Alberta Electric System Operator
Long Range Significant Transmission Outages for the period of 24 months starting 2026-08-01

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.

Previous Version
Download CSV

Owner From To Duration Element Scheduled Activity Affected Intertie
ATCO 25-Nov-25 17:46 18-Sep-26 18:00 7,127.23 Hours
Continuous		 876s 901T (876s Brintnell) forced outage oil leaking  
SUNCOR 04-Jan-26 08:00 02-Sep-26 16:00 5,791 Hours
Continuous		 29EDD-34 260kV Bus 29PP-45 (29EDD-34), 29EDD-34 29-952-113 (29EDD-34), 29EDD-34 29PS-216 (29EDD-34) urgent repairs on 29PT-224 at 29EDD34 on 29PP-45 bus  
ATCO 14-Jul-26 11:56 31-Aug-26 00:00 1,140.07 Hours
Continuous		 7L91 (715s Leming Lake - 826s Marguerite Lake) forced outage  
ALTALINK 15-Jul-26 14:01 05-Oct-26 09:00 1,962.98 Hours
Continuous		 417L (55s Olds - 281s Johnson), 55s T1 (55s Olds), 55s T2 (55s Olds), 55s 417 (55S Olds), 287s 552 (287s Hazelwood), 55s 2 (55s Olds) mobile install at 55s for P_C major upgrade, repair/replace s80, s83, s84. salvage s51.  
EPCOR 20-Jul-26 07:00 02-Aug-26 17:00 322 Hours
Continuous		 987s T1 (987s Clover Bar), 987s CCP7213 (987s Clover Bar), 987s CCP7214 (987s Clover Bar), 987s C2401 (987s Clover Bar), 987s C2403 (987s Clover Bar), 987s CDS25 (987s Cloverbar) Cloverbar: breaker maintenance and CT doble and relay maintenance  
ALTALINK 20-Jul-26 14:30 07-Aug-26 17:00 434.5 Hours
Continuous		 1083L (63s Red Deer - 288s Wolf Creek), 63s 452 (63s Red Deer), 63s 552 (63s Red Deer), 288s 352 (288s Wolf Creek), 288s 152 (288s Wolf Creek), 288s 1083 (288s Wolf Creek), 63s 1083 (63s Red Deer) 63s452 breaker replacement  
Syncrude 26-Jul-26 08:00 08-Aug-26 16:00 272 Hours
Continuous		 14 (Aurora), 213 (Aurora), 223 (Aurora), 24 (Aurora), 34 (Aurora), 260kV Bus 2 (Aurora), 72 kV Bus 2 (Aurora), T11 (Aurora), 89-216 (Aurora), 89-52 (Aurora) zone 1 6 year PM at Aurora  
EPCOR 27-Jul-26 07:00 04-Sep-26 17:00 946 Hours
Continuous		 EP 805s J2401 (EP 805s Jasper) Jasper: J2401 replacement LCR  
SUNCOR 31-Jul-26 08:00 06-Aug-26 16:00 156 Hours
Continuous		 29EDD-1 29EDD1s152 (29EDD-1 Millennium) maintenance & trip test  
SUNCOR 01-Aug-26 08:00 31-Aug-26 20:00 732 Hours
Continuous		 29EDD-60 29PT-702 (29EDD-60 Inglis Island) 30PD-32 IPB PRESSURE LOW - Requires 29PT-702 to be 300691658  
ALTALINK 03-Aug-26 08:00 04-Aug-26 17:00 33 Hours
Continuous		 310p 1452 (310p Sundance) Test 310p1452 CTs  
ENMAX, ALTALINK 04-Aug-26 08:00 21-Aug-26 16:00 416 Hours
Continuous		 24.83L (74s Janet - SS-24) Wood pole installation  
ALTALINK, ENMAX 04-Aug-26 08:00 21-Aug-26 16:00 416 Hours
Continuous		 74s 24.83X (74s Janet), 24.83L (74s Janet - SS-24) Enmax Wood pole installation  
ENMAX, ALTALINK 04-Aug-26 09:00 04-Aug-26 17:00 8 Hours
Continuous		 5s T2 (5s East Calgary) Altalink outage. Altalink will be removing 5s T2 from service for maintenance  
ALTALINK, TRANSALTA 04-Aug-26 09:00 06-Aug-26 17:00 56 Hours
Continuous		 179s 733 (179s Gleichen), 428s 733X (428s Namaka), 733L (179s Gleichen - 428s Namaka) 733Lstr. 161-211 Crossarm work. Maintenance/repairs.  
ENMAX, ALTALINK 04-Aug-26 09:00 06-Aug-26 17:00 56 Hours
Continuous		 5s T2 (5s East Calgary) 5sT2 PRC Doble , Major Maint.  
ATCO 04-Aug-26 09:00 06-Aug-26 17:30 56.5 Hours
Continuous		 2029s 1301 (2029s Heathfield) DC HIGH SPEED SWITCH MAINTENANCE - 1302 @ 2029S
**EATL will need to run in P2 Return while 1302 is out of service		  
SUNCOR 04-Aug-26 09:00 07-Aug-26 20:00 83 Hours
Continuous		 29EDD-1 29EDD1s952 (29EDD-1 Millennium) 29EDD1s952 - Faulty SF6 Sensors / No visibility risk, No line outage - BPC-26-014 - 300677553  
BCH 04-Aug-26 09:00 23-Aug-26 13:00 460 Hours
Continuous		 5L91 (BCH Ashton Creek - BCH Selkirk) maintenance AB-BC
ALTALINK 04-Aug-26 10:00 05-Aug-26 16:30 30.5 Hours
Continuous		 74s 104 (74s Janet), 74s 103 (74s Janet), 74s 102 (74s Janet), 74s C3 (74s Janet), 74s C4 (74s Janet) 74s103 Major maint  
ATCO 04-Aug-26 10:00 05-Aug-26 17:00 31 Hours
Continuous		 7L131 (834s Wesley Creek - 905s Meikle) 708 Densimeters Replacement at 834s Wesley Creek
Investigate Heater Fail - 708 at 834S Wesley Creek
Investigate inoperable switch 708B		  
ALTALINK 04-Aug-26 10:00 06-Aug-26 17:30 55.5 Hours
Continuous		 310p 2652 (310p Sundance), 310p 2752 (310p Sundance), 77s 29 (77s Sagitawah), 77s 26 (77s Sagitawah), 989L (77s Sagitawah - 310p Sundance) 989L Line Maintenance. 77s26 Breaker maintenance  
ALTALINK 05-Aug-26 07:00 06-Aug-26 16:00 33 Hours
Continuous		 310p 2852 (310p Sundance) Test 310p2852 CTs  
ATCO 05-Aug-26 08:00 06-Aug-26 13:00 29 Hours
Continuous		 7L85 (803s ATC Bullpound - 7LA85 tap) Interphase spacer install, Deficiency repairs & insulator replacement between Badlands and Bullpound  
ATCO 05-Aug-26 09:00 05-Aug-26 17:00 8 Hours
Continuous		 7L22 (790s Poplar Hill - 7L88 tap), 790s 702 (790s Poplar Hill) ASEA IMBD CT Testing at 790S POPLAR HILL - CT702 - PRIORITY 2  
ATCO 06-Aug-26 09:00 06-Aug-26 17:00 8 Hours
Continuous		 7L07 (790s Poplar Hill - 815s Goodfare), 790s 703 (790s Poplar Hill) ASEA IMBD CT Testing at 790S POPLAR HILL - CT703 - PRIORITY 2  
SUNCOR 06-Aug-26 14:01 06-Aug-26 20:00 5.98 Hours
Continuous		 29EDD-1 29EDD1s252 (29EDD-1 Millennium) 29EDD1 29CVT-1/29PL9-2 SYS PVM 5Y 10Y PRC-005 Trip Test 29EDD1s252, We will trip and reclose the breaker  
SUNCOR 07-Aug-26 10:00 07-Aug-26 12:59 2.98 Hours
Continuous		 29EDD-1 29EDD1s952 (29EDD-1 Millennium) 29EDD1 / N260B2 NORTH BUS PRC-005 Relay Testing - Trip open 29EDD1S952 - - 450338056
In conjunction with Outage 1-00529372		  
SUNCOR 07-Aug-26 13:00 07-Aug-26 16:00 3 Hours
Continuous		 29EDD-1 29EDD1s752 (29EDD-1 Millennium) 29EDD1 / N260B2 NORTH BUS PRC-005 Relay Testing - Trip open 29EDD1S752 - following outage: 1-00529374 - 450338056
In conjunction with Outage 1-00529372 		 
ENMAX, ALTALINK 08-Aug-26 08:00 08-Aug-26 18:00 10 Hours
Continuous		 832L (SS-10 - SS-12), 12.1TR (SS-12) Substation Structure Painting  
SUNCOR 08-Aug-26 09:00 11-Aug-26 20:00 83 Hours
Continuous		 29EDD-1 29EDD1s852 (29EDD-1 Millennium) 29EDD1S852 Replace Densimeter  
ENMAX, ALTALINK 09-Aug-26 08:00 09-Aug-26 18:00 10 Hours
Continuous		 833L (SS-2 - SS-12), 12.2TR (SS-12) Substation Structure Painting  
ATCO 10-Aug-26 07:00 14-Aug-26 17:00 106 Hours
Continuous		 7L03 (749s Flyingshot Lake - 7L09 tap) Tie in of a bypass for 7L03 to facilitate Alberta highways construction project.  
EPCOR 10-Aug-26 07:00 16-Aug-26 17:00 154 Hours
Continuous		 665s T3 (665s Dome), 665s D721 (665s Dome), 665s D2404 (665s Dome), S721 (Strathcona) DS26/Dome/Strathcona: Dome TX3 Doble and DAB3/DDS15/DDS16 Disconnect Maintenance and Strathcona DS26/CVT Doble and SDS3 Disconnect Maintenance  
ATCO 10-Aug-26 09:00 13-Aug-26 16:00 79 Hours
Continuous		 969s 701T (969s Lindbergh), 969s Protection & Control (969s Lindbergh) total station outage to replace failing HO/XO bushings on transformer, updates to anti-islanding RAS logic and alarming, replace NGR resistor and relay

