RV Transfer Switch "Buzz"

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
Son has an RV and noticed the transfer switch (house power vs inverter) "Buzzing". Cycling it did not elevate the problem. Connections are tight, no obvious overheating, just annoying.
Anyone experienced this ??
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
If the transfer switch is electrically held and it buzzes when energized, look for rust, dirt, or corossion on the contact points of the coil armature.
 

synchro

Senior Member
Location
Chicago, IL
Occupation
EE
Does the buzzing stop if all loads are shut off in the RV, or if the cord to the house is disconnected?
If disconnecting the cord stops it, then perhaps there's some current flowing between the neutral and the EGC because they are bonded together in the RV as well as in the house panel. Not having a good N-to-EGC bond in the panel would aggravate this. Now why this would cause buzzing is questionable, but perhaps there is some light gauge magnetic material like steel between the N and EGC conductors that is buzzing due to the magnetic field produced between them.
 

hillbilly1

Senior Member
Location
North Georgia mountains
Occupation
Owner/electrical contractor
Does the buzzing stop if all loads are shut off in the RV, or if the cord to the house is disconnected?
If disconnecting the cord stops it, then perhaps there's some current flowing between the neutral and the EGC because they are bonded together in the RV as well as in the house panel. Not having a good N-to-EGC bond in the panel would aggravate this. Now why this would cause buzzing is questionable, but perhaps there is some light gauge magnetic material like steel between the N and EGC conductors that is buzzing due to the magnetic field produced between them.
A properly installed panel in a rv has the neutral and grounds separated. At one campground, a couple of women were having problems with the pedestal gfi tripping when they plugged in. Their husbands just remodeled the camper, and “rewired” it. I knew exactly what he had done. Opened the panel, and sure enough, they bonded the neutral and ground together. Removed the bond, and everything worked fine. The campground maintenance guy was just going to remove the gfi breaker!
 
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