Alberta Electric System Operator
System Co-ordination Plan
2026-04-11 to 2026-04-17
Approved Outages

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From To Owner Type Element Scheduled Activity Date/Time Comments Interconnection
26-Jul-24 10:00 31-Jul-26 16:00 ATCO Outage 826s 504R (826s Marguerite Lake) emergency removal to replace failed 502R @834S 735.25 Days
Continuous		  
23-Aug-24 13:45 21-May-26 14:29 ALTALINK Outage 157s C1 (157s Lac La Biche) forced outage 636.03 Days
Continuous		  
20-Mar-25 08:00 29-May-26 17:00 ALTALINK Outage 256s C1 (256s Harmattan) forced outage 435.38 Days
Continuous		  
31-Mar-25 07:00 01-May-26 17:00 EPCOR TE Protection & Control (Woodcroft) Woodcroft: protection blocking for merging unit and protection upgrade. 396.42 Days
Continuous		  
25-Jul-25 17:01 17-Apr-26 17:00 EPCOR Outage T2 (EP Riverview) bushing test failure (found during OE110184) 266 Days
Continuous		  
12-Sep-25 08:00 19-Jun-26 16:00 ENMAX Outage 33.1TR (SS-33) tap changer refurbishments. soak test required 280.33 Days
Continuous		  
25-Nov-25 17:46 18-Sep-26 18:00 ATCO Outage 876s 901T (876s Brintnell) forced outage oil leaking 296.97 Days
Continuous		  
27-Nov-25 08:30 27-Nov-27 16:30 ALTALINK TE 89s Protection & Control (89s Ellerslie) DSP card replacements on1057L B87/L3 and B240B1 B87/240B1 730.33 Days
Daily		  
04-Jan-26 08:00 02-Sep-26 16:00 SUNCOR Outage 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 241.29 Days
Continuous		  
12-Jan-26 07:00 03-Jul-26 17:00 EPCOR TE 330p Protection & Control (330p Genesee) protect blocking, annual relay maintenance and password changes 172.38 Days
Continuous		  
12-Jan-26 07:00 01-May-26 17:00 EPCOR TE Protection & Control (Rossdale) protection blocking, relay maintenance 109.38 Days
Continuous		  
17-Jan-26 11:00 30-Apr-26 17:00 BHE Canada Outage 120s C2 (120s Picture Butte) forced outage 103.21 Days
Continuous		  
21-Jan-26 08:00 30-Oct-26 16:00 ENMAX Outage 5.7TR (SS-5) 25kV switchgear replacement 282.29 Days
Continuous		  
03-Feb-26 09:00 30-Jun-26 17:00 ATCO TE 972s RTU/SCADA (972s Tinchebray) config changes needed throughout the CETO project 147.29 Days
Continuous		  
09-Feb-26 09:00 26-Jun-26 17:00 ATCO TE 972s Protection & Control (972s Tinchebray) block all 50BF protection until cutovers and associated commissioning are complete 137.29 Days
Continuous		  
06-Mar-26 17:00 13-Nov-26 17:00 EPCOR Outage T1 (Woodcroft) woodcroft: TX1 LCR civil 252 Days
Continuous		  
10-Mar-26 09:00 14-Apr-26 17:00 ATCO Outage 972s 240kV Bus 900BS2 (972s Tinchebray), 972s 903 (972s Tinchebray) install breakers 905/906, 905CT/906CT, switches 905A/906B
 35.33 Days
Continuous		  
10-Mar-26 10:00 30-Nov-26 17:00 ATCO TE 743s RTU/SCADA (743s Sarah Lake) throughout the course of the project, different apparatus are being replaced, RTU will be blocked prior to download 265.33 Days
Continuous		  
11-Mar-26 13:45 19-Apr-26 16:00 ALTALINK Outage 535s C1 (535s Joffre) breaker maintenance 39.09 Days
Continuous		  
13-Mar-26 16:00 24-Apr-26 17:00 ATCO Outage 7L122 (791s Rainbow Lake - 930s Arcenciel), 791s 701 (791s Rainbow Lake) phase replacement 42.04 Days
Continuous		  
16-Mar-26 07:30 16-Apr-26 15:30 CMH TE MHS-2 RTU/SCADA (MHS-2 North Industrial) replacement of existing Axiom Scout RTAC with SEL 3350 RTAC. 31.33 Days
Continuous		  
22-Mar-26 13:00 30-Jun-26 17:00 BHE Canada Outage 120s C1 (120s Picture Butte), 120s C2 (120s Picture Butte) forced outage 100.17 Days