coordinated with dates provided by Strathcona Resources, awaiting confirmation from IPL		  
ALTALINK, BCH 10-Aug-26 09:00 20-Aug-26 17:00 248 Hours
Continuous		 1L274 (48s Pocaterra - 978s BCH Britt Creek) maintenance AB-BC
ALTALINK 10-Aug-26 09:30 13-Aug-26 17:00 79.5 Hours
Continuous		 702L (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
ATCO, ALTALINK 10-Aug-26 10:00 13-Aug-26 16:30 78.5 Hours
Continuous		 7L702 (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
ATCO 10-Aug-26 10:00 14-Aug-26 17:30 103.5 Hours
Continuous		 959s SVC (959s Lanfine), 959s 921 (959s Lanfine) DFR Upgrade / Replacement
SVC Transformer Maintenance
Fire system inspection
Install Blocking Switches
Mechanical Maintenance & Capital
BATTERY CHARGER COMPLETE TESTING @ LANFINE 959S SVC DC MOTOR		  
ALTALINK 10-Aug-26 11:00 10-Aug-26 18:00 7 Hours
Daily		 77s 29 (77s Sagitawah) trip test 77s29  
ALTALINK 10-Aug-26 11:00 13-Aug-26 16:30 77.5 Hours
Continuous		 71s 152 (71s Lamoureux), 71s 552 (71s Lamoureux), 71s 1052 (71s Lamoureux), 71s 952 (71s Lamoureux), 71s T1 (71s Lamoureux), 71s 138kV West Bus (71s Lamoureux) Transformer maintenance, switch maintenance (71s13, 71s44, 71s45), breaker maintenance (71s1052)  
ALTALINK 10-Aug-26 12:30 13-Aug-26 17:00 76.5 Hours
Continuous		 17s 85 (17s Benalto), 17s T2 (17s Benalto) 17s85 CT replacement  
ATCO 10-Aug-26 13:00 10-Aug-26 14:00 1 Hour
Continuous		 951s 1205 (951s Thickwood Hills) PRC-005 Trip Coil testing, SOC ill open and close breaker (tests TC #1), Techs will isolate A protection tripping this breaker, TOC will open and close breaker (tests TC #2)  
ALTALINK 10-Aug-26 14:00 18-Aug-26 17:00 195 Hours
Continuous		 275s T1 (275s Jenner) Replace LV bushings, TC Maint, Cooper cutouts  
ATCO 10-Aug-26 14:01 10-Aug-26 15:00 0.98 Hours
Continuous		 951s 1206 (951s Thickwood Hills) PRC-005 Trip Coil testing, SOC ill open and close breaker (tests TC #1), Techs will isolate A protection tripping this breaker, TOC will open and close breaker (tests TC #2)  
ATCO 10-Aug-26 15:00 10-Aug-26 16:00 1 Hour
Continuous		 951s 1213 (951s Thickwood Hills) PRC-005 Trip Coil testing, SOC will open and close breaker (tests TC #1), Techs will isolate A protection tripping this breaker, TOC will open and close breaker (tests TC #2)  
ALTALINK 11-Aug-26 06:30 11-Aug-26 12:30 6 Hours
Daily		 77s 40 (77s Sagitawah) trip test 77s40  
ALTALINK 11-Aug-26 07:00 12-Aug-26 17:00 34 Hours
Continuous		 102s 552 (102s Langdon), 102s 252 (102s Langdon), 102s T4 (102s Langdon), 102s SVC (102s Langdon) To install a config change on the MACH controls from the controls system upgrade. During testing it was found some settings required changing. This is to implement those changes.  
ALTALINK 11-Aug-26 07:00 13-Aug-26 18:00 59 Hours
Continuous		 310p 1852 (310p Sundance) Replace 310p1852 CT's  
ATCO 11-Aug-26 09:00 14-Aug-26 17:00 80 Hours
Continuous		 834s 902T (834s Wesley Creek) TRANSFORMER CLASS1 TAP CHANGER - 902T @ 834S
Investigate Heater Fail - 503 at 834S Wesley Creek		  
ATCO 11-Aug-26 10:00 11-Aug-26 11:00 1 Hour
Continuous		 939s 1206 (939s Livock) PRC-005 Trip Coil testing,  
ATCO 11-Aug-26 11:00 11-Aug-26 12:00 1 Hour
Continuous		 939s 1207 (939s Livock) PRC-005 Trip Coil testing, SOC will open and close breaker (tests TC #1), Techs will isolate A protection tripping this breaker, TOC will open and close breaker (tests TC #2)  
ATCO 11-Aug-26 12:00 11-Aug-26 13:00 1 Hour
Continuous		 939s 1214 (939s Livock) PRC-005 Trip Coil testing, SOC will open and close breaker (tests TC #1), Techs will isolate A protection tripping this breaker, TOC will open and close breaker (tests TC #2),  
ALTALINK 11-Aug-26 12:31 11-Aug-26 18:00 5.48 Hours
Daily		 77s 57 (77s Sagitawah) trip test 77s57  
ATCO 11-Aug-26 13:00 11-Aug-26 14:00 1 Hour
Continuous		 939s 1216 (939s Livock) PRC-005 Trip Coil testing, SOC will open and close breaker (tests TC #1), Techs will isolate A protection tripping this breaker, TOC will open and close breaker (tests TC #2)  
SUNCOR 12-Aug-26 09:00 15-Aug-26 20:00 83 Hours
Continuous		 29EDD-1 29EDD1s1052 (29EDD-1 Millennium) 29EDD1S1052 Densimeter Replacement - No visibility outage, no line outage - BPC-26-017 - 300347749  
EPCOR 17-Aug-26 07:00 18-Aug-26 17:00 34 Hours
Continuous		 987s T3 (987s Clover Bar), 987s C2407 (987s Clover Bar) Cloverbar: TX3, Relay Maintenance  
ENMAX, ALTALINK 17-Aug-26 08:00 17-Aug-26 12:00 4 Hours
Continuous		 21.80L (42s Sarcee - SS-21), 21B138-21.80 (SS-21) HV Breaker SF6 Gas Sample - 21B138-21.80  
ALTALINK 17-Aug-26 08:00 20-Aug-26 17:00 81 Hours
Continuous		 310p 1252 (310p Sundance), 310p 1152 (310p Sundance) Replace 310p1152 BKR CT's and repair switch 310p11A.  
ALTALINK, EPCOR 17-Aug-26 09:30 22-Aug-26 17:00 127.5 Hours
Continuous		 920L (71s Lamoureux - 557s Castle Downs), 557s CD2405 (557s Castle Downs), 557s CD2404 (557s Castle Downs) 920LE/Castledowns: CT/CVT Doble and Surge Arrestor LCR  
ALTALINK, EPCOR 17-Aug-26 09:30 22-Aug-26 17:00 127.5 Hours
Continuous		 920L (71s Lamoureux - 557s Castle Downs) 920LE/Castledowns: CT/CVT Doble and Surge Arrestor LCR  
SUNCOR 17-Aug-26 10:00 17-Aug-26 12:59 2.98 Hours
Continuous		 29EDD-1 29EDD1s1052 (29EDD-1 Millennium) 29EDD1 / X260B2 SOUTH BUS PRC-005 / Relay Test -Trip open 29EDD1s1052 (29EDD-1 Millennium) - 450338057
In conjunction with Outage 1-00529388
  
ATCO, ALTALINK 17-Aug-26 10:00 20-Aug-26 16:30 78.5 Hours
Continuous		 7L702 (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
ALTALINK 17-Aug-26 10:00 20-Aug-26 16:30 78.5 Hours
Continuous		 702L (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
ALTALINK 17-Aug-26 11:00 20-Aug-26 16:45 77.75 Hours
Continuous		 71s 1752 (71s Lamoureux), 71s 1452 (71s Lamoureux), 71s 1352 (71s Lamoureux), 71s 32 (71s Lamoureux), 71s T2 (71s Lamoureux), 71s 240kV East Bus (71s Lamoureux) Multiple switch repair/replacement and maintenance
71s36, 71s37, 71s46, 71s47		  
ALTALINK 17-Aug-26 12:00 20-Aug-26 17:00 77 Hours
Continuous		 777L (48s Pocaterra - 245s Seebe), 245s 777X (245s Seebe) 245s777X 138kV CT replacement AB-BC
ALTALINK 17-Aug-26 12:30 20-Aug-26 17:00 76.5 Hours
Continuous		 320p 652 (320p Keephills) Replace 320p652 external CT's  
SUNCOR 17-Aug-26 13:00 17-Aug-26 17:00 4 Hours
Continuous		 29EDD-1 29EDD1s852 (29EDD-1 Millennium) 29EDD1 / X260B2 SOUTH BUS PRC-005 / Relay Test -Trip open 29EDD1s852 (29EDD-1 Millennium) - 450338057
In conjunction with Outage 1-00529388, following outage 1-00529393
  
ATCO 17-Aug-26 13:00 20-Aug-26 13:00 72 Hours
Continuous		 9L10 (876s Brintnell - 939s Livock), 939s 903T (939s Livock), 939s 910A (939s Livock) PRC-005 - SPR TESTING - TRANSFORMER 903T @ 939S
Repair and adjust 910A @ 939S APL
Repalce OLTC Filters, 903T @ 939S Livock		  
ATCO 17-Aug-26 13:00 20-Aug-26 13:00 72 Hours
Continuous		 828s 702 (828s Sulphur Point), 7L93 (828s Sulphur Point - 930s Arcenciel) BREAKER SF6 LTB145D1/B COMPLETE TESTING - 702 @ 828S
SLD notes that 7L93 relays should be on alt settings at 828S Sulphur Point		  
ALTALINK 17-Aug-26 14:00 20-Aug-26 16:30 74.5 Hours
Continuous		 574s T1 (574s Nilrem) Transformer maintenance  
ALTALINK 18-Aug-26 07:00 18-Aug-26 18:00 10.5 Hours
Daily		 1112L (89s Ellerslie - 289s Saunders Lake) transmission line maintenance  
ALTALINK, ATCO, FMGW 18-Aug-26 08:00 19-Aug-26 17:00 33 Hours
Continuous		 964AL (1024s Granlea - 964L tap), 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), 1024s 489-600201 (1024s Granlea) maintenance activities (testing and inspection) of electrical equipment  
SUNCOR 21-Aug-26 10:00 21-Aug-26 11:59 1.98 Hours
Continuous		 29EDD-1 952-103 (29EDD-1 Millennium) 29EDD1 / X260B1 SOUTH BUS PRC-005 / Relay Test - Trip Open 952-103 (29EDD-1 Millennium) - 450338059
In conjunction with outage 1-00529405		  
SUNCOR 21-Aug-26 12:00 21-Aug-26 13:59 1.98 Hours
Continuous		 29EDD-1 952-106 (29EDD-1 Millennium) 29EDD1 / X260B1 SOUTH BUS PRC-005 / Relay Test - Trip Open 952-106 (29EDD-1 Millennium) - 450338059
In conjunction with outage 1-00529405, following outage 1-00529407		  
SUNCOR 21-Aug-26 14:00 21-Aug-26 16:00 2 Hours
Continuous		 29EDD-1 29EDD1s652 (29EDD-1 Millennium) 29EDD1 / X260B1 SOUTH BUS PRC-005 / Relay Test - Trip Open 29EDD1s652 (29EDD-1 Millennium) - 450338059
In conjunction with outage 1-00529405, following outage 1-00529409		  
ALTALINK 23-Aug-26 11:30 23-Aug-26 17:30 6 Hours
Daily		 77s 29 (77s Sagitawah) trip test 77s29  
ALTALINK 24-Aug-26 06:30 24-Aug-26 12:30 6 Hours
Daily		 77s 40 (77s Sagitawah) trip test 77s40  
EPCOR 24-Aug-26 07:00 30-Aug-26 17:00 154 Hours
Continuous		 557s T2 (557s Castle Downs), 557s CD2403 (557s Castle Downs), 557s CD2404 (557s Castle Downs), 557s CDAB2 (557s Castle Downs) Castledowns: TX2 tap changer and disconnect switch maintenance  
ALTALINK, BCH 24-Aug-26 08:00 01-Sep-26 17:00 201 Hours
Continuous		 Path 1 (AIES Islanding), 1201L (520s Bennett - BCH Cranbrook), 5L94 (BCH Cranbrook - 520s Bennett) South Crew will be doing Insulator and guy wire replacements AB-BC
ALTALINK, BCH 24-Aug-26 08:00 01-Sep-26 17:00 201 Hours
Continuous		 799s 786W (799s Coleman), 786L (799s Coleman - BCH Natal) Opened because 1201L is out of service. AB-BC
ALTALINK, BHE 24-Aug-26 08:00 01-Sep-26 17:00 201 Hours
Continuous		 MATL (120s Picture Butte - Montana) align with 1201L outage AB-MATL
ALTALINK, EPCOR 24-Aug-26 09:00 25-Aug-26 17:00 32 Hours
Continuous		 908AL (52S East Industrial - 908L tap), 52s T2 (52s East Industrial), 52s E2402 (52s East Industrial) East Industrial/908LW: CVT JB Rewiring  
ALTALINK 24-Aug-26 09:00 25-Aug-26 18:00 33 Hours
Continuous		 908L (38s East Edmonton - 908AL tap), 908L (89s Ellerslie - 908AL tap) East Industrial/908LW: CVT JB Rewiring  
BCH 24-Aug-26 09:00 01-Sep-26 17:00 200 Hours
Continuous		 5L92 (BCH Cranbrook - BCH Selkirk) replace spacers, markerballs and insulators AB-BC
ALTALINK 24-Aug-26 11:30 27-Aug-26 17:00 77.5 Hours
Continuous		 71s 1452 (71s Lamoureux), 71s 1352 (71s Lamoureux), 71s 997E (71s Lamoureux) switch replacement 71s997E, switch repair 71s46
 
