours
Continuous
934s 240kV Bus 900BS1 (934s Blackfly) REPAIR - 934S 900SST1 C Phase Gas Pressure near low
Top up Power PT gas levels
 
EPCOR 09-Apr-25 07:00 10-Apr-25 17:00 1.42 Days
Continuous
665s T1 (665s Dome) Dome: TX1 Tap Changer Maintenance  
ENMAX, ALTALINK 09-Apr-25 08:00 10-Apr-25 16:00 1.33 Days
Continuous
932L (74s Janet - SS-162) HV SW Maint. 162SW145, 162SW144, MD-932L  
ENMAX, ALTALINK 09-Apr-25 08:00 10-Apr-25 16:00 1.33 Days
Continuous
932L (74s Janet - SS-162) HV SW Maint. 162SW145, 162SW144, MD-932L  
SUNCOR 09-Apr-25 08:00 16-Apr-25 20:00 7.5 Days
Continuous
29EDD-34 29PT-340 (29EDD-34) BP (Corey) - 29EDD34;29PT-340 SYSTEM;PM 5y,10y; 29EDD34;29PP-102 SYSTEM;PM 5y,10y
 
ALTALINK 09-Apr-25 09:00 09-Apr-25 15:00 6 Hours
Daily
618s 725 (618s Riverbend), 725AL (618s Riverbend - 725L tap), 725L (111s Coalbanks - 725AL tap), 725L (674s Bowron - 725AL tap) Urgent outage to replace 138kV Susp. Insulators.  
ATCO 09-Apr-25 10:00 09-Apr-25 13:00 3 Hours
Continuous
934s 901 (934s Blackfly) 901 TRIP COIL TESTING  
ATCO 09-Apr-25 13:01 09-Apr-25 17:00 3.98 Hours
Continuous
934s 902 (934s Blackfly) 902 TRIP COIL TESTING  
ALTALINK 09-Apr-25 14:00 09-Apr-25 17:00 3 Hours
Daily
879L (244s Bowmanton - 879AL tap), 879L (368s Burdett - 879L tap) Close west jumper at Str 457A.  
ATCO 10-Apr-25 10:00 10-Apr-25 13:00 3 Hours
Continuous
934s 905 (934s Blackfly) TRIP COIL TESTING  
ATCO 10-Apr-25 13:01 10-Apr-25 17:00 3.98 Hours
Continuous
934s 906 (934s Blackfly) TRIP COIL TESTING  
ALTALINK 11-Apr-25 07:00 14-Apr-25 18:00 3.46 Days
Daily
336s 607 (336s Fincastle), 607L (336s Fincastle - 607AL tap), 607L (135s Conrad - 607AL tap), 135s T1 (135s Conrad), 135s T2 (135s Conrad) Breaker outage to add CT circuit to new PMU  
ALTALINK 11-Apr-25 07:00 14-Apr-25 18:00 3.46 Days
Continuous
607L (135s Conrad - 607AL tap), 607L (336s Fincastle - 607AL tap), 135s T1 (135s Conrad), 135s T2 (135s Conrad) Reconductoring from Structures 2 -7 and replacing structures 5 & 6, for Hwy 3 widening.  
ALTALINK 11-Apr-25 08:30 11-Apr-25 12:59 4.48 Hours
Daily
72s 652 (72s Leismer) 240kV Breaker Maintenance  
BCH 11-Apr-25 09:00 11-Apr-25 17:00 8 Hours
Continuous
1L275 (799s Coleman - BCH Natal) NTL Station Upgrade Project. Tie in 138kV line taps to two new line terminals at NTL BC maintenance does not affect the Alberta ATC AB-BC
ENMAX 12-Apr-25 08:00 13-Apr-25 18:00 1.42 Days
Continuous
162.1TR (SS-162), 138kV North Bus (SS-162) HV SW Maint. 162SW110, 162SW96, 162SW81, MD13-162.1TR, Check reversing switch.  
ATCO, ALBIAN 13-Apr-25 08:00 23-Apr-25 16:00 10.33 Days
Continuous
920s 901T (920s Jackpine) CNRL to repair 72kV Cables  
ATCO, ALBIAN 13-Apr-25 08:00 23-Apr-25 16:00 10.33 Days
Continuous
920s 901T (920s Jackpine), 919s 905 (919s Hartley), 920s 901 (920s Jackpine) Work to be done in coordination with CNRL outage.
919s - 905 Breaker Complete
920s - 901 Breaker Complete
920s - 901T Major Testing
 
ALTALINK 14-Apr-25 07:00 16-Apr-25 18:00 2.46 Days
Continuous
727A1L (303s Saddlebrook - 727L tap), 727AL (142s Magcan - 727L tap), 727L (65s High River - 727AL tap), 727L (678s Okotoks - 727AL tap), 142s 138kV Bus (142s Magcan), 142s C1 (142s Magcan) Fire mitigation program to change arms and insulation along with dead end insulation on Structures 7, 11 & 20.  
EPCOR 14-Apr-25 07:00 23-May-25 17:00 39.42 Days
Continuous
52s E2402 (52s East Industrial), 52s T2 (52s East Industrial) East Industrial: Emergency Investigation and Possible Replacement of Secondary Cable and followed by TX2 Protection Upgrade Cutovers  
Lethbridge, ALTALINK 14-Apr-25 08:00 15-Apr-25 17:00 1.38 Days
Continuous
674s 725W (674s Bowron), 725L (674s Bowron - 725BL tap), 674s T1 (674s Bowron) 674s725LW Open end Outage to Test Trip Protections and install risers on 674s T1 New Transformer  
ALTALINK 14-Apr-25 08:00 15-Apr-25 17:00 1.38 Days
Continuous
725L (674s Bowron - 725BL tap) Test/Trip 674ss T1 Protections  
SUNCOR 14-Apr-25 08:00 20-Apr-25 20:00 6.5 Days
Continuous
29EDD-56 29PT-191 (29EDD-56) BP (Corey) - 29EDD56;29PT-191 SYSTEM;PM 5Y/10Y;29EDD56;29PP-41C SYSTEM;PM 5y  
BCH 14-Apr-25 09:00 14-Apr-25 17:00 8 Hours
Continuous
1L275 (799s Coleman - BCH Natal) NTL Station Upgrade Project. Test-energize new NTL 138kV ring 1L274-NEW BC maintenance does not affect the Alberta ATC AB-BC
ALTALINK, EPCOR 14-Apr-25 09:00 17-Apr-25 17:30 3.35 Days
Continuous
930L (37s North Calder - Poundmaker) Epcor performing relay maintenance requiring line to be OOS.  
ALTALINK, EPCOR 14-Apr-25 09:30 17-Apr-25 17:00 3.31 Days
Continuous
930L (37s North Calder - Poundmaker), PM2403 (Poundmaker), PM2404 (Poundmaker) 930L Zone: Relay Maintenance  
ATCO 14-Apr-25 09:30 18-Apr-25 17:30 4.33 Days
Continuous
730s STATCOM (730s Rycroft), 730s 705 (730s Rycroft) SVC ANNUAL INSPECTION .  
ATCO 14-Apr-25 11:00 16-Apr-25 16:00 2.21 Days
Continuous
827s SVC (827s Cranberry Lake) 827s Spring SVC Maintenance  
ATCO 15-Apr-25 07:00 18-Apr-25 15:00 3.33 Days
Continuous
7L101 (790s Poplar Hill - 944s Lowe Lake) customer request  
ATCO 15-Apr-25 07:00 18-Apr-25 15:00 3.33 Days
Continuous
7L101 (790s Poplar Hill - 944s Lowe Lake), 790s 705 (790s Poplar Hill) PRC-005 - TRIP COIL TESTING  
Lethbridge 16-Apr-25 08:00 16-Apr-25 17:00 9 Hours
Continuous
674s 725E (674s Bowron) 674s725LE Open end Outage to Test Trip New Protections for 674s T1 New Transformer  
ALTALINK 16-Apr-25 08:00 16-Apr-25 17:00 9 Hours
Daily
725L (674s Bowron - 725AL tap) Test/Trip 674ss T1 Protections  
ALTALINK, TRANSALTA 16-Apr-25 08:00 16-Apr-25 17:00 9 Hours
Daily
33s T2 (33s Spray) maintenance  
ALTALINK, TRANSALTA 16-Apr-25 08:00 17-Apr-25 17:00 1.38 Days
Continuous
33s T2 (33s Spray) maintenance  
ENMAX 17-Apr-25 13:00 20-Apr-25 18:00 3.21 Days
Continuous
2GSU-XF-001 (SS-25) Power Factor Test - 25PT240-Z44, 25BUS240-25MCT2, 25 Sub Zone 44 PT Oil Leaks (North and South PT)  
ENMAX, ALTALINK 17-Apr-25 13:00 20-Apr-25 18:00 3.21 Days
Continuous
1003L (74s Janet - SS-25) Outage required to allow 2GSU 240kV bus isolation  
SUNCOR 21-Apr-25 08:00 27-Apr-25 20:00 6.5 Days
Continuous
29EDD-1 Millennium 260kV West Bus 1, 29EDD-1 29EDD1s1052 (29EDD-1 Millennium) (BP) Corey - 300347749 29EDD1S1052 Densimeter Replacement; 450501635 - 29EDD1;W260B1 WEST BUS SYSTEM; 5Y/10Y (PRC5)  
EPCOR 22-Apr-25 07:00 27-Apr-25 17:00 5.42 Days
Continuous
805s T3 (805s Jasper), EP 805s J2404 (EP 805s Jasper), EP 805s J2405 (EP 805s Jasper) Jasper: TX3 Zone Relay Maintenance and J2404 Bay Doble and Tap Changer Maintenance and TX3 PRD Repair  
ENMAX 22-Apr-25 08:00 30-Apr-25 16:00 8.33 Days
Continuous
65.1TR (SS-65) Tap Changer Inspection  
ATCO 22-Apr-25 09:00 23-Apr-25 17:30 1.35 Days
Continuous
2075s ACF22 (2075s Newell) FILTER BANK AC MAINTENANCE  
ATCO 22-Apr-25 09:30 22-Apr-25 12:00 2.5 Hours
Continuous
790s 702 (790s Poplar Hill), 7L22 (790s Poplar Hill - 7L88 tap) PRC-005 - TRIP COIL TESTING - BREAKER 702 @ 790S  
ATCO 22-Apr-25 09:30 02-May-25 17:30 10.33 Days
Continuous
2029s 1201 (2029s Heathfield), 2029s 1204 (2029s Heathfield), 2029s 1207 (2029s Heathfield), 2029s 1214 (2029s Heathfield) Will return to service on the weekend and the continue with the outage on Apr 28
PRC-005 - TRIP COIL TESTING - BREAKER 1201 @ 2029S
PRC-005 - TRIP COIL TESTING - BREAKER 1214 @ 2029S
PRC-005 - Relays & Aux Relays for 1200BS1 and bus breakers
 
ALTALINK 22-Apr-25 13:00 02-May-25 17:00 10.17 Days
Continuous
163s T1 (163s Amoco Empress) 163sT1 Oil Reclaim and Maintenance  
ATCO 22-Apr-25 13:30 22-Apr-25 16:00 2.5 Hours
Continuous
939s 912 (939s Livock) PRC-005 - TRIP COIL TESTING - BREAKER 912-NORTH @ 939S
PRC-005 - TRIP COIL TESTING - BREAKER 912-SOUTH @ 939S
PRC-005 - TRIP COIL TESTING - BREAKER 912-CENTER @ 939S
 
