Solar array fire at New Jersey school linked to design flaw, officials say

What happened

A fire damaged the solar panels at Emma Havens Young Elementary School in Brick, New Jersey, in September 2017. The school was evacuated and dismissed early on 14 September, and no one was injured. Power was shut off to the wider complex, so Drum Point Elementary students were relocated to Brick Township High School. Officials told the Brick Township Board of Education that the failure occurred when the transformer forming part of the solar unit allowed positive voltage to return onto the neutral.

Jersey Central Power and Light crews identified a design flaw while investigating the fire. The flaw affects the solar units at all district schools except Brick Memorial High School, and those units have been shut down until it is fixed. Emma Havens students lost a day of school, which was made up with a half day on 26 January 2018.

Contributing factors

Officials said the failure was caused by a design flaw in the solar units, identified by Jersey Central Power and Light, which affects multiple schools in the district. The transformer within the solar unit allowed positive voltage to return onto the neutral. The investigation was ongoing at the time of reporting, and the source does not describe any further cause of the fire.

Lessons learned

1. Check that inverter and transformer designs in grid-connected solar units prevent voltage from being fed back onto the neutral, and verify this during commissioning.
2. When one installation fails, check identical units across the same portfolio before returning them to service.
3. Plan repairs that require isolating power to occupied buildings around school timetables and the needs of any neighbouring sites that lose supply.

More lessons on design, standards and commissioning, electrical protection and isolation, from every incident on the register.

Source

patch.com