Path Rating Catalog 2013 - Western Electricity Coordinating Council

Revised November 2008
23. Four Corners 345/500 Qualified
Path
Accepted Rating
Existing Rating
Other
Location:
Northeastern Arizona
Definition: Flow on 345/500 kV transformer (see Fig. 1)
Transfer Limit:
Critical
Disturbance
that limits the
transfer
capability:
When:
System
Conditions:
Study Criteria:
Remedial
Actions
Required:
Formal
Operating
Procedure:
Allocation:
Interaction
w/Other
Transfer Paths:
345 to 500 kV: 1000 MW
500 to 345 kV: 1000 MW
Metered End: 345 KV terminal of transformer
Loss of Four Corners #5 (750 MVA) with high transfers on Four Corners-
Moenkopi 500 kV for westbound flows.
Path is normally limited due to N-0 conditions in both directions.
The new path rating was established in 2012 as described in the report Four
Corners 525/345 kV Transformer (Path 23) Upgrade Project performed by
APS and the Four Corners Technical task force.
Flows in this area are historically from east to west due to the large amount of
generation located in the area.
Path loading not to exceed 100% of continuous rating (1025 MVA) of the
transformer.
None.
None
Owners of the path are:
Southern California Edison Company
Arizona Public Service Company
Public Service Company of New Mexico
Salt River Project
El Paso Electric Company
Tucson Electric Power Company
None
480 MW
150 MW
130 MW
100 MW
70 MW
70 MW
1000 MW
PART VI Item 1-64