Alberta Electric System Operator
Long Range Significant Transmission Outages for the period of 24 months starting 2025-10-18

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
EPCOR 31-Mar-25 07:00 24-Oct-25 17:00 207.42 Days
Continuous		 987s T1 (987s Clover Bar), 987s CCP7213 (987s Clover Bar), 987s CCP7214 (987s Clover Bar) Cloverbar - TX1 LCR  
EPCOR 25-Jul-25 17:01 20-Feb-26 17:00 210.04 Days
Continuous		 T2 (EP Riverview) bushing test failure (found during OE110184)  
ATCO 02-Aug-25 23:30 07-Nov-25 18:00 96.81 Days
Continuous		 827s SVC (827s Cranberry Lake) forced outage  
ALTALINK, TRANSALTA 30-Sep-25 16:00 25-Oct-25 18:00 25.08 Days
Continuous		 320p GT3 (320p Keephills), 320p 2952 (320p Keephills), 320p 3052 (320p Keephills) maintenance  
ALTALINK 06-Oct-25 10:00 19-Nov-25 16:00 44.29 Days
Continuous		 102s SVC (102s Langdon), 102s T4 (102s Langdon), 102s 252 (102s Langdon), 102s 552 (102s Langdon) the controls change AB-BC
SUNCOR 11-Oct-25 08:00 20-Oct-25 20:00 9.5 Days
Continuous		 29EDD-61 29PT-653 (29EDD-61 Stony Island), 29EDD-61 30-252-500001 (29EDD-61 Stony Island) 29PT-653 - Repair / Replace Burned Bonding Conductor (9000808061)  
EPCOR 13-Oct-25 07:00 24-Oct-25 17:00 11.42 Days
Continuous		 987s T1 (987s Clover Bar), 987s C2401 (987s Clover Bar), 987s C2403 (987s Clover Bar), 987s CCP7213 (987s Clover Bar), 987s CCP7214 (987s Clover Bar) Cloverbar: TX1 LCR P&C Commissioning and Initial Energization  
ATCO 13-Oct-25 14:01 27-Oct-25 14:00 14 Days
Continuous		 732s 701 (732s Mitsue), 732s 702 (732s Mitsue), 732s 901T (732s Mitsue), 732s 501R (732s Mitsue) Protection upgrade. Remove old protection, cut over to new protection and cut over equipment status, control and alarms to new station controller.  
ALTALINK, EPCOR 14-Oct-25 07:00 18-Oct-25 17:00 4.42 Days
Continuous		 1058L (657s Summerside - EP 803s Lambton), EP 803s L2403 (EP 803s Lambton), EP 803s L2404 (EP 803s Lambton) Lambton CVT and surge arrestors LCR's  
ALTALINK 14-Oct-25 07:00 24-Oct-25 13:30 10.27 Days
Continuous		 102s 924 (102s Langdon), 924L (102s Langdon - 356s Milo), 102s 6852 (102s Langdon), 102s 6952 (102s Langdon), 356s 952 (356s Milo), 356s 852 (356s Milo), 356s 924 (356s Milo) line protection replacements and RAS175 scheme upgrades  
ATCO 14-Oct-25 11:00 30-Oct-25 17:30 16.27 Days
Continuous		 840s McNeill Station replace failed control system parts AB-SK
ALTALINK 14-Oct-25 13:00 18-Oct-25 16:00 4.13 Days
Continuous		 753L (65s High River - 253s Blackie), 65s 753E (65s High River), 253s 753W (253s Blackie) replace CTs and protection upgrade  
ALTALINK 15-Oct-25 06:00 18-Oct-25 18:00 3.5 Days
Continuous		 935L (324s Cassils - 356s Milo) performing mtce  
EPCOR 15-Oct-25 19:00 20-Oct-25 23:00 5.17 Days
Continuous		 330p 1208 (330p Genesee), 330p 1207 (330p Genesee), 330P GT3 (330p Genesee) Genesee: TX-GT3 Connection Repair and 12GT3GS Repair.  
ALTALINK 18-Oct-25 07:00 25-Oct-25 18:00 7.46 Days
Continuous		 777L (48s Pocaterra - 245s Seebe) Replacement of 48s CTs (CT#3) associated with the 777L .Cts located on the line side of 48s below note 12. See also 887L R/Bs that go with this work due to proximity 401105 / 401106 887L/1L274 (48s-B1s) - RBs. AB-BC
ENMAX 18-Oct-25 08:00 18-Oct-25 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) Substation - Insulator Washing (Fall)  
ENMAX, ALTALINK 18-Oct-25 08:00 18-Oct-25 18:00 10 Hours
Daily		 36.81L (44s Bearspaw Plant - SS-36) Substation - Insulator Washing (Fall)  
EPCOR 20-Oct-25 07:00 24-Oct-25 17:00 4.42 Days
Continuous		 805s T3 (805s Jasper), EP 805s J2404 (EP 805s Jasper), EP 805s J2405 (EP 805s Jasper) Jasper: TX3 Zone Relay Maintenance  
ALTALINK 20-Oct-25 07:00 25-Oct-25 18:00 5.46 Days
Continuous		 612L (336s Fincastle - 368s Burdett), 368s 612 (368s Burdett) 368s612 Breaker maintenance. Prep 612L reroute, and str replacement (Strs 79-83, 158).  
