Alberta Electric System Operator
System Co-ordination Plan
2026-04-02 to 2026-04-10
Approved Outages

Previous Version
Download CSV

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 30-Jun-26 14:29 ALTALINK Outage 157s C1 (157s Lac La Biche) forced outage 676.03 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		  
12-Jan-26 07:00 03-Apr-26 17:00 EPCOR TE 987s Protection & Control (987s Clover Bar) protection blocking, relay maintenance 81.38 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		  
17-Feb-26 12:00 09-Apr-26 13:31 ATCO TE 882s RTU/SCADA (882s Triangle) updating RTU/station controller configuration during SCADA upgrade project 51.02 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 10-Apr-26 16:00 ALTALINK Outage 535s C1 (535s Joffre) breaker maintenance 30.09 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		  
16-Mar-26 09:00 10-Apr-26 17:00 ALTALINK Outage 773L (127s Bruderheim - 308s Albchem Beaverhill Creek), 308s 773E (308s Albchem Beaverhill Creek), 127s 773W (127s Bruderheim) CT replacement associated with 308s773E. 25.33 Days
Continuous		  
22-Mar-26 07:00 02-Apr-26 17:00 EPCOR Outage 72JW19 (EP 805s Jasper - Woodcroft), T1 (Woodcroft), W721 (Woodcroft), W722 (Woodcroft), EP 805s J724 (EP 805s Jasper), WAB1 (Woodcroft), EP 805s JDS28 (EP 805s Jasper) Woodcroft - TX1 LCR civil (pile installs) 11.42 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		  
23-Mar-26 08:00 06-Apr-26 16:00 ATCO, ALTALINK Outage 199L (347s AML Fox Creek - 741s ATC Fox Creek), 347s 199W (347s AML Fox Creek), 741s 702 (741s ATC Fox Creek) breaker replacement 14.33 Days
Continuous		  
24-Mar-26 08:00 02-Apr-26 15:00 CMH TE MHS-7 Protection & Control (MHS-7 Brier Park) PRC-005 testing - remove TPR-138-T71-B from service to complete element, functional 9.29 Days
Continuous		  
26-Mar-26 10:04 14-Apr-26 17:00 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
19.29 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 07:00 08-Apr-26 18:00 ALTALINK Outage 914L (86s Bigstone - 87s Gaetz), 87s 240kV East Bus (87s Gaetz), 87s T2 (87s Gaetz), 87s 2352 (87s Gaetz), 87s 1252 (87s Gaetz), 87s 1652 (87s Gaetz), 87s 1952 (87s Gaetz), 87s 1352 (87s Gaetz), 87s 1552 (87s Gaetz) installing new 87s1352 & 87s1552, closing open points 'E', 'J', 'K' & 'L', creating permanent bus cut between 87s27 & 87s 240kV East bus 9.46 Days
Continuous		  
30-Mar-26 07:00 03-Apr-26 17:00 EPCOR Outage RR723 (Rossdale) Rossdale RR723 breaker fail upgrade project 4.42 Days
Continuous		  
30-Mar-26 07:00 02-Apr-26 17:00 ALTALINK TE 87s RTU/SCADA (87s Gaetz) SCADA change for CETO project 3.42 Days
Continuous		  
30-Mar-26 08:00 08-Apr-26 16:00 ALTALINK TE 87s Protection & Control (87s Gaetz) relay setting and wiring changes to A87/W138B & B87/W138B 9.33 Days
Continuous		  
30-Mar-26 08:00 08-Apr-26 16:00 ALTALINK TE 87s Protection & Control (87s Gaetz) relay setting and wiring changes to A87/W240B & B87/W240B 9.33 Days
Continuous		  
30-Mar-26 08:00 08-Apr-26 16:00 ALTALINK TE 87s Protection & Control (87s Gaetz) relay setting and wiring changes to A87/E138B & B87/E138B 9.33 Days
Continuous		  
30-Mar-26 08:00 02-Apr-26 16:00 ALTALINK Outage 726L (37s North Calder - 71s Lamoureux), 37s 726E (37s North Calder) p&c upgrades (37s726E) 3.33 Days
