Sharing a Recent BMS Investigation Experience - Toilet Exhaust Fans Not Operating.
I recently attended a service call regarding a BMS issue where three toilet exhaust fans were not operating.
Upon arrival, I began with the BMS side and confirmed that the controller outputs were enabled and showing “On” at the BMS panel. I then proceeded to the roof, where the site electrician had verified that power was present at the fan isolators. However, I found no voltage at the fan terminals themselves.
This led me to suspect that the fans may be controlled via enable contactors located elsewhere in the building. After further investigation, we located the contactors within a ceiling space. All three overloads had tripped, which explained the issue.
This was a good reminder that applying some logical steps and digging a bit deeper can often lead to the root cause.
Suggested BMS Fault Investigation Procedure:
1. Check BMS Output Status: Confirm that the BMS point is enabled or…
