TWsystems
Member
- Location
- California
Hi Pros
A little help please ... I'm out of ideas.
I have a remodel project with an existing 600 Amp Service with 5 subpanels (3 of which are new).
The 3 new Panels make a noticeable buzzing noise. The 3 new panels are Murray - the 2 existing are Square D
Nothing is even close to being overloaded and we're not talking about the buzzing from the arc fault breakers.
There is a 3 Phase converter in the system for a couple 3 Phase Laundry Machines and there are several UPS battery backup units throughout on different panels for some sensitive AV and Network Electronics. None of which seem to affect the buzzing noise whether on or off.
There is a backup generator and transfer switch - which does not affect the buzzing noise whether on or off.
If we shut down all the breakers the buzzing goes away - if we start to turn loads back on - any loads - the buzzing will start again as soon as there is about a 5 amp draw on it.
We have tried isolating which circuits might be the culprit - but it makes no difference which loads are on or off - the buzzing will start after a small amount of current starts to pass through any circuit on any of the 3 panels - we have changed guts and breakers - to no avail
I'm totally baffled - we can't seem to figure this one out - after 30 years in the trade I thought I'd seen about everything - but this is bizarre
Has anyone encountered this before and what was the solution?
A little help please ... I'm out of ideas.
I have a remodel project with an existing 600 Amp Service with 5 subpanels (3 of which are new).
The 3 new Panels make a noticeable buzzing noise. The 3 new panels are Murray - the 2 existing are Square D
Nothing is even close to being overloaded and we're not talking about the buzzing from the arc fault breakers.
There is a 3 Phase converter in the system for a couple 3 Phase Laundry Machines and there are several UPS battery backup units throughout on different panels for some sensitive AV and Network Electronics. None of which seem to affect the buzzing noise whether on or off.
There is a backup generator and transfer switch - which does not affect the buzzing noise whether on or off.
If we shut down all the breakers the buzzing goes away - if we start to turn loads back on - any loads - the buzzing will start again as soon as there is about a 5 amp draw on it.
We have tried isolating which circuits might be the culprit - but it makes no difference which loads are on or off - the buzzing will start after a small amount of current starts to pass through any circuit on any of the 3 panels - we have changed guts and breakers - to no avail
I'm totally baffled - we can't seem to figure this one out - after 30 years in the trade I thought I'd seen about everything - but this is bizarre
Has anyone encountered this before and what was the solution?