Powerstar LW LF Inverter noise

[Rotary]

I have a Powerstar LW LF inverter (24v 3000w). I've noticed that its started to make a humming noise when there is a small load. This happens when the fan is not running so i don't believe its fan bearing noise.

When i increase the load the fan kicks in and when the load is reduced the humming has disappeared. It has been very loud on one occasion.

There is no AC input connected

Has anyone else experienced this ?

 

[Steve_S]

Hahaha, no worries, That is the Torodial Coil making that noise. Also, the cover on that unit is not tight, it has some slack/float where the tangs of the cover slip into teh base. They will vibrate/rattle relative to the magnetic field - YES, these inverters are magnetically noisy ! I solved teh issue by bending the tangs outward a bit and then brushing on some electrical "liquid tape" onto the tangs as insulators. That made it much quietter but the hum remained because that's just the coil.

Cover OFF (24V/3000 Unit)
See the 4 slots along the bottom of the pic where the tangs slip in, it is the same on the other side too.
I would also suggest brushing some of that "Liquid Electrical Tape" on the flat face the lid sits against the sides to handle the vibrations.

NOTE, when removing the cover, make sure you are unpowered and the capacitors are discharged ! Then as you lift the cover GO SLOW & GENTLE as you will have to unplug the RJ11 plug that goes to the controls and the wire is short.

Good Luck, Hope it helps.

 

[Rotary]

Thanks @Steve_S . I'll try that

 

[Steve_S]

Thanks @Steve_S . I'll try that

Nothing like a bit of BTDT to help out another.
Mine is a Yiyen APC3024 which is the same thing (they make the powerstar) which I keep for backup as I upgraded to a Samlex EVO4024 a few yrs ago. The ol noisy gurl will be going into the toolshed to handle that task on it's own.