A fast-food place called me, complaining that they kept losing power to their deep-fryers. FWIW, it turned out that the fryers were gas, and used electirc only for the controls and igniters.

I know why they were losing power; anyone out there care to guess?




For a closer look:

And they probably thought they were helping theirselves out. I cant stand those kind of calls, good cash but messy and busy to work around.

That is a problem as non-dwelling kitchens require GFCI protection.

Sounds like they have a problem with the equipment if it's tripping the GFCI.

Well, I suppose I ought to explain some about this install.

First of all, the fryer cords connect outside of the hood. This means that they will NOT be turned off when the Ansul system is operated.

The immediate problem, though, is the presence of the cord connections and GFI unit just above the fryers. When food is placed in the fryer, a great deal of moisture / oil enters the air. This will then condense on anything in it's path that is cooler. TRhat would include "cold" electrical connections.

Condensing moisture would allow current to leak across the face of the plug, to both the neutral and ground prongs. The GFI would see this, and trip.

Simply re-locating the connection outside of the condensation area eliminated the problem. (Of course, this was done without using extension cords, etc.)

None of the electric has been tied into the Ansul as yet; a bid has been submitted.

If condensation is causing current to "leak" from the receptacle, why not just install a GFCI OCPD as required by 210.8 (B) (2)?

(I love using those big electricial abbreviations)

Oh wait... that wouldn't solve the problem.

My bad.

John as these are 120 volt 20 amp circuits they can not provide the source of heat to the appliances.

It's not the power under a hood that must be killed it is the source of heat.

If these are Gas appliances a cable operated gas valve is in order.

At least that is how it's done in my area.

Bob

I've only installed a few "Ansul" systems, Iwire, so I am no expert. However, here it is required, when the system is tripped, that ALL sources of ignition be disconnected, as well as make-up air be stopped. This meands that the lights under the hood, any receptacles, and all electric equipment be shut off- in addition to the gas being shut off.

You are quite correct; the circuit only powered the controls and the gas igniter. Were these deep fryers to be all electric, they would likely need a 100 amp circuit. (Bit much for that extension cord!)

It is similar here, the last ansul I wired killed the make up air, the hood lights, and ran the exhuast fan for 30 seconds then shut it off. As the range was gas fired there was a cable operated valve that was tied into the trigger mechanism.

Maybe I am wrong I will try to find the requirements.

As far as I can recall its not the source of ignition that needs to be killed....the ignition has already happened at the point the ansul trips.

But it is hard to extinguish a fire if heat is still being pumped into the bottom of the fire.

Remember the fire triangle Fuel, Oxygen, Heat.

I have never seen an Ansul system kill the under hood lights.

the last time i done that. I did wired the hood lumaires separted from fan circuits due the ansual system and yeah i did see a braided steel cable tied to spring loaded gas valve for cooking equmenit.

( that place i did work on it have both gas and electric breaker[shunt breaker type ] tied together ]

Merci , marc

[This message has been edited by frenchelectrican (edited 10-19-2006).]

Bob: (Iwire)
I have to agree with you. Ansul activates gas valve via spring loaded cable; activates shunt trip for ALL electric appliance power; kills MU air; exhaust remains 'ON'.

I've never seen one kill lights or anything but the above.

John

I am no expert on these systems. It does seem that there have been some major sode changes relating to them over the past decade- changes made in codes other than the NEC.

In the inspections I've had, 'all possible sources of ignition' was the phrase used. This meant all electric, including the lights, in the hood area.
It may be relevant that the newer hood extinguishing agents are water based- and NOT the dry chemical of earlier days. Manufacturers are phasing out the dry chem systems. Likewise, the extinguisher in the hood area also uses a water-based agent. Besides the old "A,B,C, and D" classifications, there is a new one just for cooking fires.

Some words were heard about the 'hood area' extending 6" beyond the actual hood enclosure. As this was not an issue -no questionable receptacles- I'm not sure if this is a rule or not.
In some areas here, they want the exhaust killed, as well as the make-up air.

So my advice to anyone who is contemplating installing one of these systems to work closely with the fire guy. Best to make the inspector happy on the first visit.

Other observations: The fire guy will have access to special fittings, should you wish to pass a pipe through the hood itself.
The fire guy usually has a mechanically activated valve, but electric ones do exist (mainly on larger pipes).
A kitchen may very well have several different fans. Each hood may have a separate Ansul system, or they may all be on a common system. In other words, it is common to need more than one contactor.
Your circuits may very well come from different panels, and be of different voltages.


Getting back to the pics- I think we can agree that an extension cord, to a receptacle outside the hood, in a place where it will collect moisture, is a poor plan!
Nor is the use of a GFCI a substitute for proper wiring.