EPCOR, ALTALINK 20-Oct-25 07:00 26-Oct-25 17:00 6.42 Days
Continuous		 240BA2 (629s Argyll Transfer Station - 814s Bellamy), 1056L (89s Ellerslie - 629s Argyll Transfer Station), 814s B2402 (814s Bellamy), 814s B2401 (814s Bellamy) 240BA2 Zone: ADS1 LCR, Bellamy Transducer and DFR Cutovers, Bellamy 240kV SF6 Gas Tests and Leak Checks  
Syncrude 20-Oct-25 08:00 20-Oct-25 16:00 8 Hours
Continuous		 Mildred T3 (Syncrude Mildred Lake), 335 (Syncrude Mildred Lake), 334 (Syncrude Mildred Lake), 3235 (Syncrude Mildred Lake) replace a failed relay  
ATCO 20-Oct-25 09:30 20-Oct-25 17:30 8 Hours
Continuous		 811s 709 (811s Clairmont Lake), 7L39 (722s Crystal Lake - 7LA39 tap) 709 Low Gas Top-up at 811s Clairmont  
ALTALINK, EPCOR 20-Oct-25 09:30 26-Oct-25 17:30 6.33 Days
Continuous		 1056L (89s Ellerslie - 629s Argyll Transfer Station) 240BA2 Zone: ADS1 LCR, Bellamy Transducer and DFR Cutovers, Bellamy 240kV SF6 Gas Tests and Leak Checks  
ATCO 20-Oct-25 12:00 23-Oct-25 17:00 3.21 Days
Continuous		 951s SVC (951s Thickwood) Semi Annual inspection & maintenance  
ALTALINK 20-Oct-25 14:00 30-Oct-25 16:00 10.08 Days
Continuous		 368s T2 (368s Burdett), 368s 42 (368s Burdett) Bushing replacement  
EPCOR 21-Oct-25 07:00 21-Oct-25 17:00 10 Hours
Continuous		 PM2405 (Poundmaker) Poundmaker: PM2405 Leak Inspection w/Siemens  
ALTALINK 21-Oct-25 07:00 30-Oct-25 18:00 9.46 Days
Continuous		 912L (63s Red Deer - 766s Nevis) Arctic Arrow will be stringing overtop 912L STR 147-148 with the new CETO 962L/986L spans 165-166.  
ATCO 21-Oct-25 09:30 21-Oct-25 17:30 8 Hours
Continuous		 790s 702 (790s Poplar Hill), 7L22 (790s Poplar Hill - 7L88 tap) 702CT Oil Leak Repairs at 790s Poplar Hill  
ENMAX, ALTALINK 22-Oct-25 08:00 22-Oct-25 16:00 8 Hours
Continuous		 21.80L (42s Sarcee - SS-21) 21.1TR Replacement. Emergency outage to swap bus phasing to 21.1TR.  
ALTALINK, TRANSALTA 22-Oct-25 10:00 22-Oct-25 14:00 4 Hours
Continuous		 250p T1 (250p Bighorn Plant) maintenance  
ENMAX, ALTALINK 23-Oct-25 08:00 23-Oct-25 12:00 4 Hours
Continuous		 21.80L (42s Sarcee - SS-21), 21B138-21.80 (SS-21) 21.2TR Replacement. Commissioning checks.  
ENMAX, ALTALINK 23-Oct-25 08:00 23-Oct-25 12:00 4 Hours
Daily		 21.80L (42s Sarcee - SS-21) 21.2TR Replacement. Commissioning checks.  
ALTALINK 23-Oct-25 08:00 23-Oct-25 18:00 10 Hours
Continuous		 678s 850 (678s Okotoks), 850L (525s Carseland - 678s Okotoks) Major SCADA Upgrade Project. Cutting over supervisory controls to breaker and recloser to new RIO.  
ALTALINK, TRANSALTA 23-Oct-25 10:00 23-Oct-25 14:00 4 Hours
Continuous		 250p T2 (250p Bighorn Plant) maintenance  
ALTALINK 23-Oct-25 11:01 23-Oct-25 14:00 2.98 Hours
Daily		 69s T4 (69s North Barrhead) 138kV breaker control wiring changes for trips and block close from the T2 "A" and "B" protections. Functions tests required on the breaker  
EPCOR 27-Oct-25 07:00 31-Oct-25 17:00 4.42 Days
Continuous		 52s T1 (52s East Industrial), 52s E2401 (52s East Industrial) East Industrial: TX1, Protection Upgrade Cutovers  
EPCOR, ALTALINK 27-Oct-25 07:00 02-Nov-25 16:00 6.42 Days
Continuous		 240BA3 (629s Argyll Transfer Station - 814s Bellamy), 814s B2406 (814s Bellamy), 814s B2407 (814s Bellamy), 1055L (629s Argyll Transfer Station - 816s Petrolia) 240BA3 Zone: ADS2 LCR, Bellamy Transducer and DFR Cutovers, Bellamy 240kV SF6 Gas Tests and Leak Checks  
ALTALINK, EPCOR 27-Oct-25 07:00 02-Nov-25 16:00 6.42 Days
Continuous		 1055L (629s Argyll Transfer Station - 816s Petrolia) 240BA3 Zone: ADS2 LCR, Bellamy Transducer and DFR Cutovers, Bellamy 240kV SF6 Gas Tests and Leak Checks  
ATCO, ALTALINK 27-Oct-25 07:00 06-Nov-25 18:00 10.5 Days
Continuous		 1036L (356s Milo - 554s Travers) Installing interphase spacers and repairing the inner of the conductor (STR 5-45)  
Syncrude 27-Oct-25 08:00 27-Oct-25 16:00 8 Hours
Continuous		 D05 518 (D05), D05 517 (D05), D05 517B (D05), D05 513 (D05), D05 513A (D05), T2 (D05 Syncrude), D05 78 (D05), D05 78A (D05) SCL - Need to replace secondary PT-518 & 5B2 fuse blocks due to poor insulation resistance.  
BCH 27-Oct-25 09:00 04-Nov-25 17:00 8.38 Days
Continuous		 5L98 (BCH Nicola - BCH Vaseux Lake) Repair damaged conductor and install new mid-span structure in the 102 mile AB-BC
BCH 27-Oct-25 09:00 05-Nov-25 17:00 9.38 Days
Continuous		 2L112 (BPA Boundary - BCH Nelway), 2D24 (BCH Nelway), 2D2CB7 (BCH Nelway) NLY 2SA2 2SA12 replacement AB-BC
ALTALINK 27-Oct-25 12:00 30-Oct-25 16:00 3.17 Days
Continuous		 899s 749N (899s Edgerton), 749L (899s Edgerton - 7LB749 tap) Replace 749LN A21/L8 LZ921 protection. Settings change on 749LN B21/L8.  