ENMAX, ALTALINK 23-Apr-25 08:00 24-Apr-25 16:00 1.33 Days
Continuous
24.83L (74s Janet - SS-24) Replace structure 70 on line. Breaker SF6 Gas Sample - 24B138-24.83  
ENMAX, ALTALINK 23-Apr-25 08:00 24-Apr-25 16:00 1.33 Days
Continuous
24.83L (74s Janet - SS-24) Replace structure 70 on line. Breaker SF6 Gas Sample - 24B138-24.83  
ENMAX, ALTALINK 23-Apr-25 08:00 26-Apr-25 14:00 3.25 Days
Continuous
7.82L (42s Sarcee - SS-7) Replace connection point on shield wire weld tabs on structure  
ALTALINK 23-Apr-25 09:00 23-Apr-25 16:00 7 Hours
Daily
12s 952 (12s Heartland) Breaker outage to implement flashover protection setting/wiring on breaker 12s and Implement Cross block function on T1.  
ATCO 23-Apr-25 09:30 23-Apr-25 11:30 2 Hours
Continuous
939s 901 (939s Livock) PRC-005 - TRIP COIL TESTING - BREAKER 901-NORTH @ 939S
PRC-005 - TRIP COIL TESTING - BREAKER 901-SOUTH @ 939S
PRC-005 - TRIP COIL TESTING - BREAKER 901-CENTER @ 939S
 
ATCO 23-Apr-25 11:31 23-Apr-25 14:00 2.48 Hours
Continuous
939s 903 (939s Livock) PRC-005 - TRIP COIL TESTING - BREAKER 903-NORTH @ 939S
PRC-005 - TRIP COIL TESTING - BREAKER 903-SOUTH @ 939S
PRC-005 - TRIP COIL TESTING - BREAKER 903-CENTER @ 939S
 
ATCO 23-Apr-25 14:01 23-Apr-25 16:30 2.48 Hours
Continuous
939s 904 (939s Livock) PRC-005 - TRIP COIL TESTING - BREAKER 904-NORTH @ 939S
PRC-005 - TRIP COIL TESTING - BREAKER 904-SOUTH @ 939S
PRC-005 - TRIP COIL TESTING - BREAKER 904-CENTER @ 939S
 
ATCO 24-Apr-25 09:00 24-Apr-25 17:30 8.5 Hours
Continuous
2075s ACF23 (2075s Newell) FILTER BANK AC MAINTENANCE  
ATCO 24-Apr-25 09:30 24-Apr-25 15:30 6 Hours
Continuous
939s 910 (939s Livock), 939s 911 (939s Livock), 939s 903T (939s Livock) PRC-005 - TRIP COIL TESTING - BREAKER 910 @ 939S
PRC-005 - TRIP COIL TESTING - BREAKER 911 @ 939S
Study Will indicate if we close 912 when available
 
ATCO, ALBIAN 24-Apr-25 10:00 02-May-25 12:00 8.08 Days
Continuous
920s 902T (920s Jackpine), 919s 907 (919s Hartley), 920s 902 (920s Jackpine) Work to be done in coordination with CNRL upon completion of their 920s outage on 901T
919s - 907 Breaker Complete
920s - 902 Breaker Complete
920s - 902T Major Testing
 
ATCO 25-Apr-25 09:00 25-Apr-25 17:30 8.5 Hours
Continuous
2075s ACF24 (2075s Newell) FILTER BANK AC MAINTENANCE  
ATCO 26-Apr-25 07:00 30-Apr-25 18:00 4.46 Days
Continuous
7L86 (822s Wolf Lake - 1200s Foster Creek) Cenovus is expanding their 1200S substation 26m to the south, toward structure 449.
We will be relocating the conductor north of structure 449 to the new A-Frame structure that Cenovus is installing inside their substation.
 
ENMAX, ALTALINK 27-Apr-25 08:00 29-Apr-25 18:00 2.42 Days
Continuous
833L (SS-2 - SS-12), 12.2TR (SS-12) 12.2TR CT Replacement  
EPCOR 28-Apr-25 07:00 02-May-25 17:00 4.42 Days
Continuous
T4 (Poundmaker), PM2403 (Poundmaker), PM2402 (Poundmaker), PM721 (Poundmaker) Poundmaker: TX4 Zone Relay Maintenance  
BCH 28-Apr-25 09:00 30-Apr-25 17:00 2.33 Days
Continuous
5L52 (BPA Custer - BCH Ingledow), 5CB5 (BCH Ingledow), 5CB6 (BCH Ingledow) ING 5GD25, 5D25, 5CT25 and 5CVT5 INSPs AB-BC
ALTALINK, EPCOR 28-Apr-25 09:00 30-Apr-25 17:30 2.35 Days
Continuous
1056L (89s Ellerslie - 629s Argyll Transfer Station) 1056L Zone Doble and Bellamy BA2 Pothead Leak Repair. EPCOR work  
ATCO 28-Apr-25 09:00 02-May-25 17:30 4.35 Days
Continuous
2075s ACF21 (2075s Newell), 2075s 902T (2075s Newell), 2075S 930 (2075s Newell) SVC TRANSFORMER MAINTENANCE, ANNUAL SVC MAINTENANCE, FIRE SUPPRESSION INSPECTION AND RECERTIFICATION.  
BCH 28-Apr-25 09:00 09-May-25 17:00 11.33 Days
Continuous
T4 (BCH Natal) ING 5GD25, 5D25, 5CT25 and 5CVT5 INSPs AB-BC
ALTALINK, EPCOR 28-Apr-25 09:30 30-Apr-25 17:00 2.31 Days
Continuous
1056L (89s Ellerslie - 629s Argyll Transfer Station), 240BA2 (629s Argyll Transfer Station - 814s Bellamy), 814s B2401 (814s Bellamy), 814s B2402 (814s Bellamy) Argyll: 1056L Zone Doble and Bellamy BA2 Pothead Leak Repair  
ENMAX, ALTALINK 29-Apr-25 09:00 29-Apr-25 13:00 4 Hours
Continuous
833L (SS-2 - SS-12) Transfer from JMUX to JPAX circuits  
ATCO 29-Apr-25 09:00 08-May-25 12:00 9.13 Days
Continuous
7L95 (715s Leming Lake - 889s Mahkeses), 7L66 (715s Leming Lake - 717s Ethel Lake), 715s 703 (715s Leming Lake), 715s 704 (715s Leming Lake) Replacing 700PT1 wood structure with new steel structure and 7L95 protection upgrade.  
ATCO 29-Apr-25 10:30 02-May-25 15:30 3.21 Days
Continuous
7L66 (715s Leming Lake - 717s Ethel Lake) GOI needed for climbing inspection and deficiency repairs on 7L66  
ALTALINK, EPCOR 30-Apr-25 07:00 02-May-25 17:00 2.42 Days
Continuous
1045L (EP 805s Jasper - 1045AL tap), EP 805s J2407 (EP 805s Jasper), EP 805s J2406 (EP 805s Jasper) 1045L: Insulator Repair  
ALTALINK, EPCOR 30-Apr-25 07:00 02-May-25 17:30 2.44 Days
Continuous
1045AL (320p Keephills - 1045L tap), 1045L (310p Sundance - 1045AL tap), 1045L (EP 805s Jasper - 1045AL tap) Epcor insulator repair  
ALTALINK 30-Apr-25 08:00 30-Apr-25 14:00 6 Hours
Daily
320p 552 (320p Keephills), 320p 652 (320p Keephills), 190L (17s Benalto - 320p Keephills) Move Summated 190L CT from 320p552 & 320p652 to next available slot on the PMU to make room for a new Card in slot B. Changes requested at the project level to allow the PMUs in 240kV to operate separately from 500kV PMU.  
ENMAX, ALTALINK 30-Apr-25 08:00 30-Apr-25 16:00 8 Hours
Continuous
21.80L (42s Sarcee - SS-21), 21B138-21.80 (SS-21) HV Breaker Maintenance - 21B138-21.80  
ENMAX, ALTALINK 30-Apr-25 08:00 30-Apr-25 16:00 8 Hours
Daily
21.80L (42s Sarcee - SS-21) HV Breaker Maintenance - 21B138-21.80  
ENMAX, ALTALINK 30-Apr-25 08:00 02-May-25 15:00 2.29 Days
Continuous
832L (SS-10 - SS-12), 12.1TR (SS-12) 12.1TR CT Replacement  
ATCO 30-Apr-25 09:30 01-May-25 17:30 1.33 Days
Continuous
892s 702 (892s Ribstone Creek), 7L696 (508s Lakesend - 892s Ribstone Creek) BREAKER SF6 GL312 COMPLETE TESTING - BREAKER 702 @ 892S  
ALTALINK, TRANSALTA 30-Apr-25 10:00 30-Apr-25 14:00 4 Hours
Daily
250p T1 (250p Bighorn Plant) maintenance  
ENMAX, ALTALINK 30-Apr-25 14:00 30-May-25 14:00 30 Days
Continuous
1109L (SS-25 - SS-65) Complete Termination of new Cables on 1109L str 1.  
ENMAX, ALTALINK 30-Apr-25 14:00 30-May-25 14:00 30 Days
Continuous
1109L (SS-25 - SS-65) Altalink outage. Complete Termination of new Cables on 1109L str 1.  
ENMAX, ALTALINK 01-May-25 08:00 01-May-25 16:00 8 Hours
Continuous
693L (42s Sarcee - SS-10), 10B138-693 (SS-10) HV Breaker Maintenance - 10B138-693  
ENMAX, ALTALINK 01-May-25 08:00 01-May-25 16:00 8 Hours
Daily
693L (42s Sarcee - SS-10) HV Breaker Maintenance - 10B138-693  
BCH 01-May-25 09:00 03-May-25 17:00 2.33 Days
Continuous
5L51 (BPA Custer - BCH Ingledow) ING 5GD23, 5D23, 5CT23 and 5CVT3 INSPs AB-BC
ALTALINK, TRANSALTA 01-May-25 10:00 01-May-25 14:00 4 Hours
Daily
250p T2 (250p Bighorn Plant) maintenance  
ENMAX, ALTALINK 02-May-25 08:00 02-May-25 16:00 8 Hours
Continuous
832L (SS-10 - SS-12), 10B138-832 (SS-10) HV Breaker Maintenance - 10B138-832  
ENMAX, ALTALINK 02-May-25 08:00 02-May-25 16:00 8 Hours
Daily
832L (SS-10 - SS-12) HV Breaker Maintenance - 10B138-832  
ATCO, ALBIAN 02-May-25 08:00 13-May-25 08:00 11 Days
Continuous
919s 906 (919s Hartley) CNRL Request to isolate 906  
SUNCOR 03-May-25 09:00 15-May-25 16:00 12.29 Days
Continuous
29EDD-1 T2 (29EDD-1 Millennium) BP-29EDD-1 - TA - T2 OLTC Maintenance and Testing; 29EDD-1 T2 72LV Arrester replacement (CG)
300199837, 300203566
 
