Alberta Electric System Operator
System Co-ordination Plan
2026-03-12 to 2026-03-20
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 30-Jun-26 14:29 ALTALINK Outage 157s C1 (157s Lac La Biche) forced outage 676.03 Days
Continuous		  
20-Mar-25 08:00 20-Mar-26 17:00 ALTALINK Outage 256s C1 (256s Harmattan) forced outage 365.38 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		  
14-May-25 08:00 13-Mar-26 16:00 ENMAX TE Protection & Control (SS-32) 32sub 138kV autoswitching protection outage 303.33 Days
Continuous		  
22-Jul-25 08:30 31-Mar-26 16:30 ALTALINK Outage 263s C1 (263s Strachan) forced outage 252.33 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		  
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) urgent repairs on 29PT-224 at 29EDD34 on 29PP-45 bus 241.29 Days
Continuous		  
05-Jan-26 08:00 22-Mar-26 16:00 ENMAX Outage 1.80L (SS-1 - SS-28), 28B138-1.80 (SS-28) 1 sub transmission line cut over 76.29 Days
Continuous		  
05-Jan-26 08:00 22-Mar-26 16:00 ENMAX Outage 1.81L (SS-1 - SS-20), 20B138-1.81 (SS-20) 1 sub transmission line cut over 76.29 Days
Continuous		  
08-Jan-26 15:00 27-Mar-26 17:00 ALTALINK Outage 42s C2 (42s Sarcee) forced outage 78.04 Days
Daily		  
12-Jan-26 07:00 03-Apr-26 17:00 EPCOR TE 330p Protection & Control (330p Genesee) protect blocking, annual relay maintenance and password changes 81.38 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 27-Mar-26 17:00 BHE Canada Outage 120s C2 (120s Picture Butte) forced outage 69.21 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		  
06-Feb-26 07:00 15-Mar-26 17:30 ALTALINK RB 793L (87s Gaetz - 535s Joffre) crews will be setting structures on 986L/962L STR’s 41-56 & 24-41 and will require a Reclosure Block on
793L		 37.4 Days
Daily		  
08-Feb-26 07:00 06-Apr-26 18:00 ALTALINK Outage 799L (235s Entwistle - 443s South Mayerthorpe), 235s 799N (235s Entwistle) 799L rebuild between Str 721B-758 (Section B) 57.42 Days
Continuous		  
09-Feb-26 08:00 13-Mar-26 16:00 ENMAX TE Protection & Control (SS-32) 32sub zone 31 and zone 32 bus differential protection outage 32.29 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		  
17-Feb-26 13:00 12-Mar-26 13:00 ATCO TE 733s Protection & Control (733s Simonette), 733s RTU/SCADA (733s Simonette) tying in RAS circuits to relays, updating RTU 22.96 Days
Continuous		  
17-Feb-26 17:30 12-Mar-26 17:30 ALTALINK RB 202L (178s Cynthia - 202AL tap), 202L (61s Lodgepole - 202AL tap) safety requirement; create/close 202L open point 'B' 22.96 Days
Continuous		  
23-Feb-26 07:00 23-Mar-26 07:00 EPCOR Outage 805s T3 (805s Jasper) bushing change 27.96 Days
Continuous		  
25-Feb-26 14:00 12-Mar-26 14:00 ALTALINK Outage 202L (178s Cynthia - 202AL tap), 178s 202X (178s Cynthia) installing a new deadend and air break (202L336B) 14.96 Days
Continuous		  
02-Mar-26 07:00 12-Mar-26 16:00 ALTALINK TE 275s RTU/SCADA (275s Jenner) update RTU to modify alarms for 944L line protection 10.33 Days
Continuous		  
02-Mar-26 07:00 12-Mar-26 16:00 ALTALINK TE 132s RTU/SCADA (132s Ware Junction) visibility outage 10.33 Days
Continuous		  
02-Mar-26 08:00 13-Mar-26 16:00 ENMAX Outage 32B138-32BT5 (SS-32) 32BT5 p&c cut over 11.29 Days
Continuous		  
02-Mar-26 08:00 19-Mar-26 16:00 ATCO Outage 7L48 (794s Valleyview - 7LA48 tap), 794s 703 (794s Valleyview) pole and cross arm replacement 17.29 Days
Continuous		  
02-Mar-26 08:00 14-Mar-26 16:00 ENMAX Outage 8.5TR (SS-8) 8.5TR - repair leak, tap changer inspection & reversing switch check 12.29 Days
Continuous		  
02-Mar-26 09:00 16-Mar-26 12:00 ATCO Outage 882s 701T (882s Triangle), 882s 701 (882s Triangle) cutover and commission new transformer protection and SCADA station controller
 14.08 Days
Continuous		  
02-Mar-26 09:00 12-Mar-26 17:00 Lethbridge Outage 813L (146s MacDonald - 241s Uplands), 146s 813L (146s Macdonald), 146s 1 (146s Macdonald), 241s 813L (241s Uplands) replacing 146s1 disconnect switch and 146s PTL1-CVT 10.29 Days
Continuous		  
02-Mar-26 09:00 16-Mar-26 12:00 ATCO TE 882s Protection & Control (882s Triangle) demo existing protection and install/commission new protection on 701T 14.08 Days
Continuous		  
06-Mar-26 17:00 13-Nov-26 17:00 EPCOR Outage T1 (Woodcroft) woodcroft: TX1 LCR civil 252 Days
Continuous		  
08-Mar-26 08:00 12-Mar-26 17:00 EPCOR Outage T3 (Rossdale), R723 (Rossdale), R724 (Rossdale) duct bank removal and leak repair 4.38 Days
