1. Odawa Substation Outage
Odawa substation outage on Squirrel jumped between two phases on the source side of Viper three phase recloser. Opened high side trans-rupter. Caused entire substation to become de-energized.

2. Verified Cause
A and B Phase Open Jumpers
Squirrel jumped between A and B phase on source side of Viper recloser
An arc was created between A and B phase and at the very end also arced to C phase
A and B phase source side jumpers burnt off and arc extended to C phase. Next slides will show arc current and duration.

3. Electrical Events The fault/arc duration 2.5 seconds
The fault current 3855 amps
Melted A and B phase 4/0 copper jumpers
Melted viper recloser bushings and case
Fault duration due to trans-rupter on the 138 KV side of the substation transformer.
Fault current produced was near maximum available substation current.
4/0 copper load current rating is 482 amps.
Recloser was replaced with new unit. ($35,000 in damage)

4. Arc Flash Values Based on 3855 amps of fault current and 2.5 seconds:
15” = 25 Cal
30” = 6.2 Cal
60” = 1.5 Cal
Uses IEEE 1584 standard from WindMil.
Values would be similar for a fault caused by worker error

5. Back side of Viper recloser showing melted 4/0 copper jumpers and burnt recloser

6. Note close proximity between bushings/phases

7. View shows A and B Phase Source jumpers burnt.
Burnt Phases