EPCOR 05-May-25 07:00 09-May-25 17:00 4.42 Days
Continuous
330p 1207 (330p Genesee), 330p 1208 (330p Genesee), 330P GT3 (330p Genesee) 12GT3D Disconnect Repair  
EPCOR 05-May-25 07:00 17-May-25 17:00 12.42 Days
Continuous
CV5 (EP 511s Victoria - 557s Castle Downs), 557s CDDS9 (557s Castle Downs), 557s CDDS12 (557s Castle Downs), EP 511s V2401 (EP 511s Victoria), EP 511s Victoria T5 (EP 511s Victoria), RV728 (Rossdale), EP 511s V727 (EP 511s Victoria) CV5: CV5 Zone Doble and Disconnect Maintenance and Victoria TX5 Doble and UGT Manhole Inspections  
Lethbridge 05-May-25 08:00 05-May-25 12:00 4 Hours
Continuous
674s 725W (674s Bowron) 674s725LW Open End Outage To Energize New 674s T1 Transformer  
ALTALINK 05-May-25 08:00 05-May-25 12:00 4 Hours
Daily
725L (674s Bowron - 725BL tap) Test/Trip 674ss T1 Protections  
ENMAX 05-May-25 08:00 09-May-25 16:00 4.33 Days
Continuous
162.1TR (SS-162), 240kV North Bus (SS-162) HV SW Maint. 162SW131, 162SW141, MD240-162.1TR. Oil Sampling Bushing, MT, TC.  
BCH 05-May-25 09:00 20-May-25 17:00 15.33 Days
Continuous
2L112 (BPA Boundary - BCH Nelway) NLY 2SA2 2SA12 Replacement AB-BC
ATCO 05-May-25 09:30 16-May-25 17:30 11.33 Days
Continuous
2029s 1203 (2029s Heathfield), 2029s 1206 (2029s Heathfield), 2029s 1209 (2029s Heathfield), 2029s 1215 (2029s Heathfield) PRC-005 - TRIP COIL TESTING - BREAKER 1215 @ 2029S
PRC-005 - Relays & Aux Relays for 1200BS2 and bus breakers
Return on weekends
 
ATCO, ALBIAN 05-May-25 12:00 07-May-25 16:00 2.17 Days
Continuous
919s 906 (919s Hartley) 906 Breaker Complete testing. To be done in coordination with CNRL outage on 901T.  
ALTALINK 05-May-25 13:00 08-May-25 17:00 3.17 Days
Continuous
320p T6 (320p Keephills) T6 outage to install new Camlin Bushing Monitors  
ALTALINK 06-May-25 07:00 06-May-25 17:00 10 Hours
Daily
83s T3 (83s Taber), 83s 138kV East Bus (83s Taber), 83s C1 (83s Taber), 507L (83s Taber - 257s Hull), 83s 61 (83s Taber), 83s 64 (83s Taber), 83s 507 (83s Taber) Change CT ratios for contributions to 87/138B relays from 800:5 to 1200:5.  
ALTALINK 06-May-25 08:00 06-May-25 16:00 8 Hours
Daily
89s T1 (89s Ellerslie), 89s Ellerslie 240kV Bus 1, 1140L (89s Ellerslie - 289s Saunders Lake) Replace PCB lighting in 240kV bay with LEDs  
ATCO 06-May-25 08:30 09-May-25 16:00 3.31 Days
Continuous
930s SVC (930s Arcenciel) Spring Maintenance SVC  
ALTALINK 07-May-25 07:00 07-May-25 17:00 10 Hours
Daily
83s C2 (83s Taber), 83s T1 (83s Taber), 83s 65 (83s Taber), 83s 67 (83s Taber), 83s 138kV West Bus (83s Taber), 83s 172W (83s Taber), 172L (83s Taber - 172EL tap), 83s 610 (83s Taber), 610L (83s Taber - 336s Fincastle) Change CT ratios for contributions to 87/138B relays from 800:5 to 1200:5.  
ALTALINK 07-May-25 13:30 07-May-25 18:00 4.5 Hours
Daily
245s 777X (245s Seebe), 777L (48s Pocaterra - 245s Seebe) 777L Replacing 138kV Susp. Insulators @ 245s  
ATCO 08-May-25 11:00 08-May-25 16:00 5 Hours
Continuous
9L101 (957s McClelland - 2005s Secord) Repair - 957S 900SST1 Leak Severity  
ATCO 08-May-25 12:01 13-May-25 10:00 4.92 Days
Continuous
7L95 (715s Leming Lake - 889s Mahkeses), 715s 704 (715s Leming Lake) 7L95 protection upgrade.  
ALTALINK 08-May-25 13:30 08-May-25 18:00 4.5 Hours
Daily
245s 87W (245s Seebe), 87L (2s Kananaskis - 245s Seebe) 87L Replacing 138kV Susp. Insulators @ 245s  
ENMAX, ALTALINK 10-May-25 12:00 10-May-25 18:00 6 Hours
Continuous
7.82L (42s Sarcee - SS-7), 7B138-7.82 (SS-7), 7B138-7BT3 (SS-7), 7.2TR (SS-7) Summer Substation Washing  
EPCOR 12-May-25 07:00 17-May-25 17:00 5.42 Days
Continuous
805s T4 (805s Jasper), EP 805s J2405 (EP 805s Jasper), EP 805s J2406 (EP 805s Jasper) Jasper: TX4 Zone Relay Maintenance and JDS10 Repair (045351) and TX4 Tap Changer Maintenance  
EPCOR 12-May-25 07:00 17-May-25 17:00 5.42 Days
Continuous
330p 1207 (330p Genesee), 330p 1204 (330p Genesee), 330p 1201 (330p Genesee), 330P 12TC1 (330p Genesee), 330p 1210 (330p Genesee), 330p 1214 (330p Genesee), 330p 805 (330p Genesee) Genesee: 500kV BUS 1 Yard Lighting Upgrade. Arranged w/CPC. (Poles #10, 11, 12, 13)  
ATCO 12-May-25 10:00 15-May-25 16:00 3.25 Days
Continuous
7L89 (700s Bonnyville - 721s La Corey), 700s 703 (700s Bonnyville) PRC-005 RELAY TESTING, RTXP TEST SWITCH REPLACEMENTS, PRC-005 TRIP COIL TESTING  
ATCO 12-May-25 10:00 15-May-25 16:00 3.25 Days
Continuous
732s 901T (732s Mitsue) TRANSFORMER CLASS1 MAJOR TESTING - 901T @ 732S
TRANSFORMER CLASS1 TAP CHANGER - 901T @ 732S
Replace/repair densimeter glass on BKR 701 at 732S Mitsue
 
ALTALINK 13-May-25 07:00 15-May-25 17:00 2.42 Days
Continuous
320p T1 (320p Keephills), 320p T4 (320p Keephills), 320p 138kV Bus (320p Keephills) Iconic to replace 320p92. Altalink crew performing maintenance on 320p400 and 320p401.  
ALTALINK 13-May-25 08:00 22-May-25 17:00 9.38 Days
Continuous
163s T2 (163s Amoco Empress) 163sT2 Oil Reclaim and Maintenance  
ATCO, FMGW 13-May-25 08:30 15-May-25 18:00 2.4 Days
Continuous
1024s PT-6001 (1024s Granlea), 1024s PT-6002 (1024s Granlea), 1024s 952-600001 (1024s Granlea), 1024s PS-6005 (1024s Granlea), 1024s PS-6006 (1024s Granlea), 1024s PS-6007 (1024s Granlea), 1024s PS-6008 (1024s Granlea) preform transformer leak repairs and inspections. 34kv bus bird proofing install.  
ATCO, ALBIAN 14-May-25 08:00 15-May-25 08:00 24 Hours
Continuous
919s 908 (919s Hartley) CNRL Request
COG to open 908 breaker and 902TD in the Hartley 919S substation at CNRL Albian Sands. This will be an isolation point for our upcoming outage to permit work on supply side breakers/relays on our TP-2.
 
BCH 14-May-25 09:00 14-May-25 17:00 8 Hours
Continuous
2L112 (BPA Boundary - BCH Nelway) Maintenance on NLY T2 Non-electrical PM, 2CB7 and 2CB8 BFPN AB-BC
ATCO 14-May-25 09:30 15-May-25 17:30 1.33 Days
Continuous
790s 704 (790s Poplar Hill), 790s 703T (790s Poplar Hill) PRC-005 - TRIP COIL TESTING - BREAKER 704 @ 790S
BREAKER SF6 HPL COMPLETE TESTING - 704 @ 790S
 
ALTALINK 14-May-25 23:00 15-May-25 03:00 4 Hours
Continuous
62s T1 (62s Brazeau Plant) maintenance  
ALTALINK 15-May-25 03:00 15-May-25 07:00 4 Hours
Daily
62s T2 (62s Brazeau Plant) maintenance  
ENMAX, ALTALINK 17-May-25 08:00 17-May-25 12:00 4 Hours
Continuous
12B138-833L (SS-12), 833L (SS-2 - SS-12), 12.2TR (SS-12) Summer Substation Washing  
ENMAX, ALTALINK 17-May-25 12:00 17-May-25 18:00 6 Hours
Continuous
12B138-832L (SS-12), 832L (SS-10 - SS-12), 12.1TR (SS-12) Summer Substation Washing  
SUNCOR 18-May-25 07:00 21-May-25 17:00 3.42 Days
Continuous
635EDD-1000 144kV Bus 635PP-1000 (635EDD-1000), 635EDD-1000 635PT-1000 (635EDD-1000), 635EDD-1000 635PS-1002 (635EDD-1000), 635EDD-1000 635PS-1004 (635EDD-1000), 635EDD-1000 635PS-1010 (635EDD-1000), 635EDD-1000 635PS-1022 (635EDD-1000), 635EDD-1000 635PS-1026 (635EDD-1000), 635EDD-1000 635PS-1030 (635EDD-1000), 635EDD-1000 635PS-1016 (635EDD-1000), 635EDD-1000 635-752-635PT-1000 (635EDD-1000) 635PP-1000 bus maintenance  
ALTALINK, EPCOR 18-May-25 07:00 25-May-25 17:00 7.42 Days
Continuous
1055L (629s Argyll Transfer Station - 816s Petrolia), 816s P2402 (816s Petrolia), 816s P2403 (816s Petrolia) 1055L: Pole Refurbishment and Petrolia Zone Doble and PDS4/PDS5/PDS11 Disconnect Maintenance  
ENMAX, ALTALINK 18-May-25 08:00 18-May-25 12:00 4 Hours
Continuous
693L (42s Sarcee - SS-10), 10.2TR (SS-10), 10B138-693 (SS-10) Summer Substation Washing  
ENMAX, ALTALINK 18-May-25 12:00 18-May-25 18:00 6 Hours
Continuous
832L (SS-10 - SS-12), 10.1TR (SS-10), 10B138-832 (SS-10) Summer Substation Washing  
EPCOR 19-May-25 07:00 20-May-25 17:00 1.42 Days
Continuous
330p 1202 (330p Genesee) Genesee: 1202 Bay Yard Lighting Upgrade (Pole #7)  
EPCOR 20-May-25 07:00 24-May-25 17:00 4.42 Days
Continuous
1139L (367s Harry Smith - EP Riverview), RW2403 (EP Riverview), RW2405 (EP Riverview) Riverview: 1139L Zone Doble and RWDS6/RWDS9/RWDS12 Disconnect Maintenance and Relay Maintenance  
ALTALINK 20-May-25 07:00 24-May-25 17:00 4.42 Days
Continuous
367s 1139 (367s Harry Smith) Riverview: 1139L Zone Doble and RWDS6/RWDS9/RWDS12 Disconnect Maintenance and Relay Maintenance  
EPCOR 20-May-25 07:00 30-May-25 17:00 10.42 Days
Continuous
657s T1 (657s Summerside) Summerside: TX1 DGA LCR  
ALTALINK, ENEL 20-May-25 07:30 22-May-25 16:30 2.38 Days
Continuous
205s T1 (205s Castle Rock Ridge) Full site outage to facilitate 240kV CTPT replacement, MPT leak repair, and Annual Maintenance checklist items.  
BCH 20-May-25 09:00 20-May-25 17:00 8 Hours
Continuous
2L113 (BCH Cranbrook - BCH Natal) Purpose: Inspection BC maintenance does not affect the Alberta ATC AB-BC
BCH 20-May-25 09:00 22-May-25 17:00 2.33 Days
Continuous
2L113 (BCH Cranbrook - BCH Natal) Purpose: Replace end-of-life timbers BC maintenance does not affect the Alberta ATC AB-BC
BCH 20-May-25 09:00 23-May-25 17:00 3.33 Days
Continuous
1L274 (BCH Elkford tap - BCH Line Creek tap) Purpose: Replace structures BC maintenance does not affect the Alberta ATC
AB-BC
BCH 20-May-25 09:00 30-May-25 17:00 10.33 Days
Continuous
T3 (BCH Natal) NTL Station Upgrade Project. Reconfigure NTL T3 bus connection and cut over to new station equipment BC maintenance does not affect the Alberta ATC AB-BC
BCH 20-May-25 10:00 20-May-25 18:00 8 Hours
Continuous
2L113 (BCH Cranbrook - BCH Natal) Placeholder NTL 2D21 & 2L113 OOS for 2D21 control cutover and testing. For Natal Substation rebuild project. BC maintenance does not affect the Alberta ATC AB-BC
ATCO 20-May-25 11:00 29-May-25 17:00 9.25 Days
Continuous
7L199 (347s AML Fox Creek - 741s ATC Fox Creek), 741s 702 (741s ATC Fox Creek) Fox Creek Substation Upgrade project. Demo old cables, install and terminate new cables, cut over to new protection.
 