ALTALINK 27-Oct-25 12:00 31-Oct-25 18:00 4.25 Days
Continuous		 749L (899s Edgerton - 7LB749 tap) Component replacement from 749L338 - 749L463  
EPCOR 28-Oct-25 07:00 28-Oct-25 17:00 10 Hours
Continuous		 EP 805s J2407 (EP 805s Jasper) Jasper: J2407 NAIT Student Substation Tour and Switching Demo  
ATCO, FMGW 28-Oct-25 07:00 29-Oct-25 18:00 1.46 Days
Continuous		 1024s PT-6001 (1024s Granlea), 1024s PT-6002 (1024s Granlea), 1024s 952-600001 (1024s Granlea) preform transformer leak repairs and inspections. 34kv bus bird proofing install.  
ALTALINK 28-Oct-25 08:30 29-Oct-25 17:00 1.35 Days
Continuous		 28s 12 (28s West Brooks) 28s12 First Trip + CT maintenance  
BCH 28-Oct-25 09:00 29-Oct-25 17:00 1.33 Days
Continuous		 5L98 (BCH Nicola - BCH Vaseux Lake) replace broken insulators, helicopter site. AB-BC
ALTALINK 30-Oct-25 08:00 30-Oct-25 17:30 9.5 Hours
Daily		 17s 12 (17s Benalto) 17s12 PRC005 brk maint + first trip  
ATCO 31-Oct-25 06:00 31-Oct-25 19:00 13 Hours
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 Part1.  
ALTALINK 31-Oct-25 07:00 02-Nov-25 18:00 2.5 Days
Continuous		 944L (132s Ware Junction - 275s Jenner) Modifying existing structure 944L156 from a tangent assembly to a floating DE/phase raise configuration to tap onto a new adjacent substation. See also SAP: 294514 951L RB required due to proximity  
ALTALINK 31-Oct-25 08:00 31-Oct-25 13:00 5 Hours
Continuous		 44s T1 (44s Bearspaw Plant), 44s T2 (44s Bearspaw Plant) Outage required to remove PCB Lighting fixture located within LOA.  
ATCO 03-Nov-25 06:00 08-Nov-25 18:00 5.5 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. Part 2.  
ATCO, ALTALINK 03-Nov-25 07:00 08-Nov-25 18:00 5.46 Days
Continuous		 923L (356s Milo - 2075s Newell) Performing mtce. between Structures #74 - 162  
EPCOR 03-Nov-25 07:00 09-Nov-25 17:00 6.42 Days
Continuous		 814s T1 (814s Bellamy), 814s B2401 (814s Bellamy), 814s B2407 (814s Bellamy), BR721 (Rossdale) Bellamy: TX1 Bushing Replacement and 240kv SF6 Gas Tests and Leak Checks  
ALTALINK, Lethbridge 03-Nov-25 08:00 03-Nov-25 17:00 9 Hours
Continuous		 667L (146s MacDonald - 370s North Lethbridge), 146s 667 (146s Macdonald) 146s667L Open End Outage required to add CT circuit into new SEL DDR. Test DDR Recording and commission . Require Protection outages on 667L "A" Protection relay (SEL 311L) , "B" Protection relay (GE L90), "352" Breaker Protection relays Redundant Protections will be in service at all times

  
ALTALINK, Lethbridge 03-Nov-25 08:00 03-Nov-25 17:00 9 Hours
Daily		 667L (146s MacDonald - 370s North Lethbridge) 146s667L Open End Outage required to add CT circuit into new SEL DDR. Test DDR Recording and commission . .  
Syncrude 03-Nov-25 08:00 15-Nov-25 16:00 12.33 Days
Continuous		 222 (Aurora), 222A (Aurora), 222B (Aurora), 223 (Aurora), 223A (Aurora), 223B (Aurora), D05 514 (D05), D05 511 (D05), D05 511A (D05), D05 511B (D05), D05 512 (D05), D05 512A (D05), D05 512B (D05) SCL - Complete D05 Substation, Zone 3 260kV PM  
ATCO 03-Nov-25 09:00 10-Nov-25 16:00 7.29 Days
Continuous		 7L45 (798s Bridge Creek - 813s Little Smoky) Pole replacement line to ground issue ( Line raise )  
BCH 03-Nov-25 09:00 18-Nov-25 09:00 15 Days
Continuous		 T3 (BCH Natal), 12CB23 (BCH Natal) natal substation replacement and ETM install AB-BC
ENMAX, ALTALINK 03-Nov-25 12:30 03-Nov-25 17:00 4.5 Hours
Continuous		 50L (44s Bearspaw Plant - SS-21) 44s50X Heater replacement / Site Inspection  
ALTALINK 03-Nov-25 14:00 04-Nov-25 17:30 27.5 Hours
Continuous		 39s 26 (39s Bickerdike) First trip & breaker maintenance on 39s26  
ENMAX, ALTALINK 04-Nov-25 08:00 05-Nov-25 16:00 1.33 Days
Continuous		 7.82L (42s Sarcee - SS-7) Replace connection point on shield wire weld tabs on structure  
ENMAX, ALTALINK 04-Nov-25 08:00 05-Nov-25 16:00 1.33 Days
Continuous		 7.82L (42s Sarcee - SS-7) Replace connection point on shield wire weld tabs on structure  
ALTALINK 05-Nov-25 08:00 05-Nov-25 13:00 5 Hours
Daily		 405s 796 (405s Waupisoo), 796L (405s Waupisoo - 796AL tap), 796L (282s Grassland - 796AL tap), 796AL (242s Flat Lake - 796L tap) SCADA alarm splitting and ACC visibility upgrades  
ALTALINK, CascadeP 05-Nov-25 08:00 05-Nov-25 18:00 10 Hours
Daily		 39s 26 (39s Bickerdike), 39s 29 (39s Bickerdike), 1135L (39s Bickerdike - 1047s Whisky Jack) First trip & breaker maintenance on 39s29. Repair 39s28.  
