Commercial Kitchen Eq. Trip gfi

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cschmid

Senior Member
bob multi-wire worked fine until the 2008 code now easier to install regular circuits..going to be allot safer working behind the unqualified wont have to worry about all the screw ups they could do with a multi-wire..
 
We did a restaurant last year that was using a lot of used equipment they had from other restaurants they owned. The other restaurant were built at least 10 to 15 years ago, so did not have GFI receptacles through out the kitchens. We had several problems also with tripping GFIs. We found many damaged cords or cords that had been replaced over the years that had not been install correctly to begin with, ie ground and neutrals tied together in the make up j-box. Just saying we found a lot of small problems causing the headaches!
 

iwire

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Location
Massachusetts
cschmid said:
bob multi-wire worked fine until the 2008 code now easier to install regular circuits.
Well yes now they need handle ties, I don't see that as a show stopper.

.going to be allot safer working behind the unqualified wont have to worry about all the screw ups they could do with a multi-wire..
I never let that enter my mind, I do my work correctly, how someone else works is not my concern.
 

peter d

Senior Member
Location
New England
iwire said:
I never let that enter my mind, I do my work correctly, how someone else works is not my concern.
I wish there was a way we could get the "Let's make everything safe for the unqualified/handyman/DIY" mentality out of the trade.
 

cschmid

Senior Member
you are right working behind the unqualified is never going to be safe..I also agree that as long as these unqualified/handyman/DIY exsist there are going to be problems..that group of people create allot of problems especially with multi-wire as they have no clue normally..we have all been to the repair that was created by the unqualified/handyman/DIY group..I have pictures and have seen pictures of it on this site..:D remember all you need to do is hook the white to the white and the black to the black..:D
 

electricman2

Senior Member
Location
North Carolina
Occupation
Retired Electrical Contractor
peter d said:
I wish there was a way we could get the "Let's make everything safe for the unqualified/handyman/DIY" mentality out of the trade.
It would sure make the code book a pound or two lighter.:)
 
Interesting discussion, but back to the question. One of the first things I did was to check the boxes for moisture, and added w.p. in use covers. I'm using Pass & Seymor devices. I have opened different machines and looked for moisture, or any other connections to ground. In some I found moisture and grease, which I corrected. But that hasn't totally alleviated the problem. At times a machine will trip the GFI and it can immediatly be reset. Other times it can't. I may have problems with one, then it will be fine for hours, days weeks, and another will develope a problem. I have 5 ovens and 3 ref. units, that all trip at different times. The ovens sit under a large hood, and the dishwasher is vented, and they operate at 450, so I doubt there is moisture in them. I agree there is a drain to ground somewhere, and a GFI doesn't trip for no reason, any input on why?
 

csparkrun

Member
Location
orygun
you could try a motor rated gfci, can you still get around installing a gfci with a single outlet thinking that that appliance (refer or warmer) would be occupying the receptacle?
 

iwire

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csparkrun said:
you could try a motor rated gfci,
Never heard of such a device and I have never had a 'good' motor trip a GFCI.


can you still get around installing a gfci with a single outlet thinking that that appliance (refer or warmer) would be occupying the receptacle?
No.
 

cschmid

Senior Member
I can see the Refrigerators having some motor leakage current as they grow old..Here is GFCI Rule that out weighted dedicated circuits that is wrong..to fix motor leakage that poses no threat to human safety you must replace referigerator..because they are sealed units and can not be repaired..

Now on to the ovens do they have fan motors on them and / or an electric solenoid valve..the fan motors are not normally sealed units and they are not over expensive to change..If I were a gambling man I would think that would be your problem..even though they work and pose no threat they can trip the GFCI..
 

iwire

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Location
Massachusetts
cschmid said:
to fix motor leakage that poses no threat to human safety you must replace referigerator..
The leakage current is a threat to human safety, if the EGC becomes compromised the case of the unit will be at a full 120 volts.

Basically if the leakage current is enough to trip the GFCI it is enough to injure a person and the likely hood that the leakage current is high enough to trip the GFCI but not high enough to kill is a very slim possibility.
 

cschmid

Senior Member
I guess we then say the way we use to wire was unsafe..all the summer youth camps who have these appliances donated to them and are dedicated outlets that are not GFCI should quit using there appliances..because I bet if you went out and put GFCI on them 1% of the GFCI's would hold..

I will bet allot of place just remove the GFCI's and continue to do business and when the refig fails they replace it..and in the mean time no one was hurt..the 6ma GFCI was made to protect your 80lb child from a shock hazard associated with water in the bath room..

I believe we could run 30ma GFCI on kitchen equipment and be just fine..But I have not seen any thing except a 6ma GFCI..I have asked but just see dazed looks but what is the GFCI rating on the combo AFCI is that not 30ma..

I think we get carried away and over regulate sometimes...
 

iwire

Moderator
Staff member
Location
Massachusetts
In any of your examples the loss of the EGC would create an electrical hazard that could kill.

It always amazes me that the same people that would never suggest using a larger breaker for a malfunctioning appliance are quite quick to suggest the elimination of a GFCI as the solution for a bad appliance. :-?
 
L

Lxnxjxhx

Guest
leakage current effects, probably from IEEE GFI tests in the 70's

leakage current effects, probably from IEEE GFI tests in the 70's

10 mA = painful, 100 mA = the low end of fatal.
 

iwire

Moderator
Staff member
Location
Massachusetts
Lxnxjxhx said:
10 mA = painful, 100 mA = the low end of fatal.
For one that sounds high for the other it brings us back to this


iwire said:
the likely hood that the leakage current is high enough to trip the GFCI but not high enough to kill is a very slim possibility.
 

iwire

Moderator
Staff member
Location
Massachusetts
Shock in the range of 6 to 30 milliamps can be very painful, and the person in contact cannot let go of the circuit. At around 50 milliamps respiratory arrest is possible, with severe muscular contractions. Ventricular fibrillation starts around 67 milliamperes of current. This is when the heart basically starts fluttering and is not pumping blood through the system. If not stabilized, death is a real possibility.
From here

Keep in mind these values are for healthy adults, not children.
 
L

Lxnxjxhx

Guest
Here's some more stuff

Here's some more stuff

http://wiki.4hv.org/index.php/Electrical_Safety

What I hardly ever see mentioned is that the skin is punctured at >600v so you lose the benefit of skin resistance. I dunno', but maybe this threshold is expressed or implied in the NEC somewhere, by using different procedures.
 
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