ALTALINK 20-May-25 11:00 29-May-25 17:00 9.25 Days
Continuous
199L (347s AML Fox Creek - 741s ATC Fox Creek) Fox Creek Substation Upgrade project. Demo old cables, install and terminate new cables, cut over to new protection.  
EPCOR 21-May-25 07:00 22-May-25 17:00 1.42 Days
Continuous
330p 1205 (330p Genesee) Genesee: 1205 Bay Yard Lighting Upgrade (Pole #8)  
ATCO, CNRL 21-May-25 09:00 21-May-25 12:30 3.5 Hours
Continuous
847s 902 (847s Muskeg River) PRC-005 - TRIP COIL TESTING  
ATCO, CNRL 21-May-25 13:00 21-May-25 17:00 4 Hours
Continuous
847s 903 (847s Muskeg River) PRC-005 - TRIP COIL TESTING  
ATCO, CNRL 22-May-25 09:00 22-May-25 12:30 3.5 Hours
Continuous
847s 904 (847s Muskeg River) PRC-005 - TRIP COIL TESTING  
ATCO, CNRL 22-May-25 13:00 22-May-25 17:00 4 Hours
Continuous
847s 901 (847s Muskeg River) PRC-005 - TRIP COIL TESTING  
EPCOR 23-May-25 07:00 24-May-25 17:00 1.42 Days
Continuous
330p 1208 (330p Genesee) Genesee: 1208 Bay Yard Lighting Upgrade (Pole #9)  
SUNCOR 25-May-25 07:00 28-May-25 17:00 3.42 Days
Continuous
635EDD-1000 144kV Bus 635PP-1001 (635EDD-1000), 635EDD-1000 635PT-1001 (635EDD-1000), 635EDD-1000 635-752-635PT-1001 (635EDD-1000), 635EDD-1000 635PS-1003 (635EDD-1000), 635EDD-1000 635PS-1009 (635EDD-1000), 635EDD-1000 635PS-1015 (635EDD-1000), 635EDD-1000 635PS-1021 (635EDD-1000), 635EDD-1000 635PS-1025 (635EDD-1000), 635EDD-1000 635PS-1029 (635EDD-1000), 635EDD-1000 635PS-1035 (635EDD-1000) 635PP-1001 bus maintenance  
ENMAX, ALTALINK 25-May-25 08:00 31-May-25 16:00 6.33 Days
Continuous
37.2TR (SS-37), 37.82L (74s Janet - SS-37) 37sub Capacity Upgrade. Accommodate the commissioning of the new relays (Z31/Z32 bus diff, ASW and BMR-BT5).  
ALTALINK, EPCOR 26-May-25 07:00 01-Jun-25 17:00 6.42 Days
Continuous
1056L (89s Ellerslie - 629s Argyll Transfer Station) 1056L: Pole Refurbishment  
ALTALINK, EPCOR 26-May-25 07:00 01-Jun-25 17:00 6.42 Days
Continuous
1056L (89s Ellerslie - 629s Argyll Transfer Station) Pole Refurbishment  
EPCOR 26-May-25 07:00 06-Jun-25 17:00 11.42 Days
Continuous
805s T1 (805s Jasper), 72JM18 (EP 805s Jasper - Meadowlark), 72JW19 (EP 805s Jasper - Woodcroft), EP 805s J724 (EP 805s Jasper), EP 805s J722 (EP 805s Jasper), EP 805s J2401 (EP 805s Jasper) Jasper: TX1 Zone, JM18 Zone, Doble and JDS15/JDS21/JAB5/JDS3/JDS2/JDS29/JDS16/MDS1 Disconnect Maintenance, and TX1, J2403, J2408 Relay Maintenance  
ATCO 26-May-25 09:00 08-Jun-25 17:30 13.35 Days
Continuous
2029S BUILDING VALVE HALL, 2029s 1205 (2029s Heathfield), 2029s 1206 (2029s Heathfield) Annual EATL outage at 2075s & 2029s.

2029s & 2075s AC & DC O&M.

USE 2-70215 FOR 13L50 GOI
USE 2-70216 FOR 2029s GOI
USE 2-70217 FOR 2075s GOI
 
ATCO 26-May-25 09:00 08-Jun-25 17:30 13.35 Days
Continuous
2075S BUILDING VALVE HALL, 2075s 916 (2075s Newell), 2075s 917 (2075s Newell) Annual EATL outage at 2075s & 2029s.

2029s & 2075s AC & DC O&M.

USE 2-70215 FOR 13L50 GOI
USE 2-70216 FOR 2029s GOI
USE 2-70217 FOR 2075s GOI
 
ATCO 26-May-25 09:00 08-Jun-25 17:30 13.35 Days
Continuous
13L50 (DC LINK), 13L50 (2029s Heathfield - 2075s Newell) Annual EATL outage at 2075s & 2029s.

2029s & 2075s AC & DC O&M.

USE 2-70215 FOR 13L50 GOI
USE 2-70216 FOR 2029s GOI
USE 2-70217 FOR 2075s GOI
 
ATCO 26-May-25 10:00 30-May-25 17:30 4.31 Days
Continuous
813s 901T (813s Little Smoky) PRC-005 - SPR TESTING - TRANSFORMER 901T @ 813S
TRANSFORMER CLASS1 MAJOR TESTING - 901T @ 813S
TRANSFORMER CLASS1 TAP CHANGER - 901T @ 813S
PRC-005 - TRIP COIL TESTING - BREAKER 501 @ 813S
BREAKER VACUUM VA8012 COMPLETE TESTING - 501 @ 813S
 
ALTALINK 26-May-25 11:30 29-May-25 17:30 3.25 Days
Continuous
102s SVC (102s Langdon), 102s T4 (102s Langdon) 102sT4 PRC5, Doble and replace PD monitor.  
ALTALINK 26-May-25 12:30 29-May-25 18:00 3.23 Days
Continuous
410s T2 (410s Josephburg) Replace H2 bushing, doble, maint, oil leaks  
ALTALINK 26-May-25 13:30 29-May-25 17:30 3.17 Days
Continuous
310p 452 (310p Sundance) Replacement of 240kV Koncar CTs associated with 310p452  
ALTALINK, TRANSALTA 27-May-25 23:00 29-May-25 07:00 1.33 Days
Continuous
250p T1 (250p Bighorn Plant) maintenance  
ALTALINK, TRANSALTA 28-May-25 07:00 29-May-25 07:00 24 Hours
Continuous
250p T2 (250p Bighorn Plant) maintenance  
ATCO 28-May-25 09:00 29-May-25 14:00 29 Hours
Continuous
717s 702 (717s Ethel Lake), 7L66 (715s Leming Lake - 717s Ethel Lake) breaker maintenance  
Saskpower 28-May-25 09:00 29-May-25 18:00 1.38 Days
Continuous
SASK POWER P2C maintenance AB-SK
ATCO 29-May-25 14:01 29-May-25 16:00 119 Mins
Continuous
717s 701 (717s Ethel Lake), 7L28 (717s Ethel Lake - 846s Grand Centre) PRC-005 TRIP COIL TESTING  
ENMAX, ALTALINK 30-May-25 14:00 09-Jun-25 14:00 10 Days
Continuous
1109L (SS-25 - SS-65) Cable testing, close cable open points on 1109L and salvage Temp O/H 1109L  
ENMAX, ALTALINK 30-May-25 14:00 09-Jun-25 14:00 10 Days
Continuous
240kV West Bus (SS-25), 1109L (SS-25 - SS-65) Altalink outage. Cable testing, close cable open points on 1109L and salvage Temp O/H 1109L. Expanding zone to include 1109L C25s Bus. Enmax grounding required, and Enmax to close 1109L risers removed from bus to potthead.  
EPCOR 02-Jun-25 07:00 08-Jun-25 17:00 6.42 Days
Continuous
816s P2401 (816s Petrolia), 816s P2402 (816s Petrolia), 816s T1 (816s Petrolia) Petrolia: TX1 Zone Doble and Disconnect Maintenance  
ALTALINK 02-Jun-25 07:30 06-Jun-25 16:30 4.38 Days
Continuous
AML 511s 240kV ACF 1 Bus (511s Crossings) 511s1652 Breaker Maintenance, SVC+ Inspections and Maintenance  
ATCO, CNRL 02-Jun-25 08:00 08-Jun-25 17:00 6.38 Days
Continuous
859s 701T (859s Primrose), 859s 701TD (859s Primrose), 859s 704 (859s Primrose), 859s 701 (859s Primrose) Perform maintenance activities in 859S.  
ALTALINK, EPCOR 02-Jun-25 09:30 02-Jun-25 17:00 7.5 Hours
Daily
1057L (89s Ellerslie - 657s Summerside), 89s 452 (89s Ellerslie), 89s 352 (89s Ellerslie) Summerside: 1057L Zone Doble and SUDS1/SUDS3/SUDS9 Disconnect Maintenance  
ALTALINK, EPCOR 02-Jun-25 09:30 05-Jun-25 17:00 3.31 Days
Continuous
1057L (89s Ellerslie - 657s Summerside), 657s SU2402 (657s Summerside), 657s SU2401 (657s Summerside) Summerside: 1057L Zone Doble and SUDS1/SUDS3/SUDS9 Disconnect Maintenance  
ALTALINK, BCH 03-Jun-25 06:00 03-Jun-25 19:00 13 Hours
Continuous
1L274 (BCH Natal - BCH Line Creek tap), T1 (BCH Natal), T2 (BCH Natal) NTL Station Upgrade Project. Extend 1L274 to new NTL section; isolate NTL T1 & T2 section
NTL T1, NTL T2 (permanent removal)
AB-BC
ALTALINK 03-Jun-25 07:00 05-Jun-25 18:00 2.46 Days
Daily
861L (71s Lamoureux - 258s Dow Hydrocarbons) Maintenance and component replacements on various structures between 4-55.  
ALTALINK, ENEL 03-Jun-25 07:30 05-Jun-25 16:30 2.38 Days
Continuous
205s T2 (205s Castle Rock Ridge) Full site outage to facilitate 240kV CTPT replacement, MPT leak repair, and Annual Maintenance checklist items.  
EPCOR 09-Jun-25 07:00 15-Jun-25 17:00 6.42 Days
Continuous
H726 (EP Hardisty), EP 803s L721 (EP 803s Lambton), S724 (Strathcona), S723 (Strathcona), EP 803s T3 (EP 803s Lambton) Lambton/Strathcona/Hardisty: LH8 Zone Doble and Relay Maintenance, LS24 Zone Doble, Strathcona TX3 Doble, LDS13/SDS10/SDS8/SDS9/SAB3/HDS13 Disconnect Maintenance  
EPCOR 09-Jun-25 07:00 20-Jun-25 17:00 11.42 Days
Continuous
657s T2 (657s Summerside) Summerside: TX2 DGA LCR  
EPCOR 09-Jun-25 07:00 27-Jun-25 17:00 18.42 Days
Continuous
557s T1 (557s Castle Downs) Castle Downs S/S Tx1 bay outage  
EPCOR 09-Jun-25 07:00 27-Jun-25 17:00 18.42 Days
Continuous
52s E2401 (52s East Industrial), 52s T1 (52s East Industrial) East Industrial: TX1 Protection Upgrade Cutovers  
ATCO 09-Jun-25 09:30 10-Jun-25 17:30 1.33 Days
Continuous
801s 902 (801s Anderson) BREAKER MIN OIL HLR PARTIAL TESTING - BREAKER 902 @ 801S  
ATCO 09-Jun-25 12:00 12-Jun-25 17:00 3.21 Days
Continuous
951s SVC (951s Thickwood) Semi Annual inspection & maintenance  
ATCO 11-Jun-25 09:30 12-Jun-25 17:30 1.33 Days
Continuous
801s 903 (801s Anderson) BREAKER MIN OIL HLR PARTIAL TESTING - BREAKER 903 @ 801S  
EPCOR 16-Jun-25 07:00 20-Jun-25 17:00 4.42 Days
Continuous
1164L (816s Petrolia - EP Riverview), RW2402 (EP Riverview), RW2401 (EP Riverview), 816s P2403 (816s Petrolia), 816s P2404 (816s Petrolia) Riverview: 1164L Zone Doble and Relay Maintenance  
ENMAX, ALTALINK 16-Jun-25 08:00 19-Jun-25 16:00 3.33 Days
Continuous
28.80L (42s Sarcee - SS-28) HV SW Replacement 28SW80  
ATCO 16-Jun-25 10:00 20-Jun-25 17:30 4.31 Days
Continuous
959s 901T (959s Lanfine) TRANSFORMER CLASS1 MAJOR TESTING - 901T @ 959S
TRANSFORMER CLASS1 TAP CHANGER - 901T @ 959S
Qualitrol ITM/ETM Settings Updates - 901T Updates at 959s Lanfine
 
