Automatic Transfer Switch buzz

[Dave-DJ]

Hi

I have new Thor RV on a Ram 3500 Promaster.

When I am hooked up to shore power, there is a noticeable hum- buzzing sound, from the Southwire Model 41301 Automatic Transfer Switch.

Some have said "it's normal with a newer model" and "no, it shouldn't be doing that."

Does your Automatic Transfer Switch hum -buzz?

Thank you.

[SteveJ]

Kinda hard to tell without actually being there and hearing it. I would check the transfer switch's internal contacts and connections. Due note if the contactors get warm/hot with a good size electrical load.

[mloganusda]

Never noticed my transfer switch made a noise. I would check your internal wire connectors to make sure they are tight, as fires have been know to start because of loose connections heating up.

[avanti]

My guess would be 60hz hum from the internal relay coil. Check to see that the relay is securely mounted.

[Dave-DJ]

Hi,
You are correct coil buzz. Found only one maker uses DC coils, that do not buzz.
Ordered a ESCO LPT30BRD 30 Amp 120 Volts AC Automatic Transfer Switch with 120V DC coils.
Should be quiet.
Thank you.