artyone Posted November 1, 2014 Share Posted November 1, 2014 Not big ones and only once the motor, electric 240VAC, is spinning. Almost as if the chassis is acting like a capacitor and the magnetic field created by the motor is being stored on the earth. Any ideas? Quote Link to comment Share on other sites More sharing options...
Yowzer Posted November 1, 2014 Share Posted November 1, 2014 Earth it. 2 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 1, 2014 Share Posted November 1, 2014 Lol. It can't be stored on the earth. The whole point of the earth is that it gets rid of any stray electricities that might escape. I think. Take a photo of the drill please. I want to ascertain that it is/is not suitable for the fab fails thread 2 Quote Link to comment Share on other sites More sharing options...
Nominal Posted November 1, 2014 Share Posted November 1, 2014 Suggest you stop using it until fixed (unless death wish). Check that frame is earthed properly as a starting point. Quote Link to comment Share on other sites More sharing options...
magpie-man Posted November 1, 2014 Share Posted November 1, 2014 Not big ones and only once the motor, electric 240VAC, is spinning. Almost as if the chassis is acting like a capacitor and the magnetic field created by the motor is being stored on the earth. Any ideas? Your earth isn't working if you are getting shocks. Unplug the drill press right away and pull it apart to check for faults. Lethal stuff 240 volts. 1 Quote Link to comment Share on other sites More sharing options...
h4nd Posted November 1, 2014 Share Posted November 1, 2014 Also check other earths in the system, faulty plug board? (more death awaits) Quote Link to comment Share on other sites More sharing options...
TheAudioDude Posted November 1, 2014 Share Posted November 1, 2014 The earth must not be connected because any charge build up or short to the case will go straight to ground and blow the circuit breaker/fuse. Are you using an RCD? Quote Link to comment Share on other sites More sharing options...
magpie-man Posted November 1, 2014 Share Posted November 1, 2014 Also check other earths in the system, faulty plug board? (more death awaits) Yep. There are two faults to be found. 1. The lack of earthing. 2. The leakage from the live phase.  You need to find and fix both of them. 1 Quote Link to comment Share on other sites More sharing options...
artyone Posted November 1, 2014 Author Share Posted November 1, 2014 Don't worry chaps, even though I don't know what I'm doing... I've done rather alot of it. And not to brag but 240 isn't so bad as my surface resistance is quite high... it's not nice, of course, and I don't like it, but it's nowhere near what others get who's skin surface resistance is in the hundreds of ohms... mines about 2 megs. Â Yup, plug point was going to be next and that would seem to be culprit... worn contacts or something. Quote Link to comment Share on other sites More sharing options...
artyone Posted November 1, 2014 Author Share Posted November 1, 2014 I'm tempted to spin it up and measure the voltage sitting on the chassis... I'm thinkin' about 70V. the other one might be to attach a light bulb across the windings of a small transformer and then hold the transformer in the vicinity of the motor powered up. This computer is on the same line and theres no other problems anywhere else so it must be the earth connection on the multi point. Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 1, 2014 Share Posted November 1, 2014 At a guess I'm going to say the wiring was done by you and the whole building is a deathtrap 5 Quote Link to comment Share on other sites More sharing options...
Llama Posted November 1, 2014 Share Posted November 1, 2014   as my surface resistance is quite high  Holy lol.  Computer will have an isolated power supply anyway. Not sure what your light-bulb idea is going to achieve.  Like everyone has said, earth the damn chassis before you make a darwin award of yourself. 1 Quote Link to comment Share on other sites More sharing options...
Yowzer Posted November 2, 2014 Share Posted November 2, 2014 Don't worry chaps, even though I don't know what I'm doing... I've done rather alot of it. And not to brag but 240 isn't so bad as my surface resistance is quite high... it's not nice, of course, and I don't like it, but it's nowhere near what others get who's skin surface resistance is in the hundreds of ohms... mines about 2 megs. Uuuhhhhhhh wot? Your own personal conductivity does not negate the fact that you are operating a very potentially unsafe electrical appliance. The hazards do not stop at you zapping yourself, that's your own dumb fault if you choose not to get it fixed properly. Others could unwittingly shock themselves, if it has an internal short it could pose a fire risk, so on and so forth. The chassis should be solidly earthed and run through a RCD. If you don't have an RCD, get one. If the chassis is not adequately earthed, get it fixed so it is. 2 Quote Link to comment Share on other sites More sharing options...