Continuous		  
08-Mar-26 08:30 24-Mar-26 16:00 ENMAX Outage 38.83L (SS-38 - SS-39), 39.3TR (SS-39), 39.1TR (SS-39), 38B138-38.83 (SS-38), 39B138-38.83 (SS-39), 39MD138-39.1TR (SS-39), 39MD138-39.3TR (SS-39) HV SW replacement 16.31 Days
Continuous		  
09-Mar-26 07:00 13-Mar-26 17:00 EPCOR Outage 987s GT3 (987s Clover Bar), 987s CGB3 (987s Clover Bar) repair GDS3 4.42 Days
Continuous		  
09-Mar-26 07:00 12-Mar-26 17:00 ALTALINK TE 87s RTU/SCADA (87s Gaetz) change SCADA for CETO project 3.42 Days
Continuous		  
09-Mar-26 07:00 27-Mar-26 17:00 EPCOR TE 816s Protection & Control (816s Petrolia) relay maintenance 18.42 Days
Continuous		  
09-Mar-26 08:00 13-Mar-26 17:00 ALTALINK RB 514BL (322s Cowley Ridge Windplant - 514L tap), 514L (396s Pincher Creek - 514BL tap), 514L (513s Lundbreck - 514BL tap) south crew will be doing line maintenance on 514L from STR 48-453 4.38 Days
Continuous		  
09-Mar-26 08:00 12-Mar-26 16:00 ALTALINK TE 108s RTU/SCADA (108s Amelia) update RTU configuration for BMI project 3.33 Days
Continuous		  
09-Mar-26 08:00 13-Mar-26 17:00 ALTALINK Outage 749L (899s Edgerton - 749AL tap) 749L Line maintenance 4.38 Days
Continuous		  
09-Mar-26 08:00 12-Mar-26 16:00 ALTALINK TE AltaLink Telecom Equipment, 233s RTU/SCADA (233s Beamer) upgrade MPLS and firewall 3.33 Days
Continuous		  
09-Mar-26 08:00 12-Mar-26 16:00 ALTALINK TE 324s RTU/SCADA (324s Cassils) 2026 firewall program - 1 firewall 3.33 Days
Continuous		  
09-Mar-26 08:00 13-Mar-26 17:00 ALTALINK Outage 712L (99s North St. Albert - 595s Spruce Grove), 595s 712 (595s Spruce Grove), 99s 712X (99s North St. Albert) component replacement on 712L (STR 81 - 166) 4.38 Days
Continuous		  
09-Mar-26 09:00 13-Mar-26 17:00 ALTALINK Outage 776L (308s Albchem Beaverhill Creek - 410s Josephburg), 308s 776W (308s Albchem Beaverhill Creek) replace CT associated with 308s776W breaker 4.33 Days
Continuous		  
10-Mar-26 08:00 12-Mar-26 16:00 ALTALINK TE 504s RTU/SCADA (504s Queenstown), AltaLink Telecom Equipment 202 firewall program - 1 firewall, 1 LAN switch, 2 mpls node 2.33 Days
Continuous		  
10-Mar-26 08:00 12-Mar-26 16:00 ALTALINK TE 419s Protection & Control (419s Chestermere) PRC maintenance on redundant protection: 765L A21/L2 SEL311C, 765L B21/L2 URD60, non- redundant recloser S252 96/79/252 URC60 no more than 6 hrs. 2.33 Days
Continuous		  
10-Mar-26 09:00 14-Apr-26 17:00 ATCO Outage 972s 240kV Bus 900BS2 (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		  
10-Mar-26 14:42 20-Mar-26 17:00 ALTALINK Outage 897L (38s East Edmonton - 45s Bretona), 38s 897 (38s East Edmonton) forced outage due to leaking CT 10.1 Days
Continuous		  
11-Mar-26 07:00 13-Mar-26 17:00 EPCOR Outage 816s T2 (816s Petrolia), 816s P2404 (816s Petrolia), 816s P2405 (816s Petrolia), 816s PAB2 (816s Petrolia) Petrolia T2 relay maintenance 2.42 Days
Continuous		  
11-Mar-26 08:00 16-Mar-26 18:00 ATCO Outage 7L36 (820s Hangingstone - 2009s Willow Lake), 820s 701 (820s Hangingstone) 7L36 pole change 5.42 Days
Continuous		  
11-Mar-26 08:00 18-Mar-26 16:00 ATCO, USPCE RB 7L15 (841s Long Lake - 856s Kinosis) pole changes 7.33 Days
Continuous		  
11-Mar-26 08:00 16-Mar-26 17:00 ALTALINK Outage 728L (353s Plamondon - 405s Waupisoo), 405s 728 (405s Waupisoo), 353s 452 (353s Plamondon) 728L line maintenance. 5.38 Days
Continuous		  
11-Mar-26 08:00 16-Mar-26 15:00 ATCO RB 9L23 (848s Ruth Lake - 977s Salt Creek) work underneath on 7L36 (L-G Mitigation Spans 7L36-38) 5.29 Days
Continuous		  
12-Mar-26 08:00 13-Mar-26 18:00 ENMAX, ALTALINK Outage 7.82L (42s Sarcee - SS-7), 42s 7 (42s Sarcee), 7B138-7.82 (SS-7) replace connection point on shield wire weld tabs on structure 1.42 Days
Continuous		  
12-Mar-26 08:00 13-Mar-26 17:00 ALTALINK RB 174L (197s Bardo - 289s Saunders Lake) line maintenance on 858L (adjacent to 174L)
1.38 Days
Continuous		  
12-Mar-26 08:00 12-Mar-26 16:00 ALTALINK TE 237s Protection & Control (237s Foothills) PRC maintenance on 237s 240kV bus 1 8 Hours
Continuous		  
12-Mar-26 08:00 12-Mar-26 16:00 ALTALINK TE 138s RTU/SCADA (138s Windy Flats) updating RTU config to meet standards 8 Hours
Daily		  
12-Mar-26 08:00 12-Mar-26 16:00 ALTALINK TE 62s Protection & Control (62s Brazeau Plant) standard relay maintenance
8 Hours
Continuous		  