ALTALINK 24-Aug-26 12:31 24-Aug-26 18:00 5.48 Hours
Daily		 77s 57 (77s Sagitawah) trip test 77s57  
ALTALINK 24-Aug-26 13:00 28-Aug-26 17:00 100 Hours
Continuous		 28s R1 (28s West Brooks) 28sR1 leak category 5, Doble R1
28s44 PRC5 (no first trip)		  
ATCO 24-Aug-26 13:00 04-Sep-26 13:00 264 Hours
Continuous		 7L228 (845s Big Mountain - 7L20 tap), 7L20 (740s H.R. Milner - 810s Dome Cutbank) 7L228D2 Line Switch Failure Replacement
Install BKR 703		  
EPCOR 26-Aug-26 07:00 30-Aug-26 17:00 106 Hours
Continuous		 52s T1 (52s East Industrial) East Industrial: TX1 Doble  
ENMAX, ALTALINK 26-Aug-26 08:00 27-Aug-26 16:00 32 Hours
Continuous		 833L (SS-2 - SS-12), 2B138-D87 (SS-2), 2B138-D88 (SS-2) Install ITBs - 2RLY138-D87-D88 (BMR4). Relay maint.  
ENMAX 28-Aug-26 08:00 28-Aug-26 18:00 10 Hours
Continuous		 162.2TR (SS-162), 138kV South Bus (SS-162), 240kV South Bus (SS-162) Summer Substation Washing  
EPCOR, ALTALINK 31-Aug-26 07:00 13-Sep-26 17:00 322 Hours
Continuous		 EP 803s T3 (EP 803s Lambton), EP 803s L2403 (EP 803s Lambton), EP 803s L2405 (EP 803s Lambton), EP 803s L721 (EP 803s Lambton), 72LS24 (EP 803s Lambton - Strathcona), 72LH8 (EP 803s Lambton - EP Hardisty), H726 (EP Hardisty), S724 (Strathcona) Lambton: LDS14 LCR and L721 Breaker Maintenance (Min Oil) and TX3 Zone Doble and L2405 Breaker Maintenance (SF6) and LDS12 Drive Pipe Repair and TX3 Relay Maintenance  
ATCO 31-Aug-26 09:30 04-Sep-26 17:30 104 Hours
Continuous		 801s 902 (801s Anderson) BREAKER MIN OIL HLR COMPLETE TESTING  
ATCO 31-Aug-26 10:00 03-Sep-26 15:00 77 Hours
Continuous		 813s 906 (813s Little Smoky) BREAKER SF6 HGF COMPLETE TESTING - 906 @ 813S
Breaker 906 Counter Inoperable - Correct Counter Arm at 813s Little Smoky		  
ATCO 31-Aug-26 10:00 03-Sep-26 16:00 78 Hours
Continuous		 826s 902T (826s Marguerite Lake) transformer maintenance  
ALTALINK 31-Aug-26 11:00 03-Sep-26 17:00 78 Hours
Continuous		 71s 1752 (71s Lamoureux), 71s 1652 (71s Lamoureux), 71s 942 (71s Lamoureux), 942L (71s Lamoureux - 681s Bannerman) Switch replacement 71s942
Switch repair 71s49, 71s50		  
ALTALINK 01-Sep-26 08:00 02-Sep-26 11:30 27.5 Hours
Continuous		 650s 252 (650s Hansman Lake) Adding a maintenance switch to 650s252  
ALTALINK 01-Sep-26 08:30 01-Sep-26 17:00 8.5 Hours
Daily		 17s 4 (17s Benalto) PRC5 breaker maintenance & First Trip  
ATCO, ALTALINK 01-Sep-26 09:00 03-Sep-26 17:30 56.5 Hours
Continuous		 9L961 (13s Deerland - 825s Whitefish Lake) 9L961L structure 3 Replace synthetic insulators, pins & cotter keys  
BCH 02-Sep-26 09:00 21-Sep-26 13:00 460 Hours
Continuous		 5L96 (BCH Selkirk - BCH Vaseux Lake) maintenance. BC maintenance does not affect the Alberta ATC AB-BC
ALTALINK 02-Sep-26 12:30 03-Sep-26 14:00 25.5 Hours
Continuous		 650s 352 (650s Hansman Lake) Adding a maintenance switch to 650s352  
EPCOR 03-Sep-26 07:00 03-Sep-26 17:00 10 Hours
Continuous		 987s C2405 (987s Clover Bar) Cloverbar: C2405 Capacitor Nameplate Pictures  
SUNCOR 06-Sep-26 08:00 01-Oct-26 20:00 612 Hours
Continuous		 29EDD-61 29PT-653 (29EDD-61 Stony Island) 30PD-33 IPB PRESSURE LOW - Requires 29PT-653 to be isolated - 300691659  
EPCOR 07-Sep-26 07:00 11-Sep-26 17:00 106 Hours
Continuous		 987s GT2 (987s Clover Bar), 987s CGB2 (987s Clover Bar) Cloverbar:  
EPCOR 08-Sep-26 07:00 13-Sep-26 17:00 130 Hours
Continuous		 72PM25 (Poundmaker - Meadowlark), PM2402 (Poundmaker), PM2403 (Poundmaker), PM721 (Poundmaker), T4 (Poundmaker) Poundmaker: TX4 Doble  
EPCOR 08-Sep-26 07:00 23-Oct-26 17:00 1,090 Hours
Continuous		 805s T4 (805s Jasper), EP 805s J2405 (EP 805s Jasper), EP 805s J2406 (EP 805s Jasper) Jasper: J2406/JDS10 Replacement LCR  
ENMAX, ALTALINK 08-Sep-26 08:00 08-Sep-26 16:00 8 Hours
Continuous		 1065L (74s Janet - 102s Langdon) Fall transmission pothead washing  
ENMAX, ALTALINK 08-Sep-26 08:00 08-Sep-26 16:00 8 Hours
Continuous		 1064L (74s Janet - 102s Langdon) Fall transmission pothead washing  
ATCO 08-Sep-26 08:00 11-Sep-26 16:00 80 Hours
Continuous		 7L228 (845s Big Mountain - 7L20 tap), 2091s 7L228D3 (2091s Thornton) ET 1138135 7L228D2 Line Switch Failure Replacement
- Remove 7L228D2 and jumper out permanently.
- Rename 7L228D3 to D2.		  
CNRL, ATCO 08-Sep-26 08:00 13-Sep-26 16:00 128 Hours
Continuous		 842s 75-1902 (842s Horizon Upgrading), 842s 75-1903 (842s Horizon Upgrading), 75-PLH-903 (838s Horizon Mining - 842s Horizon Upgrading), 838s 75-BC-1911 (838s Horizon Mining), 838s 75-BC-1918 (838s Horizon Mining) 5YR PMs of Breakers, Disconnects, and Protective Relays  
ALTALINK 08-Sep-26 09:00 09-Sep-26 17:30 32.5 Hours
Continuous		 1202L (89s Ellerslie - 320p Keephills) Transmission line maintenance  
ATCO 08-Sep-26 10:00 22-Sep-26 17:30 343.5 Hours
Continuous		 930s Syn Condenser (930s Arcenciel) - Level 4 service / overhaul by ABB
- DFR replacement		  
ATCO 08-Sep-26 10:00 10-Dec-26 16:00 2,239 Hours
Continuous		 2015s 902 (2015s Yeo) Remove circuit breaker for use at 2102S Armistead. New breaker to be installed at 2015S Yeo substation once received from manufacturer.  
ENMAX, ALTALINK 08-Sep-26 12:00 08-Sep-26 18:00 6 Hours
Continuous		 28.80L (42s Sarcee - SS-28), 28.2TR (SS-28) Fall Substation Washing. Reversing Switch Check - 28.2-TC  
ALTALINK 08-Sep-26 12:30 11-Sep-26 17:00 76.5 Hours
Continuous		 370s 2152 (370s North Lethbridge), 370s T3 (370s North Lethbridge) 370sT3 Leak repair, major TC maint. PRC5  
ALTALINK 08-Sep-26 23:00 09-Sep-26 07:00 8 Hours
Continuous		 250p 2 (250p Bighorn Plant) maintenance  
ALTALINK 09-Sep-26 07:00 10-Sep-26 07:00 24 Hours
Continuous		 250p 1 (250p Bighorn Plant) maintenance  
ENMAX, ALTALINK 09-Sep-26 08:00 09-Sep-26 16:00 8 Hours
Continuous		 1064L (74s Janet - 102s Langdon) Fall transmission pothead washing  
ENMAX, ALTALINK 09-Sep-26 08:00 09-Sep-26 16:00 8 Hours
Continuous		 1065L (74s Janet - 102s Langdon) Fall transmission pothead washing  
ENMAX, ALTALINK 09-Sep-26 08:00 09-Sep-26 16:00 8 Hours
Continuous		 20.82L (SS-20 - SS-21), 21.80L (42s Sarcee - SS-21), 21.1TR (SS-21), 21.4TR (SS-21) Fall Substation Washing. Altalink required to remove AML VT4 60S100 fuses  
ENMAX, ALTALINK 10-Sep-26 08:00 10-Sep-26 16:00 8 Hours
Continuous		 50L (44s Bearspaw Plant - SS-21), 21.1C (SS-21), 21.2TR (SS-21) Fall Substation Washing  
ALTALINK, EPCOR 10-Sep-26 08:00 10-Sep-26 17:30 9.5 Hours
Continuous		 1209L (89s Ellerslie - 330p Genesee) 1209L Structure 45 and 145, Change saddles and pins.  
ALTALINK 10-Sep-26 19:00 15-Sep-26 12:00 113 Hours
Continuous		 1141L (1172s Laramide - 237s Foothills) End to end testing with Laramide 1172s  
ATCO, CNRL 11-Sep-26 08:00 14-Sep-26 16:00 80 Hours
Continuous		 838s 75-SD-901 (838s Horizon Mining) SEL-411L Firmware Update and Testing, and Breaker and Disconnect Testing  
ENMAX 12-Sep-26 08:00 12-Sep-26 18:00 10 Hours
Continuous		 7.84L (SS-7 - SS-36), 36B138-36BT3 (SS-36), 36.1TR (SS-36), 36.3TR (SS-36), 36B138-36.81 (SS-36) Fall Substation Washing  
CNRL 12-Sep-26 08:00 20-Sep-26 16:00 200 Hours
Continuous		 842s 75-TR-4701 (842s Horizon Upgrading), 842s 75-1903 (842s Horizon Upgrading), 842s 75-1904 (842s Horizon Upgrading) 5YR PMs of Transformer, Breakers, Disconnects, and Protective Relays  
EPCOR 14-Sep-26 07:00 20-Sep-26 17:00 154 Hours
Continuous		 EP 803s L2402 (EP 803s Lambton) Lambton: L2402 (Min Oil) Breaker Maintenance and CT Doble  
EPCOR 14-Sep-26 07:00 21-Sep-26 17:00 178 Hours
Continuous		 987s GT3 (987s Clover Bar), 987s CGB3 (987s Clover Bar) Cloverbar:  
ALTALINK, EPCOR 14-Sep-26 09:30 17-Sep-26 17:00 79.5 Hours
Continuous		 920L (37s North Calder - 557s Castle Downs), 557s CD2401 (557s Castle Downs), 557s CD2403 (557s Castle Downs) 920LW/Castledowns: Surge Arrestor LCR  
ALTALINK, EPCOR 14-Sep-26 09:30 17-Sep-26 17:00 79.5 Hours
Continuous		 920L (37s North Calder - 557s Castle Downs) 920LW/Castledowns: Surge Arrestor LCR  
ATCO 14-Sep-26 10:00 28-Sep-26 17:30 343.5 Hours
Continuous		 840s 901T (840s McNeill Station), 840s 701 (840s McNeill Station), 840s 901 (840s McNeill Station), 840s 701T (840s McNeill Station) Replace 901T bushings
901T Oil Leak Absorption Repairs At 840s McNeill
TRANSFORMER CLASS1 MAJOR TESTING - 901T @ 840S
TRANSFORMER CLASS1 TAP CHANGER - 901T @ 840S
FIRE SUPPRESSION SYSTEM RE-CERTIFICATION @ MCNEILL 840S
PRC testing
DFR Replacement		 AB-SK
ALTALINK 14-Sep-26 12:30 17-Sep-26 17:00 76.5 Hours
Continuous		 71s 452 (71s Lamoureux), 71s 852 (71s Lamoureux), 71s 708N (71s Lamoureux), 71s 31 (71s Lamoureux), 71s T2 (71s Lamoureux), 71s 138kV East Bus (71s Lamoureux) 138kV switch repairs 71s8, 71s42, 71s708N  
ALTALINK 15-Sep-26 07:00 16-Sep-26 18:00 35 Hours
Continuous		 691L (74s Janet - 419s Chestermere) Foundation installation on structure 9 & 9A.  
ALTALINK 15-Sep-26 07:30 15-Sep-26 12:00 4.5 Hours
Continuous		 927L (102s Langdon - 356s Milo), 102s 6652 (102s Langdon), 102s 6552 (102s Langdon), 356s 927 (356s Milo) CT cutovers to new DLR protections LTO testing to RAS protections  
ATCO, CNRL 15-Sep-26 08:00 19-Sep-26 16:00 104 Hours
Continuous		 838s 75-SD-902 (838s Horizon Mining) SEL-411L Firmware Update and Testing, and Breaker and Disconnect Testing  
ALTALINK 15-Sep-26 08:30 15-Sep-26 16:30 8 Hours
Continuous		 264s 352 (264s Elkwater) CT testing  
ALTALINK, Lethbridge 15-Sep-26 09:00 24-Sep-26 17:30 224.5 Hours
Continuous		 618s 725 (618s Riverbend), 725AL (618s Riverbend - 725L tap), 725L (111s Coalbanks - 725AL tap), 725L (674s Bowron - 725AL tap) Outage required to replace 674s12-Disconnect Switch and 674sPT5-CVT  
ALTALINK 15-Sep-26 12:30 15-Sep-26 15:30 3.98 Hours
Continuous		 924L (102s Langdon - 356s Milo), 102s 6952 (102s Langdon), 102s 6852 (102s Langdon), 356s 924 (356s Milo) CT cutovers to new DLR protections LTO testing to RAS protections  
CNRL 16-Sep-26 08:00 20-Sep-26 16:00 104 Hours
Continuous		 842s 75-1904 (842s Horizon Upgrading), 842s 75-1905 (842s Horizon Upgrading), 842s 75-TR-7701 (842s Horizon Upgrading) 5YR PMs of Transformer, Breakers, Disconnects, and Protective Relays  
ALTALINK 16-Sep-26 08:30 16-Sep-26 16:30 8 Hours
Continuous		 264s 452 (264s Elkwater) CT testing  
ENMAX, ALTALINK 16-Sep-26 12:00 16-Sep-26 18:00 6 Hours
Continuous		 23.80L (74s Janet - SS-23), 23.4TR (SS-23) Fall Substation Washing  
ALTALINK 16-Sep-26 23:30 17-Sep-26 02:30 3 Hours
Continuous		 62s 1 (62s Brazeau Plant) maintenence  
ALTALINK 17-Sep-26 03:30 17-Sep-26 06:30 3 Hours
Continuous		 62s 2 (62s Brazeau Plant) maintenence  
ALTALINK 17-Sep-26 08:00 17-Sep-26 12:30 4.5 Hours
Continuous		 33s 1 (33s Spray) testing  
ALTALINK 17-Sep-26 08:30 17-Sep-26 16:30 8 Hours
Continuous		 264s 252 (264s Elkwater) CT testing  
BCH, BPA 17-Sep-26 09:00 17-Sep-26 17:00 8 Hours
Continuous		 5L51 (BPA Custer - BCH Ingledow) maintenance AB-BC
ALTALINK 17-Sep-26 13:00 17-Sep-26 17:00 4 Hours
Continuous		 33s 2 (33s Spray) testing  
ENMAX, ALTALINK 19-Sep-26 07:00 19-Sep-26 12:00 5 Hours
Continuous		 771L (SS-47 - SS-162), 162B138-RB82 (SS-162), 47.1TR (SS-47), 47B138-771/1 (SS-47), 47B138-771 (SS-47), 47.2TR (SS-47), 162B138-RB81 (SS-162) Summer Substation Washing 162SUB, 138kV, 162MD138-771  
ALTALINK 21-Sep-26 07:00 28-Sep-26 18:00 179 Hours
Continuous		 691L (74s Janet - 419s Chestermere) Line move for structures 4-12.  
CNRL 21-Sep-26 08:00 28-Sep-26 16:00 176 Hours
Continuous		 842s 75-1901 (842s Horizon Upgrading), 842s 75-1905 (842s Horizon Upgrading), 842s 75-1906 (842s Horizon Upgrading), 842s 75-TR-5701 (842s Horizon Upgrading), 842s 75-TR-8701 (842s Horizon Upgrading) 5YR PMs of Transformer, Breakers, Disconnects, and Protective Relays  
Syncrude 21-Sep-26 08:00 06-Oct-26 16:00 368 Hours
Continuous		 34 (Aurora), 33B (Aurora), 34A (Aurora), 89-37 (Aurora), G21 (Aurora) Zone 3 6yr PM  
ATCO 21-Sep-26 10:00 22-Sep-26 16:00 30 Hours
Continuous		 815s 702 (815s Goodfare), 7L07 (790s Poplar Hill - 815s Goodfare) BREAKER SF6 LTB145D1/B COMPLETE TESTING - 702 @ 815S  
ATCO 21-Sep-26 10:00 24-Sep-26 16:00 78 Hours
Continuous		 888s 906 (888s Dover) 21B/9L74 relay replacement. Cutover breaker and CT to new protection  
ALTALINK 21-Sep-26 13:30 22-Sep-26 12:00 22.5 Hours
Continuous		 251s 1352 (251s Whitla) 251s1352 HPL Major Maintenance.  
EPCOR 22-Sep-26 07:00 25-Sep-26 17:00 82 Hours
Continuous		 987s GT1 (987s Clover Bar), 987s SST2 (987s Clover Bar), 987s CS2 (987s Clover Bar), 987s CGB1 (987s Clover Bar), 987s CCP7214 (987s Clover Bar), 987s CC24 (987s Clover Bar), 987s CH724 (987s Clover Bar), 987s CK726 (987s Clover Bar), 987s 72kV Bus 4 (987s Clover Bar) Cloverbar: , SST2, BUS 4 Outage. CDS18 Disconnect Replacement  
ATCO, CNRL 22-Sep-26 08:00 01-Oct-26 16:00 224 Hours
Continuous		 838s 75-BC-1917 (838s Horizon Mining), 838s 75-BC-1916 (838s Horizon Mining), 838s 75-TR-2801 (838s Horizon Mining) Upgrade 75-RPX-2801B From SEL 387 to SEL 487, Transformer, Breaker and Disconnect testing  
ALTALINK 22-Sep-26 11:00 23-Sep-26 13:00 26 Hours
Continuous		 251s 1452 (251s Whitla) 251s1452 HPL Major Maintenance  
ALTALINK, WPLP 23-Sep-26 09:00 23-Sep-26 17:00 8 Hours
Daily		 268s 268 (268s Whitecourt), 268s 503 (268s Whitecourt), 503L (268s Whitecourt - 323s Whitecourt Power) 268s268 Breaker Maint. and heater replacement  
SUNCOR 24-Sep-26 08:00 05-Oct-26 18:00 346 Hours
Continuous		 29EDD-63 29PT-179 (29EDD-63 Firebag Co-Gen), 29PL7-2 (29EDD-18 Firebag - 29EDD-63), 29EDD-63 30-252-11301 (29EDD-63), 29EDD-63 91-152-500201 (29EDD-63), 29EDD-18 29-752-105 (29EDD-18 Firebag), 29EDD-18 29-752-104 (29EDD-18 Firebag) FIREBAG: Replace air bladder on 29PT-179, test 29PT-179, and execute 29PT-179 T60 replacement  
ATCO 25-Sep-26 10:00 28-Sep-26 16:00 78 Hours
Continuous		 888s 905 (888s Dover) 21B/9L74 relay replacement. Cutover breaker and CT to new protection  
ENMAX, ALTALINK 27-Sep-26 08:30 09-Oct-26 14:00 293.5 Hours
Continuous		 37.2TR (SS-37), 37.82L (74s Janet - SS-37) HV SW Replacement. 37SW85, 37SW86, 37SW89  
ALTALINK 28-Sep-26 07:00 08-Oct-26 17:00 250 Hours
Continuous		 510s 2652 (510s Sunnybrook), 510s 2752 (510s Sunnybrook), AML 511s 4852 (AML 511s Crossings), AML 511s 4952 (AML 511s Crossings), 1325L (510s Sunnybrook - AML 511s Crossings) Annual Valve Hall Maintenance, PRC Tx Maintenance, Doble Testing of the Transformers, PRC Relay Maintenance, Annual Yard Inspections, TDC settings changes, VCS Maintenance  
ATCO 28-Sep-26 08:00 05-Oct-26 16:00 176 Hours
Continuous		 7L44 (749s Flyingshot Lake - 845s Big Mountain) Changing str 71,72,73 and 74 for high load move line raise  
ALTALINK, TRANSALTA, Lethbridge 28-Sep-26 09:00 28-Sep-26 15:00 6 Hours
Continuous		 15s 725 (15s Fort Macleod), 725BL (240s McBride Lake - 725L tap), 725L (15s Fort MacLeod - 725BL tap), 725L (674s Bowron - 725BL tap) Outage required to create open point 'A' on 725L to keep 240s online  
SUNCOR 28-Sep-26 09:00 04-Oct-26 20:00 155 Hours
Continuous		 29EDD-34 260kV Bus 29PP-45 (29EDD-34) 29EDD34 29PP45 A,C phase rebuild bus and supports that were removed as part of the 29PT-224 outage.

