Progressive Industries EMS-HW30C install

SLJ

Never had any noise or hum from mine. Just put a second one in a new camper and no noise from that one either. No hum at all.

Freespirit

Second @SLJ, original HW30C installed 5 years ago and no hum at all. 

subkron

I installed mine behind the electrical panel in my 400 and located the remote display in the nautilus compartment on a side wall.  The display is way to bright and having it in the nautilus which is adjacent to the shore connection it is easy to check when I power up.  

As far as the noise, my original EMS had the hum as well which was a bit annoying.  I called PI and ended up getting a replacement, they were pretty good about it.

valkraider

With such a small space and as hard as it is to get to things, I have no interest in trying again and potentially having the same problem. My body still hurts from the contortions it took to do the first one.  

Maxcamp

Ditto on the hum.  45 dB about right.  Very annoying, my ears ring.  Neoprene isolator washers keep it from vibrating plywood.  Under the foam bed dampens a bit.

The device has a bypass if shore power is under or over voltage thresholds.