A hum running through the whole building, traced to a 400 amp contactor still switching for ceiling heaters that came out years ago.
Suzuki New Zealand had a noise running through the building. Not one room or one fitting, the whole building, and it had been doing it for years. It turned out to be a contactor, the heavy switch that throws a big circuit on and off, sitting in the main board.
What we found
- A 400 amp contactor, still live and still holding in
- Put there years ago to switch the building's ceiling heaters
- The heaters were taken out long ago and nobody took the contactor with them
- It had been carrying the power, and humming, ever since
We took it out. Suzuki New Zealand went quiet.