Continuous		  
30-Mar-26 08:00 03-Apr-26 17:00 ALTALINK TE 37s RTU/SCADA (37s North Calder) RTU database updates 4.38 Days
Continuous		  
30-Mar-26 08:00 08-Apr-26 16:00 ALTALINK TE 87s Protection & Control (87s Gaetz) reconfiguration of the B DC chain fed from B8-4 9.33 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		  
30-Mar-26 09:00 09-Apr-26 17:00 Lethbridge Outage 823L (146s MacDonald - 593s Lakeview), 146s T2 (146s Macdonald), 146s 823L (146s Macdonald), 593s 823L (593s Lakeview), 146s 9 (146s Macdonald) replace switch 10.33 Days
Continuous		  
30-Mar-26 09:00 15-Apr-26 17:00 BCH RB 2L294 (BCH A. A. Lambert - BCH Cranbrook), 2L294 (BCH A. A. Lambert - BCH Nelway) ANRP for tree removal 16.33 Days
Continuous		 AB-BC
30-Mar-26 12:00 02-Apr-26 16:00 ATCO TE 898s Protection & Control (898s Heart Lake) PRC-005 relay testing, relay software vulnerability upgrades
3.17 Days
Continuous		  
30-Mar-26 13:00 02-Apr-26 16:00 ALTALINK Outage 430s 652 (430s Ursus) 430s652 CT replacement 3.13 Days
Continuous		  
30-Mar-26 13:30 03-Apr-26 18:00 ALTALINK, EPCOR RB 1045L (EP 805s Jasper - 1045AL tap) Altalink - CT replacement for 320p 1352 4.19 Days
Continuous		  
31-Mar-26 07:00 07-Apr-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) 50BF/701, 50BF/702, 50BF/703, 50BF/704 for relay testing 7.44 Days
Continuous		  
31-Mar-26 07:00 07-Apr-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) relay settings change for 51HV/701T 7.44 Days
Continuous		  
31-Mar-26 07:00 07-Apr-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) relay settings for 51MV/701T 7.44 Days
Continuous		  
31-Mar-26 08:00 03-Apr-26 16:00 ALTALINK TE 37s Protection & Control (37s North Calder) trip testing 37s726E 3.33 Days
Continuous		  
31-Mar-26 09:00 05-Apr-26 17:00 SUNCOR TE 29EDD-34 RTU/SCADA (29EDD-34) change few setting / parameter in server RTU (SEL-3350) configuration and download again 5.33 Days
Continuous		  
31-Mar-26 09:00 02-Apr-26 17:00 ATCO Outage 819s 702 (819s Whitby Lake) 702 low gas 2.33 Days
Continuous		  
31-Mar-26 10:00 07-Apr-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) 21B/7L55 for relay testing,
21B/7L172 for relay settings change
, 21B/7L67 for relay settings change
 7.31 Days
Continuous		  
31-Mar-26 10:00 07-Apr-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) 21B/7L67 for relay settings change 7.31 Days
Continuous		  
01-Apr-26 07:00 02-Apr-26 17:00 EPCOR TE 72LS24 (EP 803s Lambton - Strathcona) protection blocking, SOM module replacement 1.42 Days
Continuous		  
01-Apr-26 08:00 02-Apr-26 18:00 ALTALINK, NOVACORP, NOVAC Outage 330L1 (535s Joffre - 330s Nova Joffre), 535s 5652 (535s Joffre), 535s 5552 (535s Joffre), 330s BR-52 (330s Nova Joffre), 196s R3-BR-A (196s Nova Chemicals), 535s 96N (535s Joffre) electrical equipment maintenance, corrective work, line OPGW fiber testing and PRC-005 testing 1.42 Days
Continuous		  
01-Apr-26 08:00 02-Apr-26 16:00 ENMAX Outage 16.2TR (SS-16) tap changer inspection - 16.2-TC, reversing switch check, oil sampling MT, TC 1.33 Days
Continuous		  
01-Apr-26 09:00 02-Apr-26 17:00 ALTALINK IO 535s 5652 (535s Joffre), 535s 5552 (535s Joffre) repair hot spot on 535s96N 1.33 Days