12-Mar-26 08:00 12-Mar-26 16:00 ENMAX TE Protection & Control (SS-2) SS-2 86 BF-D82 protection outage - relay lockout testing 8 Hours
Continuous		  
12-Mar-26 08:00 12-Mar-26 16:00 ENMAX, ALTALINK TE 36.81L (44s Bearspaw Plant - SS-36) 36.81L A protection outage - I&R SS-36 36.81L GE L90 internal battery fail 8 Hours
Continuous		  
12-Mar-26 08:30 12-Mar-26 16:30 ALTALINK TE 993s Protection & Control (993s Abee) DSP card rplacement and FW updates - CRU 8 Hours
Continuous		  
12-Mar-26 08:30 13-Mar-26 18:00 ALTALINK, ENMAX IO 42s 7 (42s Sarcee), 7.82L (42s Sarcee - SS-7) replace connection point on shield wire weld tabs on structure 1.4 Days
Continuous		  
12-Mar-26 09:30 12-Mar-26 16:00 ALTALINK Outage 310p 552 (310p Sundance) 240kV breaker maintenance 6.5 Hours
Continuous		  
12-Mar-26 10:00 12-Mar-26 16:00 ATCO TE 825s Whitefish Lake RTU/SCADA 825S CIP password changes 6 Hours
Continuous		  
12-Mar-26 11:00 12-Mar-26 16:00 ALTALINK IO 102s SVC (102s Langdon) urgent: run compliance scans on the newly installed computers since they have been accepted.


5 Hours
Continuous		  
12-Mar-26 12:00 12-Mar-26 17:00 ALTALINK TE 120s RTU/SCADA (120s Picture Butte) RTU outage 5 Hours
Continuous		  
12-Mar-26 14:00 12-Mar-26 17:00 ALTALINK Outage 202L (178s Cynthia - 202AL tap), 178s 202X (178s Cynthia) close 202L open point 'B' 3 Hours
Daily		  
13-Mar-26 07:00 13-Mar-26 17:00 EPCOR Outage 72RG1 (Garneau - Rossdale), RG7210 (Rossdale) (SF6) breaker maintenance 10 Hours
Continuous		  
13-Mar-26 07:00 13-Mar-26 17:00 EPCOR Outage 240BA3 (629s Argyll Transfer Station - 814s Bellamy), 814s B2406 (814s Bellamy), 814s B2407 (814s Bellamy) 240BA3: emergency BDS20 SF6 Gas Top Up 10 Hours
Continuous		  
14-Mar-26 07:00 14-Mar-26 17:00 EPCOR TE 816s RTU/SCADA (816s Petrolia) substation firewall replacement 10 Hours
Continuous		  
14-Mar-26 07:00 29-Mar-26 17:00 EPCOR Outage 330p 500kV Bus 1 (330p Genesee), 330P 12TC1 (330p Genesee), 330p 1207 (330p Genesee), 330p 1204 (330p Genesee), 330p 1201 (330p Genesee), 330p 1210 (330p Genesee), 330p 1214 (330p Genesee), 330p 12TC1D (330p Genesee), 330p 805 (330p Genesee) POW project installation 15.42 Days
Continuous		  
14-Mar-26 08:00 14-Mar-26 16:00 ENMAX TE Protection & Control (SS-2) relays and lockout testing 8 Hours
Continuous		  
15-Mar-26 07:00 01-Apr-26 17:00 EPCOR Outage 330p 1211 (330p Genesee), 330p 1210 (330p Genesee) POW project installation 17.42 Days
Continuous		  
15-Mar-26 07:00 01-Apr-26 17:00 EPCOR Outage 330P GT6 (330p Genesee) maintenance and POW project installation 17.42 Days
Continuous		  
16-Mar-26 07:00 16-Mar-26 17:00 EPCOR Outage 816s P2403 (816s Petrolia) Petrolia: P2403 Relay Maintenance 10 Hours
Continuous		  
16-Mar-26 07:00 19-Mar-26 17:00 ALTALINK, EPCOR Outage 1058L (657s Summerside - EP 803s Lambton), EP 803s L2403 (EP 803s Lambton), EP 803s L2404 (EP 803s Lambton), 657s SU2403 (657s Summerside), 657s SU2404 (657s Summerside) 1058L: Lambton Surge Counter Install and Summerside SUDS10 Ice Shield Repair 3.42 Days
Continuous		  
16-Mar-26 07:00 20-Mar-26 17:00 EPCOR Outage T2 (Poundmaker) TX2 bladder and sample pipe repair 4.42 Days
Continuous		  
16-Mar-26 07:00 01-Apr-26 17:00 EPCOR Outage 987s GT1 (987s Clover Bar), 987s CGB1 (987s Clover Bar) maintenance 16.42 Days
Continuous		  
16-Mar-26 07:00 20-Mar-26 17:00 EPCOR Outage 665s T2 (665s Dome) Dome: TX2, neutral bar move for building expansion (UGT) 4.42 Days
Continuous		  
16-Mar-26 07:00 19-Mar-26 17:00 ALTALINK TE 87s RTU/SCADA (87s Gaetz) SCADA change for CETO project 3.42 Days
Daily		  
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 08:00 19-Mar-26 17:00 ALTALINK RB 514BL (322s Cowley Ridge Windplant - 514L tap), 514L (396s Pincher Creek - 514BL tap), 514L (513s Lundbreck - 514BL tap) south crew will be doing line maintenance on 514L from STR 48-453 3.38 Days
Continuous		  
16-Mar-26 08:00 25-Mar-26 17:00 ALTALINK Outage 87s 2352 (87s Gaetz), 87s 1652 (87s Gaetz), 87s T1 (87s Gaetz), 87s 240kV West Bus (87s Gaetz), 914L (63s Red Deer - 87s Gaetz) installing new 87s1752 & 87s1952 9.38 Days
Continuous		  
16-Mar-26 08:00 25-Mar-26 16:00 ALTALINK TE 87s Protection & Control (87s Gaetz) relay setting and wiring changes to A87/W138B & B87/W138B 9.33 Days
Continuous		  
16-Mar-26 08:00 20-Mar-26 15:00 CMH Outage MHS-3 MH69-308 (MHS-3 Southridge), MHS-5 MH69-502 (MHS-5 NE Crescent Heights) Replacing broken transmission pole 65866.
