Dave Hounddriver Posted August 9, 2012 Posted August 9, 2012 I know this is off topic but it is an interesting bit of trivia. Back in high school physics we learned to take a fan and run it backwards so the motor generated electricity instead of consuming it. Not all fans can do this. But maybe the one Mike touched the plug of could. Out of curiosity, Mike, was the fan still turning when you got the shock? Link to comment Share on other sites More sharing options...
i am bob Posted August 9, 2012 Posted August 9, 2012 sometimes I get a shock when I unplug an appliance like a fan and accidentally touch the metal plug of the appliance even though it's not plugged in But the kind of shock you mention, I only get that when the appliance has a capacitor in it.. It's a fan. It could be a stored capacitor discharging, I can't think of another explanation. I'm careful not to touch the ends anymore. Your fan for some reason is picking up a static charge and not dispersing it on shutdown. Assuming you have not done any modifications to the fan, there are only a few reasons for this to happen. First thing to check - do you have a ground on the socket it is plugged into? Try a different outlet on a different circuit breaker or fuse - if it still does this, then that ain't the problem! Have you taken your fan apart and cleaned the dust and grime out? Wash the blades and use something sharp to get the hard to reach areas. Certain dusts can induce (and retain) quite a large static charge! Especially on a fan! Is this an oscillating fan and, if so, is it electronic or a mechanical set-up? Mechanical should make no difference but an electronic oscillator may have a capacitive circuit that is faulty. Do you have another fan or one you can borrow from a neighbour? Just to see if it does the same thing in the same outlet? If it doesn't, it's the fan... If it does.... ohoh! There are a few other reasons I could list but I don't think there have been any UFO sightings in your neighbourhood lately and thus I have ruled these out! :mocking: 1 Link to comment Share on other sites More sharing options...
CebuAndy Posted August 9, 2012 Posted August 9, 2012 Andy, this is not static electricity there are no rugs and it's a solid jolt definitely not static. Has to be a capacitor discharge, as Dave mentioned. The copper wire down to a short ground pole is exactly what we have on the electric water heater in the shower. I appreciate the advice but making expensive renovations on a rented house or apt is not going to happen. I'm sure the owner wouldn't mind though. Mike, you don't need a rug to create static electricity and chock, you just need to be on the same ground surface. Why did you get a chock when unplugging an appliance that was already turned off? The switch to the appliance is down stream from where the power comes in from the plug. Even though the appliance was turned off, >>> the appliance still had electricity up to the switch. <<< On a 3-blade plug, the ground pin is longer that the hot and neutral blades. When plugging in a device the ground is made first and when un-plugging the ground is the last to be disconnected. Taken that the outlets ares not grounded in most places here, electric fire chock is common. Was you holding the appliance when disconnecting? If holding the appliance, you were at the same ground potential as the appliance. By touching the 'hot' side of the plug when pulling it out, you became the return path for the electricity flow. If you had touched the neutral side of the plug when pulling it out -- you would have felt nothing. Anyway I'm not an electrician (just remember from Uni, so I better stop my mouth before I get people 'executed'), but in cases like this, you definitely need a electrician. Expensive renovation? Not necessary, might be P2-3.000 only (in a house), might be much more in a high floor condo. Why not ask a electrician? 1 Link to comment Share on other sites More sharing options...
i am bob Posted August 9, 2012 Posted August 9, 2012 I went back and read what you wrote again and I am wondering... how far are you and the plug from the socket when you get zapped? Just out or a few inches (or more)? Static electricity is simply a DC charge. Depending on what is causung it, you can build up enough for a mini version of a lightening strike. I'm starting to think that either the ground on you fan or the socket is faulty and allowing a large static buildup to occur - once it's unplugged and you touch the good electrical lead - ouch! It's easy to test for on both sides if you have a meter. 1 Link to comment Share on other sites More sharing options...
