Electric shocks with lathe

[Tiger]

Hi everyone,

While preparing to rough something down, I reached for the variable speed lever and felt what I thought was a minor shock:eek: , touched it again and yes it was a shock. Every metal component of the lathe gave out a shock. I attached the multimeter and it would give a reading from 12 volts to 100 volts (depending on where I touched) and then it would race down to 0. The shocks are only felt when the machine is on. Could anyone tell me what is going on?:confused: . BTW my lathe is the 900 b/w centres from Hare and Forbes.

[CameronPotter]

Sounds to me like it is trying to earth through the body of the lathe - ie dangerous. :eek:

Check your earth pin and also any other connections you can find (without it plugged in)!!

Cam

[A-Marks]

That sounds like leakage from the capacitor used to start the motor
IF you have Earth leakage detection devices installed (usually in your meter box) you should be safe but I'd have the lathe checked out by somebody qualified to do so.

[soundman]

NNNAAAAA:eek: :eek:
Sounds like insulation break down somewhere, but you must have some sort of earthing problem too.
No point speculating.
This machine needs a full set of standard electrical safety checks.
Electrician required if you don't have the smarts yourself.
Many of the machines I have purchased, sooner or later require " electrical revision".
I am constantly surprised at the lack of local electrical quality controll on imported gear across the board.

get it checked and made safe.
cheers

[CameronPotter]

:D That sounds suspicously like what I said...

(Although I should have said to get it properly checked out). :o

[Tiger]

Thanks for the replies so far. I have found that the capacitor is at the heart of the problem, but I'm not sure why. A few months ago, the original capacitor failed. Hare and Forbes told me it would be a couple of weeks before they could get one, so I sourced one from an air-conditioning place, however the new one was slightly different dimension, longer and a little more narrow so it didn't sit as snugly inside the capacitor cover like the original. For the past few months, no problem until yesterday. When I removed the capacitor cover and ran the lathe, no shocks:confused: . I retightened the connections put the cover on and the shocks returned:eek: . Is it safe to run the lathe without the capacitor cover? To use this current capacitor I could make another cover but what material is suitable, plexiglass, wood? I can't see any exposed wires, why is this happening:mad: ?

[hcbph]

Tiger

I suspect that when you are tightening the metal cover over the capacitor down, one of the wiring connectors is touching the frame somewhere. I'd try putting some electrical tape over the connections (basically insulating them) and put the cover back on. Does it still have an electrical leak? I would be reluctant to leave it that way as the tape could wear through over time due to vibrations. If it doesn't leak, you might be able to bend the cover a little to make the necessary space.
As far as a new cover goes, I think anything non-conductive would work so long as it doesn't fail due to vibrations.

I'm not an electrician, so this is my best guess.

Paul

[Ivan in Oz]

Tiger,
Could you pack out the Cover by a few Mill;
use some "compressable" packing which is NON CONDUCTIVE;
and Tape around the resultant gap between Cover and Body.
Something like this might get you working,
until it is repaired permanently.

[MICKYG]

Tiger

Make sure you switch off the mains power and unplug, and discharge the capacitor with an insulated screwdriver to earth before you get booted from the cap. They store quite a wallop, the bigger ones can kill if discharged through you body accidently. It does sound like you are installing the cover and creating your problem.

Regrads Mike;)

[Tiger]

Thanks guys for your input. I had put some insulation tape around the connectors but there is still some leakage. I will try some packing and see what happens, thanks for getting back to me so quickly, I hate being without my lathe for long.

[TTIT]

I've been in the electrical industry for 30 years and have seen too many people dead from mucking with problems like this when they are not sure of what they're dealing with. IMHO, you should get a sparky to fix it permanently - we don't need to lose a fellow turner before his time!:)

[Buzza]

Tiger, thanks for the info on lathes from Hare and Forbes. As far as I know, electrickery products must go through stringent standards testing in Australia.

Or have we done away with that good idea as well?

Buzza.

[hingston]

Tiger,

I have been a licenced electrician for more than 25 years.

My advise is to

Turn the lathe off, unplug from the wall and call an electrican or make a warranty claim if you can.

You can end up DEAD for the few lousy bucks you pay to get someone who knows what they are doing to fix it. It is simply not work the risk.

[Rossluck]

I havn't been an electrician ever, but your problem sounds scary to me because of an apparent total lack of earth leakage protection. Any shorting out of your lathe should instantly turn the power off.