ATCO 05-Nov-25 09:00 05-Nov-25 16:00 7 Hours
Continuous		 822s 701 (822s Wolf Lake), 7L587 (822s Wolf Lake - 826s Marguerite Lake) Inspect CT wiring at RTXP test switch
Replace RTXP Test switch if no issue found with wiring terminations
Recommission affected test switch (Burden, logic testing)		  
ALTALINK 05-Nov-25 17:00 06-Nov-25 18:00 25 Hours
Continuous		 39s 29 (39s Bickerdike) Breaker maintenance on 39s29  
ATCO, CNRL 06-Nov-25 08:00 13-Nov-25 16:00 7.33 Days
Continuous		 838s 75-TR-1801 (838s Horizon Mining), 838s RTU/SCADA (838s Horizon Mining), 842s RTU/SCADA (842s Horizon Upgrading) 260kV Transformer Relay Upgrade .  
BCH 06-Nov-25 09:00 16-Nov-25 17:00 10.33 Days
Continuous		 2L113 (BCH Cranbrook - BCH Natal) F26 AOP AB-BC
ENMAX, ALTALINK 08-Nov-25 08:00 16-Nov-25 15:00 8.29 Days
Continuous		 28.80L (42s Sarcee - SS-28), 28.2TR (SS-28) 28.2TR protection upgrade. SW80 replacement.  
BCH 10-Nov-25 09:00 17-Nov-25 17:00 7.33 Days
Continuous		 2L294 (BCH A. A. Lambert - BCH Cranbrook), T3 (BCH Cranbrook) F26 AOP AB-BC
EPCOR 12-Nov-25 07:00 12-Nov-25 17:00 10 Hours
Continuous		 805s T3 (805s Jasper) Jasper: TX3 LV Bushing Measurements and Inspection w/Engineering  
ALTALINK 12-Nov-25 08:00 18-Nov-25 18:00 6.42 Days
Daily		 102s SVC (102s Langdon) Live Commissioning  
ATCO 12-Nov-25 14:00 15-Nov-25 16:00 3.08 Days
Continuous		 7L85 (803s ATC Bullpound - 7LA85 tap) GOI on 7L85 between Badlands and Bull Pound to pole change for L-G Clearance Mitigation.
Install conductor weights 7L85 between structures 401 to 457.
PLEASE ADD/FIX THE BELOW ISOLATIONS AS IS IN THE OTHER ISOLATION POINTS		  
ALTALINK 13-Nov-25 07:00 13-Nov-25 16:30 9.5 Hours
Daily		 AML 511s 148 (AML 511s Crossings), AML 511s 1152 (AML 511s Crossings), AML 511s T30 (AML 511s Crossings), AML 511s SVC Plus (AML 511s Crossings) annual fire system maintenance on the SVC+  
ALTALINK 13-Nov-25 08:00 13-Nov-25 18:00 10 Hours
Daily		 1005AL (991s Little Bow - 1005L tap), 1005L (120s Picture Butte - 1005AL tap), 1005L (356s Milo - 1005AL tap) Modifying 1005L85A and creating Open Point 'A' on the 356s Milo side of 1005L85A  
ATCO 13-Nov-25 09:00 13-Nov-25 17:00 8 Hours
Continuous		 834s 903 (834s Wesley Creek) 903 B Phase Counter Replacement at 834s Wesley Creek  
BCH 13-Nov-25 09:00 18-Nov-25 17:00 5.33 Days
Continuous		 2L113 (BCH Cranbrook - BCH Natal) NTL Substation Replacement + ETM Install AB-BC
BCH 13-Nov-25 13:00 28-Nov-25 17:00 15.17 Days
Continuous		 T4 (BCH Natal) Natal substation replacement and ETM install AB-BC
ALTALINK 13-Nov-25 18:00 24-Nov-25 12:00 10.75 Days
Continuous		 1005L (356s Milo - 1005AL tap) Repairing the inner between STR 3-75 on 1005L  
ALTALINK 14-Nov-25 07:00 19-Nov-25 18:00 5.46 Days
Continuous		 612L (336s Fincastle - 368s Burdett) Reroute Str 153-157 for road widening.  
ENMAX, ALTALINK 14-Nov-25 08:00 14-Nov-25 12:00 4 Hours
Continuous		 28.80L (42s Sarcee - SS-28), 28.2TR (SS-28) Substation - Insulator Washing (Fall)  
ENMAX, ALTALINK 14-Nov-25 08:00 14-Nov-25 12:00 4 Hours
Daily		 28.80L (42s Sarcee - SS-28) Substation - Insulator Washing (Fall)  
ATCO 16-Nov-25 08:00 16-Nov-25 16:00 8 Hours
Continuous		 7L85 (803s ATC Bullpound - 7LA85 tap) GOI on 7L85 between Badlands and Wintering Hills to pole change for L-G Clearance Mitigation.
Install conductor weights 7L85 between structures 401 to 457.
PLEASE ADD/FIX THE BELOW ISOLATIONS AS IS IN THE OTHER ISOLATION POINTS		  
EPCOR 17-Nov-25 07:00 23-Nov-25 17:00 6.42 Days
Continuous		 814s B2402 (814s Bellamy), 814s B2406 (814s Bellamy), 814s T2 (814s Bellamy), BR722 (Rossdale) Bellamy: TX2 Bushing Replacement and 240kv SF6 Gas Tests and Leak Checks  
ENMAX 17-Nov-25 08:00 17-Nov-25 18:00 10 Hours
Continuous		 162B240-RB131 (SS-162), 162B240-RB132 (SS-162), 1-GSU-XF-0001 (SS-162) HV SW Maint. 162SW133, 162SW132.  
ALTALINK 17-Nov-25 08:30 20-Nov-25 16:30 3.33 Days
Continuous		 913L (69s North Barrhead - 732s Mitsue) Protection upgrade. Remove old protection, cut over to new protection and cut over equipment status, control and alarms to new station controller.  
BCH 17-Nov-25 09:00 18-Nov-25 17:00 1.33 Days
Continuous		 T3 (BCH Natal), 2CB1 (BCH Natal) NTL 2CB1 BFPN AB-BC
ATCO 17-Nov-25 09:00 20-Nov-25 16:00 3.29 Days
Continuous		 732s 903 (732s Mitsue), 732s 904 (732s Mitsue), 9L913 (69s North Barrhead - 732s Mitsue) Protection upgrade. Remove old protection, cut over to new protection and cut over equipment status, control and alarms to new station controller.  
