Thread: Bandsaw wont stay on

It could be a capacitor problem on the motor.
Worth getting it checked.
Tom

Does the saw uses a contactor? (A separate grey or white box in between the switch and the motor) if so the locking solenoid section of the contractor is damaged or broken

IT does have a capacitor, see image.. would a faulty capacitor still allow the unit to start up as normal and run full speed when the button is held ?

not sure about a contactor, the wires disappears into the main frame of the bandsaw, ill have a look and follow the wiring between the two

IMG_0939.jpg

When you push the GO button it applies power to the start capacitor and to the run winding. The motor runs. When you release the button the start capacitor is disconnected and the run winding, which is powered by the contactor, disconnects because the contactor is no longer powered. It gets its power from a contact on the contactor, which can be interupted by the stop button to stop the motor.

You have a fault in either the contact on the contactor or in the stop button. This may simply be dirt, or an insect, stopping the contacts connecting so I would recommend a good blowout of the contactor and stop button with compressed air, perferably with the covers off and power cord unpluged.

Ok don't know what this means exactly, but strangely if I remove the switch and just directly connect the terminals (IE now use the power point as the switch) it works fine.

so surely it has to be the switch that's faulty ? both of them ?

Try the blowout trick is this may be all that is required.

Originally Posted by Bohdan

When you push the GO button it applies power to the start capacitor and to the run winding. The motor runs. When you release the button the start capacitor is disconnected and the run winding, which is powered by the contactor, disconnects because the contactor is no longer powered. It gets its power from a contact on the contactor, which can be interupted by the stop button to stop the motor.

You have a fault in either the contact on the contactor or in the stop button. This may simply be dirt, or an insect, stopping the contacts connecting so I would recommend a good blowout of the contactor and stop button with compressed air, perferably with the covers off and power cord unpluged.

Thank you for your detailed reply,

Ill head out there shortly and give it a good blow out and see what I can find.

so im guessing holding the GO button in is probably not great for the capacitor ?

Originally Posted by Darklink

so im guessing holding the GO button in is probably not great for the capacitor ?

Not so much an issue for the capacitor but it will overheat the motor.

The switch has nothing to do with the capacitor on a modern saw. In the old days they used to start a big motor like that where you had to hold in the button till it got up to speed.
Could you put up a photo of the switch, particularly the connections on the back. Some need a small linking wire to maintain closed contacts, others have it internal. If it's one of those all in one switches which I'm guessing it is.

I have a bench grinder which sometimes won’t stay on unless you hold the button in, at other times it’s fine. The best theory I have is that it’s related to dodgy incoming power - I’m out on a farm with lots long longish low voltage cable runs, and the rural supply leave a bit to be desired too. They replaced a breaker recently and my grinder has behaved since then, so hopefully that’s the problem sorted out.

I have the same bandsaw and I've always had to hold the on button for a couple of seconds to get it running. If I just press the button quickly it will start to spin and then stop.

I have a similar problem.
Mine starts up fine but stops after about thirty seconds.
Holding the Go button doesn't do anything.

I guess it is the switch. I gave it all a good clean and blowout but no help.

A sparky is two weeks away.

Hey Darklink, any updates on this issue? I've just started having the same issue and Hafco rep said to replace the switch. I did this but no change. Cheers

I just bought this bandsaw brand new - assembled it, went to turn it on and it only runs when I hold the green button in.

So, I unscrewed the yellow shroud that goes around the on/off switch (with the big red stop button) and removed it. Low and behold - works perfectly.

The plastic cover was not letting the green start button be pressed the the full way, but now it’s working like a charm!