Drill tripping earth leakage protector

"Glenn Pure"

** Fit a 0.1 uF 250 volt AC rated suppression cap across the switch - bursts of radiated RF energy can trip an ELCB.

Also consider replacing the switch as it may have burnt contacts causing the arcing.

............... Phil

While it may be completly irrelevent to your problem, it may be of interest that when an electrician was installing an earth leakage breaker in my home, he mentioned that many fridges will trip the breaker even though they are not faulty, and that I should install a non-protected outlet for the fridge. I did.

David

Glenn Pure wrote:

Glenn Have you tried using a different RCD or ELCB? What Wattage/HP? Has the drill got a built-in electronic varispeed control? If so, there may be unwanted leakage to Earth there. Regarding Phil's suggested 250VAC 100nf cap, it could have a 100r 1/2W resistor put in series with it.

This is not legal any longer. While allowed under the older wiring rules, the current AS3000:2000 do not make an exemption for RCD protection on fridges.

David

may

Also, What is the actual insulation resistance of the windings .You need a

500 Volt Meggar or equivilent for this test . Maybe the insulation resistance is a little low , due to infrequent use or possible minor damage .

You need to do this first to acertain the actual resistance to earth to see if its a problem before the switch mod .

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Thanks for various suggestions. I don't have access to a megger so won't be able to check. The drill is fairly old single speed so it may have some insulation breakdown. If so, would this typically only manifest at switch on?

The switch mod sounds simple and inexpensive so may be worth a try anyway. The switch was replaced recently so unlikely that faulty switch is the cause.

Cheers Glenn Glenn Pure Canberra, Australia Web page:

GP If the insulation is breaking down, and it's getting old, I think you may deserve a new varispeed /2-speed drill (with reverse rotation, if poss) with a good-sized 15+mm chuck. Assuming the stand's adjustable grip will accommodate the new collar, of course. At least 500W for a bench-press drill. A "hammer" facility may be standard, I believe they are inexpensive nowadays.

Phil is, most likely, quite correct. I have a double insulated vacuum cleaner which does not even have an earth pin on the 240V plug and I can reliably trip the ELCB by switching it on and off a few times.

Mike Harding

Or, it might be time to have your wiring checked!... Snipping the earth pin usually fixes those sort of problems. :)

-- John H

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Whats the brand and tripping current of the core balance unit ?

Im not sure but I suspect 20 ma is the most common on switchboards

The problem is the better the core balance unit , the smaller the tripping current.This gives better people protection , however nuisance tripping can occur and thats the balance .

I suppose the other argument could be to have a larger tripping , current core balance unit , but you need to find out from an electrician what is the maximum allowed under law .Also would cost too much unless the workshop has some legacy power tools around that may intermittantly trip the protection devices .

Merlin Gerin - 30mA, but you'll find that will be the maximum current it is supposed to trip at - the minimum from unit to unit may be less.

Of course and therefore one would expect it to trip at random times, perhaps more often on very damp days for example but it doesn't - however I can always make my vacuum cleaner trip it.

Mike Harding

I'm an electronics engineer - I _know_ how to check wiring.

As I said: the vacuum cleaner doesn't have an earth pin.

Mike Harding

That oughta stir up a few leccies! :)

-- John H

Could that be due to voltage & current being out of phase or something? I'd be surprised that RF switching hash could be strong enough to trip an RCD.

Nope , that's when we turn off, engineers know everything, no point in trying to explain anything to them! JKM

And what would you wish to explain to me about testing wiring? It's hardly rocket science, is it?

Mike Harding

As I said previously, I think I (and others) have already explained what RCD stands for and how they work quite comprehensively. The fact that you keep repeating the same question over and over again leads me to suspect that you still don't quite get it, which is fair enough, I guess they are relatively complex devices, depending upon your level of knowledge and experience.

Perhaps if you could contain your anger and frustration just a little and try and express which bit confuses you. I'm not suggesting I'll be able to help, but perhaps somone a little more knowledgeable in this forum can step in and educate both of us!

Goodness me Phyllis! Do you think you would manage OK if you only made about three posts a year?

Mike Harding

Really? I could have sworn he was a some spotty teenager, priapic with frustration, rage and unsatisfied needs. The fact the he might be as old as you say is kind of scary.

Frankly I have no desire to confront him - from what you say he sounds like a bit of a sad case, and while his attitude and conduct is repulsive, I can't see how beating up the poor fellow would help anything.

As you suggest the wisest approach is probably to ignore him - I do apologise for extending this thread into a kind of "flame war".