ATCO 17-Nov-25 10:00 26-Nov-25 16:00 9.25 Days
Continuous		 7L106 (834s Wesley Creek - 905s Meikle) Soil around the tower footings has eroded ( Tower Replacement )  
ATCO 17-Nov-25 10:00 26-Nov-25 16:00 9.25 Days
Continuous		 7L131 (834s Wesley Creek - 905s Meikle) Soil around the tower footings has eroded ( Tower Replacement )  
ENMAX, ALTALINK 17-Nov-25 14:00 20-Nov-25 17:00 3.13 Days
Continuous		 7.82L (42s Sarcee - SS-7) 42s7 CT replacement  
ENMAX 18-Nov-25 08:00 18-Nov-25 16:00 8 Hours
Continuous		 162B240-RB135 (SS-162), 162B240-RB134 (SS-162), 2-GSU-XF-0002 (SS-162) HV SW Maint. 162SW143, 162SW142.  
BCH 18-Nov-25 09:00 19-Nov-25 17:00 1.33 Days
Continuous		 T3 (BCH Natal), 2CB1 (BCH Natal) NTL 2CB1 BFPN AB-BC
BCH 20-Nov-25 09:00 21-Nov-25 17:00 1.33 Days
Continuous		 T4 (BCH Natal) NTL 2CB2 BFPN, 2CT2 Inspection AB-BC
ATCO 21-Nov-25 09:00 24-Nov-25 16:00 3.29 Days
Continuous		 732s 904 (732s Mitsue), 732s 906 (732s Mitsue), 9L56 (720s Wabasca - 732s Mitsue) Protection upgrade. Remove old protection, cut over to new protection and cut over equipment status, control and alarms to new station controller.  
ENMAX, ALTALINK 21-Nov-25 18:00 23-Nov-25 08:00 1.58 Days
Continuous		 936L (5s East Calgary - 102s Langdon) Crew working in vicinity of 937L  
ENMAX, ALTALINK 21-Nov-25 18:00 23-Nov-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 21-Nov-25 18:00 23-Nov-25 08:00 1.58 Days
Continuous		 936L (5s East Calgary - 102s Langdon) Crew working in vicinity of 937L  
ENMAX, ALTALINK 21-Nov-25 18:00 23-Nov-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  
Syncrude 22-Nov-25 08:00 26-Nov-25 16:00 4.33 Days
Continuous		 D05 512 (D05), D05 512A (D05), D05 512B (D05), D05 513 (D05), D05 513A (D05), D05 513B (D05), D05 515 (D05) SCL - D05 Substation Zone 4 260kV PM with isolation of RL-2.  
ALTALINK, EPCOR 24-Nov-25 07:00 28-Nov-25 17:00 4.42 Days
Continuous		 1044L (EP 805s Jasper - 816s Petrolia), 816s P2405 (816s Petrolia), 816s P2406 (816s Petrolia) 1044L: Petrolia 1044L CT LCR  
EPCOR 24-Nov-25 07:00 30-Nov-25 17:00 6.42 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 and LDS12 LCR  
ENMAX, ALTALINK 24-Nov-25 07:00 02-Dec-25 12:00 8.21 Days
Continuous		 832L (SS-10 - SS-12), 10.1TR (SS-10), 10MD138-10.1TR (SS-10) 10.1TR 'S' protection replacement. Trip test 10B138-832L. Protection operation 10MD138-10.1TR.  
ENMAX, ALTALINK 24-Nov-25 07:00 02-Dec-25 12:00 8.21 Days
Daily		 832L (SS-10 - SS-12) 10.1TR 'S' protection replacement. Trip test 10B138-832L. Protection operation 10MD138-10.1TR.  
ATCO 24-Nov-25 09:00 08-Dec-25 17:30 14.35 Days
Continuous		 2075s ACF21 (2075s Newell) Valve Cooling Skid Modifications  
ALTALINK 24-Nov-25 12:00 24-Nov-25 18:00 6 Hours
Daily		 1005AL (991s Little Bow - 1005L tap), 1005L (120s Picture Butte - 1005AL tap), 1005L (356s Milo - 1005AL tap) Modifying 1005L85A and closing Open Point 'A' and creating Open Point 'B' on the 120s Picture Butte side of 1005L85A  
ALTALINK 24-Nov-25 18:00 04-Dec-25 08:30 9.6 Days
Continuous		 1005L (120s Picture Butte - 1005AL tap) Completing maintenance on 1005L (STR 88-228)  
EPCOR 25-Nov-25 07:00 29-Nov-25 17:00 4.42 Days
Continuous		 814s T1 (814s Bellamy), BR721 (Rossdale), 814s B2401 (814s Bellamy), 814s B2407 (814s Bellamy) Bellamy: TX1 Metering Upgrade Cutovers  
ALTALINK 25-Nov-25 08:30 25-Nov-25 13:00 4.5 Hours
Daily		 562s 152 (562s Cypress) ACC Visibility project work - Breaker alarms splitting.  
ALTALINK 25-Nov-25 09:00 25-Nov-25 12:00 3 Hours
Continuous		 33s 5 (33s Spray) testing  
ALTALINK, TRANSALTA 25-Nov-25 13:00 25-Nov-25 16:00 3 Hours
Daily		 33s T2 (33s Spray) testing  
ALTALINK 25-Nov-25 13:00 25-Nov-25 17:00 4 Hours
Daily		 562s 252 (562s Cypress) ACC Visibility project work - Breaker alarms splitting.  
ALTALINK 26-Nov-25 08:30 26-Nov-25 13:00 4.5 Hours
Daily		 562s 1052 (562s Cypress) ACC Visibility project work - Breaker alarms splitting.  
ATCO 26-Nov-25 09:00 28-Nov-25 16:00 2.29 Days
Continuous		 13L50L2 (2029s Heathfield - 2075s Newell) Repair Shield wire that has broken strands
Only Pole 2 will be out of service
T11D1 is NOT an isolation.
