Commercial Kitchen Eq. Trip gfi

[mdshunk]

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.

Feel free to do some self experimentation. I'd suggest a live webcam feed in case you are wrong, then we'll still have the results. :grin:

 

[Lxnxjxhx]

self experimentation

self experimentation

As you may expect; been there, done that, but only because I couldn't find willing subjects or neighborhood strays.

In fact, I have a prototype device ready to be tried. I'm all hooked up, so all I have to do is flip this swi[CLICK]

 

[cschmid]

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. :-?

No where did you see me advocate the removal of the GFCI..I just used an example of where there are no GFCI's used and I advocate proper wiring..I just think that they could make a larger GFCI for these applications and still be code and safe..

The code does not say the GFCI has to be 6ma it says it needs to be an GFCI..so why cant there be a GFCI for this application..If I remember my readings correctly..polarized means that the equipment is designed to fail to the grounded conductor..and cord and plug devices have been that way for years..

So if the cord and plug thing is a hassle then hard wire the appliance..the code states receptacles are to be GFCI..So if your stainless steel coolers ( refrigerator) is hard wired then it does not need to be GFCI..this appliance will last a long time and be safe as it is wired correctly..

 

[iwire]

No where did you see me advocate the removal of the GFCI..I just used an example of where there are no GFCI's used and I advocate proper wiring..I just think that they could make a larger GFCI for these applications and still be code and safe..

Larger GFCI or remove the GFCI the result is the same.

Your trying to keep a faulty appliance in service.

The code does not say the GFCI has to be 6ma it says it needs to be an GFCI..so why cant there be a GFCI for this application.

For what application? The use of faulty equipment?

.If I remember my readings correctly..polarized means that the equipment is designed to fail to the grounded conductor..and cord and plug devices have been that way for years..

I don't believe that is the case, if it is leakage current it will be somewhere between the two conductors.

So if your stainless steel coolers ( refrigerator) is hard wired then it does not need to be GFCI..this appliance will last a long time and be safe as it is wired correctly..

I agree, but you can only hardwire appliances that are designed to be hardwired.

This rule went into the NEC because kitchen workers have been electrocuted.

 

[cschmid]

If the leakage current is between the 2 conductors that means it is between the hot and neutral (grounded conductor) is that correct..

I guess we have a area in which we disagree on refrigeration equipment..as I don't believe the refrigeration equipment in the OP question is bad but all signs point to a minute amount of leakage current..So what would you do; tell the client to buy new equipment and what proof can you provide that indicates this equipment is faulty..

If you are going to retain a service contract then you need a solution to the problem..What is your solution..

 

[cschmid]

I guess what I am saying what is the best and safest way to fix this..because there comes a point when Joe hack comes in..you know a friend of a friend of the manager and he comes in during the down time and replaces the faulty outlets and problem goes away..Oh and by the way so did the GFCI's..

A hard wired dedicated circuit will fix the problem and retain the safety..

 

[iwire]

I don't believe the refrigeration equipment in the OP question is bad but all signs point to a minute amount of leakage current.

UL limits the amount of leakage current any appliance can have, I don't know what that value is but is well under the trip point of a GFCI.

If the unit trips the GFCI it needs repair or replacement.

.So what would you do; tell the client to buy new equipment

Yes.

and what proof can you provide that indicates this equipment is faulty..

It's tripping the code required GFCI, or you could buy one of these Current Leakage Meter

If you are going to retain a service contract then you need a solution to the problem..What is your solution..

Replace the fault equipment, just like we would replace the equipment if the motor burnt up.

 

[mdshunk]

UL limits the amount of leakage current any appliance can have, I don't know what that value is but is well under the trip point of a GFCI.

For most things, it's 3/4ths of a milliamp.

 

[cschmid]

Bob I would like to say I do enjoy conversing with you as you are very knowledgeable..Thanks for the link on the leak current device I did not know it existed but I have not searched for one and that might actually be a good tool to have.

Marc thanks you say 3/4 of an amp..

a GFCI trips out at 6ma correct (.0006 amp)

You say the motor is allow 3/4 amp leakage (.75 amp)

I guess I don't see a GFCI holding it..If I interpreted the info correctly..

