Thread: Waldown 8SN/Workmax tripping power

Hi everyone, I'm new here, but I've learned a lot from reading your posts, thanks for sharing all that.

Anyhow, I've "borrowed" my old man's drilling machine, told him I'd give it a clean, and do some restoration, have been using it nearly every day though, have been reluctant to pull it apart, outer and cosmetics only so far. All aside.

Today when using the drill on a soft block of wood, I flicked the switch on and it tripped the 20A safety breaker at the switchboard back near the meter that runs my whole shed.

I reset the breaker, moved the plug to a wall outlet in case it was a power board issue (I know, it should have been there in the first place, shut up ), and tested again, same result.

So now I'm wondering where to start in terms of diagnosis, troubleshooting and repair, I'm hoping you kind folks could guide me. Preamble complete.

Is it really obviously or likely a blown motor?
Should I even attempt to look at it, or leave it until I can get a sparky?
Are replacement motors available?
Any of you interested/able/qualified to work on it for me?

I'll post some images that should help identify the model, let me know if there's anything else I could provide to help figure it out.

Welcome to the forum.

To state the obvious, something in there is shorting out. That's about all that can be said with confidence at the moment. It needs someone who is electrically savvy to trace through the system. It could be wires in the plug adrift, a broken switch or a bung motor. My first thoughts would be that it is likely not the motor as the breaker is going when you hit the switch (the switch is the part that I would try to rule out first).

One question I would ask - Do you (or did your father) blow down the drill with air to 'clean' it? I ask because I once had a machine that was (intermittantly) not running and it was because fine swarf had been blown into the motor and causing issues there. Another piece of information to add to the mix

Michael

That's good thinking Michael, thanks.

I'll make a start by checking the cables and open up the switch box.

Definitely blew a bunch of dust around, including aluminium so there's a chance that's a cause too.

I've asked an electrician friend to come over, says he'll bring his Mega, whatever that is, but couldn't hurt for me to get it open and visually inspect before he can get here.

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I'll send some more pictures with it open as I go.

Is the breaker that tripped just a circuit breaker, an earth leakage breaker, or a combination of both? If either of the last two, the breaker would have a button marked TEST as well as the ON/OFF paddle.

An earth leakage breaker (safety switch) will isolate the circuit being supplied if it detects a current imbalance between the supply and return cables greater than typically 30mA. Faults that trigger this type of unit are invariably caused by a leakage path between either the supply cable and earth or the return cable and earth. This could be debris in switch housings, junction boxes or the motor, a pinched, frayed or crushed cable, a damaged winding within the motor shorting to earth, or a similar failure in the motor capacitors or starting capacitor switch within the motor.

A common circuit breaker will trip immediately if there is significantly more than the rated current shown on the face of the breaker passing through it. It can also trip if currents a little greater than rated flow through the breaker for a reasonable time. Basically, they should pass the rated current indefinitely without tripping, and trip for currents exceeding the rating progressively quicker as the excess current increases in magnitude. Thus they protect against the circuit being overloaded short term, e.g. switching in another significant device when the circuit is already loaded close to rated current would trip a short time after the device is added, or against excess current caused by a major fault like a short to ground.

A combination unit monitors for and trips out if the current exceeds rated current or the supply and return legs are out of balance, i.e. either of the above circumstances.

Providing info about the type of breaker would help us to suggest areas to investigate. For example Michael's suggestions above are relevant for a common circuit breaker, but don't seem to suggest much for an earth leakage breaker or the earth leakage element of a combination breaker being the issue. For these, some common things are pinched or crushed cables, damp dust, spider web or insect infection into junction boxes or the motor and similar things that cause low to moderate currents to flow to earth.

One final thought, was the unit protected with an earth leakage breaker when at your father's place. Earth leakage detectors have been compulsory for some time for new installations or installations that have had any form of upgrade, but there could still be plenty of older installations that have not been retrofitted with them. If your father's place was one without earth leakage protection, it's possible that an earth leakage fault has existed for some time but not detected because there was nothing to detect it.

A Mega is an insulation tester that operates at a variety of high voltages, typically selectable between around 200V and 1000V. A typical multimeter can measure resistance or insulation but uses 9V or less as the test voltage. This low voltage measurement can mask faults that are caused by components leaking or failing at higher working voltages, and a high voltage test with a Mega type meter is the best way to detect and isolate these types of faults.

Hey Mal, tha ks for the detailed explanation, the thing that tripped is this

20220508_103745.jpg

From your description that makes it a circuit breaker. The route back to there has it going through another circuit breaker in the shed for the power point, and one for the whole shed circuit. I can't recall if I had to reset the shed ones because I mucked about with them after the trip before I started paying attention.

The drill has been 'up at the farm' for years, not in use there, so I couldn't report on the previous situation.

I should have time to open the switch box today to check for scraggles.

Thanks again, Linc.

Thanks Mal, it's a circuit breaker by the looks

20220508_103745.jpg

It does go through these switches in the shed as well, can't recall if they were tripped as well cos I stuffed around with them when it first when out

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It has been up at the farm and not in use for tears, so I couldn't speak to the previous situation of earth protection, I imagine not.

Thanks to everyone watching, I've opened up the switch box, it looks pretty tidy to me:

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There's only a little bit of very fine crud, can't see anything that looks like enough to cause a short in the switch
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The motor on the other hand, a fair build up of sticky dust+ in the top near the drive spindle:
20220508_150901.jpg

This gap looks like a place where chips could be blown in to the motor housing by my haphazard use of my blower eh Michael:
20220508_151914.jpg

The underside shows me that there's an easy way in there for cuttings etc, not sure about the top. What's the big red button do?

20220508_151844.jpg

The big red button is normally for resetting the motor after it has been tripped.
https://inspectapedia.com/electric/M...%20motor%20off.

You could try a reset and see what happens. Steve

Hi Linc,

That red button is the motor thermal trip. You can press it to reset the thermal trip !

Steve beat me to it

This connection came loose from its terminal when I was testing for continuity and resistance with my multimeter:

Attachment 398437

Also, I've tested the lead, when I move it about and flex some, there's a position where the positive is disconnected.

I've just checked the negative as well, there's a cable flexing position where that cuts out too.

I checked for continuity between the positive and negative terminals on the plug, its reading connected, with about 7 ohms resistance when the switch is in the on position, so through the motor. I have no idea if that's normal or short, or if that test even makes sense.

Ah so not this kind of little red button then:



I've pushed said button, did not click, I think the motor hadn't thermally cut.

FYI also checked that it still spins, though for a minute it could have jammed and current spike from not being able to move, but seems to move normal, freely as expected.

Sounds like an issue could be with the lead then. Replace and continue on...

Michael

Something isn’t right with that switch box. Looks like there’s an active and neutral switched to each other and an active and neutral joined to each other. At the very minimum the wrong colours have been used on one of the cables.
Have you had the wires off the switch?

Racing tadpole for the win!

My sparky mate Jack Cameron over

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Tested with the Mega:

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Popped this cover off to check why the wiring is unusual

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And concluded that the wiring at the switch is indeed off, which might have been masked by no circuit breaker at the farm.

He tells me that they had switched the earth. I don't think dad would have done it, so maybe it's been that way since 1978, or from so.etime during its service at the tafe.

Anyhow, it's re-wired now, safe and working.

Thanks very much all!

The neutral was being switched, not earth.