Continuous		  
26-Mar-26 10:04 12-Apr-26 12:07 ALTALINK Outage 937L (5s East Calgary - 102s Langdon) 937L (5s-102s) tripped, B-G fault 16.29KM from 102s (str.56)
ACC test energized @ 03:07 - failed, B-G fault 14.91KM from 102s (str.58)
work on underground facility
17.09 Days
Continuous		  
28-Mar-26 12:00 14-May-26 17:00 ATCO TE 833s RTU/SCADA (833s Mariana) updating RTU/station controller configuration during SCADA upgrade project 47.21 Days
Continuous		  
30-Mar-26 08:30 04-May-26 16:30 ALTALINK Outage 62s T1 (62s Brazeau Plant), 62s 1 (62s Brazeau Plant) maintenance 35.33 Days
Continuous		  
02-Apr-26 08:00 13-Apr-26 16:00 ENMAX Outage 33.84L (SS-33 - SS-43), 33B138-33.84 (SS-33), 43B138-33.84 (SS-43) shield wire and O-ring replacement 11.33 Days
Continuous		  
06-Apr-26 07:00 01-May-26 17:00 EPCOR Outage 72JM18 (EP 805s Jasper - Meadowlark), T1 (Meadowlark), M721 (Meadowlark), M722 (Meadowlark), EP 805s J722 (EP 805s Jasper), EP 805s JDS29 (EP 805s Jasper), MAB1 (Meadowlark) Meadowlark - T1 LCR demo 25.42 Days
Continuous		  
06-Apr-26 08:00 14-Apr-26 16:00 ENMAX Outage 65.2TR (SS-65) tap changer inspection - 65.2-TC 8.33 Days
Continuous		  
06-Apr-26 08:00 16-Apr-26 16:00 ALTALINK Outage 747L (37s North Calder - 711L tap), 37s 747W (37s North Calder) P&C upgrades 10.33 Days
Continuous		  
06-Apr-26 08:00 16-Apr-26 16:00 ALTALINK TE 37s Protection & Control (37s North Calder) P&C protections upgrades to occur under the 37s747W GOI 10.33 Days
Continuous		  
06-Apr-26 08:00 19-Jun-26 16:00 ALTALINK TE 37s RTU/SCADA (37s North Calder) RTU database updates 74.33 Days
Continuous		  
07-Apr-26 07:00 21-Apr-26 17:00 ALTALINK TE 1012s Protection & Control (1012s Deer Hill) settings changes and testing associated with 685L line splitting 14.42 Days
Continuous		  
07-Apr-26 07:00 21-Apr-26 17:00 ALTALINK TE 397s Protection & Control (397s Benbow) settings changes and testing associated with L3 protection upgrades 14.42 Days
Continuous		  
07-Apr-26 07:00 21-Apr-26 17:00 ALTALINK TE 39s Protection & Control (39s Bickerdike) protection outages required on A21/L1 and B21/L1 (854L) protections for settings changes and testing associated with 685L line splitting 14.42 Days
Continuous		  
07-Apr-26 07:00 21-Apr-26 17:00 ALTALINK TE 397s RTU/SCADA (397s Benbow) alarm/control updates and testing of new L3 protections for the Berland River project 14.42 Days
Continuous		  
07-Apr-26 07:00 21-Apr-26 17:00 ALTALINK TE 1012s RTU/SCADA (1012s Deer Hill) alarm/control updates and testing for the Berland River project 14.42 Days
Continuous		  
07-Apr-26 07:30 14-Apr-26 16:30 ALTALINK RB 936L (5s East Calgary - 102s Langdon) urgent request for crews working within close proximity building temporary bypass on 937L 7.38 Days
Continuous		  
07-Apr-26 07:30 14-Apr-26 16:30 ALTALINK RB 925L (63s Red Deer - 74s Janet) urgent request to bypass on 937L structures 47 and 48 7.38 Days
Continuous		  
07-Apr-26 07:30 14-Apr-26 16:30 ALTALINK RB 901L (74s Janet - 901AL tap) urgent request to bypass on 937L structures 47 and 48 7.38 Days
Continuous		  
07-Apr-26 07:30 14-Apr-26 16:30 ENMAX, ALTALINK RB 932L (74s Janet - SS-162) urgent - working within close proximity building temporary bypass on 937L structures 47 and 48 7.38 Days
Continuous		  
07-Apr-26 07:30 14-Apr-26 16:30 ALTALINK RB 929L (74S Janet - 287s Hazelwood) urgent - working within close proximity building temporary bypass on 937L structures 47 and 48 7.38 Days
