Another leccie question

How can this happen?
Everything in my workshop is working fine.
Suddenly the bandsaw starts to play up and trigger the safety switch.
I unplug it, reset the switch and everything works fine.
I plug the bandsaw back in and, before I even have time to turn the power on at the wall, the safety switch goes out again. It doesn't matter which powerpoint I use, the same thing happens.
I thought that, as long as the powerpoint is off, there is no connection to the power but STILL the switch gets triggered.
If there is a white elephant to be bought, I will be the one to buy it :(
Can a possibly damaged cord do this?
I cannot remember anything happening to the cord but, hey, anything is possible in a workshop.
Wolffie

either an extension cord or cable in the wall has been damaged, and is creating a path to earth. it could possibly a loose connection at a powerpoint into which dust or moisture has entered.

Wolfie, for your own safety, get a sparky to check the Bandsaw and your shed's electrical system.

I would if I could but I can't so I won't.
It is easier to pull teeth on a chook than to get a sparky to come out here, too many much more profitable jobs around on the farms.

"Sorry, we are too busy to travel that far, maybe in 6 months!!":(

It is only the bandsaw that is causing the problem. MIght be cheaper to buy a new one even though this one is less than 6 months old.
I have tested all the wires on the machine with the multitester for conductivity and cannot find any problems even when wriggling the wires vigorously, the magnetic switch only shows contact when on, as soon as I release it (pretending there is no power on it) there is no contact.
I wonder whether this thing condenser? could cause the problem seeing it is intermittent?
I do not know how to test it.
If I use an extension cord to another part of the house, the same thing happens, so I do not thing it is the electrical system in the house.

Wolffie

I was reading on another post about multiple RCDs.
Here is a pic of my circuitboard, do I need to have another RCD installed?
http://www.woodworkforums.ubeaut.com...chmentid=73251
The incoming power is 40A.
When we had the circuitboard installed, we thought it better to have several circuitbreakers installed, in case something short circuited but was told one RCD was enough, as we never use that many things at the same time.
Wolffie

What an electrician would do is to isolate the problem.

They would disconnect the motor and see if was causing the problem, then the wiring between the switch and the motor etc until they found what was causing the problem.

With the cord disconnected from the power point, ask an electrician to measure for continuity between active and neutral, active and earth and neutral and earth. There should be no continuity between any of these terminals. If there is, that will be your problem.

I am not suggesting that you perform these tests because it sounds like you are not a qualified electrician and that would not be legal.

Quote:

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Originally Posted by Wood Borer

They would disconnect the motor and see if was causing the problem, then the wiring between the switch and the motor etc until they found what was causing the problem.

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The point is that if his description is correct the motor has absolutely nothing to do with the issue (at the stage he is at) because the switch at the wall is still off. It should be isolating the component from the power. Open circuit.

It really sounds like the switch at the wall has fried itself at a minimum and is no longer working correctly and causing a short when a cord is plugged in either because the motor is blown or the outlet itself is shorting internally when pins are inserted. An electrician would probably change over the outlet with a new one because it's obviously failing without a doubt since it's no longer isolating correctly. Don't need to do any tests if the description is correct.

That's be my guess if the fuse is being triggered even if the switch is off.

You'd then need to see whether the bandsaw itself suffered damage from the powerpoint short or was the one causing the damage. You know that if it happens again it's most likely the bandsaw once it powers on again.

Edit: Actually reading the problem again you say it happens on all switches. You didn't try to plug the bandsaw and run it from the other switches did you before coming to this conclusion. Perhaps your safety switch is on the way out though your outlets should isolate anyway. Certainly a werid problem. Hell the power points may be incorrectly wired in the first place would be my guess if it's a happening on all of them. Who knows. Best to get a pro in for something like this.

Wolffie, your RCD is doing exactly what it should be doing. There is a fault in the appliance. Whether the GPO is switched on or off, the very act of plugging in the cord is tripping the RCD and so it should be checked out.

Try plugging another known appliance into the same GPO and I'll bet pounds to a pinch of wallby poop that it doesn't trip the RCD. Process of elimination => appliance faulty.

Mate you have the same problem as before

https://www.woodworkforums.com.au/showthread.php?t=71539

Two things IMO it can be

!/WIreing
If you plug a another appliance into any Power point on the circuit that keeps tripping and the RCD don't trip Its not wiring its probably the Band saw.

2/ The RCD is detecting a low resistance between the neutral and earth in the appliance
IE when you switch off the power point the switch is only in the active conductor so it still sees the fault between neutral and earth.