Continuous		  
01-Apr-26 18:00 02-Apr-26 18:30 ATCO, ALTALINK IO 7L199 (347s AML Fox Creek - 741s ATC Fox Creek), 347s 199W (347s AML Fox Creek) operate A741s 702 to facilitate 1st energization of 347s199W 24.5 Hours
Continuous		  
02-Apr-26 08:00 02-Apr-26 16:00 ENMAX RB 11.82L (SS-11 - SS-14) spring transmission line washing 8 Hours
Continuous		  
02-Apr-26 08:00 02-Apr-26 16:00 ENMAX RB 14.83L (SS-14 - SS-36) spring transmission line washing 8 Hours
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		  
02-Apr-26 08:00 02-Apr-26 17:00 ALTALINK TE AltaLink Telecom Equipment firmware upgrade on MPLS node A, firewall upgrade 9 Hours
Continuous		  
02-Apr-26 08:00 02-Apr-26 16:00 ALTALINK TE 535s Protection & Control (535s Joffre) communication card change/end to end testing 8 Hours
Continuous		  
02-Apr-26 08:00 02-Apr-26 16:00 ENMAX Outage 162.4TR (SS-162) relays, lockout testing 162RLY138-162.4TR, tap changer reversing switch check 8 Hours
Continuous		  
02-Apr-26 08:00 02-Apr-26 16:00 ENMAX Outage 21.1C (SS-21), 21B138-21.CAP (SS-21) HV breaker maintenance 8 Hours
Continuous		  
03-Apr-26 08:00 03-Apr-26 16:00 ENMAX, ALTALINK Outage 36.81L (44s Bearspaw Plant - SS-36), 44s 36.81E (44s Bearspaw Plant), 36B138-36.81 (SS-36) shield wire replacement 8 Hours
Continuous		  
03-Apr-26 08:00 03-Apr-26 12:00 ENMAX Outage 15.62L (SS-15 - SS-16) spring transmission line washing 4 Hours
Continuous		  
03-Apr-26 08:00 03-Apr-26 12:00 ENMAX Outage 16.60L (SS-16 - SS-34) spring transmission line washing 4 Hours
Continuous		  
03-Apr-26 08:00 03-Apr-26 16:00 ENMAX RB 3.84L (SS-3 - SS-13) pole hold on a new development outside 3 sub 8 Hours
Continuous		  
03-Apr-26 08:00 03-Apr-26 16:00 ALTALINK TE 28s RTU/SCADA (28s West Brooks) split the existing SCADA VLAN from 1 to 1 and 2 8 Hours
Continuous		  
03-Apr-26 09:00 03-Apr-26 16:00 ALTALINK, ENMAX IO 44s 36.81E (44s Bearspaw Plant), 36.81L (44s Bearspaw Plant - SS-36) shield wire replacement 7 Hours
Continuous		  
03-Apr-26 12:00 03-Apr-26 16:00 ENMAX Outage 15.60L (SS-15 - SS-21) spring transmission line washing 4 Hours
Continuous		  
03-Apr-26 12:00 03-Apr-26 16:00 ENMAX Outage 21.61L (SS-21 - SS-34) spring transmission line washing 4 Hours
Continuous		  
04-Apr-26 08:00 04-Apr-26 18:00 ENMAX, ALTALINK Outage 1003L (74s Janet - SS-25), 25B240-D135 (SS-25), 25B240-D136 (SS-25), 25MD240-1003 (SS-25) surge arrestor power factor test - 25MD240-1003 10 Hours
Continuous		  
04-Apr-26 08:00 04-Apr-26 18:00 ENMAX, ALTALINK Outage 1003L (74s Janet - SS-25) surge arrestor power factor test - 25MD240-1003 10 Hours
Continuous		  
04-Apr-26 08:00 04-Apr-26 16:00 ALTALINK RB 936L (5s East Calgary - 102s Langdon) spring transmission line washing 8 Hours
Continuous		  
04-Apr-26 08:00 04-Apr-26 16:00 ALTALINK RB 937L (5s East Calgary - 102s Langdon) spring transmission line washing 8 Hours
Continuous		  
04-Apr-26 08:00 04-Apr-26 16:00 ALTALINK RB 936L (5s East Calgary - 102s Langdon) spring transmission line washing 8 Hours
Continuous		  
04-Apr-26 08:00 04-Apr-26 16:00 ALTALINK RB 937L (5s East Calgary - 102s Langdon) spring transmission line washing 8 Hours
Continuous		  
