My question is, when replacing a 3 phase 30 amp shunt trip breaker for a receptacle located under a commercial kitchen (ansul equipped) exhaust hood, do i need to put the ansul system in a "deactivated state" for the purpose of not setting it off accidentally due to the shunt trip interaction?
commercial kitchens
- Thread starter devine
- Start date
- Status
- Location
- Massachusetts
If wired correctly there is no way the shunt trip breaker or its control circuit can set off the system.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
I haven't wired a kitchen since the 70s, so I have questions.
Is it common to use shunt trip breakers for the circuits needing to be shut off, activated by the ansul switch? If so, I guess there would be one circuit that was used to send power to the shunt trip breakers (through the ansul switch)? Do you have to use a breaker lock to insure no one turns that breaker off? How would anyone know if that breaker was turned off (thereby making the fire suppression system unable to deactivate the required circuits).
FrancisDoody
Senior Member
- Location
- Durham, CT
I never use a breaker to control any of the equipment under a grease hood system. All the control can be created using the micro switches built into the Ansul system.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Will you elaborate? IE: How would a micro switch control an electric deep fat fryer?
- Location
- Massachusetts
In my experience yes.
Yes.
I have but do not know of any requirement to do so.
They would not.
electricguy61
Senior Member
Via a contractor.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
I'm assuming you install the circuit conductors through a NO set of contacts and let the Ansul switch open the circuit to the coil, right?
Rewire
Senior Member
- Location
- Lake of the Ozarks
On the last kithcen we did all the circuits supplying power under the hood were in a sub panel and the main had a shunt.
shepelec
Senior Member
- Location
- Palmer, MA
The ansul system when fired, closes to send power to the shunt trip.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
That's my understanding of a common way to do it. I've always considered it to be inferior to using a contactor. I've always wondered why no one raised the concern that you don't know there is a problem with any part of the control circuit to send a signal to the shunt trip breaker until it's time to use it and it doesn't work. With a contactor, if any part of the control circuit is not operational, you lose power.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Unless you are using a contactor then the control circuit is opened by the Ansul system to drop out the contactor.
gadfly56
Senior Member
- Location
- New Jersey
- Occupation
- Professional Engineer, Fire & Life Safety
Really? How do you control the 30 amp fryer with the 15 amp rated micro switch? And what do you do for the second three-phase fryer, since the Auto-Man control head has room for just four micro switches?
- Location
- Massachusetts
I agree, but short of code or specification it is all about the money.
My WAG is lack of hard data showing that the shunt trips are not working.
hardworkingstiff
Senior Member
- Location
- Wilmington, NC
Never a more accurate statement has been made.
Makes perfect sense, but it doesn't mean the problem does not exist, just that it has not manifested itself, right?
- Status