Noisy Transfer Switch

Unscrew it from the floor. Isolate it from all surfaces with rubber.

Just curious, what about it makes noise, is there a big transformer in there or something? Seems to me something passive like a switch would be silent until it came time to actually switching.

Have you tried contacting progressive dynamics? Could be the replacement was a dud too.

I have seen a number of threads on this site and irv2 about humming PD52 ATS's. Isolating with rubber seems to be at least a partial solution. Also there are specific orientations for the switch stated in the installation manual. Not sure what the difference is between the PD52 and the PD5200, but here is the 5200 manual which is what we have.

PD 5200/5300 manual

Our 5200 has only a very very light hum even with it being mounted a basement back steel wall in our electronics bay.

KD4UPL wrote:
Unscrew it from the floor. Isolate it from all surfaces with rubber.

This works. I have a noisy switch too and I unscrewed it from the battery box and have foam behind it. It still makes noise but its far quieter than before.

The transfer switch is really a relay and all mechanical relays are subject to chatter. It can sound like humming but humming is a little different. Swipe the core of the coil where the armature hits it with a piece of coarse paper, a brown paper bag strip will work. It may help but probably not. The problem may be a loose coil, (humming) a worn armature or just a lousy relay engineering wise (vibrating). We had tens of thousands of relays in traffic signal controllers and we found the only way to make sure they were quiet was to buy really expensive replacements or as we finally did, we changed to soft start solid state relays.