Inspection and Preventative maintenance. 		4.29 Days
Continuous		  
16-Mar-26 08:00 19-Mar-26 16:00 ENMAX Outage 162.2TR (SS-162) investigate tap changer oil leak. oil sampling, relay fault pressure test, reversing switch check. transformer and gas monitor maintenance 3.33 Days
Continuous		  
16-Mar-26 08:00 19-Mar-26 16:00 ALTALINK TE AML 793s RTU/SCADA (AML 793s Horse Creek), AltaLink Telecom Equipment firewall program - 1 firewall, 1 lan switch, 2 mpls nodes, 1 mpls raw socket 3.33 Days
Continuous		  
16-Mar-26 08:00 19-Mar-26 16:00 ALTALINK TE 478s RTU/SCADA (478s Tucuman) upgrade firewall and LAN switch 3.33 Days
Continuous		  
16-Mar-26 08:00 16-Mar-26 10:00 ALTALINK TE 256s Protection & Control (256s Harmattan) temp relay settings changes for 717L project 2 Hours
Continuous		  
16-Mar-26 08:00 17-Mar-26 17:00 ALTALINK Outage 305s 677 (305s Acheson), 595s 677 (595s Spruce Grove), 677L (305s Acheson - 595s Spruce Grove) pole and foundation work between existing structures 677L57 & 677L58
1.38 Days
Continuous		  
16-Mar-26 08:00 17-Mar-26 16:00 ENMAX TE Protection & Control (SS-36) 36 sub auto switching protection outage, relay protection test 1.33 Days
Continuous		  
16-Mar-26 08:00 20-Mar-26 16:00 ENMAX TE Protection & Control (SS-162) 162 sub 86-Z44A, 86-Z44B lockout relay, 87-Z44A, 87-Z44B differential protection outage. relay protection test 4.33 Days
Daily		  
16-Mar-26 08:00 19-Mar-26 16:00 ENMAX TE Protection & Control (SS-162) 162.2TR 86-T2A, 86-T2B lockout relay outage. relay protection test - 162RLY138/240 - 86 Lockouts. 3.33 Days
Continuous		  
16-Mar-26 08:00 17-Mar-26 17:00 ALTALINK RB 747L (37s North Calder - 711L tap), 747L (99s North St. Albert - 711L tap) install screw pile cluster foundation for new structure 747L69 1.38 Days
Continuous		  
16-Mar-26 08:00 20-Mar-26 17:30 ATCO TE 2075s Protection & Control (2075s Newell) PRC-005 relay testing on AC filter 1 protection & AC filter 1 connection protection 4.4 Days
Continuous		  
16-Mar-26 08:00 20-Mar-26 16:00 ENMAX Outage 9.83L (SS-9 - SS-43) 9B138-9.83 CT Junction Box replacement. Power Factor Test - 9B138-9.83-CT. Capacitor Bank Maintenance - 9B138-9.83CAP. Oil Sampling, Sheath testing, O-ring replacement 4.33 Days
Continuous		  
16-Mar-26 08:00 19-Mar-26 16:00 ENMAX Outage 47B138-771/1 (SS-47) investigate the leak and possible repair 3.33 Days
Continuous		  
16-Mar-26 08:00 16-Mar-26 16:00 ALTALINK TE 289s RTU/SCADA (289s Saunders Lake) SCADA VLAN split 8 Hours
Continuous		  
16-Mar-26 09:00 19-Mar-26 16:00 ATCO, ALTALINK IO 788L (898s Heart Lake - 788AL tap) component replacement on 788L (STR 157 - 218) 3.29 Days
Continuous		  
16-Mar-26 09:00 20-Mar-26 17:00 BCH Outage 5L92 (BCH Cranbrook - BCH Selkirk) replace end of life spacers 4.33 Days
Continuous		 AB-BC
16-Mar-26 09:00 16-Mar-26 13:00 ALTALINK Outage 763L (28s West Brooks - 763AL tap), 28s 47 (28s West Brooks), 28s 31 (28s West Brooks), 28s 763X (28s West Brooks) crew will be doing general maintenance 4 Hours
Continuous		  
16-Mar-26 09:00 20-Mar-26 17:00 ALTALINK Outage 308s 773E (308s Albchem Beaverhill Creek), 773L (127s Bruderheim - 308s Albchem Beaverhill Creek) CT Replacement w/ RMH CTs associated w/ 308s773E. 4.33 Days
Continuous		  
16-Mar-26 09:00 19-Mar-26 16:00 ATCO, ALTALINK Outage 788L (898s Heart Lake - 788AL tap) component replacement on 788L (STR 157 - 218) 3.29 Days
Continuous		  
16-Mar-26 09:00 18-Mar-26 17:00 ATCO TE 845s Protection & Control (845s Big Mountain) change relay settings on 7L33 2.33 Days
Continuous		  
