Bandsaw motor not starting

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9fingers":2pgzgxoh said:
OK, a rubbing noise as it slows down suggests a centrifugal switch.
The fact that you can spin start in either direction means that the starting circuit is not having any influence.
This is causes by
1) open circuit capacitor ( not likely in this case as you have tried a new one)
2) defective contacts on centrifugal switch (if fitted and in this case possibly so)
3) open circuit starter winding - bad news very likely not to be repairable but usually rare.

...
Bob

Bob:

What about a bad connection in the wiring itself? Say, a loose wire nut? Terry, have you double-checked the connections inside the junction box?

Kirk
 
Could be Kirk, although mercifully we not used wire nuts here for decades - they might even have been banned for all I know. If Terry has been in and out fitting capacitors then he will have moved nearly all the connections already.

Bob
 
I have the same type of saw BAS 315 GWN 55, my capacitor is rated at 16uF at 450v even though the saw is only 230V. I don't hear the centrifugal switch click off when I switch mine off so I suspect that there isn't one. Hope this helps you to try and troubleshoot your machine.

Let me know if you need me to check anything else out to compare against your machine.
 
Andy, The only thing to be careful of is that most machine manufacturers don't always use the same motor throughout the production run.
I'm not expert on EB machines but certainly Startrite bandsaws use all sorts of different motors even different speeds and pulleys sizes.

So it would be quite likely to find the same machine with different motors which may or may not both have centrifugal switches.
There is even one manufacturer who is now fitting electronic switches so we have a switching type motor design but no audible clues that it is of that design.

Bob
 
Hi Bob
Sorry to be so long getting back to you.
I unbolted back plate and pulled it out, with attached fan, as far as it wished to come, about an inch. I could see only the shaft, nothing else.
Took photo on iPhone, but forum rejects it as invalid, so will try to email to you directly.

Cheers
Terry
 
Hi Terry,

It rather looks like your motor does not have a centrifugal switch from what I can see but that is not consistent with the rubbing noise unless that was bearing noise in the motor of from any belts etc inside the saw.

This is a diagram of a typical single phase motor

Motorcircuit.jpg


Assume for now that the starting switch is closed all the time ie you don't have one.

Make sure the machine is unplugged from the mains!!

Locate the wires coming from inside the motor - seem to be the yellow ones in your photo. You might have four with two connected together or that connection could be inside in which case you will have three (maybe plus earth?)

Set you meter to read resistance (ohms or the Omega greek letter)

one of the three (four?) should go to the capacitor only connect one meter lead to that junction.
Measure the resistance to the common connection going to both windings ( far right on the circuit). Note the reading; this should be the resistance of the Start winding.
Put one meter lead on that common connection again and the other to the winding terminal that so far you have not tested. This is the left hand end of the top coil on the diagram. Note the reading; this should be the resistance of the Run winding.
I would expect both readings to lie in the range say 5-25 ohms

If your meter has a capacitance range (not all do) disconnect one end of the capacitor from the motor, short it briefly to the other capacitor lead (it may spark - we want to make sure it is discharged!) Then measure the capacitance of your old - maybe suspect capacitor. Note the reading it should roughly agree with the value printed on the case.

Please report back.

Bob
 
There are a couple of pros on the forum Terry, but the input of another would be good, hope to see you there.

Roy.
 
Hi Bob
I have tried to follow your instructions, but have had difficulty getting the info back to you through the forum.
Email with diagram of my saws wiring etc has been sent.
Regds
Terry
 
Bob completed diagnosis off line- problem was failure of starter coil windings. Solution a replacement motor.
Many thanks to Bob for his generous help and advice.
 
Hi I have recently received an electra beckum bandsaw.

The person I got it off said it worked but was not good to him as it didn't havery a kill switch.

I was also talking to another fella about it and he told me the motor went on it and that's why they got rid of the bandsaw.

I plugged it in and nottin is happening in changed the fuse and still nothing is there anyway of telling if I is the motor or could it be something else?
 
Did you check the capacitor for any bulging?
This is a common thing with single phase motors
You can buy them for less than a fiver, if there's no shroud covering it you can buy near any one
with the UF (microfarad) rating for cheaper, rather than one that needs to be a specific size to fit into the shroud.
Good luck
Tom
 
I have cheacked the capacitor and don't see or feel any lumps how else could I tell ifrom it is the capacitor?
 
Nothing to loose, at the very least taking the motor terminal cover off and having a smell.
If it smells suspicious like its burnt out, I would investigate further, it might be OK.
It may be clogged with sawdust either, so I wouldn't be in a rush to just be on the look out
for burnt windings.
Take the motor off and have a look, I suppose.
If you do decide to do so, draw a continuous line with marker or whatever, markings the length of the motor before disassembly, to aid putting it back together if its not obviously only one way it goes.
You might as well get a capacitor if you see nothing wrong with it, only costing less than a fiver.
Don't know much troubleshooting with single phase motors, only that it's nearly always the capacitor that's the fault.
It might clear up some things before someone more knowledgable comes along.
Good luck
Tom
 
Hi I had a friend look at it and it works it's something to do with the on and off switch that's not letting it work. He was able to bypass the switch so it would work. He doesn't know why the switch isin working so I think I need to buy a new one. I haven't really looked at it since last Friday so I don't know if I can clean the switch or just buy a new one. Have you ever heard of this happening before? Do I need a new switch?
 
I took it apart and Its clean I think something is broke in it as the switch won't flip unless I hold down a spring of some sort. I think I need a new switch or to find out how to fix the spring?
 

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