restaurant hood ansul utilizing mua and ef wiring diagram

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michael1electrician

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a customer ordered a restaurant hood with ansul protection and an exhaust fan and make up air fan on roof where could i find a typical wiring diagram for this type of system. i understand that needs a shunt trip mechanism.
 
michael1electrician said:
a customer ordered a restaurant hood with ansul protection and an exhaust fan and make up air fan on roof where could i find a typical wiring diagram for this type of system. i understand that needs a shunt trip mechanism.
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Generally a shunt trip or contactor turns off the supply fan. Also, any electrical equipment under the hood has to be shut off when the ansul system is activated. Don't know if you can get something typical. I'll bet you can google and get several variations. Some hoods come with a control panel through which the motors are wired and has a shunt-trip or contactor to shut down the appropriate motors. Not usual that you have to supply and build all the control components. You'll need a 120-volt control circuit as well as the motor circuits.
 
michael1electrician said:
a customer ordered a restaurant hood with ansul protection and an exhaust fan and make up air fan on roof where could i find a typical wiring diagram for this type of system. i understand that needs a shunt trip mechanism.
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I believe that the make-up air fan is required to be turned off, but that the exhaust fan for the hood is specifically required to remain running in the event of a system trip in most cases. (NFPA 96, 2014, 8.2.3.1)
 
Is it required to have exhaust fan and mua on one switch or could they be on separate switches? and, What about the location of the switches, does it need to be in sight of rangehood or could it be in the next room?
 
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Seeing as we can no longer make control panels in the field* the customer should be purchasing a hood control panel that will have the proper connections for the fire panel, the ansul, the shut down etc.

The wiring diagram will be specific to that.







*We could make a control panel if we could provide all the items listed in Article 409 including the short circuit rating. For most ECs this is not possible.
 
mtnelectrical said:
Is it required to have exhaust fan and mua on one switch or could they be on separate switches? and, What about the location of the switches, does it need to be in sight of rangehood or could it be in the next room?
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Separate switches. One of the things you'll have to wire in is a thermostat in parallel with the exhaust fan to turn it on in the event there is a high temperature condition under the hood, due to kitchen personel failing to turn on the exhaust manually.
 
gadfly56 said:
Separate switches. One of the things you'll have to wire in is a thermostat in parallel with the exhaust fan to turn it on in the event there is a high temperature condition under the hood, due to kitchen personel failing to turn on the exhaust manually.
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Sounds like a good idea but I have never had to do that and I have installed and worked on a great many hoods.
 
mtnelectrical said:
Is it required to have exhaust fan and mua on one switch or could they be on separate switches? and, What about the location of the switches, does it need to be in sight of rangehood or could it be in the next room?
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Well, if you put the exhaust fan and the makeup air fan on separate switches, you will have to figure out how to provide the MUA automatically whenever the exhaust fan is running, at least under some codes.

In some cases a simple makeup air duct with a pressure controlled damper will meet the makeup air requirement without the need for a fan.
 
You guys sure like to complicate things.

The building I am in now has at least 3 large kitchen hoods and none of them have the things being suggested here and all are modern, recently installed, inspected hoods with make up air.
 
Aha, that expains it.

Aha, that expains it.

gadfly56 said:
Separate switches. One of the things you'll have to wire in is a thermostat in parallel with the exhaust fan to turn it on in the event there is a high temperature condition under the hood, due to kitchen personel failing to turn on the exhaust manually.
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I have a thermostat in my residential kitchen (built circa 1960) that turns on the vent fan in the hood over the range. That must be where it came from.

Of course it is on the wall and not under the hood.

One mystery solved.
 
iwire said:
Sounds like a good idea but I have never had to do that and I have installed and worked on a great many hoods.
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From the 2009 edition of the IMC (currently adopted in NJ):

507.2.1.1 Operation. Type I hood systems shall be designed and installed to automatically activate the exhaust fan whenever cooking operations occur. The activation of the exhaust fan shall occur through an interlock with the cooking appliances, by means of heat sensors [emphasis added] or by means of other approved methods.
 
gadfly56 said:
From the 2009 edition of the IMC (currently adopted in NJ):

507.2.1.1 Operation. Type I hood systems shall be designed and installed to automatically activate the exhaust fan whenever cooking operations occur. The activation of the exhaust fan shall occur through an interlock with the cooking appliances, by means of heat sensors [emphasis added] or by means of other approved methods.
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Interesting and thank you for posting it.

The company I work for has likely done 25 hoods since spring this year and I don't see anything that would bring the fan on by heat. These would have been designed by various engineers.

We work in MA, RI and CT mostly.
 
I just realized how that code section it is being complied with.

Sail switch in exhaust vent controls a gas valve. No airflow means no gas to make heat.
 
iwire said:
I just realized how that code section it is being complied with.

Sail switch in exhaust vent controls a gas valve. No airflow means no gas to make heat.
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There you go. More than one way to skin a cat.
 
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