Continuous		  
07-Apr-26 09:00 21-Apr-26 15:00 ALTALINK Outage 685L (397s Benbow - 1012s Deer Hill), 614L (397s Benbow - 328s Pine Creek), 1012s 685 (1012s Deer Hill), 397s 685 (397s Benbow), 328s 614 (328s Pine Creek), 328s 685 (328s Pine Creek) split 685L into new 614L and 685L for in/out @ 328s, energize 328s614, 328s685, & 328s 138kV Bus 1, return temporary phase swap back to normal at flying tap location at 1012s
14.25 Days
Continuous		  
07-Apr-26 10:00 20-Apr-26 16:00 ATCO Outage 743s 702T (743s Sarah Lake), 743s 706 (743s Sarah Lake), 743s 502 (743s Sarah Lake) 743S rebuild - replace breaker 502 13.25 Days
Continuous		  
08-Apr-26 07:00 10-May-26 17:00 ALTALINK, ALPAC IO 796L (282s Grassland - 796AL tap) note for area assessments 32.42 Days
Continuous		  
08-Apr-26 09:00 22-Apr-26 17:00 ATCO Outage 833s 701T (833s Mariana), 833s 701TCS (833s Mariana) full protection and SCADA upgrades, replacement of battery bank, charger, and addition of BMS
 14.33 Days
Continuous		  
09-Apr-26 17:01 13-May-26 07:00 EPCOR Outage 72RW3 (Rossdale - Woodcroft), RW727 (Rossdale) termination rebuild at the Woodcroft end 33.58 Days
Continuous		  
11-Apr-26 07:00 11-Apr-26 17:00 EPCOR TE RTU/SCADA (Strathcona) substation firewall replacement 10 Hours
Continuous		  
11-Apr-26 08:00 11-Apr-26 16:00 ENMAX Outage 162B138-RB82 (SS-162) HV breaker maintenance, breaker dashpot checks, SF6 gas sample 8 Hours
Continuous		  
11-Apr-26 08:00 11-Apr-26 16:00 ALTALINK Outage 535s 1152 (535s Joffre) cutover CT circuit, trip & breaker fail for 1152 breaker & CT5 to new 138B1 relay 8 Hours
Continuous		  
12-Apr-26 07:00 12-Apr-26 17:00 EPCOR TE 52s RTU/SCADA (52s East Industrial) RTU outage, substation firewall replacement 10 Hours
Continuous		  
12-Apr-26 08:00 12-Apr-26 12:00 ENMAX Outage 39.82L (SS-39 - SS-162), 162B138-RB82 (SS-162), 162B138-RB83 (SS-162) summer substation washing 4 Hours
Continuous		  
12-Apr-26 16:00 19-Apr-26 12:00 ALTALINK Outage 525s T1 (525s Carseland) 525sT1 doble test, maintenance, PT4 testing 6.83 Days
Continuous		  
13-Apr-26 07:00 17-Apr-26 17:00 ALTALINK, EPCOR Outage 947L (89s Ellerslie - 987s Clover Bar), 987s C2402 (987s Clover Bar), 987s C2404 (987s Clover Bar), 89s 947 (89s Ellerslie) Cloverbar: 947L relay maintenance 4.42 Days
Continuous		  
13-Apr-26 07:00 29-May-26 17:00 EPCOR Outage 805s T4 (805s Jasper) bushing replacement and fan repair 46.42 Days
Continuous		  
13-Apr-26 07:00 20-Apr-26 18:00 ALTALINK Outage 87s 240kV West Bus (87s Gaetz), 914L (86s Bigstone - 87s Gaetz), 87s T1 (87s Gaetz), 87s 2352 (87s Gaetz), 87s 1252 (87s Gaetz), 87s 1352 (87s Gaetz), 87s 1552 (87s Gaetz), 87s 1752 (87s Gaetz) closing open point 'I' and creating second permanent bus cut between 87s26 and 87s 240 kV west bus 7.46 Days
Continuous		  
13-Apr-26 07:00 17-Apr-26 17:00 EPCOR Outage VHBB1 (Rossdale) breaker fail upgrade 4.42 Days
Continuous		  
13-Apr-26 07:00 17-Apr-26 17:00 EPCOR Outage T2 (EP Riverview), RW2402 (EP Riverview), RW2403 (EP Riverview) T2 zone, scaffold removal 4.42 Days
Continuous		  
13-Apr-26 07:00 17-Apr-26 15:00 CMH, TCPL Outage MH-65L (MHS-7 Brier Park - Cancarb Energy Medicine Hat), MHS-7 MH69-709 (MHS-7 Brier Park), BKR-900 (Cancarb Energy Medicine Hat) maintenance on MH69-709 4.33 Days
Continuous		  
13-Apr-26 07:00 16-Apr-26 17:00 ALTALINK TE 87s RTU/SCADA (87s Gaetz) SCADA change for CETO project 3.42 Days
Continuous		  