04-Apr-26 08:00 04-Apr-26 16:00 ENMAX TE Protection & Control (SS-2) 2 sub 86 BF-D95 protection outage -relays, lockout testing 8 Hours
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 07:00 09-Apr-26 17:00 ALTALINK TE 87s RTU/SCADA (87s Gaetz) SCADA change for CETO project 3.42 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 09-Apr-26 16:00 ALTALINK Outage 850L (525s Carseland - 678s Okotoks), 525s 850N (525s Carseland), 678s 850 (678s Okotoks) 525s CT replacement for 152 (850N) breaker 3.33 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		  
06-Apr-26 08:00 06-Apr-26 18:00 ENMAX Outage 20.82L (SS-20 - SS-21), 20B138-20.82 (SS-20), 21B138-20.82 (SS-21) switch maintenance - 20SW86, HV breaker SF6 gas sample - 20B138-20.82 10 Hours
Continuous		  
06-Apr-26 13:00 09-Apr-26 17:00 ALTALINK Outage 430s 152 (430s Ursus) replace 430s152 breaker CTs 3.17 Days
Continuous		  
07-Apr-26 07:00 09-Apr-26 17:00 EPCOR Outage 72RW3 (Rossdale - Woodcroft), W724 (Woodcroft), W725 (Woodcroft), RW727 (Rossdale) termination rebuild at the Woodcroft end 2.42 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) supervisory outages required for 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 07:00 10-Apr-26 17:00 EPCOR TE 52s RTU/SCADA (52s East Industrial) RTU/SCADA maintenance 3.42 Days
Continuous		  
07-Apr-26 07:00 10-Apr-26 17:00 EPCOR Outage T2 (Namao), N723 (Namao) oil temp gauge repair 3.42 Days
Continuous		  
07-Apr-26 07:00 07-Apr-26 17:00 EPCOR Outage T3 (Rossdale), R723 (Rossdale), R724 (Rossdale) leak repair 10 Hours
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 08:00 08-Apr-26 16:00 ENMAX TE Protection & Control (SS-21) 21PT138-Z31 secondary voltage outage - move 50L voltage source to 21PT138-Z31 1.33 Days
Daily		  
07-Apr-26 08:00 09-Apr-26 16:00 ATCO RB 7L90 (741s ATC Fox Creek - 7LA90 tap), 7L90 (813s Little Smoky - 7LA90 tap) walk up and climbing inspection 2.33 Days
Continuous		  
07-Apr-26 08:00 07-Apr-26 17:00 ALTALINK TE 194s RTU/SCADA (194s South Red Deer), 63s RTU/SCADA (63s Red Deer), AltaLink Telecom Equipment firmware and firewall upgrade 9 Hours
Continuous		  
07-Apr-26 08:00 07-Apr-26 16:00 ALTALINK Outage 831L (339s Duchess - 831AL tap), 339s T1 (339s Duchess), 339s 831 (339s Duchess) install bird mitigation on 339s18, 339s 25 kV bay, 339s10, 339s23E and associated bus 8 Hours
Continuous		  
07-Apr-26 08:00 07-Apr-26 16:00 ALTALINK Outage 535s T2 (535s Joffre) cutover CT circuit from T2 and trip for 1252 (535s4565) and operate interposing main breaker relay for 552 (535s19) to new 138B1 relay 8 Hours
Continuous		  
07-Apr-26 08:00 09-Apr-26 16:00 ALTALINK TE 852s RTU/SCADA (852s Round Hill) firewall upgrade, LAN switch replacement and raw socket 2.33 Days
Continuous		  
07-Apr-26 08:00 08-Apr-26 16:00 ENMAX TE Protection & Control (SS-162) 162 Sub 138 kV Z31 A and B (86) lockout relay and (87) bus differential protection - relays, lockout testing 86-Z31-A, 86-Z31-B 1.33 Days
Daily		  
07-Apr-26 09:00 07-Apr-26 11:00 ATCO, NextEra TE ATCO Telecom Equipment, 770s RTU/SCADA (770s Three Hills), 114s RTU/SCADA (114s Ghost Pine) Elnora_T-Telecom/GhostPine_T-Telecom- Upgrade ELNORA, GHOSTPINE, THREE HILLS, HEATBURG SAR OS' to V21, then V22.
