Minimax j/p hums when plugged in but not turned on

[Ian Wormsbecker]

I have an older MiniMax FS30 jointer/planer (the yellow version) that I bought used about 1 year ago. It worked fine until today when I switched the power cord on it for a longer one. Now it hums when it isn't even turned on! When I do turn it on, it appears to run fine.

I was extra careful when I hooked the cord up to make sure I attached everything exactly as it was before.


I am very confused as to what is going on. Any thoughts / suggestions?


Cheers

Ian

[Rod Sheridan]

Hi Ian, it may have a control transformer with a loose lamination, or loose mounting bolts.

Try unplugging it and check all the component mounting screws.

If the noise is from a control transformer, it's not a problem, just an annoyance.......Rod.

[Chuck Wintle]

I would double check all the connections again. If it was not humming prior to the cord switch it should not do it after provided something has not failed.

[kenneth kayser]

Hum with the switch off is a danger sign. The switch should open the high side wire. With the high side disconnected there is no way you can get hum without a wiring problem in the machine or the outlet. Unless you are familiar with house wiring, I would call an electrician to check your wiring.

[Thomas S Stockton]

Like Rod said it is probably in the switch, my old mini-max band saw hums sometimes. Not a big deal if it bothers you unplug it between uses or if it has a second switch on the motor turn it off there I believe that should cut power to the switch
Tom

[Ian Wormsbecker]

Thanks for the info guys.

I have obviously left it unplugged, and will double check everything in the morning.


Ian

[Rick Fisher]

I had a magnetic starter on my bandsaw that did the exact same thing..

The contactor on the switch was half welded .. So when I plugged it in .. it put 1/2 power to the motor..

When I replaced the switch, it worked fine..

[Myk Rian]

Sounds like a wire got switch with the ground lead.

[Ian Wormsbecker]

I just did some exploration. The motor is not making noise. The switch is making the humming/buzzing. It also 'clicks' when it is plugged in, then starts the humming.

I have confirmed that all the wiring is correct (plug to machine. only parts I changed).

I am puzzled why the switch would make noise.

I think the machine WAS a 3phase machine, and has been converted to 2phase at some point in the past. The switch, however, looks like it might still be the three phase switch? It has markings stating 380V. The documents that came with the machine (typewritten! hah) also show 3 power lines rather than the 2. The switch looks to be 'jimmy rigged' somehow to make it work with the black wire exiting and re-entering the switch?

I am still confused as to what I could have done to cause the humming though :( And still not sure if I should be concerned about it or not.

I have attached 4 images of the 'easy to photograph' stuff in case that helps.

Ian

[Larry Heflin]

My cu300 hums when plugged in. Always has. No hum with my mm16 though. Maybe Charlie Plesums will pipe in. He's very knowledgeable about MM machines as well as electricity.

Larry