13-Apr-26 07:00 17-Apr-26 17:00 EPCOR TE 72CK13 (987s Clover Bar - Kennedale) protection blocking, relay maintenance 4.42 Days
Continuous		  
13-Apr-26 07:00 17-Apr-26 17:00 EPCOR TE 72CK12 (987s Clover Bar - Kennedale) protection blocking, relay maintenance 4.42 Days
Continuous		  
13-Apr-26 07:30 17-Apr-26 16:00 ENMAX IO 2GSU-XF-001 (SS-25), 25B240-D135 (SS-25), 25B240-D134 (SS-25) breaker maintenance 4.35 Days
Continuous		  
13-Apr-26 07:30 17-Apr-26 16:00 ENMAX Outage 25B240-D135 (SS-25), 2GSU-XF-001 (SS-25), 25B240-D134 (SS-25) degassing oil/oil processing 4.35 Days
Continuous		  
13-Apr-26 08:00 17-Apr-26 16:00 ALTALINK, TRANSALTA, GLEI Outage 179s T1 (179s Gleichen), 179s 23N (179s Gleichen), 179s 52-M (179s Gleichen) 179s t1 oil reclaim and tx maintenance 4.33 Days
Continuous		  
13-Apr-26 08:00 16-Apr-26 16:00 ATCO RB 7L90 (741s ATC Fox Creek - 7LA90 tap), 7L90 (813s Little Smoky - 7LA90 tap) walk up and climbing inspection 3.33 Days
Continuous		  
13-Apr-26 08:00 16-Apr-26 16:00 ALTALINK Outage 851L (253s Blackie - 525s Carseland), 525s 851X (525s Carseland), 253s 851W (253s Blackie) replace 525s851X breaker CTs 3.33 Days
Continuous		  
13-Apr-26 08:00 14-Apr-26 16:00 ALTALINK TE 370s Protection & Control (370s North Lethbridge) migration of line protections to new City of Lethbridge communications system 1.33 Days
Continuous		  
13-Apr-26 08:00 14-Apr-26 17:00 Lethbridge TE 111s Protection & Control (111s Coalbanks) transfer TPR (Teleprotection) circuits from existing JMUX to new SEL ICON 1.38 Days
Continuous		  
13-Apr-26 08:00 17-Apr-26 16:00 ENMAX Outage 27.1TR (SS-27) sub 27 PT Outage 4.33 Days
Continuous		  
13-Apr-26 08:00 14-Apr-26 16:00 ENMAX TE Protection & Control (SS-25) relays, lockout testing 1.33 Days
Daily		  
13-Apr-26 08:00 16-Apr-26 16:00 ATCO RB 7L73 (730s Rycroft - 829s Boucher Creek), 7L73 (800s Friedenstal - 829s Boucher Creek) high load move on 7L73 str 336 3.33 Days
Continuous		  
13-Apr-26 08:00 24-Apr-26 15:00 CMH TE MHS-7 Protection & Control (MHS-7 Brier Park) preventative maintenance 11.29 Days
Continuous		  
13-Apr-26 08:00 16-Apr-26 16:00 ALTALINK TE 37s Protection & Control (37s North Calder) trip testing 3.33 Days
Continuous		  
13-Apr-26 09:00 13-Apr-26 10:00 ATCO TE ATCO Telecom Equipment, 892s RTU/SCADA (892s Ribstone Creek) upgrading fleet sar 60 Mins
Continuous		  
13-Apr-26 09:00 15-Apr-26 17:00 ALTALINK, BHE, BHE Canada Outage MATL (120s Picture Butte - Montana), 120s 1052 (120s Picture Butte), PDB2401 (BHE Hay Lake), PDB2405 (BHE Hay Lake) align with 1201L outage 2.33 Days
Continuous		 AB-MATL
13-Apr-26 09:00 23-Apr-26 17:00 BCH RB 2L294 (BCH A. A. Lambert - BCH Cranbrook), 2L294 (BCH A. A. Lambert - BCH Nelway) ANRP for tree removal 10.33 Days
Daily		 AB-BC
13-Apr-26 09:00 21-May-26 10:00 ALTALINK Outage 157s C1 (157s Lac La Biche) replace breaker and disconnect switch 38.04 Days
Continuous		  
13-Apr-26 09:00 13-Apr-26 11:25 ALTALINK, BCH Outage 1201L (520s Bennett - BCH Cranbrook), 5L94 (BCH Cranbrook - 520s Bennett), 520s 552 (520s Bennett), 520s 12 (520s Bennett), 5D25 (BCH Cranbrook) BC hydro outage for insulator replacement program - 500 kV switchyard work 2.42 Hours
Continuous		 AB-BC
13-Apr-26 10:00 17-Apr-26 16:00 ATCO Outage 951s SVC (951s Thickwood), 951s 919 (951s Thickwood Hills), 951S 902 (951s Thickwood Hills), 951s 903 (951s Thickwood Hills), 951s 919A (951s Thickwood Hills) maintenance/inspection of SVC 4.25 Days
Continuous		  
