Kitchen Hood Shunt Trip Equipment

M

mbrunner

New User
Location
Florida
Occupation
Senior Electrical Designer
Ok, I have a hood that has a number of equipment that is 208V which we are sending to its own panel for the shunt trip. Here comes the BUT, the Kitchen Designer also placed a couple pieces of equipment that are 480V under same hood, and he cannot get that type of equipment in lower voltage.

How should I shunt trip the 480V along with the 208V with (1) push button to shut everything down?
 
You can use 480v breakers with shunt trip or contactors. The coil and shunt trips can be the same voltage as your 208 shunt trip.
 
augie47 said:
You can use 480v breakers with shunt trip or contactors. The coil and shunt trips can be the same voltage as your 208 shunt trip.
Click to expand...
Exactly.

I will insert my usual comment here on kitchen system shutdowns. We prefer to use contactors when possible. With shunt trips, you have to worry about the source of voltage for the shunt coil, unless you tap that from a hot off the breaker itself, which may or may not be kosher. With a contactor, if you have a power failure generally or at the contactor coil, the system will fail safe. If you lose your shunt coil circuit, you may not know that until it's too late.
 
gadfly56 said:
With shunt trips, you have to worry about the source of voltage for the shunt coil, unless you tap that from a hot off the breaker itself, which may or may not be kosher. With a contactor, if you have a power failure generally or at the contactor coil, the system will fail safe. If you lose your shunt coil circuit, you may not know that until it's too late.
Click to expand...
Agreed, plus even if you tap off the breaker you are trying to trip, you still have the risk of poor splices, terminations, etc. causing the system to fail, all of which is removed with the fail safe properties of the contactor as you mentioned.

Another benefit is you don't have to waste a pole for the ST, and you can locate the contactor elsewhere in some dead space.

The biggest counterpoint I see to the contactor is energy usage.
 
Tyler C said:
Agreed, plus even if you tap off the breaker you are trying to trip, you still have the risk of poor splices, terminations, etc. causing the system to fail, all of which is removed with the fail safe properties of the contactor as you mentioned.

Another benefit is you don't have to waste a pole for the ST, and you can locate the contactor elsewhere in some dead space.

The biggest counterpoint I see to the contactor is energy usage.
Click to expand...
Fair point. I just looked up an Eaton definite purpose contactor, the sort you might use for controlling kitchen equipment. A double pole contactor for 240 volts and 50 amps with a 120VAC coil has an inrush of 41 VA and holding of 6.5 VA, or 3 "maximum sealed watts", whatever that means. If we take the 3 watts, the vampire load over the year is 3 x 24 x 365 = 26,280 watt-hours/yr or 26.280 kW-hr/yr. At $0.15/kW-hr, that would be $3.94/yr. I hope I got the math right.

 
You must log in or register to reply here.
Top