scott branch
New member
Use of shunt trip breakers: Required to disconnect all power in a commercial kitchen, or only to supply air? I do know that it is good to maintain power on exhaust air.
Shunt trip breakers
- Thread starter scott branch
- Start date
- Status
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
I don't think this is an NEC requirement, and I am not familiar enough with building codes to help you on this one. Sorry. Perhaps someone else has an answer?
shunt trip
shunt trip
Scott: I'm sure you will get more qualified answeres, and some that may vary depending on what Code is being enfoeced. I would say that shunt-trip breakers are only one method of acccomplishing shut-down in kitchens.
In the areas I work, the standard I see enforced is the shut-down of make-up air and all equipment under the hood that produce heat, in addition, if your fire supression system is "wet" ie: conductive; then all items (under the hood) with voltage must be shut-down on system activation.
Again, that has been my experience from working with several fire inspectors in my area....it is not based on actual law.
shunt trip
Scott: I'm sure you will get more qualified answeres, and some that may vary depending on what Code is being enfoeced. I would say that shunt-trip breakers are only one method of acccomplishing shut-down in kitchens.
In the areas I work, the standard I see enforced is the shut-down of make-up air and all equipment under the hood that produce heat, in addition, if your fire supression system is "wet" ie: conductive; then all items (under the hood) with voltage must be shut-down on system activation.
Again, that has been my experience from working with several fire inspectors in my area....it is not based on actual law.
paul
Senior Member
- Location
- Snohomish, WA
The last one that I worked on shut down all gas and cooking equipment under the hood. It also killed the lights and supply air in the hood, but left the exhaust fan still going. This was done through several relays.
paul said:
This is the method we will be using shortly....equipment arrived over the week end.
At this point in time, there are 2 additional threads related:
Commercial exhaust hoods and make up air.
(by RM Electric )
Comm. Kitchen Equipment
(by me, celtic)
All three of us seem to be doing very similar jobs .... a collaboration won't hurt
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
I've wired a couple of dozen of these systems, and each was generally different in some ways. I'd be happy to give any advice needed, including diagrams, and I know several easy ways to simplify the setups.
One example is that I used three simple 3-pole contactors, each with contacts sized to suit the loads, wired the coils across the intake-fans' contactor coil, and placed them in a single box atop the existing breaker panel.
One example is that I used three simple 3-pole contactors, each with contacts sized to suit the loads, wired the coils across the intake-fans' contactor coil, and placed them in a single box atop the existing breaker panel.
mikeames
Senior Member
- Location
- Gaithersburg MD
- Occupation
- Teacher - Master Electrician - 2023 NEC
paul said:
I have wired them the same. In my area there are several ways one includes a manual reset gas valve and a pull cable. The other involves a solenoid actuated gas valve and a shunt trip.
They also require the fan hoods to come on regardless of the state of the switch / starter. I also accomplished this with the relays provided in the fire suppression unit. Ask the fire guy what the switch contacts are rated for.
I almost went ahead and started getting a control cabinet set then I asked what the switch contacts were rated for and he said 25 amps so I just used them since the fans were only on a 20A OCP. Another fan involved a 25 HP motor and that was slightly different but the same rules applied.
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