16-Mar-26 09:00 18-Mar-26 17:00 ATCO TE 749s Flyingshot Lake Protection & Control change relay settings on 7L33 2.33 Days
Continuous		  
16-Mar-26 09:00 20-Mar-26 17:00 ALTALINK, BCH, AESO Outage 1201L (520s Bennett - BCH Cranbrook), Path 1 (AIES Islanding), 786L (799s Coleman - BCH Natal), 887L (48s Pocaterra - 978s BCH Britt Creek) 5L92 reliability concern mitigation 4.33 Days
Continuous		 AB-BC
16-Mar-26 09:00 20-Mar-26 17:00 BHE Canada Outage MATL (120s Picture Butte - Montana) align with 1201L outage (mitigation for 5L92) 4.33 Days
Continuous		 AB-MATL
16-Mar-26 09:00 20-Mar-26 17:00 ALTALINK, BCH Outage 1201L (520s Bennett - BCH Cranbrook) BC hydro to replace the end of life spacers on 5L92.
1201L to be open due to reliability concerns as per AESO request.		 4.33 Days
Continuous		  
16-Mar-26 09:00 20-Mar-26 17:00 ALTALINK, BCH IO 48s 887X (48s Pocaterra), 887L (48s Pocaterra - 978s BCH Britt Creek) BC hydro to replace the end of life spacers on 5L92 4.33 Days
Continuous		  
16-Mar-26 09:00 20-Mar-26 17:00 ALTALINK, BCH IO 786L (799s Coleman - BCH Natal), 799s 786W (799s Coleman) BC hydro to replace the end of life spacers on 5L92 4.33 Days
Continuous		  
16-Mar-26 10:00 26-Mar-26 16:00 ALTALINK, Lethbridge Outage 618s 824 (618s Riverbend), 824L (593s Lakeview - 618s Riverbend) City Of Lethbridge outage, Outage required to replace 593s1-Disconnect Switch and 593sPTL1-CVT. 10.25 Days
Continuous		  
16-Mar-26 10:00 20-Mar-26 17:30 ATCO TE 768s Protection & Control (768s Rowley) PRC-005 relay testing 4.31 Days
Continuous		  
16-Mar-26 10:00 16-Mar-26 16:00 ALTALINK TE 378s Protection & Control (378s Shell Caroline) temp settings changes to support 717L outage
6 Hours
Continuous		  
16-Mar-26 10:00 16-Mar-26 16:00 ALTALINK TE 575s Protection & Control (575s Sundre) temporary settings changes for 717L outage

6 Hours
Continuous		  
16-Mar-26 10:00 20-Mar-26 14:00 ATCO RB 7L08 (830s Carmon - 834s Wesley Creek) maintenance program, 32 pole changes, 21 crossarm changes, other structure deficiencies 4.17 Days
Continuous		  
16-Mar-26 10:00 19-Mar-26 15:00 ATCO Outage 898s 708 (898s Heart Lake) isolating 788L for ALtalInk 3.21 Days
Continuous		  
16-Mar-26 10:00 16-Mar-26 17:00 ALTALINK TE 55s Protection & Control (55s Olds) A87/138B1 bus protection will be removed from service during the outage to 55s88W for repair to DC cable for the tripping ccts 7 Hours
Continuous		  
16-Mar-26 11:00 19-Mar-26 16:00 ALTALINK TE 158s Protection & Control (158s Vauxhall) 2026 GE DSP card replacements CRU

3.21 Days
Continuous		  
16-Mar-26 11:30 16-Mar-26 16:00 ALTALINK Outage 38s 897 (38s East Edmonton) 38s897 Breaker Maintenance 4.5 Hours
Continuous		  
16-Mar-26 12:00 20-Mar-26 17:00 ATCO TE ATCO Telecom Equipment replacement of existing damaged elliptical wave guide
 4.21 Days
Continuous		  
16-Mar-26 12:00 20-Mar-26 12:00 ALTALINK Outage 163s 1752 (163s Amoco Empress), 163s 1552 (163s Amoco Empress), 1002L (163s Amoco Empress - 275s Jenner) Urgent Protection change, salvage old over voltage protections and incorporate overvoltage SPS2608 into 1002L Line protections. 4 Days
Continuous		  
16-Mar-26 12:00 20-Mar-26 12:00 ALTALINK TE 163s RTU/SCADA (163s Amoco Empress) update RTU config for 1002L protection replacement 4 Days
Continuous		  
16-Mar-26 12:00 19-Mar-26 16:00 ATCO TE 898s Protection & Control (898s Heart Lake) PRC-005 relay testing 3.17 Days
Continuous		  
16-Mar-26 12:00 20-Mar-26 07:59 ATCO Outage 813s 705 (813s Little Smoky) Emergency 705CT Replacement 3.83 Days
Continuous		  