13-Apr-26 10:00 17-Apr-26 16:00 ATCO TE 951s RTU/SCADA (951s Thickwood Hills) password changes, computer patching 4.25 Days
Continuous		  
13-Apr-26 10:00 16-Apr-26 16:00 ALTALINK TE 525s Protection & Control (525s Carseland) protection maintenance 3.25 Days
Continuous		  
13-Apr-26 10:00 13-Apr-26 16:00 ALTALINK TE 69s Protection & Control (69s North Barrhead) settings change
6 Hours
Continuous		  
13-Apr-26 11:00 13-Apr-26 16:00 ALTALINK TE 254s Protection & Control (254s Coaldale) event recording settings change 5 Hours
Continuous		  
13-Apr-26 11:00 13-Apr-26 16:00 ALTALINK TE 432s RTU/SCADA (432s Carvel) RTU database update 5 Hours
Continuous		  
13-Apr-26 11:25 15-Apr-26 17:00 ALTALINK, BCH Outage Path 1 (AIES Islanding), 1201L (520s Bennett - BCH Cranbrook), 5L94 (BCH Cranbrook - 520s Bennett), 520s 552 (520s Bennett), 520s 12 (520s Bennett), 5D25 (BCH Cranbrook) BC hydro outage for insulator replacement program - 500 kV switchyard work 2.23 Days
Continuous		 AB-BC
13-Apr-26 11:25 15-Apr-26 17:00 ALTALINK, BCH Outage 799s 786W (799s Coleman), 786L (799s Coleman - BCH Natal) 1201L is out of service 2.23 Days
Continuous		 AB-BC
13-Apr-26 11:25 15-Apr-26 17:00 ALTALINK, BCH Outage 48s 887X (48s Pocaterra), 887L (48s Pocaterra - 978s BCH Britt Creek) 1201L is out of service 2.23 Days
Continuous		 AB-BC
13-Apr-26 11:30 16-Apr-26 16:30 ALTALINK Outage 430s 352 (430s Ursus) 430s352s CT replacement 3.21 Days
Continuous		  
13-Apr-26 12:00 15-Apr-26 10:00 ATCO, Athabasca Oi Outage 7L126 (2009s Willow Lake - 279s AHS), 279s PSW8800 (279s AHS) isolation for AOC to perform maintenance 1.92 Days
Continuous		  
13-Apr-26 13:00 13-Apr-26 17:00 ALTALINK Outage 434s T1 (434s East Stony Plain) replace 434s15 and 434s30 station service fuses
4 Hours
Continuous		  
13-Apr-26 13:00 16-Apr-26 16:00 ALTALINK TE 525s RTU/SCADA (525s Carseland) RTU maintenance 3.13 Days
Continuous		  
13-Apr-26 13:30 16-Apr-26 16:00 ALTALINK Outage 905L (19s Wabamun - 37s North Calder), 19s 905 (19s Wabamun) PRC5 breaker maintenance and first trip 3.1 Days
Continuous		  
13-Apr-26 17:00 15-Apr-26 08:00 ENMAX Outage 20.82L (SS-20 - SS-21), 20B138-20.82 (SS-20), 21B138-20.82 (SS-21) re-string section of line for 21 sub phasing 1.63 Days
Continuous		  
13-Apr-26 22:00 14-Apr-26 06:00 ENMAX Outage 1.80L (SS-1 - SS-28) re-string section of line for 21 sub phasing line 8 Hours
Continuous		  
14-Apr-26 07:00 17-Apr-26 13:00 ATCO, CONS Outage 7L101 (790s Poplar Hill - 944s Lowe Lake), 790s 705 (790s Poplar Hill), 944s 7L101 (944s Lowe Lake) maintenance 3.25 Days
Continuous		  
14-Apr-26 07:00 27-Apr-26 17:00 EPCOR Outage 330p 500kV Bus 2 (330p Genesee), 330p 12TC2 (330p Genesee), 330p 1209 (330p Genesee), 330p 1206 (330p Genesee), 330p 1203 (330p Genesee), 330p 1211 (330p Genesee), 330p 1215 (330p Genesee), 330p 12TC2D (330p Genesee), 330p 809 (330p Genesee) Genesee 500 kV bus 2, POW project installation 13.42 Days
Continuous		  
14-Apr-26 07:00 20-Apr-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) relay testing 6.44 Days
Continuous		  
14-Apr-26 07:00 20-Apr-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) relay testing 6.44 Days
Continuous		  
14-Apr-26 07:00 20-Apr-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) relay testing 6.44 Days
Continuous		  
14-Apr-26 07:00 14-Apr-26 18:00 ALTALINK Outage 477s 841X (477s Amoco West Pembina), 841L (477s Amoco West Pembina - 489s Petro-Canada Brazeau River) north crew will be completing P5 notifications on structures 39 & 95.