Don't worry about the little shocks. That is not your real problem. Turn the lathe off, ask an electrician in to check (or install) the earth leakage circuit breaker, and then ask him or her to have a look at the lathe.

If I felt a shock from anything like that I'd be amazed and horrified that the earth leakage circuit breaker allowed it to happen.

[Tiger]

Dear all,

Thanks for advice so far. I think I've discovered the problem. The capacitor I bought had 4 tabs on it compared to the one that came with the machine which really only had 2 wires for connection. It seems that when one of the 2 tabs which aren't connected to the motor go anywhere near the metal cover then the shocks occur. By placing insulation tape over the tab and bending it so that it's not in contact with anything (as best as I can), there are no shocks:) . Does anyone know why the new capacitor had 4 tabs, can I remove the 2 surplus tabs without undermining the capacitor?

[Auld Bassoon]

Mate: as has been said loudly and in multiplicate: call a sparky!

[Tiger]

Discovered something interesting while having all these electrical problems with my lathe. The powerpoint that I normally use for the lathe does not seem to have the Earth leakage circuit breaker but every other powerpoint in the garage does:confused: . I would assume that if I use another powerpoint with the lathe that I will be safe until someone comes out to look at it:confused: .

[Gil Jones]

It is probably a dual capacitor, if you are connected to the correct terminals, you may 'carefully' clip off the others and/or insulate them with silicone rubber. Just ensure that they do not touch anything, and do not break the seal into the unit. Tape is maybe okay, but it could come loose. Look on the data plate, and you will see the capacity rating, a dual capacitor will be like > 30/3 &#181;f <[microfarads] (the numbers being the rating).
I also agree with the others that suggest you have it properly inspected. If you do not have "ground fault protection" on this circuit, you might consider installing it, it will help keep you alive.

[Simomatra]

I also have been a liscensed electrician for 40 years. As it is not pertinent to trouble shoot at a distance and with safety in mind you really should geta qualifed electrician around to

1. Test and repair the lathe
2. Find out why the power point is not connected to the earth leakage system
3. Test al your eatrh leakage controlled circuits with an approved teser to ensure they are working correctly

Electricity bites and usually does not give second chances. Is your life or one of the families worth the cost of an electrician for an hour.

Don't be misled and think plugging into the other socket will be safe

Think safety get it checked out!!!!

Unplug it until tested

[Tiger]

Have had an electrician come over and yes the powerpoint that the lathe was connected to did have a problem, the wire around the Earth terminal had come loose. We do have an Earth Leakage detector and it is working properly.

Asked the electrician about the capacitor. He seemed to think it was connected OK and possibly the motor was at fault. A couple of days later, the capacitor comes apart into 2 pieces:confused: . So I took the headstock/motor to Hare and Forbes, and on the phone they said they'd test it for no charge and give me another capacitor because they may have some spare ones. So I get there, and the bloke from the Service dept says it'll cost you $85 an hour to look at it and it will take a while for them to do that:mad: . I then told him what was stated on the phone and he reluctantly said he'd get one of the boys to test it but that I would have to wait in the store. 20 mins later he appears and says he thinks the motor's ok but that he couldn't let me have the capacitor he was using as it was a slightly different rating. He suggested that I order one of their capacitors and have them install it, all for about $100 :eek: as I would have to be charged for the testing of the motor (the lathe is only a few months out of warranty). I picked up a capacitor at an electrical store for $13, I bent the 2 surplus tabs out of the way and installed it. The lathe is working fine, but who knows down the track. There have been many threads regarding what sort of lathe to buy, the one I have bought is not the one to buy!

[journeyman Mick]

Tiger,
I think your treatment at Hare and Forbes shows a total lack of understanding of the term "customer service" by their staff. It left a bad taste in my mouth and I was only reading about it:eek: .

Mick

[TTIT]

Tiger - Glad to hear you got a sparky in to make sure everything is safe - wise move. :D
Not all that surprised to hear of the way you have been treated by the vendor of the lathe. I find more and more that it doesn't matter what color they paint it or how fancy the badge looks, cheap is cheap and the service is usually the same. The woes of being stuck in the bargain basement eh!:(

[Simomatra]

Tiger

Good to see that you are up and working again and your system, ckecked out by and electrician

As you are probably aware you only get one life as human not nine like the cats so err on the side of safety with electricity

[Stuart]

Tiger,
I think your treatment at Hare and Forbes shows a total lack of understanding of the term "customer service" by their staff. It left a bad taste in my mouth and I was only reading about it:eek: .

Mick

Hear hear