Impact to the following traffic for up to 90 mins:7L159 A&B, RAS A #199 7L159 OL, RAS B #199 7L159 OL, OL RAS A&B - NEVIS / KNEE HILLS, #134 RAS A&B LOGIC 3 OL, KNEE HILLS RTU
2 Hours
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		  
07-Apr-26 11:00 07-Apr-26 16:00 ALTALINK TE 535s Protection & Control (535s Joffre) PRC maintenance 5 Hours
Continuous		  
07-Apr-26 11:00 08-Apr-26 17:00 ENMAX, ALTALINK TE 50L (44s Bearspaw Plant - SS-21) PT wire swap, VT module installation, as per ENMAX request 30 Hours
Continuous		  
07-Apr-26 12:00 10-Apr-26 16:00 ATCO TE 898s Protection & Control (898s Heart Lake), 898s Heart Lake RTU/SCADA PRC-005 relay testing 3.17 Days
Continuous		  
07-Apr-26 13:00 08-Apr-26 16:00 ALTALINK Outage 237s 652 (237s Foothills) PRC5 first trip and breaker maintenance, heater and anchor bolt replacement 27 Hours
Continuous		  
07-Apr-26 13:00 08-Apr-26 17:00 ATCO Outage 732s 701 (732s Mitsue) 732s 701 - low SF6 gas and ASEA IMBD CT testing 28 Hours
Continuous		  
07-Apr-26 13:30 09-Apr-26 16:00 ALTALINK Outage 71s 852 (71s Lamoureux) 71s852 breaker maintenance 2.1 Days
Continuous		  
07-Apr-26 14:00 07-Apr-26 16:00 ALTALINK Outage 149s T1 (149s Nisku) replace 149s6 and 149s7 2 Hours
Continuous		  
08-Apr-26 06:00 08-Apr-26 17:00 ATCO IO ATCO RTU/SCADA SOC2 backup control centre activation 11 Hours
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 07:00 08-Apr-26 19:00 ATCO Outage 7L110 (774s Monitor - 903s Loyalist), 903s 701T (903s Loyalist), 903s 701 (903s Loyalist), 774s 706 (774s Monitor) maintenance 12 Hours
Continuous		  
08-Apr-26 07:30 09-Apr-26 17:30 ATCO, ALTALINK RB 9L912 (63s Red Deer - 766s Nevis) Altalink work on 9L912 1.42 Days
Continuous		  
08-Apr-26 08:00 08-Apr-26 17:00 ALTALINK TE 247s RTU/SCADA (247s Piper Creek), AltaLink Telecom Equipment LAN switch work 9 Hours
Continuous		  
08-Apr-26 08:00 08-Apr-26 16:00 ALTALINK TE 254s Protection & Control (254s Coaldale) PRC maintenance 8 Hours
Continuous		  
08-Apr-26 08:00 08-Apr-26 16:00 ALTALINK Outage 535s T4 (535s Joffre) cutover CT circuit from T4, operate interposing main breaker relay for 535s44 (1052) breaker to new 138B1 relay 8 Hours
Continuous		  
08-Apr-26 08:00 09-Apr-26 16:00 ATCO RB 7L63 (780s Lubicon - 812s Norcen), 7L63 (788s Hotchkiss - 7LA63 tap) cross arm replacement 1.33 Days
Continuous		  
08-Apr-26 08:00 09-Apr-26 17:00 ALTALINK RB 756L (87s Gaetz - 535s Joffre) installing marker cones on 986L/962L 1.38 Days
Continuous		  
08-Apr-26 08:00 09-Apr-26 17:00 ALTALINK RB 759L (87s Gaetz - 276s Prentiss) installing marker cones on future 986L/962L 1.38 Days
Continuous		  
08-Apr-26 08:00 09-Apr-26 17:00 ALTALINK RB 775L (276s Prentiss - 535s Joffre) installing marker cones on future 986L/962L 1.38 Days
Continuous		  
08-Apr-26 08:00 09-Apr-26 17:00 ALTALINK RB 784AL (482s Haynes - 784L tap), 784L (332s Ellis - 784AL tap), 784L (535s Joffre - 784AL tap) installing marker cones on future 986L/962L 1.38 Days
Continuous		  