16-Mar-26 12:00 20-Mar-26 17:00 ATCO TE 813s Protection & Control (813s Little Smoky) relay isolations and CT shorting in conjunction with GOI on BKR 705 4.21 Days
Continuous		  
16-Mar-26 13:00 16-Mar-26 17:00 ATCO RB 7L48 (794s Valleyview - 7LA48 tap), 7L48 (787s High Prairie - 7L48 tap) disconnect mobile substation 835S from 7LA48 4 Hours
Continuous		  
16-Mar-26 13:00 30-Mar-26 17:00 ATCO TE 882s Protection & Control (882s Triangle) Block 701T protection to test trip/close of breaker 503 and to test inter-relay signals to new 5L482 relay 14.17 Days
Continuous		  
16-Mar-26 13:00 19-Mar-26 17:00 ALTALINK TE 602s RTU/SCADA (602s Cold Creek) RTU database update 3.17 Days
Continuous		  
16-Mar-26 13:00 16-Mar-26 16:00 ALTALINK TE 121s Protection & Control (121s Brooks) PRC/standard maintenance 3 Hours
Continuous		  
16-Mar-26 15:00 26-Mar-26 12:00 ALTALINK Outage 17s 717W (17s Benalto), 262s 717E (262s Rocky Mountain House), 717L (17s Benalto - 262s Rocky Mountain House) Component replacement on 717L (STR 262s Bay - 391) 9.88 Days
Continuous		  
17-Mar-26 08:00 17-Mar-26 16:00 ALTALINK RB 763AL (447s Enchant - 763A1L tap), 763L (158s Vauxhall - 763AL tap), 763L (28s West Brooks - 763AL tap) 763AL152 uplift mitigation, adding line post top left (field side) phase 8 Hours
Continuous		  
17-Mar-26 08:00 19-Mar-26 20:00 SUNCOR TE 29EDD-94 RTU/SCADA (29EDD-94 Voyageur) replacement of the 29EDD-94H network switch (switch #4) with a new one 2.5 Days
Continuous		  
17-Mar-26 08:00 19-Mar-26 16:00 ALTALINK TE 409s RTU/SCADA (409s Shell Scotford) SCADA VLAN split 2.33 Days
Continuous		  
17-Mar-26 08:00 24-Mar-26 16:00 CMH TE MHS-7 Protection & Control (MHS-7 Brier Park) remove TPR-138-T71-A protection from service for element and functional testing 7.33 Days
Continuous		  
17-Mar-26 08:00 17-Mar-26 16:00 ALTALINK TE 217s Protection & Control (217s North Red Deer) PRC maintenance on 768L A87/21/L1 and 768L B87/21/L1 8 Hours
Continuous		  
17-Mar-26 09:00 17-Mar-26 11:00 ATCO TE ATCO Telecom Equipment, 791s RTU/SCADA (791s Rainbow Lake), 828s RTU/SCADA (828s Sulphur Point) Rainbow Lake_S-Telecom - upgrade Rainbow sub and Rainbow tower net 1 SARs to v21, then v22 2 Hours
Continuous		  
17-Mar-26 09:00 17-Mar-26 12:00 ATCO TE ATCO Telecom Equipment Kleskun tower replace RFU1 and RAC card
 3 Hours
Continuous		  
17-Mar-26 09:00 26-Mar-26 18:00 ALTALINK Outage 394s T2 (394s Empress) 394sVR2 replacement 9.38 Days
Continuous		  
17-Mar-26 09:00 17-Mar-26 11:00 ATCO Outage 7L93 (828s Sulphur Point - 930s Arcenciel), 828s 701 (828s Sulphur Point) open end 7L93 at 930S to accommodate telecom outage 1-00513974 2 Hours
Continuous		  
17-Mar-26 09:00 17-Mar-26 16:00 ATCO TE 898s Heart Lake RTU/SCADA, 898s Protection & Control (898s Heart Lake) SCADA upgrade for the SEL-2032 at 898S Heart Lake 7 Hours
Continuous		  
17-Mar-26 09:00 17-Mar-26 16:30 ALTALINK, EPCOR RB 1209L (89s Ellerslie - 330p Genesee) Altalink work - 500 kV breaker maintenance 7.5 Hours
Continuous		  
17-Mar-26 09:00 17-Mar-26 16:30 ALTALINK, EPCOR RB 1209L (89s Ellerslie - 330p Genesee) 500 kV breaker maintenance 7.5 Hours
Continuous		  
17-Mar-26 09:30 17-Mar-26 16:00 ALTALINK Outage 89s 2052 (89s Ellerslie) PRC5 maintenance and first trip 6.5 Hours
Continuous		  
17-Mar-26 09:30 17-Mar-26 11:30 ALTALINK Outage 108s 352 (108s Amelia) PRC5 breaker maintenance and first trip 2 Hours
Continuous		  
17-Mar-26 09:30 17-Mar-26 16:00 ALTALINK Outage 890L (58s Edson - 207s Pinedale), 58s 890 (58s Edson), 207s 890 (207s Pinedale) replace hot line LA's at 207s 6.5 Hours
Continuous		  