  
Lethbridge 28-Sep-26 09:00 15-Oct-26 17:00 416 Hours
Continuous		 674s 1 (674s Bowron), 725LW (674s Bowron - 725BL tap) Line outage required on 725LW at 674s to replace 674s1-Manual Airbreak Switch and replace 674s2 and 674s6 PT's  
ATCO 28-Sep-26 10:00 02-Oct-26 17:30 103.5 Hours
Continuous		 2029s ACF22 (2029s Heathfield), 2029s 1223 (2029s Heathfield) PRC-005 - TRIP COIL TESTING - BREAKER 1223 @ 2029S
BREAKER SF6 3AP4FI MAINTENANCE - 1223 @ 2029S
ACF22 Breaker low SF6 (breaker 1223) @2029S Heathfield
FILTER BANK AC MAINTENANCE @ HEATHFIELD 2029S ACF22		  
ALTALINK, Lethbridge 28-Sep-26 14:05 15-Oct-26 18:05 412 Hours
Continuous		 725L (674s Bowron - 725BL tap) Lethbridge outage required to replace 674s1-Disconnect Switch, 674sPT4-CVT, 674sPTB2-3phase CVT's, new screw piles and structure for 674sPTB2-CVT's  
ENMAX, ALTALINK 29-Sep-26 08:00 29-Sep-26 17:30 9.5 Hours
Daily		 1109L (SS-25 - SS-65) 1109L
Structure 15 Top Phase conductor Repair		  
ENMAX, ALTALINK 29-Sep-26 08:00 29-Sep-26 17:30 9.5 Hours
Continuous		 1109L (SS-25 - SS-65) Altalink outage. Remove 1109L from service to repair the top phase on Structure #15  
ALTALINK 29-Sep-26 08:30 29-Sep-26 15:30 7 Hours
Daily		 122s T1 (122s Alberta Newsprint) Repair leaking PRD on T1 and clean leak mitigation materials  
ENMAX, ALTALINK 29-Sep-26 08:30 29-Sep-26 17:30 9 Hours
Continuous		 1080L (SS-25 - SS-65) Altalink outage. Crews will be working within close proximity on 1109L  
ALTALINK 01-Oct-26 08:00 01-Oct-26 18:00 10 Hours
Daily		 1002L (163s Amoco Empress - 275s Jenner) 1002L - Replace top phase spacer on STR67
 
