For several minutes Friday afternoon, the entire Rim country was without electrical service due to a transmission line failure.
Over 18,000 APS customers from Strawberry, Pine, Payson, Tonto Basin, Star Valley and all points east to Forest Lakes and Young were affected by the electrical interruption, which occurred around 3 p.m.
"The outage was caused by the failure of a wooden support cross arm on the 69,000 volt overhead line that provides Payson's main power source from Preacher Canyon Substation seven miles east of town," APS District Manager Jim Spencer said. "When the arm broke, the wire fell into the 21,000 volt distribution under-built directly below and caused a ground fault or short circuit condition."
After several attempts to re-energize the circuit, the APS Phoenix Energy Control Center, which had been immediately alerted via computer, was forced to re-route the power flows to the backup transmission source from the Verde Valley.
A few minutes later, electricity was restored to Payson, Pine, Strawberry and the Tonto Basin while customers east of Payson remained powerless.
Local APS linemen dispatched to patrol the line east of Star Valley found the down wire at the Gila County Maintenance Yard. They were able to isolate the downed line and restore power to Star Valley and areas east of Preacher Canyon by 4:05 p.m.
Star Valley was re-energized at 4:17 p.m. Service to the Diamond Point area remained out until APS Crewmen made all repairs at 6:18 p.m.
Cause of the cross arm break is unknown at this time.
"Many times previous lightning, snow or windstorms can weaken our equipment and then cause subsequent failures later on," Spencer said.