 

[iwire]

Marc thanks you say 3/4 of an amp....

3/4 of a Milli amp, less then 1/6th of the trip point of a class A GFCI.

And thanks, what I know I have mostly learned from these internet forums. :smile:

 

[mdshunk]

I guess I don't see a GFCI holding it..If I interpreted the info correctly..

No, you didn't. The permitted leakage is 3/4ths of a milliamp. 0.00075 amperes

A GFCI will trip around 6 milliamps, or 0.006 amperes


An appliance with enough leakage to trip a GFCI is way, WAY out of spec, and needs condemned until repairs can be made or the appliance can be replaced.

 

[cschmid]

okay I got ya and after re-looking at your post I see you did specify milliamp my mistake..May I ask where you acquired this info at..

 

[mdshunk]

okay I got ya and after re-looking at your post I see you did specify milliamp my mistake..May I ask where you acquired this info at..

Don G mentioned it a while back, and I looked it in the material he referenced. I forget now. It was a UL document.

 

[mdshunk]

Here's an excerpt from UL 1026, ELECTRIC HOUSEHOLD COOKING AND FOOD SERVING APPLIANCES, which pretty much mirrors the requirements for any other type of cord and plug connected equipment:

32 Leakage Current Tests
32.1 The leakage current of a cord-connected appliance rated for a nominal 120-V or 240-V supply when
tested in accordance with 32.3 – 32.8 shall not be more than:
a) 0.5 mA for an ungrounded (2-wire) appliance,
b) 0.5 mA for a grounded (3-wire) appliance that is easily carried or conveyed by hand, and
c) 0.75 mA for a grounded (3-wire) permanently connected appliance, or a cord connected
appliance that is intended to be fastened in place or located in a dedicated space and employing
a standard attachment plug rated 20 A or less.
Exception: The leakage current of an appliance incorporating a sheath type heating element, when
measured in accordance with 32.3 – 32.8, shall not exceed 2.5 mA during the first 5 minutes after
reaching the leakage current limit of 0.5 mA or 0.75 mA, as applicable, and at the end of this time, the
leakage current shall be not more than the 0.5 mA or 0.75 mA limit as applicable – the leakage current
is to be monitored during heat-up and cool-down.
32.2 Leakage current refers to all currents, including capacity coupled currents, which may be conveyed
between exposed conductive surfaces of an appliance and ground or other exposed conductive surfaces
of an appliance.

 

[cschmid]

Thank you Marc..

Now back to the OP question on this commercial refrigs we are talking about does anyone know if they have heaters in the door skins to help control the moisture accumulation..

 

[iwire]

Thank you Marc..

Now back to the OP question on this commercial refrigs we are talking about does anyone know if they have heaters in the door skins to help control the moisture accumulation..

Yes, without a doubt, door heaters and usually electric defrost elements.

 

[mdshunk]

Thank you Marc..

Now back to the OP question on this commercial refrigs we are talking about does anyone know if they have heaters in the door skins to help control the moisture accumulation..

Some do, some don't. The reach-in freezers normally do. Some reach-in's are convertible (fridge or freezer), and normally feature a jamb heater. Some of the fridge only units do not. The Cadillac brands (Traulson among them) typically have heaters no matter what. Glass door merchandising cases almost always do too, but they wouldn't normally be in a kitchen. The reach in's will often also have condensate evaporator pan heaters in the bottom to boil off the condensate.

 

[iwire]

Some do, some don't.

I don't think I have ever seen one that did not have heaters at least in the door seals.

 

[mdshunk]

I don't think I have ever seen one that did not have heaters at least in the door seals.

The cheapo fridge only reach-in's without glass doors. True is one brand that comes to mind right off the bat. http://www.truemfg.com/CC_catalogs/true_master//lines/region2//area/pdf/T-12.pdf

 

[iwire]

The cheapo fridge only reach-in's without glass doors. True is one brand that comes to mind right off the bat. http://www.truemfg.com/CC_catalogs/true_master//lines/region2//area/pdf/T-12.pdf

Don't they tend to drip on the floor from condensation?