ATCO 16-Jun-25 12:00 20-Jun-25 16:00 4.17 Days
Continuous
885s 902T (885s McMillan) 885S McMillan Replace 1 Single Phase Reactor in 501R
902T Major & Tap Changer Refurbishment
 
ALTALINK 16-Jun-25 12:30 20-Jun-25 16:30 4.17 Days
Continuous
650s SVC (650s Hansman Lake), 650s T3 (650s Hansman Lake) Maintenance on SVC. SVC resistor replacement. T3 maintenance. Fire System inspection and testing. Replace palmer insulators that are failing.  
ALTALINK 17-Jun-25 09:00 21-Jun-25 09:00 4 Days
Continuous
163s T1 (163s Amoco Empress) Plains to unbolt/re-connect cabling from Altalink buss into plains substation for cable testing. Unbolt cabling/re- connect T1X, T1Y NGR feeds for cable and NGR testing. Scaffold to be built in yard behind Plains substation to access cable entries.  
ATCO 23-Jun-25 09:30 27-Jun-25 17:30 4.33 Days
Continuous
757s 912T (757s Battle River) TRANSFORMER CLASS1 MAJOR TESTING - 912T @ 757S
BREAKER MIN OIL HPF COMPLETE TESTING - 710 @ 757S
 
ATCO 23-Jun-25 10:00 27-Jun-25 17:30 4.31 Days
Continuous
963s 901T (963s Coyote Lake), 7L128 (963s Coyote Lake - 7LA128 tap), 9L29 (946s Oakland - 963s Coyote Lake) TRANSFORMER CLASS1 TAP CHANGER - 901T @ 963S
TRANSFORMER CLASS1 MAJOR TESTING - 901T @ 963S
Qualitrol ITM/ETM Settings Updates - 901T Updates at 963s Coyote Lake
 
ATCO 23-Jun-25 12:00 04-Jul-25 16:00 11.17 Days
Continuous
826s 901T (826s Marguerite Lake) transformer major maintenance  
ALTALINK 25-Jun-25 07:00 25-Jun-25 16:00 9 Hours
Daily
413L (239s Castle River - 632s Russell) We need to complete maintenance on 239s138DS4 at Castle River and need to request an advice on 413L..  
ENMAX, ALTALINK 27-Jun-25 08:00 03-Jul-25 16:00 6.33 Days
Continuous
50L (44s Bearspaw Plant - SS-21) HV SW Replacement. 37SW84, 37SW85, 37SW86  
EPCOR 30-Jun-25 07:00 18-Jul-25 17:00 18.42 Days
Continuous
557s T2 (557s Castle Downs) Castle Downs S/S Tx2 Bay Outage  
ATCO 30-Jun-25 09:30 30-Jun-25 17:30 8 Hours
Continuous
801s 907 (801s Anderson) BREAKER MIN OIL HLR PARTIAL TESTING - 905 @ 801S  
EPCOR, ALTALINK 02-Jul-25 07:00 06-Jul-25 17:00 4.42 Days
Continuous
665s D2401 (665s Dome), 665s D2404 (665s Dome), 665s T3 (665s Dome), 665s D721 (665s Dome), 72DS26 (665s Dome - Strathcona), 909L (89s Ellerslie - 665s Dome), S721 (Strathcona) Dome: TX3/DS26/909L Zone Doble and DDS1/DDS12/DDS13/DDS17/SDS3 Disconnect Maintenance and D721/D2404 Breaker Maintenance  
ALTALINK, EPCOR 02-Jul-25 07:00 06-Jul-25 17:00 4.42 Days
Continuous
909L (89s Ellerslie - 665s Dome) TX3/DS26/909L Zone Doble and DDS1/DDS12/DDS13/DDS17/SDS3 Disconnect Maintenance and D721/D2404 Breaker Maintenance  
ATCO 02-Jul-25 09:30 03-Jul-25 17:30 1.33 Days
Continuous
801s 905 (801s Anderson) BREAKER MIN OIL HLR PARTIAL TESTING - 905 @ 801S  
ATCO 02-Jul-25 10:30 04-Jul-25 15:30 2.21 Days
Continuous
7L91 (715s Leming Lake - 826s Marguerite Lake) GOI required for climbing inspection on 7L91 and for deficiency repair.  
ALTALINK 02-Jul-25 23:00 03-Jul-25 03:00 4 Hours
Continuous
62s T1 (62s Brazeau Plant) maintenance  
ALTALINK 03-Jul-25 03:00 03-Jul-25 07:00 4 Hours
Daily
62s T2 (62s Brazeau Plant) maintenance  
BCH 03-Jul-25 09:00 03-Jul-25 17:00 8 Hours
Continuous
2L293 (BCH Nelway - BCH Selkirk) Purpose: F26 AOP- This is for Maintenance on SEL AB-BC
BCH 03-Jul-25 09:00 14-Jul-25 17:00 11.33 Days
Continuous
2L113 (BCH Cranbrook - BCH Natal) Insulator Replacement BC maintenance does not affect the Alberta ATC AB-BC
EPCOR 07-Jul-25 07:00 13-Jul-25 17:00 6.42 Days
Continuous
52s E2402 (52s East Industrial) East Industrial: TX2 Doble and Tap Changer Maintenance, E2402 Doble and Breaker Maintenance  
ATCO 07-Jul-25 09:00 09-Jul-25 12:00 2.13 Days
Continuous
826s 903 (826s Marguerite Lake) BREAKER MAINTENANCE  
ATCO 07-Jul-25 10:30 10-Jul-25 15:30 3.21 Days
Continuous
7L89 (700s Bonnyville - 721s La Corey) GOI required for climbing inspection on 7L89 and for deficiency repair.  
ATCO 07-Jul-25 11:00 11-Jul-25 16:00 4.21 Days
Continuous
898s 902T (898s Heart Lake) transformer maintenance  
ALTALINK 07-Jul-25 12:30 10-Jul-25 16:30 3.17 Days
Continuous
632s PS1 (632s Russell), 632s 452 (632s Russell), 632s 552 (632s Russell) 632s PS1 FAC501 TC major, 632s452, 632s552  
ALTALINK, EPCOR 09-Jul-25 07:00 25-Jul-25 17:00 16.42 Days
Continuous
1044L (EP 805s Jasper - 816s Petrolia), EP 805s J2404 (EP 805s Jasper), EP 805s J2403 (EP 805s Jasper), EP 805s J2408 (EP 805s Jasper), 805s C1 (805s Jasper) Jasper 1044L/Cap Bank: Infrastructure Upgrade Project  
ATCO 09-Jul-25 12:01 12-Jul-25 16:00 3.17 Days
Continuous
826s 904 (826s Marguerite Lake) BREAKER MAINTENANCE  
ATCO 14-Jul-25 09:00 16-Jul-25 12:00 2.13 Days
Continuous
826s 907 (826s Marguerite Lake) BREAKER MAINTENANCE  
BCH 14-Jul-25 09:00 18-Jul-25 17:00 4.33 Days
Continuous
5L96 (BCH Selkirk - BCH Vaseux Lake) replace markerballs and insulators BC maintenance does not affect the Alberta ATC AB-BC
ATCO 14-Jul-25 09:30 15-Jul-25 17:30 1.33 Days
Continuous
801s 906 (801s Anderson) BREAKER MIN OIL HLR PARTIAL TESTING- BREAKER 906 @ 801S  
ALTALINK, EPCOR 14-Jul-25 09:30 25-Jul-25 17:00 11.31 Days
Continuous
1058L (657s Summerside - EP 803s Lambton), EP 803s L2403 (EP 803s Lambton), EP 803s L2404 (EP 803s Lambton), 657s SU2402 (657s Summerside), 657s SU2403 (657s Summerside) Summerside/Lambton: 1058L Pole Refurbishment and 1058L Summerside Zone Doble and Disconnect Maintenance, L2403 SF6 Leak Repair  
ATCO 14-Jul-25 10:30 17-Jul-25 15:30 3.21 Days
Continuous
7L89 (721s La Corey - 826s Marguerite Lake) GOI required for climbing inspection on 7L89 and for deficiency repair.  
ALTALINK 15-Jul-25 08:00 15-Jul-25 13:00 5 Hours
Continuous
786L (799s Coleman - BCH Natal) Cut in breakers for future Open Point 'B' at Str122. AB-BC
ALTALINK 15-Jul-25 08:30 15-Jul-25 16:30 8 Hours
Continuous
786L (799s Coleman - BCH Natal) Open "Open Point 'A' 170L to 786L removing bypass around 799s. AB-BC
ALTALINK 16-Jul-25 08:00 16-Jul-25 14:00 6 Hours
Continuous
786L (799s Coleman - BCH Natal) Remove breakers for Open Point 'B' at Str122. AB-BC
ATCO 16-Jul-25 09:30 17-Jul-25 17:30 1.33 Days
Continuous
801s 909 (801s Anderson) BREAKER MIN OIL HLR PARTIAL TESTING - 909 @ 801S  
ALTALINK, TRANSALTA 16-Jul-25 10:00 16-Jul-25 14:00 4 Hours
Daily
250p T1 (250p Bighorn Plant) maintenance  
ATCO 16-Jul-25 12:01 18-Jul-25 16:00 2.17 Days
Continuous
826s 908 (826s Marguerite Lake) BREAKER MAINTENANCE  
ALTALINK 16-Jul-25 13:00 16-Jul-25 15:00 2 Hours
Continuous
786L (799s Coleman - BCH Natal) Close Open Point 'A' 170L to 786L creating bypass around 799s. AB-BC
ALTALINK, TRANSALTA 17-Jul-25 10:00 17-Jul-25 14:00 4 Hours
Daily
250p T2 (250p Bighorn Plant) maintenance  
EPCOR 21-Jul-25 07:00 27-Jul-25 17:00 6.42 Days
Continuous
RW2403 (EP Riverview), RW2402 (EP Riverview), T2 (EP Riverview) Riverview: TX2 Zone Doble and Disconnect Maintenance and Relay Maintenance  
ATCO 21-Jul-25 09:00 23-Jul-25 12:00 2.13 Days
Continuous
2029s ACF11 (2029s Heathfield) FILTER BANK AC MAINTENANCE  
ATCO 21-Jul-25 09:00 01-Aug-25 17:30 11.35 Days
Continuous
2075s ACF11 (2075s Newell), 2075s ACF12 (2075s Newell), 2075s ACF13 (2075s Newell), 2075s ACF14 (2075s Newell), 2075s 901T (2075s Newell) Leak Repairs 901T/SVC MAINTENANCE/FILTER BANK AC MAINTENANCE/ACF13 Resistor Lid Replacements