structure 39 - heavy angle O/H retie
structure 95 - arms and insulation 		11 Hours
Continuous		  
14-Apr-26 08:00 14-Apr-26 16:00 ATCO RB 9L79 (755s Cordel - 757s Battle River) annual climbing inspection 9L79/9L80 8 Hours
Continuous		  
14-Apr-26 08:00 14-Apr-26 16:00 ATCO RB 9L80 (755s Cordel - 757s Battle River) annual climbing inspection 9L79/9L80 8 Hours
Continuous		  
14-Apr-26 08:00 14-Apr-26 17:00 ALTALINK TE 158s RTU/SCADA (158s Vauxhall), AltaLink Telecom Equipment firmware & firewall upgrade on MPLS node on node at a time 9 Hours
Continuous		  
14-Apr-26 08:00 16-Apr-26 17:00 Lethbridge TE 181s Protection & Control (181s Chinook) transfer TPR (Teleprotection) circuits from existing JMUX to new SEL ICON 2.38 Days
Continuous		  
14-Apr-26 08:00 17-Apr-26 17:00 ATCO RB 7L137 (768s Rowley - 770s Three Hills) climbing inspection on 7L137 3.38 Days
Daily		  
14-Apr-26 08:00 16-Apr-26 16:00 ALTALINK TE 370s Protection & Control (370s North Lethbridge) move relay to new City of Lethbridge communication system 2.33 Days
Continuous		  
14-Apr-26 08:00 16-Apr-26 20:00 ATCO TE ATCO Telecom Equipment, 939s RTU/SCADA (939s Livock), 951s RTU/SCADA (951s Thickwood Hills) bandwidth upgrades done on site 2.5 Days
Continuous		  
14-Apr-26 08:00 14-Apr-26 18:00 ENMAX Outage 9.3TR (SS-9), 2.81L (SS-2 - SS-9), 9.83L (SS-9 - SS-43), 9.2TR (SS-9), SW84 (SS-9), SW83 (SS-9), 9B8-9.2TR (SS-9), 9MD138-9.2TR (SS-9), 43B138-9.83 (SS-43), 9B138-9.83 (SS-9), 2MD138-2.81 (SS-2), 9B138-2.81 (SS-9), 9MD138-9.3TR (SS-9) spring substation washing, reversing switch check 10 Hours
Continuous		  
14-Apr-26 09:00 14-Apr-26 10:00 ATCO TE ATCO Telecom Equipment, 718s RTU/SCADA (718s Parsons Creek) upgrade parsons 'A' SAR to V21, then V22 60 Mins
Continuous		  
14-Apr-26 09:30 16-Apr-26 16:00 ALTALINK Outage 71s 752 (71s Lamoureux) 138kV breaker maintenance 2.27 Days
Continuous		  
14-Apr-26 10:00 15-Apr-26 17:00 ATCO Outage 743s 702T (743s Sarah Lake) 743S Sarah lake rebuild. Replace 502A, 502B solid blade switches 31 Hours
Continuous		  
14-Apr-26 10:00 14-Apr-26 17:30 ATCO IO 801s Protection & Control (801s Anderson), APS# 20 Anderson 801s 240 kV Line 9L933, 9L934 and 9L950 Thermal Protection Scheme to Sheerness Plant disable RAS 20 Thermal protection scheme for 9L933, 9L934 and 9L950 7.5 Hours
Continuous		  
14-Apr-26 11:00 15-Apr-26 17:00 ATCO TE ATCO Telecom Equipment, 876s RTU/SCADA (876s Brintnell) replace rectifiers
 30 Hours
Continuous		  
14-Apr-26 13:00 16-Apr-26 15:00 ATCO Outage 6L02 (769s Stettler - 873s Marion Lake), 769s 601 (769s Stettler) climbing inspection on 6L02 2.08 Days
Continuous		  
14-Apr-26 22:00 15-Apr-26 06:00 ENMAX Outage 1.80L (SS-1 - SS-28) re-string section of line for 21 sub phasing 8 Hours
Continuous		  
15-Apr-26 07:00 29-Apr-26 17:00 EPCOR Outage 330P GT7 (330p Genesee), 330p 1215 (330p Genesee), 330p 1214 (330p Genesee) POW project installation 14.42 Days
Continuous		  
15-Apr-26 07:00 29-Apr-26 17:00 EPCOR Outage 330P GT7 (330p Genesee) POW project installation 14.42 Days
