Wednesday's Outage Blamed On Power Hiccup

On Wednesday, July 28, just after noon at approximately 12:08 p.m., Belmont Municipal Light Department's supply interconnection suffered a system disturbance. This technical issue resulted in an overvoltage condition on BMLD's 13.8 kV system.

To protect customer equipment, BMLD's 15L2 circuit is programmed to open during overvoltage conditions and then re-close after five seconds. This momentary hiccup in power going to households on the circuit was developed to reduce the duration of the overvoltage condition.

"We realize that these momentary outages are an inconvenience and appreciate your continued patience as we work to resolve this issue," noted the BMLD press release.

BMLD crews continue work to isolate BMLD customers from transients along the 13.8 kV interconnection between NStar and BMLD.

According to a press release, BMLD employees have been working throughout the past several months to improve this circuit by replacing the aging cable and transferring the power to another circuit to eliminate the chance of any additional high-voltage transients that have caused sporadic outages and voltage dips in the past year. Work on this project is 90 percent complete, read the release.

It has been discovered that the , which left approximately 200 BMLD households without power for 51 minutes on the 15L2 circuit was unrelated to the ongoing problem, but rather was caused by animal contact.