Kitchen Large Electric Appliances - Shocking disposal

Hello all, I've recently installed a garbage disposal in our cabin where there previously was not one and I am having issues with grounding it I suppose. I have yet to be shocked, but my dad and my wife have both been shocked when using the disposal. The shock happens after they turn it on and when they are pushing food down the disposal (other words they are touching the sink--which is stainless). For the electrical, we tapped into an existing 2 wire circuit and ran it to a switch to interrupt power to the disposal. Anyone know the best route to take to stop the shocking!?

Stop using it immediately! :eek: I'm not an electrician, but one should be along with the specific fix. Your wiring is not three wire? You have a very dangerous hook up with no ground. No mention of this in the instructions?????

How old is the disposal? It's windings could be failing. Your safest option assuming the disposal is not failing is to run grounded cable from your main panel to the garbage disposal. Being careful to NOT touch the garbage disposal using an analog multi-meter measure voltage between a bare spot on the GD and a pipe or faucet. If you get a voltage reading of more then a volt or two junk the garbage disposal.

With out details it could be your present circuit but your present circuit is not suitable from what you have said. If the circuit is not grounded you should not have tied into it. NEC prohibits extending an ungrounded circuit.

The disposal is new--bought it specifically for this install. I just contacted my father who is at the cabin presently and he reminded me that it was a 3 wire install--the bare ground wire is installed to the disposal. Sorry for the confusion. Also had him measure between the disposal ground lug and the faucet. He is getting 116.2-118.2 V! This seems a little high, you think?:eek:

You can NOT use the GB in its present state. Disconnect it NOW to prevent its accidental use.

If it is installed with a plug I would plug it in to an extension cord plugged in to a receptacle with a known good ground and check again for voltage to plumbing. If it isn't wired with a cord and cord cap I would probably do that and run the test but you have the other option of testing the wiring.

Always turn off power at the breaker/fuse box before working with connections.

If it is hard wired before disconnecting check the black wire is fastened to the brass screw and the bare or green wire to the green screw. Now disconnect the cable from it and move it to a point that is easy to reach with individual wires not touching

Restore power and with a volt meter check between black and ground black and white and white and ground. also check ground to water pipe and white to water pipe. Turn off power and cap wires with wire nuts. Restore power and post back.

Won't try and put out any advice..plenty of that already.

I'm just wondering if the plumbing system was used as a ground? And possibly there have been some repairs?

"Restore power and with a volt meter check between black and ground black and white and white and ground. also check ground to water pipe and white to water pipe. Turn off power and cap wires with wire nuts. Restore power and post back."

They know not to use the GD, so no worries there! Looks like I will have to check voltages as you stated when I go up tomorrow. No internet access up there, so I'll have to post my results when I return on Monday! Thanks a bunch for your help on this--it is an annoying problem. Just to make sure I understand right, I have 3 wires going to the disposal--black, white and bare. I need to check voltage between black and bare, bare and white, and white and bare. Also need to check voltage between black and water pipe, and white and water pipe. Hope I'm understanding this correctly! Thanks again for your help. I will positively be posting back as you know much more than I do!

Yes, you are correct and be careful.

If I had to guess though I would suspect the GD even though new. I have seen wet sludge build up in the connection box of a GD only a few days old.

Gunguy45 also has a very valid point. I'm just wondering if the plumbing system was used as a ground? And possibly there have been some repairs? Check if the service panel has a ground to both the plumbing and a ground rod. If galvanized pipe has it been repaired with sections of PVC/CPVC or other plastic pipe?

I will definitely check the grounding issue, including gunguy's suggestion. Thank you both for the information. Also, good to know about the sludge build up problem you mentioned. In my mind I've been discounting that it could be the GD! Thanks again.

I don't think you understand. You CANNOT extend a 2 wire circuit. Run a new circuit for the GD from the circuit breaker panel.

I'm not an electrician but....

You could have a hot neutral. If the hot wire was connected to the neutral connection on the disposal, (where the white should go) then the disposal housing would be energized. The ground can't be good or it should have tripped the breaker. If there is voltage (a shock) when the switch is off then the wrong wire is switched.

Even if the wiring is right, there could be a voltage between the neutral and ground if the panel is not grounded properly. If this is the case then other fixtures could be a shock hazard too.

You should probably have an electrician look at this.

To the OP .,,

This is very serious situation right now as other poster tell you stop running the dispoal unit now.

Did you add a repectale for garbage dispoal unit ??

And the wall switch ?

What type of two wire conductor / cable it is now ? you have grounding conductor aka bare copper wire in the romex cable ?

Here what you have to do this in correct sequine.,

Unplug the unit if cord/plug attachment

Get a simple three light receptale tester to see what conferation you are on now.

You should not have hot and netural reversed at all you will have to pull the switch and recpetale to double check the connections and colours placement

all the black conductor are on brass colour screws and white conductor aka netural it will be on silver screws.

But if switch loop format PLEASE Pay attetion to the white conductor if that the case it MUST be marked with tape or marker so it is hot conductor { which way the power is comming in ? at the receptale or at the switch and where you get the power from ?}

Keep in your mind the netural is NEVER switched at all

And yes one of the poster here is correct you can NOT extend ungrounded two wire cable if there is no ground you will have to run the new cable to back to the breaker box / Fuse box.

Check your plumming system if you have mixed bag of PVC / Steel / Copper pipes in the system and also check the bonding clamp as well.

If you don't have bonding on water pipes that is a major issue there.

With the switch off at the garbage dispoal unit read the voltage between the netrual and ground { if there } it should be near zero but once you get near 120 volts then you have major issue going on.

The narrow slot is hot side { you will see brass screws there} the wide slot is netural { you will see silver screws there}

I know it can be pain in butt but you have to follow us to troubleshooting this one otherwise you may end up get a electrician to come in and check it out.

Oh yeah.,, Do you have electric waterheater also ?


Let us know more info and I know there is few other electricians in this forum they will chime in as well to give you few more advice here.

LEAVE THE GARBAGE DISPOAL UNIT OFF FOR NOW !!!
and unplug it as well.

IF this is hard wired let us know right away.

Merci,Marc