Continuous		  
15-Apr-26 07:00 16-Apr-26 17:00 EPCOR Outage 72CH9 (987s Clover Bar - EP Hardisty), 987s CH722 (987s Clover Bar), H724 (EP Hardisty) emergency valve leak repair 1.42 Days
Continuous		  
15-Apr-26 07:15 21-Apr-26 16:45 ALTALINK Outage 790L (434s Stony Plain - 790AL tap), 434s 790 (434s Stony Plain) transmission line maintenance 6.4 Days
Continuous		  
15-Apr-26 08:00 15-Apr-26 16:00 ALTALINK TE AltaLink Telecom Equipment repair 149s Nisku to 9089R Ellerslie radio 8 Hours
Continuous		  
15-Apr-26 08:00 15-Apr-26 17:00 ATCO RB 9L99 (801s Anderson - 807s Sheerness) annual climbing inspection 9L99 9 Hours
Continuous		  
15-Apr-26 08:00 15-Apr-26 17:00 ATCO RB 9L100 (801s Anderson - 807s Sheerness) annual climbing inspection 9L100 9 Hours
Continuous		  
15-Apr-26 08:00 15-Apr-26 17:00 ALTALINK TE AltaLink Telecom Equipment, 336s RTU/SCADA (336s Fincastle) firmware upgrade on MPLS nodes A and B 9 Hours
Continuous		  
15-Apr-26 08:00 17-Apr-26 16:00 ALTALINK TE 336s RTU/SCADA (336s Fincastle) split the existing SCADA VLAN from 1 to 1 and 2, change IP address of relays 2.33 Days
Continuous		  
15-Apr-26 08:00 15-Apr-26 14:00 ENMAX Outage 33.1TR (SS-33), 33.83L (SS-33 - SS-41), 33B138-33.83 (SS-33), 41B138-33.83 (SS-41) spring substation washing 6 Hours
Continuous		  
15-Apr-26 08:00 16-Apr-26 16:00 ENMAX Outage 14.3TR (SS-14) tap changer inspection - 14.3-TC, reversing switch check, oil sampling MT, TC 1.33 Days
Continuous		  
15-Apr-26 08:00 16-Apr-26 16:00 ENMAX TE Protection & Control (SS-162) relays, lockout testing 1.33 Days
Daily		  
15-Apr-26 09:00 15-Apr-26 10:00 ATCO TE ATCO Telecom Equipment, 2009s RTU/SCADA (2009s Willow Lake) Upgrade Willow Lake 'A' SAR to V21, then V22 60 Mins
Continuous		  
15-Apr-26 09:00 15-Apr-26 10:00 ALTALINK TE 336s Protection & Control (336s Fincastle) 607L B21/79/L5 URD60 relay out of service for relay setting changes 60 Mins
Continuous		  
15-Apr-26 09:00 15-Apr-26 17:30 ATCO Outage 2029s ACF12 (2029s Heathfield) Investigate and repair breaker fail 8.5 Hours
Continuous		  
15-Apr-26 09:30 15-Apr-26 17:00 ALTALINK Outage 701L (223s Strome - 395s North Holden), 395s 701X (395s North Holden) 395s701X breaker tank heater replacement 7.5 Hours
Continuous		  
15-Apr-26 10:00 15-Apr-26 11:00 ALTALINK TE 336s Protection & Control (336s Fincastle) 612L B21/79/L1 URD60 relay out of service for relay setting changes 60 Mins
Continuous		  
15-Apr-26 11:00 15-Apr-26 12:00 ALTALINK TE 336s Protection & Control (336s Fincastle) 610L B21/79/L6 URD60 relay out of service for relay setting changes 60 Mins
Continuous		  
15-Apr-26 12:00 17-Apr-26 12:00 ATCO, Athabasca Oi Outage 7L182 (2009s Willow Lake - 279s AHS) isolation for AOC to perform maintenance 2 Days
Continuous		  
15-Apr-26 12:00 15-Apr-26 13:00 ALTALINK TE 336s Protection & Control (336s Fincastle) relay setting changes 60 Mins
Continuous		  
15-Apr-26 13:00 15-Apr-26 14:00 ALTALINK TE 336s Protection & Control (336s Fincastle) take B138B1 87/138B1 URB30 relay out of service for relay setting changes 60 Mins
