I was working on a Energy Recovery Ventilation unit on an apartment complex today, the unit takes the heat from the exhaust in the building and reintroduces it to the supply air stream taking in 100 percent out door air, and retempering the incoming air. This is done by a heat recovery wheel. The motor serving this heat recovery wheel locked up and the drive did not trip on overcurrent, this caused a small fire in the vfd from the heat and melted a lot of the wiring in the area. Replaced the VFD and all of the wiring going to it and around it.

Posted by BeantownHVAC at 2021-02-23 16:45:11 UTC