Jake Posted August 9, 2012 Posted August 9, 2012 I went back and read what you wrote again and I am wondering... how far are you and the plug from the socket when you get zapped? Just out or a few inches (or more)? Static electricity is simply a DC charge. Depending on what is causung it, you can build up enough for a mini version of a lightening strike. I'm starting to think that either the ground on you fan or the socket is faulty and allowing a large static buildup to occur - once it's unplugged and you touch the good electrical lead - ouch! It's easy to test for on both sides if you have a meter. If I might add a few more advise about troubleshooting: eliminate the easy stuff first -- visual and nose inspections often times resolve the problem; for future electrical/electronics problem, may I suggest buying an inexpensive digital volt meter (DVM) and learn how to safely use it. Speaking of safety, in your particular case MikeB -- in order to eliminate possible problems, does one need to expose himself to electrical shock? If you get bitten again, that means the problem wasn't resolve. In other words, you are exposing yourself again to eliminate all the possibilities. Unless, you are handy with a DVM -- you can safely measure floating grounds and voltage measurements on metal surfaces of numerous appliances. Best of luck to you MikeB -- Jake Link to comment Share on other sites More sharing options...
Adventurer Posted August 9, 2012 Author Posted August 9, 2012 I'm waiting for my good quality surge protector to arrive in a box soon and I will look into a proper earthing system when I have my own property in the future. For now though we have a manual earthing system in place, - watching for storms and taking out the main plug when we hear thunder, although we do realize light travels faster than sound ;) the ideas written from Andy, Jake etc are helpful cheers! 1 Link to comment Share on other sites More sharing options...
Jake Posted August 9, 2012 Posted August 9, 2012 I'm waiting for my good quality surge protector to arrive in a box soon and I will look into a proper earthing system when I have my own property in the future. For now though we have a manual earthing system in place, - watching for storms and taking out the main plug when we hear thunder, although we do realize light travels faster than sound ;) the ideas written from Andy, Jake etc are helpful cheers! Well, that's an idea I never thought about Adventurer. In case of pending thunder storms, pull the main fuses or shut off the main breaker switch to prevent spikes entering your home or apartment. You're more than likely be in the dark anyway. By the way, consider where you place the candles -- the winds could knock them down towards some flammables. Be careful out there guys -- Jake 1 Link to comment Share on other sites More sharing options...
MikeB Posted August 9, 2012 Posted August 9, 2012 Your fan for some reason is picking up a static charge and not dispersing it on shutdown. Assuming you have not done any modifications to the fan, there are only a few reasons for this to happen. First thing to check - do you have a ground on the socket it is plugged into? Try a different outlet on a different circuit breaker or fuse - if it still does this, then that ain't the problem! Have you taken your fan apart and cleaned the dust and grime out? Wash the blades and use something sharp to get the hard to reach areas. Certain dusts can induce (and retain) quite a large static charge! Especially on a fan! Is this an oscillating fan and, if so, is it electronic or a mechanical set-up? Mechanical should make no difference but an electronic oscillator may have a capacitive circuit that is faulty. Bob, there are no grounds on any outlets and that's par here. Your best chance of getting that is build your own house and supervise closely or buy an overpriced house that a foreigner built and left, in a rented house or apt slim to none of finding it, imo. It's impossible to troubleshoot because it doesn't always happen and I'm not too keen on getting shocked. I do have a digital multimeter I could test with. The fan has an electronic oscillator so you could be onto the cause there. I make it a habit to unplug all sensitive electronics like TV when I'm out for any time. Thanks. 1 Link to comment Share on other sites More sharing options...
MikeB Posted August 9, 2012 Posted August 9, 2012 The switch to the appliance is down stream from where the power comes in from the plug. Even though the appliance was turned off, >>> the appliance still had electricity up to the switch. <<< Yea, I learned that one when I started working on computers and stuck my fingers into the internal switch. Couldn't understand it at first because the damn thing was "off" duh. Thanks for the advice, I'll look into getting an electrician for an estimate. 1 Link to comment Share on other sites More sharing options...
Jack Peterson Posted August 10, 2012 Posted August 10, 2012 :unsure: An Older Electrician in my forces days once told me. ' We know How it works, We should know when it works BUT! Know one seems to know, Why it works.' :) Friday's food for thought maybe! :tiphat: 2 Link to comment Share on other sites More sharing options...
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