 
ATCO 21-Jul-25 12:00 24-Jul-25 16:00 3.17 Days
Continuous
2011s 901T (2011s Dawes) TRANSFORMER CLASS1 MAJOR TESTING - 901T @ 2011S
TRANSFORMER CLASS1 TAP CHANGER - 901T @ 2011S
 
ALTALINK 21-Jul-25 16:00 21-Jul-25 18:00 2 Hours
Daily
245s 777X (245s Seebe), 777L (48s Pocaterra - 245s Seebe) Protection upgrade project on 81/138B protection at 245s Seebe. AB-BC
ATCO 22-Jul-25 07:00 23-Jul-25 18:00 1.46 Days
Continuous
7L65 (709s Vegreville - 7LA65 tap), 7L65 (710s Vermilion - 7LA65 tap), 7LA65 tap Repair/replace T-Tap switches
Station outage to 708S
 
BCH 23-Jul-25 09:00 31-Jul-25 17:00 8.33 Days
Continuous
2L294 (BCH A. A. Lambert - BCH Cranbrook), T3 (BCH Cranbrook) Insulator Replacement. BC maintenance does not affect the Alberta ATC AB-BC
ALTALINK 23-Jul-25 12:30 23-Jul-25 18:00 5.5 Hours
Continuous
777L (48s Pocaterra - 245s Seebe), 245s 777X (245s Seebe) protection upgrade project on 81/138B protection at 245s Seebe AB-BC
ATCO 23-Jul-25 13:00 25-Jul-25 17:30 2.19 Days
Continuous
2029s ACF21 (2029s Heathfield) FILTER BANK AC MAINTENANCE  
ATCO 25-Jul-25 11:00 25-Jul-25 12:00 60 Mins
Continuous
774s 701 (774s Monitor), 7L224 (650s Hansman Lake - 774s Monitor) PRC-005 - TRIP COIL TESTING - BREAKER 701 @ 774S  
ALTALINK, EPCOR 28-Jul-25 07:00 31-Jul-25 17:00 3.42 Days
Continuous
1045L (EP 805s Jasper - 1045AL tap), EP 805s J2406 (EP 805s Jasper), EP 805s J2407 (EP 805s Jasper) Jasper 1045L Zone: Infrastructure Upgrade Project  
ALTALINK, EPCOR 28-Jul-25 07:00 31-Jul-25 17:00 3.42 Days
Continuous
1045AL (320p Keephills - 1045L tap), 1045L (310p Sundance - 1045AL tap), 1045L (EP 805s Jasper - 1045AL tap) Jasper 1045L Zone: Infrastructure Upgrade Project  
ATCO 28-Jul-25 09:00 30-Jul-25 12:00 2.13 Days
Continuous
2029s ACF12 (2029s Heathfield) FILTER BANK AC MAINTENANCE  
ATCO 28-Jul-25 09:30 31-Jul-25 14:30 3.21 Days
Continuous
809s 902T (809s Louise Creek) BREAKER SF6 LTB145D1/B COMPLETE TESTING - 702 @ 809S
902TD and 910A @ 809S Louise Creek Require Readjusting
 
ALTALINK, EPCOR 28-Jul-25 09:30 01-Aug-25 17:00 4.31 Days
Continuous
920L (71s Lamoureux - 557s Castle Downs), 557s CD2404 (557s Castle Downs), 557s CD2405 (557s Castle Downs) Castledowns: 920LE Zone Doble and Disconnect Maintenance  
ALTALINK, EPCOR 28-Jul-25 09:30 01-Aug-25 17:00 4.31 Days
Continuous
920L (71s Lamoureux - 557s Castle Downs) EPCOR 920LE Zone Doble and Disconnect Maintenance  
ALTALINK, EPCOR 28-Jul-25 09:30 08-Aug-25 17:00 11.31 Days
Continuous
1059L (EP 803s Lambton - 1059AL tap), 1059L (38s East Edmonton - 1059AL tap), EP 803s L2404 (EP 803s Lambton), EP 803s L2401 (EP 803s Lambton) 1059L: Pole Refurbishment  
ALTALINK, EPCOR 28-Jul-25 09:30 08-Aug-25 17:00 11.31 Days
Continuous
1059L (38s East Edmonton - 1059AL tap) Pole Refurbishment  
ATCO 30-Jul-25 13:00 01-Aug-25 17:30 2.19 Days
Continuous
2029s ACF22 (2029s Heathfield) FILTER BANK AC MAINTENANCE  
ATCO 05-Aug-25 09:00 06-Aug-25 17:30 1.35 Days
Continuous
2029s ACF13 (2029s Heathfield) FILTER BANK AC MAINTENANCE  
ATCO 05-Aug-25 09:30 07-Aug-25 17:30 2.33 Days
Continuous
801s 912 (801s Anderson) BREAKER MIN OIL HLR PARTIAL TESTING - 912 @ 801S
Breaker 912 N.W. Pole Low Oil at 801s Anderson
 
ATCO 06-Aug-25 09:00 06-Aug-25 16:00 7 Hours
Continuous
7L85 (803s ATC Bullpound - 7LA85 tap) L-G Clearance mitigation at span 382 between Badlands and 803S Bull pound.  
ATCO 07-Aug-25 09:00 08-Aug-25 17:30 1.35 Days
Continuous
2029s ACF23 (2029s Heathfield) FILTER BANK AC MAINTENANCE  
ALTALINK 10-Aug-25 10:00 13-Aug-25 16:30 3.27 Days
Continuous
702L (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
ALTALINK, EPCOR 11-Aug-25 07:00 17-Aug-25 17:00 6.42 Days
Continuous
657s SU2403 (657s Summerside), 657s SU2402 (657s Summerside), 657s T2 (657s Summerside) Summerside: TX2 Zone Doble and Disconnect Maintenance  
ATCO 11-Aug-25 09:00 13-Aug-25 12:00 2.13 Days
Continuous
825s 901 (825s Whitefish Lake) BREAKER MAINTENANCE  
ATCO 11-Aug-25 10:00 15-Aug-25 17:00 4.29 Days
Continuous
9L16 (755s Cordel - 972s Tinchebray) Install foundations for new 9L16 structures 73 and 74 in preparation of the future line bay re-termination into 972S Tinchebray expansion.  
ATCO 11-Aug-25 10:00 15-Aug-25 17:30 4.31 Days
Continuous
959s SVC (959s Lanfine) SVC CONVERTER INSPECTION
Fire System Inspection @ LANFINE 959S
 
ATCO 11-Aug-25 11:00 13-Aug-25 17:00 2.25 Days
Continuous
876s 902T (876s Brintnell) TRANSFORMER CLASS1 MAJOR TESTING - 902T @ 876S  
ALTALINK, TRANSALTA 12-Aug-25 07:00 14-Aug-25 13:00 2.25 Days
Continuous
33s 138kV Bus (33s Spray), 33s T1 (33s Spray), 33s T2 (33s Spray) Replace 33s1 CT13 "C" Phase. Remove old TAU communication cable.  
ATCO 13-Aug-25 12:01 15-Aug-25 16:00 2.17 Days
Continuous
825s 902 (825s Whitefish Lake) BREAKER MAINTENANCE  
EPCOR 18-Aug-25 07:00 24-Aug-25 17:00 6.42 Days
Continuous
987s CC721 (987s Clover Bar), 987s T2 (987s Clover Bar) Cloverbar: TX2 Zone Doble and Leak Repair  
EPCOR, ALTALINK 18-Aug-25 07:00 24-Aug-25 17:00 6.42 Days
Continuous
657s SU2405 (657s Summerside), 657s SU2404 (657s Summerside), 657s T1 (657s Summerside) Summerside: TX1 Zone Doble and Disconnect Maintenance  
ATCO 18-Aug-25 09:00 20-Aug-25 12:00 2.13 Days
Continuous
825s 903 (825s Whitefish Lake) BREAKER MAINTENANCE  
ATCO 18-Aug-25 09:30 21-Aug-25 17:30 3.33 Days
Continuous
801s 911 (801s Anderson) BREAKER MIN OIL HLR COMPLETE TESTING - 911 @ 801S  
ALTALINK 18-Aug-25 10:00 21-Aug-25 16:30 3.27 Days
Continuous
702L (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
ATCO 20-Aug-25 12:01 22-Aug-25 16:00 2.17 Days
Continuous
825s 904 (825s Whitefish Lake) BREAKER MAINTENANCE  
ALTALINK 20-Aug-25 23:00 21-Aug-25 03:00 4 Hours
Continuous
62s T1 (62s Brazeau Plant) maintenance  
ALTALINK 21-Aug-25 03:00 21-Aug-25 07:00 4 Hours
Daily
62s T2 (62s Brazeau Plant) maintenance  
ENMAX, ALTALINK 22-Aug-25 07:00 26-Aug-25 18:00 4.46 Days
Continuous
50L (44s Bearspaw Plant - SS-21) Replacing structures 116 & 117.  
EPCOR 23-Aug-25 07:00 29-Aug-25 17:00 6.42 Days
Continuous
665s T1 (665s Dome), 665s D2401 (665s Dome), 665s D2402 (665s Dome) Dome: TX1 Zone Doble and DDS2/DDS3/DAB1 Disconnect Maintenance and Relay Maintenance  
ATCO 25-Aug-25 09:00 27-Aug-25 16:00 2.29 Days
Continuous
825s 905 (825s Whitefish Lake) BREAKER MAINTENANCE  
ALTALINK, EPCOR 25-Aug-25 09:30 29-Aug-25 17:00 4.31 Days
Continuous
915L (38s East Edmonton - 987s Clover Bar), 987s C2403 (987s Clover Bar), 987s C2405 (987s Clover Bar) Cloverbar: 915L Zone Doble and CDS35/CDS36/CDS37 Disconnect Maintenance  
ALTALINK, EPCOR 25-Aug-25 09:30 29-Aug-25 17:00 4.31 Days
Continuous
915L (38s East Edmonton - 987s Clover Bar) Cloverbar: 915L Zone Doble and CDS35/CDS36/CDS37 Disconnect Maintenance  
EPCOR 02-Sep-25 07:00 14-Sep-25 17:00 12.42 Days
Continuous
EP 803s T2 (EP 803s Lambton), EP 803s L2402 (EP 803s Lambton), EP 803s L2405 (EP 803s Lambton) Lambton: LAB2 LCR and TX2 Zone Doble and LDS4/LDS9 Disconnect and Tap Changer Maintenance  
EPCOR 02-Sep-25 07:00 26-Sep-25 17:00 24.42 Days
Continuous
805s T1 (805s Jasper) Jasper: TX1 Bushing Replacement (PCB)  
ALTALINK 03-Sep-25 08:00 10-Sep-25 17:00 7.38 Days
Continuous
1011L (163s Amoco Empress - 562s Cypress) Line outage required for 163s1352 Breaker Replacement, Breaker will be new SF6 Type  
ATCO 03-Sep-25 09:30 04-Sep-25 17:30 1.33 Days
Continuous
755s 901 (755s Cordel) BREAKER SF6 GL315 COMPLETE TESTING - BREAKER 901 @ 755S
TCM Program. RTXP Test Switch Mitigation and Replacement: 50BF/901 @ 755S
 