ALTALINK 01-Oct-26 09:00 01-Oct-26 17:30 8.5 Hours
Continuous		 1043L (320p Keephills - 367s Harry Smith) 1043L111 Conductor repair  
EPCOR 05-Oct-26 07:00 18-Oct-26 17:00 322 Hours
Continuous		 CV5 (EP 511s Victoria - 557s Castle Downs) CV5/TX5: Manhole Inspections and Maintenance and 72kV Breaker Fail Protection Upgrade Cutovers and Commissioning  
ALTALINK 05-Oct-26 08:30 28-Nov-26 06:30 1,295 Hours
Continuous		 62s 2 (62s Brazeau Plant) maintenence  
ATCO 05-Oct-26 09:00 07-Oct-26 17:30 56.5 Hours
Continuous		 2029s 1301 (2029s Heathfield) DC HIGH SPEED SWITCH MAINTENANCE - 1301 @ 2029S
**EATL will need to run in P1 DMR Return while 1301 is out of service**

AESO PLEASE ADD SWITCHED INTO DATABASE		  
ATCO 05-Oct-26 10:00 08-Oct-26 16:00 78 Hours
Continuous		 9L74 (888s Dover - 960s Birchwood Creek) 21B/9L74 relay three terminal line testing  
ATCO 05-Oct-26 12:00 09-Oct-26 12:00 96 Hours
Continuous		 786s SVC (786s High Level) ET 1136310 786S High Level SVC DFR Upgrade
SVC AIR COOLED MAINTENANCE @ HIGH LEVEL 786S		  
SUNCOR 06-Oct-26 08:00 12-Oct-26 20:00 252 Hours
Continuous		 29EDD-2 29PT-3 (29EDD-2 Tar Island), 29PL6-22 (29EDD-1 Millennium - 29EDD-2 Tar Island) 29EDD2;29PT-3, 29PL6-22 SYSTEM;PM 5y,10y
  
SUNCOR 06-Oct-26 08:00 12-Oct-26 20:00 156 Hours
Continuous		 29EDD-2 29PT-3 (29EDD-2 Tar Island), 29PL6-22 (29EDD-1 Millennium - 29EDD-2 Tar Island) 29EDD2; 29PP-2; 39PT-401 & 30PP-52 SYSTEM;PM 5y - 450504726; 29PT-3 Bushing Replacement; 29EDD2;39PT-401 & 30PP-52 SYSTEM;PM 5y
  