08-Apr-26 08:00 09-Apr-26 17:00 ALTALINK RB 793L (87s Gaetz - 535s Joffre) installing marker cones on future 986L/962L 1.38 Days
Continuous		  
08-Apr-26 08:00 09-Apr-26 17:00 ATCO, ALTALINK RB 912L (63s Red Deer - 766s Nevis) install marker cones on future 986L/962L 1.38 Days
Continuous		  
08-Apr-26 08:30 08-Apr-26 12:30 ALTALINK RB 760L (163s Amoco Empress - 760AL tap) ATCO telecom maintenance outage to prevent out of synch reclosing 4 Hours
Continuous		  
08-Apr-26 09:00 08-Apr-26 11:00 ATCO TE ATCO Telecom Equipment, 840s RTU/SCADA (840s McNeill Station) upgrading SAR 2 Hours
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		  
08-Apr-26 09:00 09-Apr-26 16:00 ALTALINK Outage 74s C1 (74s Janet), 74s C2 (74s Janet) maintenance on 74s54 and 74s56 31 Hours
Continuous		  
08-Apr-26 09:00 08-Apr-26 11:00 ATCO RB 7L760 (767s Oyen - 7LC760 tap), 7L760 (7LA760 tap - 7LC760 tap) prevent line out-of-sync closing during telecom work 1-00515218 2 Hours
Continuous		  
08-Apr-26 09:00 08-Apr-26 16:00 ATCO TE 2009s Protection & Control (2009s Willow Lake) PRC-005 relay testing on 21A/ 7L182, 21B/ 7L182 7 Hours
Continuous		  
08-Apr-26 10:00 08-Apr-26 14:00 SUNCOR TE 29EDD-65 Protection & Control (29EDD-65) replace T60 faceplate 4 Hours
Continuous		  
08-Apr-26 11:00 08-Apr-26 12:00 ATCO TE ATCO Telecom Equipment, 767s RTU/SCADA (767s Oyen) Oyen_S-Telecom- UPGRADING THE 'A' SAR OS TO V21 THEN V22. IMPACT TO THE FOLLOWING TRAFFIC FOR UP TO 1 HOUR: 7L760 A&B, 7L760 / 7LA760 DDT, RAS 204 A&B 60 Mins
Continuous		  
08-Apr-26 11:00 08-Apr-26 12:00 ATCO RB 7L760 (767s Oyen - 7LC760 tap), 7L760 (7LA760 tap - 7LC760 tap) 7L760 A reclose is required to be off for the duration of the Oyen_S-Telecom outage 2-105710 (AESO 1-00515462) 60 Mins
Continuous		  
09-Apr-26 08:00 09-Apr-26 12:00 ENMAX Outage 2.80L (SS-2 - SS-23), 23.3TR (SS-23), 23B138-2.80 (SS-23), 2MD138-2.80 (SS-2), 23MD138-23.3TR (SS-23), SW83 (SS-23) spring substation washing 4 Hours
Continuous		  
09-Apr-26 08:00 09-Apr-26 17:00 ALTALINK TE 284s RTU/SCADA (284s Nose Creek) firewall will be out of service while the unit is changed out 9 Hours
Continuous		  
09-Apr-26 08:00 09-Apr-26 16:00 ALTALINK TE 74s Protection & Control (74s Janet) protection outage to retest S2252 96/2252, S2552 96/2552 , S352 96/352 8 Hours
Continuous		  
09-Apr-26 08:00 10-Apr-26 16:00 ALTALINK Outage 535s T6 (535s Joffre), 535s 110 (535s Joffre), 535s 111 (535s Joffre) cutover T6 CT and 535s110 trip/breaker fail to new 138B1 relay, 25 kV relay maintenance 1.33 Days
Continuous		  
09-Apr-26 08:00 09-Apr-26 16:00 ALTALINK TE 284s RTU/SCADA (284s Nose Creek) split the existing SCADA VLAN from 1 to 1 and 2 8 Hours
Continuous		  
09-Apr-26 08:00 09-Apr-26 16:00 ENMAX Outage 3.4TR (SS-3) 3 sub - switchgear cleaning - 3.4TR secondary cable compartment 8 Hours
Continuous		  
09-Apr-26 08:30 09-Apr-26 16:00 ALTALINK Outage 63s 752 (63s Red Deer) CT testing - doble, IDAX, DGA 7.5 Hours
Continuous		  
09-Apr-26 08:30 09-Apr-26 16:00 ALTALINK, DOW TE 166s RTU/SCADA (166s Dow Chemical Fort Saskatchewan) RTU database troubleshooting 7.5 Hours