Please add in the isolations listed in other isolating points		  
ALTALINK 26-Nov-25 13:00 26-Nov-25 17:00 4 Hours
Daily		 562s 1152 (562s Cypress) ACC Visibility project work - Breaker alarms splitting.  
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  
ENMAX, ALTALINK 28-Nov-25 18:00 30-Nov-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 28-Nov-25 18:00 30-Nov-25 08:00 1.58 Days
Continuous		 937L (5s East Calgary - 102s Langdon) Crew working in vicinity of 936L  
ENMAX, ALTALINK 28-Nov-25 18:00 30-Nov-25 08:00 1.58 Days
Continuous		 937L (5s East Calgary - 102s Langdon) Crew working in vicinity of 936L  
ENMAX, ALTALINK 28-Nov-25 18:00 30-Nov-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  
EPCOR 01-Dec-25 07:00 04-Dec-25 17:00 3.42 Days
Continuous		 240BA2 (629s Argyll Transfer Station - 814s Bellamy), 814s B2401 (814s Bellamy), 814s B2402 (814s Bellamy) Bellamy: 240BA2 Zone Metering Upgrade Cutovers  
ALTALINK, EPCOR 01-Dec-25 07:00 04-Dec-25 17:00 3.42 Days
Continuous		 1056L (89s Ellerslie - 629s Argyll Transfer Station) Bellamy: 240BA2 Zone Metering Upgrade Cutovers.  
ATCO 01-Dec-25 10:00 02-Dec-25 17:00 31 Hours
Continuous		 876s 904 (876s Brintnell), 9L56 (720s Wabasca - 876s Brintnell) Trouble shoot CT Circuit issues on 99R-3/9L56 test handle  
ATCO 01-Dec-25 13:00 05-Dec-25 17:00 4.17 Days
Continuous		 732s 901 (732s Mitsue), 732s 902 (732s Mitsue), 9L40 (732s Mitsue - 809s Louise Creek) 240kV Bus and 144kV Breaker Fail Protection upgrade + Scada Upgrade.
Cutover 901, 902, and 9L40 to new Scada system, including end to ends with SOC.		  
ATCO 02-Dec-25 08:30 03-Dec-25 18:00 1.4 Days
Continuous		 9L99 (801s Anderson - 807s Sheerness) 801S DFR requires 9L99 inputs to meet PRC-002 compliance  
ENMAX, ALTALINK 02-Dec-25 13:00 11-Dec-25 09:00 8.83 Days
Continuous		 693L (42s Sarcee - SS-10), 10.2TR (SS-10), 10MD138-10.2TR (SS-10) 10.2TR 'S' protection replacement. Trip test 10B138-693L. Protection operation 10MD138-10.2TR.  
ENMAX, ALTALINK 02-Dec-25 13:00 11-Dec-25 09:00 8.83 Days
Continuous		 693L (42s Sarcee - SS-10) 10.2TR 'S' protection replacement. Trip test 10B138-693L. Protection operation 10MD138-10.2TR.  
ATCO 04-Dec-25 08:00 05-Dec-25 16:00 1.33 Days
Continuous		 7L32 (811s Clairmont Lake - 862s South Bezanson) TCM Pole replacement structure 1  
ALTALINK 04-Dec-25 08:30 04-Dec-25 15:00 6.5 Hours
Daily		 1005AL (991s Little Bow - 1005L tap), 1005L (120s Picture Butte - 1005AL tap), 1005L (356s Milo - 1005AL tap) Closing Open point 'B'  
EPCOR 05-Dec-25 07:00 05-Dec-25 17:00 10 Hours
Continuous		 665s T3 (665s Dome), 665s D2404 (665s Dome) Dome: Lighting Replacement on Pole #3  
EPCOR, ALTALINK 08-Dec-25 07:00 08-Dec-25 17:00 10 Hours
Continuous		 657s T3 (657s Summerside), 657s SU2401 (657s Summerside), 657s SU2405 (657s Summerside) Summerside: TX3 Zone, Lighting Upgrade on Pole #1  
EPCOR 08-Dec-25 07:00 11-Dec-25 17:00 3.42 Days
Continuous		 240BA3 (629s Argyll Transfer Station - 814s Bellamy), 814s B2406 (814s Bellamy), 814s B2407 (814s Bellamy) Bellamy: 240BA3 Metering Upgrade Cutovers  
EPCOR 08-Dec-25 07:00 12-Dec-25 17:00 4.42 Days
Continuous		 557s T1 (557s Castle Downs) Castledowns: TX1 Surge Arrestor LCR  
ATCO 08-Dec-25 10:00 15-Dec-25 16:00 7.25 Days
Continuous		 9L40 (732s Mitsue - 809s Louise Creek) Replace 4 damaged poles ( Need winter access) Structures 221, 286, 299 and 304  
EPCOR, ALTALINK 09-Dec-25 07:00 10-Dec-25 17:00 1.42 Days
Continuous		 657s T2 (657s Summerside), 657s SU2402 (657s Summerside), 657s SU2403 (657s Summerside) Summerside: TX2 Zone, Lighting Upgrade on Pole #2, #4, #5  
ALTALINK 09-Dec-25 07:00 12-Dec-25 17:30 3.44 Days
Continuous		 38s 7252 (38s East Edmonton) Replace Koncar CTs associated with 38s7252  
ENMAX, ALTALINK 11-Dec-25 09:00 11-Dec-25 15:00 6 Hours
Continuous		 832L (SS-10 - SS-12), 10.1TR (SS-10), Protection & Control (SS-10), 10MD138-10.1TR (SS-10) Trip testing 10BA8-10.1TR, 10BB8-10.1TR, 10B138-832  
ENMAX, ALTALINK 11-Dec-25 09:00 11-Dec-25 16:00 7 Hours
Daily		 832L (SS-10 - SS-12) Trip testing 10BA8-10.1TR, 10BB8-10.1TR, 10B138-832.  