17-Mar-26 09:30 17-Mar-26 16:30 ATCO TE 754s RTU/SCADA (754s Ksituan River)
SCADA updates for EPSS alarm and control		 7 Hours
Continuous		  
17-Mar-26 11:30 17-Mar-26 16:00 ALTALINK Outage 574s 652 (574s Nilrem) PRC5 breaker maintenance and first trip
4.5 Hours
Continuous		  
17-Mar-26 13:30 17-Mar-26 16:00 ALTALINK Outage 108s 452 (108s Amelia) PRC5 breaker maintenance and first trip 2.5 Hours
Continuous		  
18-Mar-26 07:00 18-Mar-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) isolating 50BF/701 for relay changes 10.5 Hours
Continuous		  
18-Mar-26 07:00 19-Mar-26 17:30 ATCO TE 743s Protection & Control (743s Sarah Lake) 87T-51HV/702T settings change 1.44 Days
Continuous		  
18-Mar-26 08:00 19-Mar-26 17:00 ALTALINK Outage 163s 1752 (163s Amoco Empress), 163s 1552 (163s Amoco Empress), 1002L (163s Amoco Empress - 275s Jenner) South Crew will be doing component replacement on 1002L (STR 67-99) 1.38 Days
Continuous		  
18-Mar-26 08:00 19-Mar-26 16:00 ENMAX TE Protection & Control (SS-36) 36 sub zone 32 138kV bus differential protection (87) and lockout relay (86) outage, relay lockout testing 36RLY138ZONE 31. 36.5TR outage required 1.33 Days
Daily		  
18-Mar-26 08:00 19-Mar-26 16:00 ENMAX Outage 16.63L (SS-16 - SS-36), 36.5TR (SS-36), 36B69-16.63/36.5TR (SS-36), 16B69-16.63 (SS-16) 36.5TR 138kV zone 31 and zone 32 relays lockout testing 1.33 Days
Continuous		  
18-Mar-26 08:00 19-Mar-26 16:00 ENMAX TE Protection & Control (SS-36) 36 sub Zone 31 138kV bus differential protection (87) and lockout relay (86) outage, lockout testing 36RLY138ZONE 31. 36.5TR outage required 1.33 Days
Daily		  
18-Mar-26 08:00 18-Mar-26 17:00 ALTALINK TE AML 511s T30 (AML 511s Crossings) working on the RS400 in T30-1 not communicating 9 Hours
Continuous		  
18-Mar-26 08:00 18-Mar-26 16:00 ALTALINK Outage 935L (324s Cassils - 356s Milo) repair failed interphase spacer 8 Hours
Continuous		  
18-Mar-26 08:00 18-Mar-26 16:00 ATCO, ALTALINK RB 923L (356s Milo - 2075s Newell) 923L reclose block required for 935L103 urgent repair work to replace damaged interphase spacer, due to proximity to 923L 8 Hours
Continuous		  
18-Mar-26 08:00 20-Mar-26 16:00 ALTALINK TE 149s RTU/SCADA (149s Nisku) SCADA VLAN split 2.33 Days
Continuous		  
18-Mar-26 08:00 18-Mar-26 18:00 ATCO TE ATCO Telecom Equipment, 751s RTU/SCADA (751s Hill), 724s RTU/SCADA (724s Hines Creek), 862s RTU/SCADA (862s South Bezanson), 784s RTU/SCADA (784s Donnelly), 880s Briker RTU/SCADA, 795s RTU/SCADA (795s Zama), 873s RTU/SCADA (873s Marion Lake), 860s RTU/SCADA (860s Crow), 812s RTU/SCADA (812s Norcen), 779s RTU/SCADA (779s Chinchaga River), 775s RTU/SCADA (775s Sullivan Lake) telecom upgrade, 751s Hill, 724s Hines Creek, 862s South Bezanson, 784s Donnelly, 880s Briker, 795s Zama, 873s Marion Lake, 860s Crow, 812s Norcen, 779s Chinchaga River, 775s Sullivan Lake 10 Hours
Continuous		  
18-Mar-26 08:30 18-Mar-26 17:00 ALTALINK Outage 28s T1 (28s West Brooks) 28sT1 out of step alarm 8.5 Hours
Continuous		  
18-Mar-26 09:00 18-Mar-26 10:00 ATCO TE ATCO Telecom Equipment, 853s RTU/SCADA (853s Ring Creek) 853s Ring Creek-telecom- SAR OS upgrade to v21, then v22 60 Mins
Continuous		  
18-Mar-26 09:00 18-Mar-26 11:30 ALTALINK Outage 574s 452 (574s Nilrem) PRC5 breaker maintenance and first trip 2.5 Hours
Continuous		  
18-Mar-26 09:00 18-Mar-26 12:00 ALTALINK TE AltaLink Telecom Equipment, 409s RTU/SCADA (409s Shell Scotford) Upgrade MPLS node. Loss of visibility of 409s, ALC01s for 2 hours in the timeframe indicated. ALC01s to manual
reporting. Affects ATCO comm circuit.