ATCO, ALTALINK 07-Oct-26 08:00 07-Oct-26 17:00 9 Hours
Continuous		 760L (760AL tap - 7LA760 tap) install interphase spacers  
ALTALINK 07-Oct-26 08:00 07-Oct-26 17:00 9 Hours
Daily		 801L (62s Brazeau Plant - 294s Brazeau Plant Outlet Works) 801L replace glass on STR 65 and 72  
ALTALINK 08-Oct-26 07:00 08-Oct-26 18:00 11 Hours
Continuous		 61s 202X (61s Lodgepole), 62s 202 (62s Brazeau Plant), 202L (61s Lodgepole - 62s Brazeau Plant) Line Maintenance  
Syncrude 10-Oct-26 08:00 28-Oct-26 16:00 440 Hours
Continuous		 1335 (Syncrude Mildred Lake), 134 (Syncrude Mildred Lake), 135 (Syncrude Mildred Lake), Mildred T1 (Syncrude Mildred Lake), Mildred T2 (Syncrude Mildred Lake), 2235 (Syncrude Mildred Lake), 234 (Syncrude Mildred Lake), 235 (Syncrude Mildred Lake), 3235 (Syncrude Mildred Lake), 335 (Syncrude Mildred Lake), 334 (Syncrude Mildred Lake), Mildred T3 (Syncrude Mildred Lake), Mildred T16 (Syncrude Mildred Lake), 1635 (Syncrude Mildred Lake), 1634 (Syncrude Mildred Lake), 1434 (Syncrude Mildred Lake), 1435 (Syncrude Mildred Lake), Mildred T14 (Syncrude Mildred Lake), Mildred T19 (Syncrude Mildred Lake), 1935 (Syncrude Mildred Lake), 1934 (Syncrude Mildred Lake), 814 (Syncrude Mildred Lake), 815 (Syncrude Mildred Lake), 816 (Syncrude Mildred Lake), Mildred Lake 72kV Bus B (Sycrude Mildred Lake), ML1 (D05 - Syncrude Mildred Lake), 914 (Syncrude Mildred Lake), 915 (Syncrude Mildred Lake), 916 (Syncrude Mildred Lake), 1224A (Syncrude Mildred Lake), 1224B (Syncrude Mildred Lake), 1225 (Syncrude Mildred Lake), D05 76 (D05), D05 76A (D05), D05 76B (D05) SCL - Perform 72kV "B" Bus PM in Plant 31 at Mildred Lake.  
ATCO 12-Oct-26 10:00 15-Oct-26 16:00 78 Hours
Continuous		 888s 906 (888s Dover) 21A/9L74 relay replacement. Cutover breaker and CT to new protection  
ALTALINK 12-Oct-26 12:00 16-Oct-26 13:00 97 Hours
Continuous		 602s T1 (602s Cold Creek) Replace 25kv MOD switch 602s10  
ATCO, ALTALINK 13-Oct-26 09:00 17-Oct-26 17:30 104.5 Hours
Continuous		 986L (87s Gaetz - 972s Tinchebray) 986L Interphase spacer work From Span 1 through 243 using HEC with a Helicopter  
ATCO, ALTALINK 13-Oct-26 09:30 17-Oct-26 17:30 104 Hours
Continuous		 962L (87s Gaetz - 972s Tinchebray) 962L Interphase spacer work From Span 1 through 243 Using HEC with a Helicopter  
ATCO, ALTALINK 13-Oct-26 09:30 17-Oct-26 17:30 104 Hours
Continuous		 9L62 (87s Gaetz - 972s Tinchebray) AltaLink Request: Interphase spacer work From Span 1 through 243 using HEC with a Helicopter.
ATCO needs to enable the following RAS logics
RAS 134 Logic 1b, RAS 134 Logic 2, RAS 211, RAS 215 , 973S RAS 134 , 615S RAS 134, 1045S RAS 134		  
ATCO, ALTALINK 13-Oct-26 09:30 17-Oct-26 17:30 104 Hours
Continuous		 9L86 (87s Gaetz - 972s Tinchebray) AltaLink Request: Interphase spacer work From Span 1 through 243 using HEC with a Helicopter.
ATCO needs to enable the following RAS logics
RAS 134 Logic 1b, RAS 134 Logic 2, RAS 211, RAS 215 , 973S RAS 134 , 615S RAS 134, 1045S RAS 134		  
ALTALINK 15-Oct-26 08:00 15-Oct-26 18:00 10 Hours
Continuous		 158s 763N (158s Vauxhall), 28s 47 (28s West Brooks), 28s 31 (28s West Brooks), 447s 763A (447s Enchant), 447s 16 (447s Enchant), 763AL (447s Enchant - 763A1L tap), 763L (158s Vauxhall - 763AL tap), 763L (28s West Brooks - 763AL tap) 447s27 Replace line VT. (Like for like replacement)  
ALTALINK, TRANSALTA, Lethbridge 15-Oct-26 17:10 15-Oct-26 21:00 3.83 Hours
Continuous		 15s 725 (15s Fort Macleod), 725BL (240s McBride Lake - 725L tap), 725L (15s Fort MacLeod - 725BL tap), 725L (674s Bowron - 725BL tap) to close 725L Open Point 'A' and restore 725L to normal  
ATCO 16-Oct-26 10:00 19-Oct-26 16:00 78 Hours
Continuous		 888s 905 (888s Dover) 21A/9L74 relay replacement. Cutover breaker and CT to new protection  
EPCOR 19-Oct-26 07:00 11-Dec-26 17:00 1,283 Hours
Continuous		 814s T2 (814s Bellamy), BR722 (Rossdale), 814s B2402 (814s Bellamy), 814s B2406 (814s Bellamy) Bellamy: TX2 Emergency Bushing Replacement  
ALTALINK, EPCOR 19-Oct-26 09:30 25-Oct-26 17:00 151.5 Hours
Continuous		 908L (89s Ellerslie - 816s Petrolia) Petrolia: 908LE Surge Arrestor and CVT LCR  
ALTALINK 19-Oct-26 11:00 23-Oct-26 11:00 96 Hours
Continuous		 163s 1552 (163s Amoco Empress) 1552 Breaker failure and control protection upgrade  
Syncrude 23-Oct-26 08:00 06-Nov-26 16:00 345 Hours
Continuous		 11A (Aurora), 21A (Aurora), 31A (Aurora), 89-210 (Aurora), 89-51 (Aurora), T1 (Aurora), 211A (Aurora), 221A (Aurora), 260kV Bus 1 (Aurora), 72 kV Bus 1 (Aurora) 6yr PM  
ALTALINK 23-Oct-26 09:00 23-Oct-26 13:00 4 Hours
Continuous		 163s 1752 (163s Amoco Empress) 11/1552 breaker fail trip testing  
ALTALINK, EPCOR 26-Oct-26 07:00 30-Oct-26 17:00 106 Hours
Continuous		 909L (89s Ellerslie - 665s Dome), 665s D2401 (665s Dome), 665s D2404 (665s Dome), 72DS26 (665s Dome - Strathcona) 909LE/Dome: Dome CVT LCR and 909LE Metering Upgrade  
EPCOR 26-Oct-26 07:00 18-Dec-26 17:00 1,283 Hours
Continuous		 805s T3 (805s Jasper), EP 805s J2404 (EP 805s Jasper), EP 805s J2405 (EP 805s Jasper) Jasper: J2404/JAB3/JDS9 Replacement LCR  
ENMAX, ALTALINK 26-Oct-26 08:00 04-Nov-26 16:00 225 Hours
Continuous		 24.83L (74s Janet - SS-24) Steel pole installation  
ENMAX, ALTALINK 26-Oct-26 08:00 04-Nov-26 16:00 225 Hours
Continuous		 24.83L (74s Janet - SS-24), 74s 24.83X (74s Janet) Enmax Steel pole installation  
ATCO 26-Oct-26 08:00 13-Nov-26 17:00 442 Hours
Continuous		 806s 701T (806s Oldman River) Telecommunications Upgrade, new UPS upgrades.  
ATCO 26-Oct-26 09:00 26-Oct-26 17:30 32 Hours
Continuous		 757s 704 (757s Battle River) BREAKER SF6 LTB145D1/B TESTING - 704 @ 757S
PRC-005 - TRIP COIL TESTING - BREAKER 704 @ 757S
  
ALTALINK 26-Oct-26 09:00 28-Oct-26 17:30 56.5 Hours
Continuous		 924L (102s Langdon - 356s Milo) 924L192 Urgent repair Interphase spacer replacement  
ALTALINK, EPCOR 26-Oct-26 09:00 30-Oct-26 17:30 104.5 Hours
Continuous		 89s 1052 (89s Ellerslie), 89s 1152 (89s Ellerslie), 909L (89s Ellerslie - 665s Dome) 909LE/Dome: Dome CVT LCR and 909LE Metering Upgrade  
ATCO 26-Oct-26 10:00 29-Oct-26 16:00 78 Hours
Continuous		 9L74 (888s Dover - 960s Birchwood Creek), 888s 905 (888s Dover), 888s 906 (888s Dover), 960s 901 (960s Birchwood Creek), 960s 902 (960s Birchwood Creek) 21A/9L74 relay three terminal line testing  
ATCO, ALTALINK 26-Oct-26 10:00 02-Nov-26 16:00 175 Hours
Continuous		 7L230 (69s North Barrhead - 888AL tap), 7L230 (743s Sarah Lake - 888AL tap) Replace 7L230D1 disconnect switch  
ALTALINK 26-Oct-26 11:00 30-Oct-26 11:00 96 Hours
Continuous		 163s 1252 (163s Amoco Empress) 1252 Breaker failure & control protection upgrade  
ALTALINK 27-Oct-26 07:00 27-Oct-26 17:00 10 Hours
Continuous		 AML 511s 5252 (AML 511s Crossings) PRC Relay Maintenance on 5252 Siemens 6MD  
ALTALINK 27-Oct-26 08:00 28-Oct-26 17:30 33.5 Hours
Continuous		 1037L (138s Windy Flats - 266s SC1), 1037L (237s Foothills - 266s SC1) 1037L Install Vibration monitors and weather stations at Structure 285 and 334.  
ALTALINK 27-Oct-26 08:30 30-Oct-26 16:30 80 Hours
Continuous		 836L (61s Lodgepole - 283s Violet Grove), 61s 836N (61s Lodgepole) CT Replacement of CTs associated with 61s836N Breaker (CTL8)  
ALTALINK 28-Oct-26 07:00 28-Oct-26 15:00 8 Hours
Continuous		 163s T1 (163s Amoco Empress) Breaker Fail upgrade project: 11/1252 & 11/1552 breaker fail trip testing. Trip testing of 163s501, 163sXA, 163sXB  
ALTALINK 28-Oct-26 07:00 28-Oct-26 15:00 8 Hours
Continuous		 AML 511s 5352 (AML 511s Crossings) PRC Relay Maintenance on 5352 Siemens 6MD  
ALTALINK 28-Oct-26 10:00 28-Oct-26 14:00 4 Hours
Continuous		 250p 1 (250p Bighorn Plant) maintenance  
ALTALINK 29-Oct-26 07:00 29-Oct-26 17:00 10 Hours
Continuous		 AML 511s 5052 (AML 511s Crossings) PRC Mnt 0511DC ACF1 (s5052) 6MD66 CI  
ALTALINK 29-Oct-26 08:00 31-Oct-26 18:00 58 Hours
Continuous		 927L (102s Langdon - 356s Milo) 927L - (Urgent repair) Replace 2 Interphase spacers in span 188  
ALTALINK 29-Oct-26 10:00 29-Oct-26 14:00 4 Hours
Continuous		 250p 2 (250p Bighorn Plant) maintenance  
ALTALINK 30-Oct-26 09:00 30-Oct-26 13:00 4 Hours
Continuous		 163s 1552 (163s Amoco Empress) 11/1252 Breaker Fail trip testing  
ALTALINK 30-Oct-26 11:00 30-Oct-26 14:00 3 Hours
Continuous		 163s 1352 (163s Amoco Empress) 11/1252 breaker fail trip testing  
ALTALINK, EPCOR 02-Nov-26 07:00 13-Nov-26 17:00 274 Hours
Continuous		 909L (310p Sundance - 665s Dome), 665s D2403 (665s Dome) Dome: 909LW/D2403, Metering Upgrade Cutovers and Commissioning  
ALTALINK 03-Nov-26 07:00 03-Nov-26 17:00 10 Hours
Continuous		 510s 2552 (510s Sunnybrook) PRC Relay Mnt 0510DC ACF1 (s2552) 6MD66 CI  
ALTALINK 04-Nov-26 07:00 04-Nov-26 17:00 10 Hours
Continuous		 510s 1952 (510s Sunnybrook) PRC Relay Mnt 0510DC ACF1 (s1952) 6MD66 CI  
ALTALINK 05-Nov-26 03:30 05-Nov-26 06:30 3 Hours
Continuous		 62s 1 (62s Brazeau Plant) maintenence  
ALTALINK 05-Nov-26 07:00 05-Nov-26 17:00 10 Hours
Continuous		 510s 2052 (510s Sunnybrook) PRC Relay Mnt 0510DC ACF2 (s2052) 6MD66 CI  
Syncrude 07-Nov-26 08:00 17-Nov-26 16:00 248 Hours
Continuous		 223 (Aurora), 222B (Aurora), 89-225 (Aurora), 223A (Aurora) Zone 4 6yr PM  
EPCOR 09-Nov-26 07:00 11-Dec-26 17:00 778 Hours
Continuous		 PM2405 (Poundmaker) Poundmaker: P2405 Breaker Replacement  
ATCO 09-Nov-26 10:00 12-Nov-26 17:00 79 Hours
Continuous		 9L24 (946s Oakland - 959s Lanfine), 959s 906 (959s Lanfine), 959s 905 (959s Lanfine), 946s 902 (946s Oakland), 946s 903 (946s Oakland) Cutover Bkr/MOD status, Commission new LTO/RAS 204 A/B - Lanfine/Oakland  
ATCO 13-Nov-26 10:00 14-Nov-26 17:00 31 Hours
Continuous		 959s 901T (959s Lanfine), 959s 904 (959s Lanfine), 959s 919 (959s Lanfine), 959s 701 (959s Lanfine), 959s 706 (959s Lanfine), 959s 722 (959s Lanfine), 959S 722C (959S Lanfine) Cutover MOD status, Commission inputs to RAS 204 A/B  
ALTALINK, EPCOR 16-Nov-26 09:30 27-Nov-26 17:00 271.5 Hours
Continuous		 908L (89s Ellerslie - 816s Petrolia), 816s P2401 (816s Petrolia), 816s P2406 (816s Petrolia) Petrolia: 908LE Surge Arrestor and CVT LCR  
ATCO 16-Nov-26 12:00 19-Nov-26 12:00 72 Hours
Continuous		 740s 705 (740s H.R. Milner), 7L80 (740s H.R. Milner - 857s Kakwa Ridge) PRC-005 - MICROPROCESSOR RELAY TESTING
TCM Program. RTXP Test Switch Mitigation and Replacement
Both RAS-A and RAS-B 7L80 will also need be OOS for the RTXP work on 21A and 21B 7L80		  
ATCO 23-Nov-26 10:00 23-Nov-26 17:00 7 Hours
Continuous		 959s 904 (959s Lanfine) Cutover and Commission Bkr 904 status to RAS 204 A/B  
ATCO 23-Nov-26 10:00 24-Nov-26 15:00 29 Hours
Continuous		 813s 901 (813s Little Smoky) 813S Little Smoky - 901 S/C Open/Close Control Mapping Issue  
ATCO 23-Nov-26 13:00 30-Nov-26 13:00 168 Hours
Continuous		 930s SVC (930s Arcenciel) ET 1137010 930S Arcenciel SVC DFR Upgrade
ET 1137018 930S Arcenciel SVC Protection Upgrade
SVC AIR COOLED MAINTENANCE @ ARCENCIEL 930S		  
ATCO 24-Nov-26 10:00 24-Nov-26 17:00 7 Hours
Continuous		 959s 919 (959s Lanfine) Cutover and Commission Bkr 919 status to RAS 204 A/B  
ATCO 25-Nov-26 10:00 25-Nov-26 17:00 7 Hours
Continuous		 959s 920 (959s Lanfine) Cutover and Commission Bkr 920 status to RAS 204 A/B  
ATCO 30-Nov-26 12:00 03-Dec-26 12:00 72 Hours
Continuous		 813s SVC (813s Little Smoky) 813S Little Smoky SVC DFR Upgrade  
ALTALINK 07-Dec-26 10:00 11-Dec-26 17:30 103.5 Hours
Continuous		 514L (396s Pincher Creek - 514BL tap) 514L
Structure 48 - Replace cross arm
Structure 99 - Replace structure
Structure 102 - Replace structure
Structure 158 - Replace Cross Arm 		 
ALTALINK, EPCOR 07-Dec-26 16:30 14-Dec-26 17:30 169 Hours
Continuous		 1056L (89s Ellerslie - 629s Argyll Transfer Station) 1056L/240BA2: ADS3 LCR (1055L and BA3 will be jumpered out and energized bypassing ADS2 for the duration of this outage)  
ALTALINK 16-Dec-26 10:00 16-Dec-26 14:00 4 Hours
Continuous		 250p 1 (250p Bighorn Plant) maintenance  
ALTALINK 17-Dec-26 10:00 17-Dec-26 14:00 4 Hours
Continuous		 250p 2 (250p Bighorn Plant) maintenance  
ALTALINK 23-Dec-26 23:30 24-Dec-26 02:30 3 Hours
Continuous		 62s 1 (62s Brazeau Plant) maintenence  
ALTALINK 24-Dec-26 03:30 24-Dec-26 06:30 3 Hours
Continuous		 62s 2 (62s Brazeau Plant) maintenence  
EPCOR 04-Jan-27 07:00 12-Feb-27 17:00 946 Hours
Continuous		 EP 805s J2405 (EP 805s Jasper) Jasper: J2405 Replacement LCR  
EPCOR 22-Jan-27 07:00 25-Jan-27 17:00 82 Hours
Continuous		 1055L (629s Argyll Transfer Station - 816s Petrolia), 240BA3 (629s Argyll Transfer Station - 814s Bellamy) 1055L/240BA3: ADS3 LCR Preparation Outage, jumpering out ADS2  
EPCOR, ALTALINK 25-Jan-27 17:00 01-Feb-27 17:00 168 Hours
Continuous		 240BA2 (629s Argyll Transfer Station - 814s Bellamy), 1056L (89s Ellerslie - 629s Argyll Transfer Station) 1056L/240BA2: ADS3 LCR (1055L and BA3 will be jumpered out and energized bypassing ADS2 for the duration of this outage)  
EPCOR 01-Feb-27 17:00 05-Feb-27 17:00 96 Hours
Continuous		 1055L (629s Argyll Transfer Station - 816s Petrolia), 240BA3 (629s Argyll Transfer Station - 814s Bellamy) 1055L/240BA3: ADS3 LCR Removing ADS2 jumper, restoring configuration  
EPCOR 16-Feb-27 07:00 30-Mar-27 17:00 1,017 Hours
Continuous		 EP 805s J2407 (EP 805s Jasper) Jasper: J2407 Replacement LCR  
ALTALINK, EPCOR 19-Feb-27 07:00 05-Mar-27 17:00 346 Hours
Continuous		 1045L (EP 805s Jasper - 1045AL tap), EP 805s J2406 (EP 805s Jasper), EP 805s J2407 (EP 805s Jasper) 1045L/Jasper: J2407 Replacement LCR  
ALTALINK 19-Feb-27 07:00 05-Mar-27 18:00 347 Hours
Continuous		 1045AL (320p Keephills - 1045L tap), 1045L (310p Sundance - 1045AL tap) 1045L/Jasper: J2407 Replacement LCR  
EPCOR 22-Feb-27 07:00 05-Mar-27 17:00 274 Hours
Continuous		 814s T1 (814s Bellamy), BR721 (Rossdale), 814s B2401 (814s Bellamy), 814s B2407 (814s Bellamy) Bellamy: TX1 Temp Monitor Install  
ATCO 08-Mar-27 10:00 17-Mar-27 17:00 222 Hours
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		  
EPCOR 05-Apr-27 07:00 07-May-27 17:00 778 Hours
Continuous		 52s T2 (52s East Industrial), 52s E2402 (52s East Industrial) East Industrial: TX2 Bushing Replacement  
SUNCOR 05-Apr-27 09:00 11-Apr-27 20:00 155 Hours
Continuous		 29PL9-12 (29EDD-34 - 29EDD-65) 29EDD34;29PL9-12 SYSTEM;PM 5y,10y
  