SOHC Posted November 2, 2014 Share Posted November 2, 2014 You can test your surface resistance by poking the relay big power lines with a steel pole 1 Quote Link to comment Share on other sites More sharing options...
artyone Posted November 2, 2014 Author Share Posted November 2, 2014 Been through it all, checking all the earths and the fault stopped when I changed the plug to another. It was piggy backed onto an extension cord which had an original PDL molded outlet end and that just happened to have a slight rattle in it which didn't show connections between phase, neutral and earth when still and shaken but I changed it anyways. Â First thing I did yesterday was check the switch on the drill press and the connections with the multi meter to see if everything was isolated and it was but it was still going shocky. Today I went through all the multi plugs, tested for isolation and pulled the cases for a visual. all good. Seems the only bit it could be ascribed to was the molded rattling plug end and that's been changed. Â RCD, good idea. I'll get one. 13 bucks. Used one once after I did a big wiring job building a recording studio for someone years ago. The electrician had me go and put it on every socket I'd put in and tell him if the light came on... which it didn't. But yes, I'll get some real soon. Quote Link to comment Share on other sites More sharing options...
artyone Posted November 2, 2014 Author Share Posted November 2, 2014 Sorry for seeming like a total unqualified dumb ass who flagrantly disregards all laws of common sense. I was building tube amps for quite a few years and performing with them and always tried to be as safe as possible by reading and asking questions especially when I actually found experts. I wired up my first building when I was 15, the little shed out the back, after watching like a hawk and asking multiple questions of the real electrician who did the hook up properly to the house. This is the first time this has actually happened in almost 40 years of doing wiring and I will find out why. Â As for the transformer with a bulb across the windings all wires passing a current generate a field of energy around them which can be picked up by another conductor in it's field. This is very relevant in tube amps with multiple signals at a high impedance running close to power at a low impedance. Often the old trick was, if running close together couldn't be helped, then the high impedance cables were shielded to ground or run at right angles which negated the phases aligning. The same method can be used to find current by aligning the lines of flux in a transformer within the electrical field generated by motors and cables. Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 2, 2014 Share Posted November 2, 2014 Jesus Christ. 1 Quote Link to comment Share on other sites More sharing options...
flyingbrick Posted November 2, 2014 Share Posted November 2, 2014 Don't worry chaps, even though I don't know what I'm doing... I've done rather alot of it. And not to brag but 240 isn't so bad as my surface resistance is quite high... it's not nice, of course, and I don't like it, but it's nowhere near what others get who's skin surface resistance is in the hundreds of ohms... mines about 2 megs. Yup, plug point was going to be next and that would seem to be culprit... worn contacts or something. Sorry. Had to add this. 1 Quote Link to comment Share on other sites More sharing options...
h4nd Posted November 2, 2014 Share Posted November 2, 2014 We grump because we care. Fix sparks, keep building 3 Quote Link to comment Share on other sites More sharing options...
DB8-TypeR Posted November 3, 2014 Share Posted November 3, 2014 As an electrician I can say that if you are getting shocks then the appliance is not earthed. Electricity is lazy and takes easiest way to ground (path of negligible resistance). So if you get a zap its because you are that easy way. So earth the drill and check all earths back to the earth peg. The voltage is NOT being induced by the magnetic fields. Its a small motor with minimal load, it cant happen. The insulation resistance of the motor is probably low mixed with a poor earth. If you have wired the place (dont care if you wired you first at 15 as it doesnt mean its been done right just that you have been potentially doing it incorrectly for ages) then be sure polarity is correct everywhere, that maximum earth resistance is less than .5ohm and that you have continuity. An rcd probably wont even work if your wiring is incorrect. 3 Quote Link to comment Share on other sites More sharing options...
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