Crock Pot Sparks

charlie b

Moderator
Staff member
Location
Seattle, WA
Occupation
Electrical Engineer
First let me state that all receptacles in our kitchen will be replaced by an electrical contractor during a complete kitchen remodel that starts in about 3 weeks. So this is not a DIY situation.

Two days ago, my wife plugged in a crock pot (in the lower half of a duplex receptacle), turned it on, and saw sparks flying. The breaker tripped, there is black discoloration on the receptacle itself (I haven’t tried to clean it yet – it might just be on the surface), there is damage to the plug, and the wire entering the pot is almost completely burnt through. She is fine. The crock pot has been discarded. The light that is plugged into the upper half of the same duplex is still working.

Question: Is there likely to be a safety hazard? Should we avoid plugging anything into the lower half of this duplex? Should we unplug the light, and avoid using the duplex entirely? Three weeks from now it will no longer matter. But if the receptacle is still functional and safe, then I will clean the outside and let things be plugged into it.
 

ptonsparky

Senior Member
Location
NE (9.06 miles @5.9 Degrees from Winged Horses)
Occupation
Electrical Contractor
First let me state that all receptacles in our kitchen will be replaced by an electrical contractor during a complete kitchen remodel that starts in about 3 weeks. So this is not a DIY situation.

Two days ago, my wife plugged in a crock pot (in the lower half of a duplex receptacle), turned it on, and saw sparks flying. The breaker tripped, there is black discoloration on the receptacle itself (I haven’t tried to clean it yet – it might just be on the surface), there is damage to the plug, and the wire entering the pot is almost completely burnt through. She is fine. The crock pot has been discarded. The light that is plugged into the upper half of the same duplex is still working.

Question: Is there likely to be a safety hazard? Should we avoid plugging anything into the lower half of this duplex? Should we unplug the light, and avoid using the duplex entirely? Three weeks from now it will no longer matter. But if the receptacle is still functional and safe, then I will clean the outside and let things be plugged into it.
My thoughts from here, it's fine, just don't use that receptacle. Guessing the crock pot cord end was the culprit?
 

kwired

Electron manager
Location
NE Nebraska
Too bad you didn't have AFCI protection it would have been nice to see if things tripped. Pull that crock pot back out of the trash and hold onto it for a few weeks.
He said breaker tripped though. Probably on magnetic trip function. Presumably AFCI breakers have thermal magnetic function also.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Based upon your description, Charlie, it sounds like the cord, at the side of the crock pot, was a line to neutral short.

The activity at the receptacle was probably a "series" event of a small point of contact between male and female that "fused", i.e., melted like a fuse element at the higher current in the short, giving rise to a plasma that would boil the metal to gas which would redeposit itself as the black mark.
 

grich

Senior Member
Based upon your description, Charlie, it sounds like the cord, at the side of the crock pot, was a line to neutral short.

The activity at the receptacle was probably a "series" event of a small point of contact between male and female that "fused", i.e., melted like a fuse element at the higher current in the short, giving rise to a plasma that would boil the metal to gas which would redeposit itself as the black mark.
Dang...you're faster typing them I am. :lol:
 

charlie b

Moderator
Staff member
Location
Seattle, WA
Occupation
Electrical Engineer
Thanks everyone. I agree that the wire shorted out at the point it enters the pot. The waste disposal company took it away yesterday, so it is too late for an autopsy. The damage to the prongs of the power cord is what led me to be concerned over the receptacle. We are just going to avoid using that outlet. It will be removed in about three weeks anyway.

As an aside, the GC suggested, and my wife loved the idea, that no outlets be installed in the countertop wall space (i.e., in the wall itself). Instead, they will run something akin to Wiremold across the back of the underside of the upper cabinets, and put the receptacles there. That way the receptacles are not visible and will not interfere with anything she wants to store on the countertop. It recently occurred to me that the 20" limit would come into play. I need to look at the cabinetry plans to make sure this idea is workable.

Edited to add: The plans show 19.5 inches from countertop surface to underside of upper cabinets. :thumbsup:
 
Last edited:

Adamjamma

Senior Member
If I could find that stuff in Jamaica I would run it myself but it is one of those things that one would b=need to import in a suitcase as no suppliers think the undercabinet lighting or outlets worth selling.
 

kwired

Electron manager
Location
NE Nebraska
When plugmold is used up at the cabinet it is usually because of fancy tile "backsplash" that the "decorator" doesn't want interrupted with receptacles.

One can also put the receptacles horizontally and as high as possible under the cabinets (as long as still no more than 20" above counter) and it still might be acceptable to the decorator
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
As an aside, the GC suggested, and my wife loved the idea, that no outlets be installed in the countertop wall space (i.e., in the wall itself). Instead, they will run something akin to Wiremold across the back of the underside of the upper cabinets, and put the receptacles there.
The key to effecting the end result lies with the depth of the under-cupboard valence in relationship to the sight line of a person seated at the lowest seat in the kitchen. The same goes for the under-cupboard lighting.

Depending upon the arrangement of amenities in your new kitchen design, the lower lip of the cupboard (the valence) should hang down enough to break the sight line, of the lowest seated person, of the receptacles and under-cupboard lights.
 

charlie b

Moderator
Staff member
Location
Seattle, WA
Occupation
Electrical Engineer
Our kitchen has no room for seating. My wife likes the idea of outlets out of sight mostly because it frees up wall space for the placement of appliances (either where stored or while in use).
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Also consider any sight lines from seating in other areas, where one might be able to see the cabinetry. I understand there might not be any.
 

kwired

Electron manager
Location
NE Nebraska
Our kitchen has no room for seating. My wife likes the idea of outlets out of sight mostly because it frees up wall space for the placement of appliances (either where stored or while in use).
Why do you/your wife place appliances on the walls and not the counter?:D
 

Sahib

Senior Member
Location
India


Two days ago, my wife plugged in a crock pot (in the lower half of a duplex receptacle), turned it on, and saw sparks flying. The breaker tripped, there is black discoloration on the receptacle itself (I haven’t tried to clean it yet – it might just be on the surface), there is damage to the plug, and the wire entering the pot is almost completely burnt through.
Question: Is there likely to be a safety hazard?
Yes. Every electrical appliance should have at least a minimum insulation resistance. It should be checked periodically before plugging in.
 
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