3 Hours
Continuous		  
18-Mar-26 09:30 18-Mar-26 16:00 ALTALINK Outage 108s 252 (108s Amelia) PRC5 breaker maint & first trip,
repair local/remote cutoff switch		 6.5 Hours
Continuous		  
18-Mar-26 09:30 18-Mar-26 16:00 ALTALINK Outage 314L (207s Pinedale - 228s T.M.P.L. Niton), 228s 314 (228s T.M.P.L. Niton), 207s 314 (207s Pinedale) replace hot line LA's at 207s 6.5 Hours
Continuous		  
18-Mar-26 10:00 18-Mar-26 16:00 ALTALINK Outage 1054L (12s Heartland - 13s Deerland), 13s 1552 (13s Deerland), 13s 1652 (13s Deerland), 13s 98 (13s Deerland) PRC5 maintenance and first trip on 13s1552
hot spot repair & switch adjustment on 13s98		 6 Hours
Continuous		  
18-Mar-26 10:00 18-Mar-26 16:00 ATCO TE ATCO Telecom Equipment, 833s RTU/SCADA (833s Mariana) update firewall and existing telecom networking 6 Hours
Continuous		  
18-Mar-26 11:00 18-Mar-26 16:00 ALTALINK TE 244s Protection & Control (244s Bowmanton) PRC relay maintenance 5 Hours
Continuous		  
18-Mar-26 13:30 18-Mar-26 16:00 ALTALINK Outage 574s 552 (574s Nilrem) PRC5 breaker maintenance 2.5 Hours
Continuous		  
18-Mar-26 15:00 18-Mar-26 17:00 ALTALINK Outage 14s T3 (14s Devon) 14s20 breaker maintenance and first trip test 2 Hours
Continuous		  
19-Mar-26 08:00 28-Mar-26 16:00 ALTALINK Outage 132s 51 (132s Ware Junction), 132s 55 (132s Ware Junction), 28s 5 (28s West Brooks), 28s 8 (28s West Brooks), 931L (28s West Brooks - 132s Ware Junction) Urgent replacement of 28s 931L A - protection. 9.33 Days
Continuous		  
19-Mar-26 08:00 24-Mar-26 16:30 ALTALINK Outage 890L (58s Edson - 207s Pinedale) Replace structures 95, 96, 102, 103, 109, 113, 114, 116, 117, 118 5.35 Days
Continuous		  
19-Mar-26 08:00 19-Mar-26 16:00 ATCO, ALTALINK Outage 923L (356s Milo - 2075s Newell) Repair interphase spacer. 8 Hours
Continuous		  
19-Mar-26 08:00 19-Mar-26 16:00 ALTALINK RB 935L (324s Cassils - 356s Milo) 935L reclose block required during 923L149 urgent repair to replace damaged interphase spacer 8 Hours
Continuous		  
19-Mar-26 08:00 20-Mar-26 16:00 ALTALINK, DOW TE 166s RTU/SCADA (166s Dow Chemical Fort Saskatchewan) SCADA VLAN split - loss of visibility of 166s for 15 minutes in the timeframe indicated 1.33 Days
Continuous		  
19-Mar-26 08:00 19-Mar-26 17:00 ATCO IO ATCO Telecom Equipment Vegreville_T(SCC)-Telecom- Vegreville Tower Upgrading Dynamic Load Rating Server for bug fixes. These dynamic values are sent over to AESO and this line rating will be set to the default rating during the outage. This outage will be around 2 hours long while we update the server. 9 Hours
Continuous		  
19-Mar-26 08:30 19-Mar-26 11:30 ALTALINK RB 760L (163s Amoco Empress - 760AL tap) reclose block required on 760L at163s for ATCO telecom work 3 Hours
Daily		  
19-Mar-26 08:30 19-Mar-26 16:00 ALTALINK, DOW TE 166s Protection & Control (166s Dow Chemical Fort Saskatchewan) setting changes 7.5 Hours
Continuous		  
19-Mar-26 09:00 19-Mar-26 11:00 ATCO, BSSL TE ATCO Telecom Equipment, 1004s RTU/SCADA (1004s Bullseye), 772s RTU/SCADA (772s Youngstown), 893s RTU/SCADA (893s Cavendish), 914s RTU/SCADA (914s Bindloss) upgrading Pollockville, Bullseye, Cappon and Youngstown Tower SARs
 2 Hours
Continuous		  
19-Mar-26 09:00 19-Mar-26 11:00 ATCO, ALTALINK RB 7L760 (767s Oyen - 7LC760 tap), 7L760 (7LA760 tap - 7LC760 tap), 760L (760AL tap - 7LA760 tap) need reclosing disabled on 7L760 for telecom request 2 Hours
Continuous		  
19-Mar-26 09:00 19-Mar-26 16:00 ALTALINK TE 132s RTU/SCADA (132s Ware Junction) port 3 on LAN-ES has failed. techs will have to tests ports P15-P20 to find working port 7 Hours
Continuous		  
19-Mar-26 10:00 19-Mar-26 16:00 ALTALINK Outage 422s 694 (422s Westwood), 54s 694 (54s Fort Saskatchewan), 694L (54s Fort Saskatchewan - 422s Westwood), 422s T1 (422s Westwood) 54s2 & 422s3 Switch Hot Spot Repair 6 Hours
Continuous		  
19-Mar-26 10:30 19-Mar-26 16:30 ATCO TE 741s RTU/SCADA (741s Fox Creek) scada updates for EPSS alarm and control 6 Hours
Continuous		  
19-Mar-26 12:00 19-Mar-26 17:00 ALTALINK TE 120s RTU/SCADA (120s Picture Butte) RTU outage 5 Hours
Continuous		  
20-Mar-26 08:00 20-Mar-26 17:00 ATCO Outage 813s 705 (813s Little Smoky), 7L46 (813s Little Smoky - 845s Big Mountain), 813s 706 (813s Little Smoky) emergency 705CT replacement in conjunction with 1-00517982 9 Hours
Continuous		  

Prepared On:   2026-03-11   15:34:39

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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