Drill tripping earth leakage protector

Do you have a question? Post it now! No Registration Necessary

Translate This Thread From English to

Threaded View


I occasionally visit an friend to use his drill press. He has been
having trouble with it for the last year or so as it has been tripping
his earth leakage protector in the fuse box. It only seems to do this
about 5% of the time, and only ever when turning the drill on (not
while it's running). The circuit breaker never trips.

I have pulled sections of the drill apart and fixed a few suspect bits
of wiring that may have been causing connection between active and
earth but the problem still persists.

The motor has a starter capacitor and this was the latest area where I
fixed some suspect wiring (by re-insulating it).

However, problem still exists.

Is it possible that when switching the drill on, the current and
voltage phasing during the in rush could be such that it is confusing
the earth leakage device (with I think is just a current comparator
between active and neutral?).

Any help in where to look to pinpoint the problem would be
appreciated. Is replacing the capacitor likely to help?

Cheers
Glenn
                                Glenn Pure
                       Canberra, Australia
Web page: http://www.evans-pure.net

Re: Drill tripping earth leakage protector



"Glenn Pure"

Quoted text here. Click to load it



**  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





Re: Drill tripping earth leakage protector


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:

Quoted text here. Click to load it


Re: Drill tripping earth leakage protector



Quoted text here. Click to load 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



Re: Drill tripping earth leakage protector


So?????  What does one do - chuck away the fridge?  Does mfg warranty cover
this situation?


David

David wrote:

Quoted text here. Click to load it


Re: Drill tripping earth leakage protector



Quoted text here. Click to load it
Best thing to do is to have a seperate RCD/MCB on each circuit. These are
very common know, and if something trips, only one circuit will trip, not
the whole house (makes finding what tripped it much quicker too).  Also,
as each circuit is seperate, then each circuit can have up to 30mA leakage
before tripping. If only one RCD is used for the whole house, then total
leakage for whole house is only 30mA. Problem with older RCDs was that
they would trip randomly etc, and take out the whole house, and if you
were not at home, the frige would stop, and you would have rotten food and
a terrible smell. If on indivual RCD/MCBs, then only one circuit would
trip. If the the fridge tripped on 30mA, then something is pretty wrong
with the fridge, and it should be fixed.

David

Re: Drill tripping earth leakage protector



Quoted text here. Click to load it

This must be a fairly recent change - when did this come in ?
 must have been in the last 6 years



Re: Drill tripping earth leakage protector



"Richard Freeman"

Quoted text here. Click to load it


**  Guess what year AS3000:2000 refers to  -  Richard.





............    Phil





Re: Drill tripping earth leakage protector


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.

Quoted text here. Click to load it



Re: Drill tripping earth leakage protector



Quoted text here. Click to load it
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 .


Quoted text here. Click to load it
message



Re: Drill tripping earth leakage protector



Quoted text here. Click to load it
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: http://www.evans-pure.net

Re: Drill tripping earth leakage protector



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.


Quoted text here. Click to load it




Re: Drill tripping earth leakage protector


On Thu, 28 Apr 2005 10:44:04 GMT, "FruitLoop"

Quoted text here. Click to load it

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


Re: Drill tripping earth leakage protector


Quoted text here. Click to load it

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

--
John H

Re: Drill tripping earth leakage protector



Quoted text here. Click to load it

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

Quoted text here. Click to load it

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

Mike Harding


Re: Drill tripping earth leakage protector


Quoted text here. Click to load it

That oughta stir up a few leccies!  :)

--
John H

Re: Drill tripping earth leakage protector



Quoted text here. Click to load it
Nope , that's when we turn off, engineers know everything, no point in
trying to explain anything to them!
JKM



Re: Drill tripping earth leakage protector



Quoted text here. Click to load it



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

Mike Harding


Re: Drill tripping earth leakage protector



Quoted text here. Click to load it
a
or
see

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 .







Quoted text here. Click to load it



Re: Drill tripping earth leakage protector


On Fri, 29 Apr 2005 03:42:30 GMT, "FruitLoop"

Quoted text here. Click to load it

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.

Quoted text here. Click to load it

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


Site Timeline