ATCO 03-Sep-25 09:30 04-Sep-25 17:30 1.33 Days
Continuous
802s 704 (802s Michichi Creek), 7L128 (802s Michichi Creek - 7LA128 tap) BREAKER MIN OIL HLR PARTIAL TESTING - BREAKER 704 @ 802S  
EPCOR 08-Sep-25 07:00 14-Sep-25 17:00 6.42 Days
Continuous
816s P2404 (816s Petrolia), 816s P2405 (816s Petrolia), 816s T2 (816s Petrolia) Petrolia: TX2 Zone Doble and Disconnect Maintenance  
ATCO 08-Sep-25 09:30 09-Sep-25 17:30 1.33 Days
Continuous
755s 902 (755s Cordel) BREAKER SF6 GL315 COMPLETE TESTING - BREAKER 902 @ 755S
TCM Program. RTXP Test Switch Mitigation and Replacement: 50BF/902 @ 755S
 
ALTALINK, EPCOR 08-Sep-25 09:30 12-Sep-25 17:00 4.31 Days
Continuous
921L (71s Lamoureux - 987s Clover Bar), 987s C2404 (987s Clover Bar), 987s C2406 (987s Clover Bar) Cloverbar: 921L Zone Doble and CDS30/CDS32/CDS40 Disconnect Maintenance  
ALTALINK, EPCOR 08-Sep-25 09:30 12-Sep-25 17:00 4.31 Days
Continuous
921L (71s Lamoureux - 987s Clover Bar) Cloverbar: 921L Zone Doble and CDS30/CDS32/CDS40 Disconnect Maintenance  
ATCO, ALTALINK 09-Sep-25 09:00 10-Sep-25 18:00 1.38 Days
Continuous
7L760D4 (7LA760 tap), 7L760D5 (7LA760 tap), 7L760 (7LA760 tap - 7LC760 tap), 760L (760AL tap - 7LA760 tap) Building Temp Bypass to replace switches 7L760D4, 7L760D5 and 7LA760D1.
Will Need COG from AltaLink at 163s1
 
ALTALINK, TRANSALTA 09-Sep-25 23:00 11-Sep-25 07:00 1.33 Days
Continuous
250p T2 (250p Bighorn Plant) maintenance  
ALTALINK, TRANSALTA 10-Sep-25 07:00 11-Sep-25 07:00 24 Hours
Continuous
250p T1 (250p Bighorn Plant) maintenance  
ATCO 10-Sep-25 09:30 11-Sep-25 17:30 1.33 Days
Continuous
755s 903 (755s Cordel) BREAKER SF6 GL315 COMPLETE TESTING - BREAKER 903 @ 755S
TCM Program. RTXP Test Switch Mitigation and Replacement: 50BF/903 @ 755S
 
ENMAX, ALTALINK 12-Sep-25 18:00 14-Sep-25 08:00 1.58 Days
Continuous
936L (5s East Calgary - 102s Langdon) Reconductor between str 15 to 18 on both Circuits for line Clearance Mitigation  
ENMAX, ALTALINK 12-Sep-25 18:00 14-Sep-25 08:00 1.58 Days
Continuous
937L (5s East Calgary - 102s Langdon) Crew working in vicinity of 936L  
EPCOR 15-Sep-25 07:00 21-Sep-25 17:00 6.42 Days
Continuous
EP 803s L2401 (EP 803s Lambton), EP 803s L2402 (EP 803s Lambton), EP 803s T1 (EP 803s Lambton) Lambton: TX1 Zone Doble and LAB1/LDS2/LDS3 Disconnect Maintenance  
ALTALINK, EPCOR 15-Sep-25 09:30 21-Sep-25 17:00 6.31 Days
Continuous
909L (310p Sundance - 665s Dome), 665s D2402 (665s Dome), 665s D2403 (665s Dome), 665s T2 (665s Dome) Dome: 909LE/TX2 Doble and DDS4/DDS5/DAB2 Disconnect Maintenance and Relay Maintenance  
ALTALINK, EPCOR 15-Sep-25 09:30 21-Sep-25 17:00 6.31 Days
Continuous
909L (310p Sundance - 665s Dome) Dome: 909LE/TX2 Doble and DDS4/DDS5/DAB2 Disconnect Maintenance and Relay Maintenance  
ATCO 15-Sep-25 10:00 03-Oct-25 17:30 18.31 Days
Continuous
840s McNeill Station CONVERTER INSPECTION @ MCNEILL 840S
BREAKER SF6 HPL COMPLETE TESTING - 702 @ 840S
BREAKER SF6 HPL COMPLETE TESTING - 703 @ 840S
TRANSFORMER CLASS1 MAJOR TESTING - 901T @ 840S
TRANSFORMER CLASS1 TAP CHANGER - 901T @ 840S
901T Oil Leak Absorption Repairs At 840s McNeill
BREAKER VACUUM VA8012 COMPLETE
AB-SK
ALTALINK 15-Sep-25 12:30 18-Sep-25 17:30 3.21 Days
Continuous
359s T2 (359s Esso West Pembina), 359s 202AX (359s Esso West Pembina) Bushing replacement, Doble, maintenance, leaks, LTC maintenance  
ALTALINK, TRANSALTA 16-Sep-25 07:00 17-Sep-25 18:00 1.46 Days
Daily
514L (396s Pincher Creek - 514BL tap), 514L (513s Lundbreck - 514BL tap), 322s T1 (322s Cowley Ridge) South will be performing maintenance on STR 16, 76 & 170  
SUNCOR 17-Sep-25 00:00 23-Sep-25 00:00 6 Days
Continuous
29PL7-4 (29EDD-65 - 29EDD-71), 29EDD-65 29PS-0284 (29EDD-65 Edd65Sub), 29EDD-71 29PS-243 (29EDD-71 Edd71Sub), 29EDD-65 29PT-0257 (29EDD-65) FB-Maintenance, Repairs and Testing - PRC-5 Testing, 29PT-260, 29PL7-4, 29PT-241, 29PT-257, 29PS-243 (300415541, 31807283, 31773784, 300109525)  
ENMAX, ALTALINK 19-Sep-25 18:00 21-Sep-25 08:00 1.58 Days
Continuous
937L (5s East Calgary - 102s Langdon) Reconductor between str 15 to 18 on both Circuits for line Clearance Mitigation  
ENMAX, ALTALINK 19-Sep-25 18:00 21-Sep-25 08:00 1.58 Days
Continuous
936L (5s East Calgary - 102s Langdon) Crew working in vicinity of 937L  
EPCOR 22-Sep-25 07:00 04-Oct-25 17:00 12.42 Days
Continuous
EP 803s T3 (EP 803s Lambton), EP 803s L721 (EP 803s Lambton), 72LH8 (EP 803s Lambton - EP Hardisty), 72LS24 (EP 803s Lambton - Strathcona) Lambton/LH8/LS24: LDS11/LDS12 LCR and L721 Breaker Maintenance (Min Oil) and PT Doble  
ALTALINK 22-Sep-25 10:00 22-Sep-25 17:00 7 Hours
Daily
725L (674s Bowron - 725BL tap) Test/Trip 674ss T1 Protections  
ALTALINK 23-Sep-25 08:00 23-Sep-25 17:00 9 Hours
Daily
725L (674s Bowron - 725AL tap) Test/Trip 674ss T1 Protections  
ATCO 29-Sep-25 13:00 02-Oct-25 16:00 3.13 Days
Continuous
7L28 (717s Ethel Lake - 846s Grand Centre) 7L28 Line to ground clearance mitigation  
ALTALINK 01-Oct-25 08:00 11-Nov-25 17:00 41.42 Days
Continuous
102s SVC (102s Langdon), 102s T4 (102s Langdon) the controls change AB-BC
ATCO 06-Oct-25 09:30 07-Oct-25 17:30 1.33 Days
Continuous
845s 703 (845s Big Mountain), 845s 710 (845s Big Mountain), 7L228 (845s Big Mountain - 7L20 tap) Replace Crank Mechanisms on 144 kV Switches at 845s Big Mountain - 703B
Replace Crank Mechanisms on 144 kV Switches at 845s Big Mountain - 704B
 
ATCO 08-Oct-25 09:30 09-Oct-25 17:30 1.33 Days
Continuous
7L85 (801s Anderson - ATC 803s Bullpound), 801s 705 (801s Anderson) BREAKER SF6 LTB145D1/B COMPLETE TESTING - 705 @ 801S  
ALTALINK 08-Oct-25 23:00 09-Oct-25 03:00 4 Hours
Continuous
62s T1 (62s Brazeau Plant) maintenance  
ALTALINK 09-Oct-25 03:00 09-Oct-25 07:00 4 Hours
Daily
62s T2 (62s Brazeau Plant) maintenance  
ALTALINK, TRANSALTA 29-Oct-25 10:00 29-Oct-25 14:00 4 Hours
Daily
250p T1 (250p Bighorn Plant) maintenance  
ALTALINK, TRANSALTA 30-Oct-25 10:00 30-Oct-25 14:00 4 Hours
Daily
250p T2 (250p Bighorn Plant) maintenance  
ATCO 03-Nov-25 12:00 09-Dec-25 17:00 36.21 Days
Continuous
9L99 (801s Anderson - 807s Sheerness) Replace Breaker 901 @ 807S Sheerness, complete line 21A, 21B/9L99 protection upgrade and Commissioning  
ATCO 17-Nov-25 10:00 24-Nov-25 16:00 7.25 Days
Continuous
7L106 (834s Wesley Creek - 905s Meikle) Soil around the tower footings has eroded ( Tower Replacement )  
ATCO 17-Nov-25 10:00 24-Nov-25 16:00 7.25 Days
Continuous
7L131 (834s Wesley Creek - 905s Meikle) Soil around the tower footings has eroded ( Tower Replacement )  
ALTALINK 26-Nov-25 23:00 27-Nov-25 03:00 4 Hours
Continuous
62s T1 (62s Brazeau Plant) maintenance  
ALTALINK 27-Nov-25 03:00 27-Nov-25 07:00 4 Hours
Daily
62s T2 (62s Brazeau Plant) maintenance  
ALTALINK, TRANSALTA 17-Dec-25 10:00 17-Dec-25 14:00 4 Hours
Daily
250p T1 (250p Bighorn Plant) maintenance  
ALTALINK, TRANSALTA 18-Dec-25 10:00 18-Dec-25 14:00 4 Hours
Daily
250p T2 (250p Bighorn Plant) maintenance  
ATCO 17-Feb-26 09:00 03-Mar-26 17:00 14.33 Days
Continuous
972s 240kV Bus 900BS1 (972s Tinchebray) Install Breaker 904 and 904CT
On release leave Bkr 904, 904A/904B closed as feed through (disable bkr trips), Bkr 901 still protecting 9L93
 
