Yep.... It hums...
Just got done installing the Progressive industries hardwired 30amp unit... luckily I installed it in the electrical bay. When I first plugged it in, it was silent. I went into the rv and turned on...
Forum Discussion
Resonant Frequency
60 Hz.
It comes from the transformer laminated winding. Silicon steel wafers in which copper windings are wrapped around. 400 Hz military transformers produce a different hum -- higher in pitch and softer in intensity. For many years GM Delco produced an automotive alternator with a 7-pole rotor that created a unique hum when it was charging hard.
Spun fiberglass as used for an enclosure wall (air needs to circulate within) will help block the noise. Harmonic resonance actually creates it's own (minor) heat in small transformers and a good deal of heat in alternators.
Make absolutely sure the noise is not being transmitted from the device to a soundboard floor.
Gum rubber mounts seem to work well for mechanical noise isolation.
60 Hz.
It comes from the transformer laminated winding. Silicon steel wafers in which copper windings are wrapped around. 400 Hz military transformers produce a different hum -- higher in pitch and softer in intensity. For many years GM Delco produced an automotive alternator with a 7-pole rotor that created a unique hum when it was charging hard.
Spun fiberglass as used for an enclosure wall (air needs to circulate within) will help block the noise. Harmonic resonance actually creates it's own (minor) heat in small transformers and a good deal of heat in alternators.
Make absolutely sure the noise is not being transmitted from the device to a soundboard floor.
Gum rubber mounts seem to work well for mechanical noise isolation.
