Convection Oven shock
 

My Convection Oven is shocking
and has a 2 wire plug no ground

so I pulled out the VOM and found 118 volts on the metal frame to a ground wire
on a 3 wire ext-cord
but the VOM shows no connection to the frame
between the two hot leads and the frame it reads open

looked for obvious shorts or other problems
none found

then the real puzzler
when I turn on the oven
the voltage drops to 44 volts on the frame
while the oven appears to work fine

thought of adding a ground
but something ain't right
and I need to figure it out before adding grounds

it is a larger made in USA 18 X 12'' unit very had to find anymore
the stores have far smaller ones

how are the volts leaking to the frame when the VOM shows no continuity
why do the volts drop drop when running

Hummm, you did not mention the brand so if we knew that it might help? So far for every appliance I have owned I have found either forums that covered them or factory websites that covered them.

farberware T-4800

tryed google
got a bunch of requests for an owners manual posts
but nothing on shorts/shocks

As far as continuity, testing a human from one end to the other will show an open, but I know from experience that I conduct electricity quite well. Throw it away before someone gets hurt or it burns your house down.

I agree with the Noob. Nota, you and I may have our differences, but I want you around!

BTW, welcome pen15

I did a search and the first result was "farberware for low price cooking" and the next one was for one at Sears! I would take it back the next chance you have.

What results do you get if you flip the plug over in the outlet?

The heat element seems to have shorted internally to ground. Depending on how you turn the plug, you might get 44V or 66V.

Change the heater element. Or better, get another oven.

I don't understand how it's legal to sell unearthed oven? Heater element is a hollow tube with resistive wire going trough. Faults do happen.

Try that!

I bought an old $100 refrigerator and it would shock me it the plug was in on way but not the other. It was a plug that was angled at 90 degrees and if the plug went down it would shock you. If I plugged it in the way that made the plug go up it did not shock me. The point of mentioning that is the people that bought my old house wanted that fridge. They even put it in the contract for the house. I let them keep it. A month later I drove by the place to see the house I lived it for years. That fridge was on the front porch with the door blocked open. I suspect they plugged it in the logical way and got shocked.

I think you got it NAILED

I filed down the big prong plug to flip it
and now get no volts when off [unfliped it was 118 volts when off]
and get no volts on the frame in convection mode running
but 70 volts running on the broiler mode [unfliped it was 40 volts]

really do NOT UNDERSTAND this as I thought A/C went both ways :confused:

so I hope it will work in convection mode without shocking
until I can find a replacement unit
I removed the nob from the switch so it will not shock now
we have a outside gas grill so broiling can be done on that

lots of smaller counter top convection ovens out there BUT no bigger 1.5 to 2.0 cft inside sized ones :confused:

The current goes both ways but the white wire is at ground potential. The black wire goes from -169 volts to + 169 volts.

If you switch the white wire side (in the appliance) you could get some capacitive coupling to the chassis which is what I assume is happening since you get a shock but aren't dead yet.

Is the outlet in the wall installed correctly?

tryed to fail safe the unit by removing the wire to the broiler coil

BUT now I am really confused as volts reappeared on the frame WTF ????????

re-attached the broiler wire and the unit shows no frame volts again

Dunno about US, this is how it works in EU:

One of wires is PHASE (brown), other is NULL (blue).
If equipment is earthed, the wire is YELLOW/GREEN.

NULL is connected to earth inside the fuse box.

Heater element is a hollow metal tube with resistive wire inside it. The wire (which is connected to AC and heated) is isolated from the tube.

In your case, heater wire shorted out to tube (and thus, chassis) roughly 30% from NULL (or PHASE, depending on how you flip your plug). If you connect the phase to heater terminal nearest the fault, you get 40V. Other way around, you get 70V.

If your equipment was grounded, a short to ground would draw 3X the current and blow your fuse (or flip the Ground Fault Switch, if you have one).

Is it's not grounded, you get a percentage of 110V on chassis, depending on where it shorted out. It all becomes a giant potentiometer.

Anyway, this is all academic. I strongly recommend discarding this equipment or disconnecting it and changing the heater. Even then, using unearthed equipment with metal chassis is questionable at best.

You were lucky as you use 110V and it shorted somewhere in-between, giving you non-lethal shock.

That works here, beepbeep

Just change PHASE to Hot & it is usually black (although it can be red) and change NULL to Neutral & it is always white. Earth is ground & a bare wire or insulated yellow/green in equipment.

Ian

You might think about pulling 3-wire (properly gauged for amps) back to the box on a dedicated circuit.
Make sure the wire, breaker, and outlet is all the same rating.

A $12 Greenlee and an outlet tester with GFI is your friend.

I had a friend who wired a welder backwards....

+1, get one of those and check all the outlets in your house.

$4 on Amazon with free shipping. GFI version are about $9.

ELECTRICAL RECEPTACLE TESTER AC OUTLET PLUG 3 PRONG GND - Amazon.com

http://forums.pelicanparts.com/uploa...1357068868.jpg

I don't understand this? Every oven I have ever owned has a plug on the back like this....

http://forums.pelicanparts.com/uploa...1357079360.jpg

Because they were 220 volts. Small counter convection top unit, 110 volts.

My dual fuel GE Cafe, top burners & middle oven is gas and the bottom oven (that goes to 400 degrees) is electrical. The whole unit is on 110 Volts.


http://forums.pelicanparts.com/uploa...1357084245.jpg