EPCOR 15-Dec-25 07:00 19-Dec-25 17:00 4.42 Days
Continuous		 557s T2 (557s Castle Downs) Castledowns: TX2 Surge Arrestor LCR  
ENMAX, ALTALINK 15-Dec-25 09:00 15-Dec-25 16:00 7 Hours
Continuous		 833L (SS-2 - SS-12) Transfer from JMUX to JPAX circuits  
ENMAX, ALTALINK 15-Dec-25 09:00 15-Dec-25 16:00 7 Hours
Continuous		 833L (SS-2 - SS-12) Transfer from JMUX to JPAX circuits  
ATCO 15-Dec-25 10:00 16-Dec-25 16:00 30 Hours
Continuous		 7L91 (715s Leming Lake - 826s Marguerite Lake) Install aerial nest platform pole and transfer osprey nest from 7L91-158  
ATCO 15-Dec-25 10:00 16-Dec-25 17:30 31.5 Hours
Continuous		 959s SVC (959s Lanfine) Troubleshoot cause of recent SVC tripping event.  
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 06-Jan-26 08:00 09-Jan-26 17:00 3.38 Days
Continuous		 732s 902T (732s Mitsue), 732s 503R (732s Mitsue) Protection upgrade. Remove old protection, cut over to new protection and cut over equipment status, control and alarms to new station controller.  
ATCO 12-Jan-26 13:00 21-Jan-26 09:00 8.83 Days
Continuous		 9L57 (939s Livock - 960s Birchwood Creek) 9L57 Line to Ground Clearance Mitigation  
ATCO 26-Jan-26 13:00 04-Feb-26 09:00 8.83 Days
Continuous		 9L57 (939s Livock - 960s Birchwood Creek) 9L57 Line to Ground Clearance Mitigation  
ATCO 09-Feb-26 13:00 18-Feb-26 09:00 8.83 Days
Continuous		 9L57 (939s Livock - 960s Birchwood Creek) 9L57 Line to Ground Clearance Mitigation  
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		  
ATCO 23-Feb-26 13:00 04-Mar-26 09:00 8.83 Days
Continuous		 9L57 (939s Livock - 960s Birchwood Creek) 9L57 Line to Ground Clearance Mitigation  
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
  
ALTALINK 03-Mar-26 07:00 09-Mar-26 17:00 6.38 Days
Continuous		 944L (132s Ware Junction - 275s Jenner) Line outage to replace line protection relays at 132s Ware Junction, replace relay comm cards and update settings on line protections at 275s Jenner and implement third terminal 1080s Jurassic line protection relays. End to end testing between all three sites.  
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 09-Mar-26 13:00 18-Mar-26 09:00 8.83 Days
Continuous		 9L57 (939s Livock - 960s Birchwood Creek) 9L57 Line to Ground Clearance Mitigation  
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 16-Mar-26 10:00 16-Mar-26 16:00 6 Hours
Continuous		 715s 701 (715s Leming Lake), 7L583 (715s Leming Lake - 970s Bourque) PRC-005 Trip Coil Testing, 701CT Inspection/ Testing  
ATCO 17-Mar-26 10:00 17-Mar-26 16:00 6 Hours
Continuous		 715s 702 (715s Leming Lake), 7L91 (715s Leming Lake - 826s Marguerite Lake) PRC-005 Trip Coil Testing, 702CT Inspection/ Testing  
ATCO 18-Mar-26 10:00 18-Mar-26 16:00 6 Hours
Continuous		 715s 703 (715s Leming Lake), 7L66 (715s Leming Lake - 717s Ethel Lake) PRC-005 Trip Coil Testing, 703CT Inspection/ Testing  
ATCO, SUNCOR 23-Mar-26 08:00 29-Mar-26 20:00 6.5 Days
Continuous		 29PL9-2 (29EDD-1 Millennium - 848s Ruth Lake) 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 01-Apr-26 08:00 10-Apr-26 20:00 9.5 Days
Continuous		 29EDD-34 29PT-341 (29EDD-34), 29EDD-34 29-952-142 (29EDD-34), 29EDD-34 29-952-143 (29EDD-34), 29EDD-34 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-0375 (29EDD-34), 29EDD-34 29PS-0380 (29EDD-34), 29EDD-34 29PS-0381 (29EDD-34), 29EDD-34 29PS-0383 (29EDD-34), 29EDD-34 29PS-609 (29EDD-34) 10 year PM on 29EDD34;29PT-341 system and 5 year, 10 year PM on 29EDD34;29PP-103 system
  
SUNCOR 01-Apr-26 08:00 11-Apr-26 20:00 10.5 Days
Continuous		 29EDD-34 29PT-340 (29EDD-34) 29EDD34;29PT-340 SYSTEM;PM 5y,10y; 29EDD34;29PP-102 SYSTEM;PM 5y,10y
  
ENMAX, ALTALINK 04-Apr-26 08:00 04-Apr-26 18:00 10 Hours
Continuous		 1003L (74s Janet - SS-25) Surge Arrestor Power Factor Test - 25MD240-1003  
ENMAX, ALTALINK 04-Apr-26 08:00 04-Apr-26 18:00 10 Hours
Continuous		 1003L (74s Janet - SS-25) Surge Arrestor Power Factor Test - 25MD240-1003  
ENMAX, ALTALINK 05-Apr-26 08:00 05-Apr-26 18:00 10 Hours
Continuous		 985L (74s Janet - SS-25) Surge Arrestor Power Factor Test - 25MD240-985  
ENMAX, ALTALINK 05-Apr-26 08:00 05-Apr-26 18:00 10 Hours
Continuous		 985L (74s Janet - SS-25) Surge Arrestor Power Factor Test - 25MD240-985  
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;
 
ENMAX 06-Apr-26 08:00 14-Apr-26 16:00 8.33 Days
Continuous		 65.2TR (SS-65) Tap Changer Inspection - 65.2-TC  
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  
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 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
  
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  
ATCO, ALTALINK 11-May-26 07:00 14-May-26 18:00 3.46 Days
Continuous		 7LA114 (658s Chard - 7L114 tap), 7L114 (72s Leismer - 7LA114 tap), 7L114 (907s Waddell - 7LA114 tap), 907s Waddell AltaLink outage on 72sT2 causing an outage to 7L114 at 907S  
ALTALINK, ATCO 11-May-26 07:00 14-May-26 18:00 3.46 Days
Continuous		 72s T2 (72s Leismer), 72s 144kV Bus (72s Leismer), 7L114 (72s Leismer - 7LA114 tap) Transformer maintenance, doble, install Coresense & Qualitrol  
ALTALINK, ATCO 11-May-26 07:00 14-May-26 18:00 3.46 Days
Continuous		 72s 114 (72s Leismer), 7L114 (72s Leismer - 7LA114 tap) Customer maintenance  
SUNCOR 18-May-26 08:00 24-May-26 20:00 6.5 Days
Continuous		 29PL9-12 (29EDD-34 - 29EDD-65) 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		 972s 905B (972s Tinchebray), 972s 906A (972s Tinchebray) 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		 9L62 (972s Tinchebray - 87s Gaetz) Work on parallel line 9L86  
ATCO, CNRL 15-Jun-26 05:00 29-Jun-26 10:00 14.21 Days
Continuous		 859s 701TD (859s Primrose), 859s 701 (859s Primrose), 859s 704 (859s Primrose), 859s Protection & Control (859s Primrose), 859s RTU/SCADA (859s Primrose), 859s 52G (859s Primrose), 859s 701T (859s Primrose) maintenance  
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 06-Jul-26 10:00 27-Nov-26 16:00 144.29 Days
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.  