SUNCOR 06-Apr-27 09:00 16-Apr-27 20:00 251 Hours
Continuous		 29EDD-34 29PT-112 (29EDD-34), 29EDD-34 29-752-121 (29EDD-34), 29EDD-34 29PS-68 (29EDD-34), 29EDD-34 29PS-67 (29EDD-34), 29EDD-34 29PS-66 (29EDD-34), 29EDD-34 29PS-65 (29EDD-34), 29EDD-34 29PS-225 (29EDD-34), 29EDD-34 29PS-230 (29EDD-34), 29EDD-34 29-952-141 (29EDD-34), 29EDD-34 29-952-131 (29EDD-34), 29EDD-34 29-952-111 (29EDD-34) 29EDD34;29PT-112 & 29PP-24 SYSTEM;PM
This will Place 29EDD-34 on one 260 kV bus and drop 29PL7-1 		 
ATCO 12-Apr-27 10:00 19-Apr-27 17:00 175 Hours
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 14-Apr-27 14:00 23-Apr-27 18:00 220 Hours
Continuous		 29EDD-65 29PT-0257 (29EDD-65), 29EDD-65 29-952-4812 (29EDD-65), 29EDD-65 29-952-4813 (29EDD-65), 29EDD-71 752-4624 (29EDD-71), 29EDD-71 752-4623 (29EDD-71), 29PL7-4 (29EDD-65 - 29EDD-71) Firebag: 29EDD65;29PT-257 & 29PL7-4 SYSTEM, 29EDD65 ;29PT-260 & 29PL7-4 SYSTEM, 29EDD71 29PT-241 & 29PL7-4  
ATCO 03-May-27 09:00 17-May-27 17:30 344.5 Hours
Continuous		 2075s T11 (2075s Newell) Annual EATL outage at 2075s & 2029s.  
ATCO 03-May-27 09:00 17-May-27 17:30 344.5 Hours
Continuous		 2029s T11 (2029s Heathfield) Annual EATL outage at 2075s & 2029s.  
ATCO 03-May-27 09:00 17-May-27 17:30 344.5 Hours
Continuous		 13L50 (2029s Heathfield - 2075s Newell) Annual EATL outage at 2075s & 2029s.
**1218 IS NOT THE ISOALTION. ATCO SENT AESO OF REQUIRED ISOLATIONS BACK IN MAY 2024 TO UPDATE 2029S AND 2075S ISOLATIONS FOR 13L50 OUTAGES**		  
ATCO 03-May-27 10:00 06-May-27 17:00 79 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-27 09:00 14-May-27 20:00 251 Hours
Continuous		 29EDD-34 29PS-214 (29EDD-34), 29EDD-34 29-952-113 (29EDD-34), 29EDD-34 29PS-215 (29EDD-34), 29EDD-34 29PS-213 (29EDD-34) 29EDD34;29PL9-13 SYSTEM;PM 5y,10y  
SUNCOR 05-May-27 14:00 14-May-27 18:00 220 Hours
Continuous		 29EDD-65 29PT-0236 (29EDD-65), 29EDD-65 29-952-4823 (29EDD-65), 29EDD-65 29-952-4822 (29EDD-65), 29EDD-71 752-4634 (29EDD-71), 29EDD-71 752-4633 (29EDD-71), 29PL7-3 (29EDD-65 - 29EDD-71) Firebag: 29EDD65;29PT-236 & 29PL7-3 SYSTEM, 29EDD65;29PT-250&29PL7-3 SYSTEM, 29PT-246 SYSTEM;29EDD71  
ATCO 10-May-27 10:00 11-May-27 17:00 31 Hours
Continuous		 7L03 (749s Flyingshot Lake - 7L09 tap) Cutover and commission RAS analogs and LTO to 790S Poplar Hill RAS Hub  
ATCO 12-May-27 10:00 13-May-27 17:00 31 Hours
Continuous		 7L03 (731s Elmworth - 7L09 tap) Cutover and commission LTO to 790S Poplar Hill RAS Hub  
ATCO 14-May-27 10:00 15-May-27 17:00 31 Hours
Continuous		 7L69 (731s Elmworth - 815s Goodfare) Cutover and commission LTO to 790S Poplar Hill RAS Hub  
ATCO 16-May-27 10:00 17-May-27 17:00 31 Hours
Continuous		 7L07 (790s Poplar Hill - 815s Goodfare) Cutover and commission LTO to 790S Poplar Hill RAS Hub  
SUNCOR 01-Jun-27 08:00 10-Jun-27 17:00 225 Hours
Continuous		 635EDD-1000 635-752-635PT-1000 (635EDD-1000), 635EDD-1000 635PT-1000 (635EDD-1000) FH - Maintenance on Transformer, associated breakers, other equipment in isolation boundary and protection system testing.  
SUNCOR 01-Jun-27 09:00 11-Jun-27 20:00 251 Hours
Continuous		 29EDD-94 407T (29EDD-94 Voyageur), 29EDD-94 29-952-9705 (29EDD-94 Voyageur), 29EDD-94 29PS-393 (29EDD-94 Voyageur), 29EDD-94 29PS-392 (29EDD-94 Voyageur), 29EDD-94 29-952-9704 (29EDD-94 Voyageur), 29EDD-94 29PS-400 (29EDD-94 Voyageur) 29EDD94;29PT-407 SYSTEM;PM 5y,10y  
ATCO 07-Jun-27 12:00 10-Jun-27 15:00 75 Hours
Continuous		 7L80 (733s Simonette - 857s Kakwa Ridge), 733s 701 (733s Simonette) BREAKER SF6 HPL COMPLETE TESTING - 701 @ 733S  
SUNCOR 11-Jun-27 08:00 20-Jun-27 17:00 225 Hours
Continuous		 635EDD-1000 635-752-635PT-1001 (635EDD-1000), 635EDD-1000 635PT-1001 (635EDD-1000) FH - Maintenance on Transformer, associated breakers, other equipment in isolation boundary and protection system testing.  
SUNCOR 15-Jun-27 09:00 25-Jun-27 20:00 251 Hours
Continuous		 29EDD-94 406T (29EDD-94 Voyageur), 29EDD-94 29-952-9702 (29EDD-94 Voyageur), 29EDD-94 29PS-388 (29EDD-94 Voyageur), 29EDD-94 29PS-389 (29EDD-94 Voyageur), 29EDD-94 29PS-399 (29EDD-94 Voyageur) 29EDD94;29PT-406 SYSTEM;PM 5y,10y  
AESO, ATCO 29-Jun-27 13:00 30-Jun-27 17:00 28 Hours
Continuous		 9LA93 (973s Lanes Lake - 9L93 tap) Line to Ground Clearance Mitigation, Span 50-51. Repair deficiency on structure 57  
ALTALINK, ATCO, FMGW 17-Aug-27 08:00 18-Aug-27 17:00 33 Hours
Continuous		 964AL (1024s Granlea - 964L tap), 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), 1024s 489-600201 (1024s Granlea) maintenance activities (testing and inspection) of electrical equipment  
ALTALINK, BCH 23-Aug-27 07:00 03-Sep-27 17:00 274 Hours
Continuous		 1201L (520s Bennett - BCH Cranbrook), Path 1 (AIES Islanding) annual maintenance AB-BC
ALTALINK, BHE 23-Aug-27 07:00 03-Sep-27 17:00 274 Hours
Continuous		 MATL (120s Picture Butte - Montana) align with 1201L outage AB-MATL
ALTALINK, BCH 23-Aug-27 07:00 03-Sep-27 17:00 274 Hours
Continuous		 48s 887X (48s Pocaterra), 887L (48s Pocaterra - 978s BCH Britt Creek) opened because 1201L is out of service . AB-BC
ALTALINK, BCH 23-Aug-27 07:00 03-Sep-27 17:00 274 Hours
Continuous		 799s 786W (799s Coleman), 786L (799s Coleman - BCH Natal) opened because 1201L is out of service. AB-BC
ATCO 08-Nov-27 09:00 11-Nov-27 17:00 80 Hours
Continuous		 ALC02L (409s Shell Scotford - 879s Upgrader) Install new Deadend corner structure on ALC02L  
ATCO 08-Nov-27 09:00 11-Nov-27 17:00 80 Hours
Continuous		 ALC01L (408s Air Liquide Scotford - 409s Shell Scotford) Install new Deadend corner structure on ALC02L.  
ATCO 08-Feb-28 09:00 10-Feb-28 17:00 56 Hours
Continuous		 7L228 (845s Big Mountain - 7L20 tap) AESO project P2716 - Install 7L228 bypass to facilitate the installation of new line switches for the new 7LA228 T-tap line connection to the new 2103S Pakenham substation
Open 7L228, replace structures 551 and 551A, connect bypass.		  
ATCO 06-Mar-28 10:00 22-Mar-28 16:00 389 Hours
Continuous		 826s 903 (826s Marguerite Lake), 826s 907 (826s Marguerite Lake), 826s 901T (826s Marguerite Lake) Expand 240kV ring bus for new 9L42 line  
ATCO 13-Mar-28 10:00 16-Mar-28 17:00 79 Hours
Continuous		 9L939 (77s Sagitawah - 809s Louise Creek) Cut over 9L939 to temp bypass structures to allow for installation of new deadend corner towers. These are required to make the final connections to the new 2105S Jackson substation  
ATCO 14-Mar-28 09:00 16-Mar-28 17:00 56 Hours
Continuous		 7L228 (845s Big Mountain - 7L20 tap) AESO project P2716 - Disconnect bypass, connect new 7LA228D1 to 7LA228 Str #2, connect 7L228 to 7L228D2, connect 7L228 to 7L228D3. Renumber existing line switches 7L228D2 - D4, 7L228D3 - D5, 7L228D4 - D6
Commission DTT		  
ATCO 17-Mar-28 10:00 17-Apr-28 17:00 751 Hours
Continuous		 9L938 (77s Sagitawah - 809s Louise Creek) Install foundations (TBD assume concrete), assemble and erect new Q-towers 9L938/9L939-155A and 9L938/9L939-156A in existing ROW centreline. Daily outage until such a time as the new towers begin to encroach on 9L938.  
ATCO 20-Mar-28 09:00 23-Mar-28 17:00 80 Hours
Continuous		 2091s 704 (2091s Thornton) AESO project P2716 - cut over new SEL 2440 wiring at 2091S, relay programming, commission DTT and LTO  
ATCO 24-Mar-28 09:00 27-Mar-28 17:00 80 Hours
Continuous		 740s 704 (740s H.R. Milner), 7L20 (740s H.R. Milner - 810s Dome Cutbank) AESO project P2716 - cut over RAS #171 wiring at 740S, relay programming, commission LTO 7L20/7L228  
SUNCOR 04-Apr-28 08:00 07-Apr-28 19:00 83 Hours
Continuous		 29PL9-16 (29EDD-1 Millennium - 29EDD-94 Voyageur) 29EDD1;29PT418/29PL9-16 SYSTEM;PM 5y,10y
  
