Jet JWBS-16 Bandsaw - electrical issues

[kmcleod]

OK - to answr some of the questions and clearly sarcastic comments...

Yes - I am electrically qualified, though not working as a sparky day to day.

No it didnt die when in use, i.e. cutting something, though I had been using it that morning, so it did work, then it didnt.

Yes, I am 'taking it apart' so that I can isolate the electical parts, and take parts out the circuit to test them individually, - a good multimeter is a useful tool.

The electrical cable from the saw to socket - commando socket on one end, 3 pin plug on the other with a 13amp fuze - which has worked absolutley fine for the past two years, but switching it out for a 16amp isnt a big deal, so will do that as part of the fault finding.

Is it an earth fault - I beleive so, but as i said above, until I get this 'taken apart', and check every wire and connection in a logical way, step by step, I wont know.

 

[Spectric]

Just an observation, you do not state location in your thingy but are you in the states? Reasoning is that you default to using fuze and not fuse which I believe may be an American term.

 

[Distinterior]

He is in the UK as he stated so in his first post...

 

[Spectric]

Yes missed that but perhaps an American heritage!

 

[Distinterior]

Yes missed that but perhaps an American heritage!

Check the NVR switch first, as I suggested earlier. Although these type of switches are supposed to be dust proof, inevitably they do suffer from an ingress of sawdust over an extended period of time. Cleaning it out certainly solved my similar problem.....

 

[Stevekane]

Yes missed that but perhaps an American heritage!

And maybe giving off american voltage!,,spooky or what!

 

[TRITON]

Im going to throw a wild possible out. Is there dust in the safety switches, that are usually to be found on the doors, to prevent opening when running.

This is a prob ive encountered twice. The first time was a mystery, and i waggled the wire, changed the fuse. hit the nvr switch several times and shouted at it too, but to no avail. Then i decided to clean out the dust as it hadnt always had an extractor attached to it and put the hose over the safety switches to remove any dust that might have gotten in, and it worked after that, 2nd time i just hoovered the safety switches and it started operating properly. So I'd suggest that as part of the process of elimination.

Mine is a record power BS250, and its been in use since about 2001, and nothing,except the dust in the safety switches has presented itself as a problem in all that time.
They are simple beasts, theres really not a lot to them. If the motor or anything electrical fails, you can usually smell it. If theres no ozone type smell I'd suggest something else, and simple as there are the only thing can be the motor and its gubbings, the switch, or the safety switches, outside of those theres nothing that can go wrong to stop it working.

I take it you've also looked at the main switchboard ?, see if anything there has tripped, or tried something else in the socket it uses

 

[Spectric]

to prevent opening when running.

wrong way round, to prevent running when open, and a good point but they would prevent operation and not result in the RCD tripping.

 

[TRITON]

wrong way round, to prevent running when open, and a good point but they would prevent operation and not result in the RCD tripping.

well thanks for that, but i guess thats exactly what i meant. you can open the doors but that trips the safety switches. And opening the doors while running trips the safety switches.

 

[kmcleod]

the trip is immediate.

Have decided that I'm going to swap out the 13amp three pin, Currently that plugs into a commando, so going to swap that out and put in a dedicated circuit for the saw in the workshop with a commando socket, and have a commando to commando lead just for the saw. Luckly there is room in the box in the workshop that will let me do it, and feed from house is sufficient, (having had a chat with my mate the sparky last night, he confirmed what i am planning will be fine.)

That will take care of the feed issues, now just need to find the earth problem....

 

[kmcleod]

so,,,at the weekend I took the monster apart. carefully removing the electrics, all still connected and putting them the bemch so i could start the process of tracking down, just where this fault is.
started at the power in, and plug to commando on the back - all fine, then thought, hold on, start at the business end - the motot/capacior - if its one of them, its potentially expensive, so carefully wired power direct to the motor, (Bypassing the switch etc), and switchec on - and the trip tripped - so its either the capacior or the motor.
carefully disconnecting everything (after cutting the power connection), started taking apart the motor/capacitor, and when i removed the cover and plastic caps from the capacitor, got the tell tale smell of something not right.
At that point i ran out of time - so next step is to put a multimeter across the capacitor and see if its blown or not......

 

[kmcleod]

30th June Update...

Its not the cpacitor - its showing 18.6 microfarad and its rated at 20, so thats fine, so the chances are its the motor itself - so have started stripping it down!

Interestingly - contacted Jet, who referred me to the distributor in the UK - ToolFrance.

Have to say the response has been really, really disappointing - they dont seem to have manuals, circuit diagrams or anything in relation to this bandsaw, which i now know is discontinued - and you can guess where thats heading.

Been chasing round in circles for days on this, and Tool France / Jet / JPW Industries have been less than helpful and are now saying I have to ship the entire bandsaw to Rugby, (I live nr Galsgow), so thats about 300miles, for them to do diagnostics.
Which will cost quite literally £100's to do

So now I'm looking for a replacement motor - any ideas ?

 

[Nick.]

Hi KM, If you want the manuals (2002 edition) and exploded parts views etc feel free to mail me direct and I'll send them as PDF/word files.

I don't have any circuit or wiring diagrams though.

Cheers, Nick
[email protected]

 

[Ttrees]

I don't know if it helps but might as well try an insulation test if you're quite familiar and have a proper megger.
Or open it up to see if it's clogged with sawdust, or something like that.
If the motor doesn't smell bad it's probably good.

 

[MorrisWoodman12]

Just a thought: capacitor measures 18.6uF but, as you may have an earth leakage fault, is there a conductive path from either capacitor terminal to it's case?

 

[kmcleod]

so last night I got the motor stripped down - and yep, its toast, clearly a burn out in the wiring in the motor, so new motor it is.

ToolFrance came back - JWBS16 motor is no longer available, had to tell them the JWBS18 fits - and they quoted me, (you may need to sit down for this) - £800, just for the motor !!

So not an option - looking a single phase, 3hp, 230V motor now,,,if that fails, its junk the bandsaw, and start saving the pennies to afford a new saw..

Oh Fudge ¬!!

 

[Spectric]

I would hope the motor is not a special, probably flange mounted and certainly not £800, their attitude is that of a company that is sell and forget which implies their machinery is a clone of something else and they do not want the bother.

Try Electric Motor Rewinds and Electric Motor Installations - Glasgow & East Kilbride and they may be your solution.

Here is a manual and it looks like the motor pivots to tension the belt, not helpful as many use a manual tensioner with a fixed motor.

 

[kmcleod]

Hi Roy,,thanks for the link, I'll definately give them a call.

You aright, the motor mounts to a plate which pivots to tension the belt.

 

[Distinterior]

Not sure where you are located @kmcleod but here is another option for you.....

https://www.colchesterrewinds.co.uk/workshop-services/repair-rewind-and-overhaul

 

[Sheptonphil]

There are many companies countrywide who rewind motors, we have two within fifteen miles.