Continuous		  
15-Apr-26 14:00 15-Apr-26 15:00 ALTALINK TE 336s Protection & Control (336s Fincastle) take S752 11(96)/752 URC60 relay out of service for relay setting changes 60 Mins
Continuous		  
15-Apr-26 14:00 15-Apr-26 16:00 ENMAX Outage 33.84L (SS-33 - SS-43), 33B138-33.84 (SS-33), 43B138-33.84 (SS-43) spring substation washing, 33B138-33.84L bay only 2 Hours
Continuous		  
15-Apr-26 15:00 15-Apr-26 16:00 ALTALINK TE 336s Protection & Control (336s Fincastle) take S852 11(96)/852 URC60 relay out of service for relay setting changes 60 Mins
Continuous		  
16-Apr-26 08:00 06-May-26 16:00 Syncrude Outage Mildred T6 (Syncrude Mildred Lake), 635 (Syncrude Mildred Lake) SCL - repair tap changer in T6 transformer 20.33 Days
Continuous		  
16-Apr-26 08:00 16-Apr-26 17:00 ALTALINK TE 251s RTU/SCADA (251s Whitla), AltaLink Telecom Equipment firmware upgrade on MPLS, firewall upgrade and split the existing SCADA VLAN 9 Hours
Continuous		  
16-Apr-26 08:00 16-Apr-26 18:00 ENMAX Outage 32.83L (SS-32 - SS-40), 26.81L (SS-26 - SS-32), 32.2TR (SS-32), 32.1TR (SS-32), 32B138-32BT5 (SS-32), 32B138-32.83 (SS-32), 32B138-26.81 (SS-32), 32MD138-32.1TR (SS-32), 32MD138-32.2TR (SS-32) spring substation washing 10 Hours
Continuous		  
16-Apr-26 09:00 16-Apr-26 11:00 ATCO TE ATCO Telecom Equipment, 885s RTU/SCADA (885s McMillan) telecom upgrade 2 Hours
Continuous		  
16-Apr-26 09:00 16-Apr-26 17:00 ALTALINK Outage 233s 6 (233s Beamer) maintenance 8 Hours
Continuous		  
16-Apr-26 09:00 16-Apr-26 16:00 ATCO TE 707s RTU/SCADA (707s St. Paul), ATCO Telecom Equipment St Paul Telecom - maintenance, switching between A and B sides of the radio 7 Hours
Continuous		  
16-Apr-26 09:00 16-Apr-26 16:00 ALTALINK, BCH TE 520s Protection & Control (520s Bennett), 1201L (520s Bennett - BCH Cranbrook) test communication channels between 520s Bennett and Cranbrook 7 Hours
Continuous		  
16-Apr-26 11:00 18-Apr-26 16:00 ALTALINK, TRANSCANADA Outage 782L (269s Wyndham - 525s Carseland), 525s 48 (525s Carseland), 269s 501 (269s Wyndham), 269s 502 (269s Wyndham), 269s 551 (269s Wyndham), 269s 552 (269s Wyndham) prevent unintended trips 2.21 Days
Continuous		  
17-Apr-26 08:00 28-Apr-26 16:00 ENMAX Outage 3.82L (SS-3 - SS-8), 3B138-3.82 (SS-3) City of Calgary traffic light rebuild 11.33 Days
Continuous		  
17-Apr-26 08:00 17-Apr-26 16:00 ALTALINK TE 244s RTU/SCADA (244s Bowmanton) split the existing SCADA VLAN from 1 to 1 and 2
8 Hours
Continuous		  
17-Apr-26 08:00 26-Apr-26 16:00 Syncrude Outage 1834 (Syncrude Mildred Lake), 1835 (Syncrude Mildred Lake), Mildred T18 (Syncrude Mildred Lake) T18 6-year maintenance 9.33 Days
Continuous		  
17-Apr-26 08:00 17-Apr-26 18:00 ENMAX Outage 31.84L (SS-31 - SS-32), 32B138-32BT5 (SS-32), 32B138-31.84 (SS-32), 32.3TR (SS-32), 32MD138-32.3TR (SS-32) spring substation washing, reversing switch check 10 Hours
Continuous		  

Prepared On:   2026-04-14   17:01:20

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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