A sparkie has a measuring instrument Commonly called a MEGGA that measures Insulation resistance.
You problem would be found within a few minutes.
But as you said you are having trouble getting one My suggestion if possible is to take the band saw to them

Quote:

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Originally Posted by Wood Borer

What an electrician would do is to isolate the problem.

They would disconnect the motor and see if was causing the problem, then the wiring between the switch and the motor etc until they found what was causing the problem.

With the cord disconnected from the power point, ask an electrician to measure for continuity between active and neutral, active and earth and neutral and earth. There should be no continuity between any of these terminals. If there is, that will be your problem.
No continuity between these points at all

I am not suggesting that you perform these tests because it sounds like you are not a qualified electrician and that would not be legal.

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That is what I meant when I said we have tested all connections and wonder whether it could be the condenser or whatever it is called in English.
I was a sparkie in a different country many years ago, in the times of porcelain fuses, before curcuit breakers and safety switches came in, hence I do know how to test for continuity, although I may not know the English terms for things.
Wolffie

Quote:

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Originally Posted by montiee

The point is that if his description is correct the motor has absolutely nothing to do with the issue (at the stage he is at) because the switch at the wall is still off. It should be isolating the component from the power. Open circuit.

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It would depend if the switch in the GPO only switched the active. If there was a path between the Neutral and Earth then this could be the problem was my thinking.

Remember he has tried it in other GPO's with the same outcome.

Quote:

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Originally Posted by nev25

Mate you have the same problem as before

https://www.woodworkforums.com.au/showthread.php?t=71539
Two things IMO it can be

!/WIreing
If you plug a another appliance into any Power point on the circuit that keeps tripping and the RCD don't trip Its not wiring its probably the Band saw.
Yes, it is the same problem as before but we thought it was the power wires and did not realise it only happened when the bandsaw was connected.

2/ The RCD is detecting a low resistance between the neutral and earth in the appliance
IE when you switch off the power point the switch is only in the active conductor so it still sees the fault between neutral and earth.

A sparkie has a measuring instrument Commonly called a MEGGA that measures Insulation resistance.
You problem would be found within a few minutes.
But as you said you are having trouble getting one My suggestion if possible is to take the band saw to them

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Thank you Nev, in that case I feel more confident about claiming warranty, I would feel such a fool if it was my wiring.
Oh yes, what I used is called an ohmmeter but I do not have a megger. Call it early onset of partsheimers :rolleyes:
I guess, I could take the white thingy (condenser?) :D and have it tested?
'cept it is crimped onto the motor wires.
Suppose, the motor weighs less than the complete unit.
Sometimes it is a bummer living in the middle of nowhere.
Oh yes, what I used is called an ohmmeter but I do not have a megger. after that many years I STILL have to learn the English terms :B
Wolffie

Quote:

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Originally Posted by scanfor

Wolffie, your RCD is doing exactly what it should be doing. There is a fault in the appliance. Whether the GPO is switched on or off, the very act of plugging in the cord is tripping the RCD and so it should be checked out.

Try plugging another known appliance into the same GPO and I'll bet pounds to a pinch of wallby poop that it doesn't trip the RCD. Process of elimination => appliance faulty.

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Exactly the conclusion we came to but I just wanted to be sure..
Any other appliance in the powerpoint does NOT trigger the RCD but the bandsaw plugged into another powerpoint DOES.
It was a process of elimination that led me to the white thing whatever it is called in English.
Wolffie

white thingy = capacitor

25 microFarad => probably for motor starting, not power-factor correction.

If it has failed, then usually the motor will not start, but just hum until you turn the motor shaft by hand and then it will spool-up.

It could be "leaky" though and causing some problems with the RCD. If an electrician took it out of the circuit to prove that it stopped the bandsaw tripping the RCD, then he'd have to be very careful that it was not still holding a charge - Bzzzt/Flash/Ash.

Quote:

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Originally Posted by scanfor

white thingy = capacitor

25 microFarad => probably for motor starting, not power-factor correction.

If it has failed, then usually the motor will not start, but just hum until you turn the motor shaft by hand and then it will spool-up.

It could be "leaky" though and causing some problems with the RCD. If an electrician took it out of the circuit to prove that it stopped the bandsaw tripping the RCD, then he'd have to be very careful that it was not still holding a charge - Bzzzt/Flash/Ash.

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Thank you, warranty call tomorrow:)

:think2: Would it be an idea, if and when I can get a sparky to attend:fingerscrossed:,to have separate RCDs for House, Shed and Workshops?
Wolffie