Power was shut off briefly Tuesday to all city of Poplar Bluff electric customers to allow emergency repairs at the Morrison Road substation by a power provider.
The outage was scheduled for 1 p.m. and lasted for just over 14 minutes while a crew from the Southwestern Power Administration took a breaker offline, said Bill Bach, Municipal Utilities director.
Phone calls this morning to SWPA regarding what caused the problem and if repairs are complete were not returned as of press time.
SWPA alerted city officials to the problem at 8:30 a.m. Tuesday and asked for an immediate shut down of the substation, Bach said.
He requested time to notify residents, factories, schools and hospitals, said Bach.
The city serves more than 9,600 homes and businesses and was experiencing heavy usage yesterday due to the extreme low temperatures, Bach said.
It is not known if the low temperatures contributed to problems with the breaker, which had a low level of a non-toxic vapor gas used to insulate the system.
The breaker, which is the size of a truck, is operated by SWPA. SWPA is a provider of hydroelectric power and operates under the Department of Energy.
It dispatched a crew from Jonesboro, Ark., to deal with the alarm, but workers were unable arrive before a second alarm was triggered, Bach said.
"It is in their procedure that when the gas breaker goes into this low, low alarm, they de-energize everything," said Bach. "I've been here over 16 years and this is the first time we've had this problem."
The system uses sulphur hexaflouride gas in a closed system, Bach said. SWPA would need to replace the gas and find out what caused the leak, he said.
The gas would not be harmful to nearby residents, Bach said.
SWPA has not notified Municipal Utilities about the status of the repairs, he said.
The breaker serves one of three transformers at the substation, which receives electricity at 161,000 volts and transmits it at 69,000 volts to city substations.
The transformer served by that breaker remains off-line until the breaker is repaired, Bach said.
The city can operate normally off of the two remaining transformers, he said.
"That's the redundancy of the system, you can lose one and everything is fine," Bach said.
The city can operate at a reduced capacity off one transformer.