# Two Ansuls



## dronai (Apr 11, 2011)

This restaurant has two hoods, and two Ansul systems. The make up air is suppose to shut down but the exhaust motors are tied into the Ansul as well. Might have been compliant before, but now the Fire inspector wants the exhaust motors (2) to stay on. I have done these before, but this one is a little more complicated. Need some help 
Anyone


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## Barjack (Mar 28, 2010)

dronai said:


> This restaurant has two hoods, and two Ansul systems. The make up air is suppose to shut down but the exhaust motors are tied into the Ansul as well. Might have been compliant before, but now the Fire inspector wants the exhaust motors (2) to stay on. I have done these before, but this one is a little more complicated. Need some help
> Anyone


First, get specifics. He wants the 2 motors to stay on, or to come on if they happen to be off? What about the lights? A lot of the inspectors are OK with the hood lights staying on if they are explosion proof.

Edit: The relays I just described won't work. I just realized the motors are 3 phase. Sorry.


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## dronai (Apr 11, 2011)

I think CR2 is the interposing relay. If someone can verify then taking the two exhaust motors control out that circuit would solve the problem


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## SdCountySparky (Aug 6, 2014)

receptacles on contactors off the normally closed fans & lights on contactors off the normally open on the microswitch.


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## dronai (Apr 11, 2011)

Forget the lights and receptacles, and how it works, that part is handled. The question is about the schematic drawing


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## Big John (May 23, 2010)

dronai said:


> ....But now the Fire inspector wants the exhaust motors (2) to stay on...


 There's something I'm missing, but it appears to me that's exactly how that would work:

_Assuming _the only thing that changes during a fire is that the "Ansul" switch closes, then CR2 changes state. CR2 opens the power for the M3 supply fan and sends power to the M1 and M2 contactor coils regardless of whether the "Kitchen" switch is closed.

I don't understand where the contacts for MP-1, MP-2, and MP-3 are being controlled from, I'm assuming they are always closed.


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## dronai (Apr 11, 2011)

The Asul Micro switches they are using are NC, unless the fire system releases the cables. This opens the NC switches and disables the (3) Motor starters, regardless of what state the toggle switch in the kitchen is in. 

Your right John, it looks to me like the drawing is correct, and who ever wired it did it wrong, so that all 3 starters are disabled. The problem is, I was alone, and nothing is labeled outside the control panel on the roof. Everything needed to be identified first, but you need two guys.

M-3 is the Makeup air that needs to be disabled


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## catsparky1 (Sep 24, 2013)

Today we got a call from a good customer to do a system they said.
This system is 6 fricking hoods and one is wood fired at 850 degrees. Ansuls pop at 500. It will take 16 4 pole 40 amp contactors and a can you can sleep in. 
It's a catering facility and 2 dish hoods and a class 2 hood for pizza. It will also have an air scrubber for smoke from the wood fired hood. This is an add on to a place built in 1940 with 2 existing hoods one of 24 feet and one at 48 feet.

Fun remodel it will be for the next month. This is the second biggest we have done. The biggest was military and that was a monster system. 

I LOVE RESTAURANTS!!!!!!!!!!!!!


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