SUNCOR 02-Mar-26 08:00 08-Mar-26 20:00 6.46 Days
Continuous
29PL9-16 (29EDD-1 Millennium - 29EDD-94 Voyageur) 29EDD1;29PT418/29PL9-16 SYSTEM;PM 5y,10y
 
SUNCOR 09-Mar-26 08:00 15-Mar-26 20:00 6.5 Days
Continuous
29PL9-17 (29EDD-1 Millennium - 29EDD-94 Voyageur) 29EDD1;29PT419/29PL9-17 SYSTEM;PM 5y,10y
 
ATCO 10-Mar-26 09:00 14-Apr-26 17:00 35.33 Days
Continuous
972s 240kV Bus 900BS2 (972s Tinchebray) Install Breakers 905/906, 905CT/906CT, switches 905A/906B
On release leave Bkrs 905/906, 905A/905B, and 906A/906B closed as feed through (disable bkr trips), Bkr 903 still protecting 9L93, leave new 9L62D1 open for future line connection
 
ATCO, SUNCOR 16-Mar-26 08:00 22-Mar-26 20:00 6.5 Days
Continuous
29PL9-1 (29EDD-1 Millennium - 848s Ruth Lake) 29EDD1;29CVT-3 SYSTEM;PM 5y,10y
 
ATCO, SUNCOR 23-Mar-26 08:00 29-Mar-26 20:00 6.5 Days
Continuous
29PL9-2 (29EDD-1 Millennium - 848s Ruth Lake) BP (Corey) - 29EDD1;29CVT-1 SYSTEM;PM 5y,10y  
ATCO, SUNCOR 30-Mar-26 08:00 05-Apr-26 20:00 6.5 Days
Continuous
6L32 (29EDD-1 Millennium - 737s ATC Horseshoe) 29EDD1;29CVT-6 SYSTEM;5y,10y
 
SUNCOR 06-Apr-26 08:00 12-Apr-26 20:00 6.5 Days
Continuous
29PL9-3 (29EDD-1 Millennium - 29EDD-3), 29EDD-3 29PT-6 (29EDD-3) 29EDD1;29CVT-4 SYSTEM;PM 5y,10y;
 
SUNCOR 13-Apr-26 08:00 19-Apr-26 20:00 6.5 Days
Continuous
29EDD-1 T1 (29EDD-1 Millennium), 29EDD-1 260kV South Bus 1 (29EDD-1 Millennium), 29EDD-1 72kV South Bus (29EDD-1 Millennium) 29EDD1;XFMR T1; X260B1; X72B1 SYSTEM;PM 5y  
ATCO 13-Apr-26 10:00 18-Apr-26 17:00 5.29 Days
Continuous
7L22 (790s Poplar Hill - 7L88 tap) Cut open 7L22, connect new line section to new 2061S Dobbs
7L22/21B relay upgrades at 790S Poplar Hill and 811S Clairmont Lake
On completion energize new 2061S Dobbs substation
 
SUNCOR 20-Apr-26 08:00 26-Apr-26 20:00 6.5 Days
Continuous
29EDD-1 T2 (29EDD-1 Millennium), 29EDD-1 260kV North Bus 2 (29EDD-1 Millennium), 29EDD-1 72kV North Bus (29EDD-1 Millennium) 29EDD1;XFMR T2; N260B2; N72B1 SYSTEM;PM 5y  
ATCO 21-Apr-26 09:00 26-Apr-26 17:00 5.33 Days
Continuous
9LA93 (973s Lanes Lake - 9L93 tap) Cutover and commission 9L93 protection ccts from Bkrs 901/903 to Bkrs 904/905
**AESO NEEDS TO ADD 9L93, 973S 9LA93D1**
 
ATCO 03-May-26 10:00 04-May-26 17:00 31 Hours
Continuous
7L22 (811s Clairmont Lake - 7L88 tap) 7L22/21B relay upgrade at 811S Clairmont Lake
Upon completion new 2061S Dobbs substation ready to energize
 
SUNCOR 04-May-26 08:00 10-May-26 20:00 6.5 Days
Continuous
29PL6-6 (29EDD-1 Millennium - 29EDD-2 Tar Island), 29EDD-2 29PT-2 (29EDD-2 Tar Island) BP (Corey) - 29EDD2;29PP-1 SYSTEM;PM 5y  
ATCO 04-May-26 09:00 18-May-26 17:30 14.35 Days
Continuous
13L50 (2029s Heathfield - 2075s Newell) Kinbrook Addition to 2075s  
ATCO 04-May-26 09:00 18-May-26 17:30 14.35 Days
Continuous
2029s T11 (2029s Heathfield) Kinbrook Addition to 2075s Newell.  
ATCO 04-May-26 09:00 18-May-26 17:30 14.35 Days
Continuous
2075s T11 (2075s Newell) Kinbrook Addition to 2075s Newell.  
ATCO 05-May-26 09:00 06-May-26 17:00 1.33 Days
Continuous
972s 240kV Bus 900BS1 (972s Tinchebray) Connect new 907B to 900BS1
Run station service on back-up generator
 
ATCO 07-May-26 09:00 08-May-26 17:00 1.33 Days
Continuous
972s 240kV Bus 900BS2 (972s Tinchebray) Connect new 909A to 900BS2  
SUNCOR 18-May-26 08:00 24-May-26 20:00 6.5 Days
Continuous
29PL9-12 (29EDD-34 - 29EDD-65) BP (Corey) - 29EDD34;29PL9-12 SYSTEM;PM 5y,10y
 
ATCO 19-May-26 09:00 19-May-26 17:00 8 Hours
Continuous
9L16 (755s Cordel - 972s Tinchebray), 755s 904 (755s Cordel), 755s 905 (755s Cordel), 972s 903 (972s Tinchebray) Disconnect 9L16 from existing A-frame deadend and 9L16D2 (to be renamed 9L86D1)
Restore bus leave renamed 9L86D1 open for future line connection.
 
ATCO 19-May-26 09:00 29-May-26 17:00 10.33 Days
Continuous
9L16 (755s Cordel - 972s Tinchebray) Disconnect 9L16 from existing A-frame deadend and 9L16D2 (to be renamed 9L86D1)
Restore bus leave renamed 9L86D1 open for future line connection.
 
ATCO 02-Jun-26 09:00 13-Jun-26 17:00 11.33 Days
Continuous
ATCO RTU/SCADA Connect new 9L62 to 972S and prepare to energize.
String Conductors/OPGW 9L62 from Str #3 to substation A-frame deadends and connect to 9L62D1, coordinate with AML conductor jumpers and OPGW termination at the TFO boundary 9L86 Str 409
 
ATCO 14-Jun-26 09:00 25-Jun-26 17:00 11.33 Days
Continuous
ATCO RTU/SCADA Work on parallel line 9L86  
ATCO 16-Jun-26 09:00 25-Jun-26 17:00 9.33 Days
Continuous
972s 240kV Bus 900BS2 (972s Tinchebray) Connect new 9L86 to 972S and prepare to energize.
String Conductors/OPGW 9L86 from Str #3 to substation A-frame deadends and connect to 9L86D1, coordinate with AML conductor jumpers and OPGW termination at the TFO boundary 9L86 Str 409
Complete protection commissioning
 
ATCO 10-Aug-26 10:00 13-Aug-26 16:30 3.27 Days
Continuous
7L702 (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
ATCO 17-Aug-26 10:00 20-Aug-26 16:30 3.27 Days
Continuous
7L702 (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
ATCO 24-Feb-27 09:00 25-Feb-27 17:00 1.33 Days
Continuous
959s 240kV Bus 900BS1 (959s Lanfine) Connect new bus from new 902B to existing switch 901A to add new line 9L141 to UK Solar farm
Cutover and commission 900PT1 ccts to new 9L141 relays
 
ATCO 26-Feb-27 09:00 27-Feb-27 17:00 1.33 Days
Continuous
959s 240kV Bus 900BS2 (959s Lanfine) Connect new bus from new Bkr 903 to existing switch 903B to add new line 9L141 to UK Solar farm
Cutover and commission 900PT2 ccts to new 9L141 relays
 
ATCO 08-Mar-27 10:00 17-Mar-27 17:00 9.25 Days
Continuous
9L24 (946s Oakland - 959s Lanfine), 959s 906 (959s Lanfine), 959s 905 (959s Lanfine), 946s 902 (946s Oakland), 946s 903 (946s Oakland) Replace A/B protection relays at 959S Lanfine and 946S Oakland
Cut in and reroute 9L24
Connect new 9LA24 T-tap
Commission Telecom and Protection to new 1072S Rose Lynn substation
 
ATCO 20-Jul-27 08:00 21-Jul-27 17:00 1.38 Days
Continuous
7L53 (706s Irish Creek - 7LA53 tap), 7LA53 (969s Lindbergh - 7L53 tap), 7L53 (700s Bonnyville - 7LA53 tap) Cold Lake Area Project to connect 1064s  
ATCO 22-Jul-27 08:00 25-Jul-27 17:00 3.38 Days
Continuous
7L91 (715s Leming Lake - 826s Marguerite Lake) Cold Lake Area Energy Centre Project
 

AB-BC, AB-SK & AB-MATL: refer to AESO web posting: http://itc.aeso.ca/itc/public/atc
Also,
AB-BC, AB-SK & AB-MATL: refer to ISO Rule 203.6: http://www.aeso.ca/rulesprocedures/18592.html

Prepared On: 2025-03-26   14:23:42


This document and the information contained herein are based upon information and data which by their nature contain a degree of uncertainty and are subject to change. In addition, this document may contain information and data from public sources and/or third parties, which have been assumed to be accurate and complete and have not been verified. Accordingly, the Independent System Operator, operating as the Alberta Electric System Operator (the "AESO") makes no warranty, representation or guarantee, express or implied, with respect to this document or the information contained herein, including, but not limited to, any warranty, representation or guarantee of accuracy, completeness, timeliness, reliability, availability, absence of computer virus, non- infringement, merchantability or suitability for any purpose. Under no circumstances will the AESO, its members, officers, employees, contractors or agents, or any of their respective affiliates, be liable for any errors or omissions in, or any losses, damages or claims whatsoever, whether in contract, tort or otherwise, arising from use of or reliance upon, this document or any information contained herein.

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