ALTALINK 10-Aug-26 09:30 13-Aug-26 17:00 3.31 Days
Continuous		 702L (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
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  
ALTALINK 17-Aug-26 10:00 20-Aug-26 16:30 3.27 Days
Continuous		 702L (137s Sedgewick - 757s Battle River) Interphase spacers and pole replacements  
ALTALINK, ATCO, FMGW 18-Aug-26 08:00 19-Aug-26 17:00 1.38 Days
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  
ATCO 21-Sep-26 10:00 24-Sep-26 16:00 3.25 Days
Continuous		 888s 906 (888s Dover) 21B/9L74 relay replacement. Cutover breaker and CT to new protection  
ATCO 25-Sep-26 10:00 28-Sep-26 16:00 3.25 Days
Continuous		 888s 905 (888s Dover) 21B/9L74 relay replacement. Cutover breaker and CT to new protection  
ATCO 05-Oct-26 10:00 08-Oct-26 16:00 3.25 Days
Continuous		 9L74 (888s Dover - 960s Birchwood Creek) 21B/9L74 relay three terminal line testing  
ATCO 12-Oct-26 10:00 15-Oct-26 16:00 3.25 Days
Continuous		 888s 906 (888s Dover) 21A/9L74 relay replacement. Cutover breaker and CT to new protection  
ATCO 16-Oct-26 10:00 19-Oct-26 16:00 3.25 Days
Continuous		 888s 905 (888s Dover) 21B/9L74 relay replacement. Cutover breaker and CT to new protection  
ATCO 26-Oct-26 10:00 29-Oct-26 16:00 3.25 Days
Continuous		 9L74 (888s Dover - 960s Birchwood Creek) 21B/9L74 relay three terminal line testing  
Syncrude 03-Nov-26 08:00 18-Nov-26 16:00 15.33 Days
Continuous		 UE-1 (D05 - UE-1 Syncrude Plant 30-2), T1 (D05 Syncrude), D05 511 (D05), D05 519 (D05), D05 71 (D05), D05 71A (D05), D05 71B (D05), D05 80 (D05), D05 80B (D05), D05 79 (D05), D05 79B (D05), D05 73 (D05), D05 73A (D05), D05 73B (D05), D05 75 (D05), D05 75A (D05), LCF (D05), ML-4 (D05), UE-1 7206 (UE-1 Syncrude Plant 30-2), UE-1 72-16 (UE-1 Syncrude Plant 30-2), D05 511A (D05), D05 519A (D05), D05 519B (D05), D05 80A (D05), D05 79A (D05), D05 75B (D05) complete 6-Year 72 kV A bus preventive maintenance in D05 substation  
ATCO 09-Feb-27 09:00 11-Feb-27 17:00 2.33 Days
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 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,
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,
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 16-Mar-27 09:00 18-Mar-27 17:00 2.33 Days
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 from Pakenham to Big Mountain		  
ATCO 26-Mar-27 09:00 29-Mar-27 17:00 3.33 Days
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  
ATCO 12-Apr-27 10:00 19-Apr-27 17:00 7.29 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		  
ATCO 03-May-27 10:00 06-May-27 17:00 3.29 Days
Continuous		 7L22 (811s Clairmont Lake - 7L88 tap) 7L22/21B relay upgrade at 811S Clairmont Lake
Upon completion new 2061S Dobbs substation ready to energize		  
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  
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
  
ALTALINK, ATCO, FMGW 17-Aug-27 08:00 18-Aug-27 17:00 1.38 Days
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 08-Nov-27 08:30 11-Nov-27 17:30 3.38 Days
Continuous		 409s 110 (409s Shell Scotford) Install new Deadend corner structure on ALC02L  
ALTALINK 08-Nov-27 08:30 11-Nov-27 17:30 3.38 Days
Continuous		 409s 107 (409s Shell Scotford) Install new Deadend corner structure on ALC02L.  
ATCO 08-Nov-27 09:00 11-Nov-27 17:00 3.33 Days
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 3.33 Days
Continuous		 ALC01L (408s Air Liquide Scotford - 409s Shell Scotford) Install new Deadend corner structure on ALC02L.  
ALTALINK 13-Mar-28 09:30 16-Mar-28 17:30 3.33 Days
Continuous		 939L (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 13-Mar-28 10:00 16-Mar-28 17:00 3.29 Days
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  
ALTALINK 17-Mar-28 09:30 17-Apr-28 17:30 31.33 Days
Continuous		 939L (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 17-Mar-28 10:00 17-Apr-28 17:00 31.29 Days
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.  

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: 2025-10-08   14:45:56


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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