ATCO 18-Apr-28 10:00 25-Apr-28 17:00 175 Hours
Continuous		 9L938 (77s Sagitawah - 809s Louise Creek) Open 9L938 conductors, complete assembly and connect to the new Q-Towers 9L938/9L939-155A and 9L938/9L939-156A, string to 2105S Jackson deadend and terminate.
Relabel 9L938 segment from 809S Louise Creek to 2105S Jackson to 9L140.		  
ATCO 01-May-28 10:00 04-May-28 17:00 79 Hours
Continuous		 9L939 (77s Sagitawah - 809s Louise Creek) Disconnect 9L939 conductors from temp structure 9L939 -155A - 155E reconnect to existing structures 9L938/9L939-156 and 9L938/9L939-155, connect to the new Q-Towers 9L938/9L939-155A and 9L938/9L939-156A, string to 2105S Jackson deadend and terminate.
Relabel 9L939 segment from 809S Louise Creek to 2		  
ATCO 08-May-28 09:00 10-Jul-28 17:00 1,520 Hours
Continuous		 959s 240kV Bus 900BS2 (959s Lanfine) GOI on 9L141 until line terminated into 1162S Fair Acres and ready to energize  
ATCO 08-May-28 09:00 10-Jul-28 17:00 1,520 Hours
Continuous		 959s 240kV Bus 900BS2 (959s Lanfine) GOI on 902/903 until line terminated and 1162S Fair Acres ready to energize  
ATCO 09-May-28 10:00 13-May-28 17:00 103 Hours
Continuous		 9L02 (809s Louise Creek - 813s Little Smoky) Install concrete foundations for new structures 9L02/320A, 320H in preparation to cut into 9L02 and convert to a t-tap.  
ATCO 15-May-28 09:00 17-May-28 17:00 56 Hours
Continuous		 959s 240kV Bus 900BS1 (959s Lanfine) Connect new bus from new 902B to existing switch 901A to add new line 9L141,
Cutover and commission 900PT1 ccts to new 9L141 relays		  
ATCO 18-May-28 09:00 20-May-28 17:00 56 Hours
Continuous		 959s 240kV Bus 900BS2 (959s Lanfine) Connect new bus from new Bkr 903 to existing switch 903B to add new line 9L141,
Cutover and commission 900PT2 ccts to new 9L141 relays		  
ATCO 29-May-28 09:00 08-Jun-28 17:00 248 Hours
Continuous		 9L24 (946s Oakland - 959s Lanfine) Cutover and commission 905/906 CT's, 9L24PT ccts to new RAS 241 SEL 451A/B relays @ 959S Lanfine and update relay settings for RAS 241 and SCADA inputs @946S Oakland.  
ATCO 19-Jun-28 10:00 30-Jun-28 16:00 270 Hours
Continuous		 9L20 (755s Cordel - 766s Nevis)
Install concrete foundations at 9L20 Structure 69 for new T-Tap connection		  
ATCO 26-Jun-28 10:00 10-Jul-28 17:00 343 Hours
Continuous		 9L02 (809s Louise Creek - 813s Little Smoky) Cut into 9L02 and connect new t-tap structures for 9LA02.
9L02-21A and 21B relay upgrades at 809S Louise Creek and 813S Little Smoky. Implement RAS
Energize new line 9LA02 and 884S Magpie substation		  
ATCO 31-Jul-28 10:00 15-Aug-28 16:00 366 Hours
Continuous		 766s 901 (766s Nevis), 9L20 (755s Cordel - 766s Nevis), 755s 906 (755s Cordel), 755s 901 (755s Cordel)
Cutover new 9L20 line section, terminate 9LA20 at customer substation. Install new line protection relays		  
ATCO 01-Oct-28 08:00 21-Oct-28 16:00 488 Hours
Continuous		 972s 904 (972s Tinchebray) CETO project
Install 904 and 904CT

Commission 904 and 904CT

Expand GOI to 900BS1
Isolation Points: 904A, 901A and 900SST1X
Connect 907B to 900BS1
Shrink GOI to 907B		  
ATCO 22-Oct-28 08:00 20-Nov-28 16:00 705 Hours
Continuous		 972s 906 (972s Tinchebray) CETO project
Install 906 and 906CT

Commission 906 and 906CT

Expand GOI to 900BS2 OCT 22 2028 - NOV 20 2028
Isolation Points: 906A, 902B and 9L16D1@ CORDEL
Connect 909A to 900BS2
Commission Logic and breaker fail
Shrink GOI to 9L86D1
String 9L86 into substation		  

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: 2026-07-22   14:22:06


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.

© 2009 Alberta Electric System Operator. All rights reserved