Continuous		  
09-Apr-26 09:00 09-Apr-26 11:00 ATCO TE ATCO Telecom Equipment, 879s Scotford Upgrader RTU/SCADA, 798s RTU/SCADA (798s Bridge Creek), 791s RTU/SCADA (791s Rainbow Lake), 808s RTU/SCADA (808s Procter & Gamble) Vegreville Telecom - upgrading the SARs (0.10 & 0.11) at Veg SOC to V21, then v22 2 Hours
Continuous		  
09-Apr-26 09:00 09-Apr-26 12:00 ALTALINK Outage 237s 552 (237s Foothills) PRC5 minor maintenance, first trip 3 Hours
Continuous		  
09-Apr-26 09:00 09-Apr-26 11:00 ATCO RB 7L65 (709s Vegreville - 7LA65 tap), 7L65 (710s Vermilion - 7LA65 tap) turn reclosing off on 7L65 for telecom work 1-00515333 2 Hours
Continuous		  
09-Apr-26 09:00 09-Apr-26 16:00 ALTALINK TE 5s Protection & Control (5s East Calgary) settings change to resolve 240-B1 bus A alarm 7 Hours
Continuous		  
09-Apr-26 09:00 09-Apr-26 16:00 ALTALINK Outage 430s 152 (430s Ursus), 430s 352 (430s Ursus), 71s 1452 (71s Lamoureux), 71s 1352 (71s Lamoureux), 997L (71s Lamoureux - 430s Ursus) tekron clock antenna replacement
7 Hours
Continuous		  
09-Apr-26 09:30 09-Apr-26 16:00 ALTALINK Outage 71s C2 (71s Lamoureux) 71s1052 breaker maintenance 6.5 Hours
Continuous		  
09-Apr-26 12:00 09-Apr-26 18:00 ALTALINK IO 74s 23.80W (74s Janet) spring substation washing
6 Hours
Continuous		  
09-Apr-26 12:00 09-Apr-26 16:00 Lethbridge Outage 593s 824L (593s Lakeview) allow energization of new PTs 4 Hours
Continuous		  
09-Apr-26 12:00 09-Apr-26 16:00 ALTALINK, Lethbridge IO 824L (593s Lakeview - 618s Riverbend) 824L OPEN END OUTAGE AT 593S TO ALLOW THE ENERGIZATION OF THE NEWLY INSTALLED 593S BUSS PT USING 593S824L BREAKER 4 Hours
Continuous		  
09-Apr-26 12:01 09-Apr-26 18:00 ENMAX, ALTALINK Outage 23.80L (74s Janet - SS-23), 23.4TR (SS-23), 23B138-23.80 (SS-23), 23MD138-23.4TR (SS-23), SW84 (SS-23) spring substation washing 5.98 Hours
Continuous		  
09-Apr-26 13:00 09-Apr-26 16:00 ALTALINK TE 67s Protection & Control (67s Stirling) PRC maintenance on 820L protection 3 Hours
Continuous		  
09-Apr-26 17:00 13-May-26 07:00 EPCOR Outage 72RW3 (Rossdale - Woodcroft), RW727 (Rossdale) RW3 - termination rebuild (Woodcroft end) 33.58 Days
Continuous		  
10-Apr-26 07:00 24-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 14.42 Days
Continuous		  
10-Apr-26 08:00 10-Apr-26 16:00 ENMAX Outage 162B138-RB81 (SS-162) CT terminal block replacement 8 Hours
Continuous		  
10-Apr-26 08:00 10-Apr-26 17:00 ALTALINK TE AltaLink Telecom Equipment, 64s RTU/SCADA (64s East Crossfield) firmware upgrade on MPLS Nodes A and B, firewall upgrade, one node at a time
9 Hours
Continuous		  
10-Apr-26 10:00 10-Apr-26 12:00 ATCO Outage 7L137 (768s Rowley - 770s Three Hills), 768s 703 (768s Rowley), 770s 702 (770s Three Hills) PRC-005 - trip coil testing 2 Hours
Continuous		  
10-Apr-26 13:00 10-Apr-26 16:00 ATCO Outage 7L25 (768s Rowley - 802s Michichi Creek), 802s 707 (802s Michichi Creek), 768s 7L25D2 (768s Rowley) PRC-005 - trip coil testing 3 Hours
Continuous		  

Prepared On:   2026-04-01   14:40:32

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