help with hood system

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GerryB

Senior Member
I need to incorporate a piece of kitchen equipment, just a 50amp single phase plug in that will be under the hood, with the ansul system. Is there an RIB for that? I havn't seen the box yet the ansul is suppose to supply. It's only a 10 foot hood, 3 lights and the intake and exhaust.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
I've never heard the term RIB so I'm not sure what you mean. I'll make an assumption based on Joe's response that you mean a multi-pole relay. That's usually provided in the Amsul panel but you may find that you'll run out of contacts quickly depending on what you are required to do. I believed the Ansul installer will use one to trigger the gas solenoid to shut down on a manual pull shutdown. You may need one to trigger a FA system, one or more to control fans, etc. However, I don't believe any of the contacts are rated for a high amperage. See if you can get some specs ahead of time.
 

GerryB

Senior Member
I've never heard the term RIB so I'm not sure what you mean. I'll make an assumption based on Joe's response that you mean a multi-pole relay. That's usually provided in the Amsul panel but you may find that you'll run out of contacts quickly depending on what you are required to do. I believed the Ansul installer will use one to trigger the gas solenoid to shut down on a manual pull shutdown. You may need one to trigger a FA system, one or more to control fans, etc. However, I don't believe any of the contacts are rated for a high amperage. See if you can get some specs ahead of time.
RIB is a brand name for "relay in a box". I've never used one but they come with a nippled thread you can mount right to a 4" sq box. Like the other poster said they they don't go past 30amps. I have a small hood system with just the make up air needs to shut down but also this 50 amp pressure cooker. The Ansul box is pretty small with two sets of 3wire leads that can be used for NC and NO. I have not done one of these in years, actually the one I did was the only one. The make up air is 240v and 4.8a and the cooker is 240v 50a. I think I have to bring 120v to the ansul to use the NO and NC contacts, probably NC. One of these NC contacts would go to one of these RIB relays for the make up air. This would be after the switch which turns on both make up air and exhaust fan. The other NC contacts would feed the coil on a contactor that would feed the pressure cooker receptacle. If any one has done these Ansul systems and wants to comment that would be great. Thanks
 

sparkyrick

Senior Member
Location
Appleton, Wi
Upon Ansul activation:

  • The exhaust fan needs to stay on (if already on) or turn on (if off).
  • The supply fan needs to shut down.
  • The shunt trip breaker(s) or contactors need to turn off all cooking appliances under the hood.
 

GerryB

Senior Member
Upon Ansul activation:

  • The exhaust fan needs to stay on (if already on) or turn on (if off).
  • The supply fan needs to shut down.
  • The shunt trip breaker(s) or contactors need to turn off all cooking appliances under the hood.
I wound up using a RIB relay for the make up air and a 50 amp contactor for the pressure cooker both with 120 volt coils coming off the Ansul micro switches .Are you sure about the exhaust fan turning on if it is off? The way it's wired now is both make up and exhaust come on together and make up shuts down with the Ansul. If for some reason they didn't turn the hood on, were using the pressure cooker or even not using it, if the Ansul activated the pressure cooker power would be killed but the exhaust fan would not come on.
 

iwire

Moderator
Staff member
Location
Massachusetts
Each area is different and I think your best bet is to speak with the inspector.

We have not field wired a hood for a long time, now they all come with factory engineered and built hood control panels that we simply tie into.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
I wound up using a RIB relay for the make up air and a 50 amp contactor for the pressure cooker both with 120 volt coils coming off the Ansul micro switches .Are you sure about the exhaust fan turning on if it is off? The way it's wired now is both make up and exhaust come on together and make up shuts down with the Ansul. If for some reason they didn't turn the hood on, were using the pressure cooker or even not using it, if the Ansul activated the pressure cooker power would be killed but the exhaust fan would not come on.

As iwire says, each jurisdiction is different, but the Ansul system is listed for either exhaust on or exhaust off.
 

GerryB

Senior Member
As iwire says, each jurisdiction is different, but the Ansul system is listed for either exhaust on or exhaust off.
I think I'm ok, both the Ansul installer and the hood installer didn't say anything about the exhaust coming on. Both said the make-up had to shut down and anything else under the hood. Not the lights though, the lights have to shut down if it's a state job they told me. I'll find out soon enough, inspection this week:).
 

mopowr steve

Senior Member
Location
NW Ohio
Occupation
Electrical contractor
Just hooked up hood this week and I had to make exhaust come on if ansul trips. Naturally that would be if the exhaust wasn't already on.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
As luck would have it I just picked up a job for almost the exact same system. I have (2) electric ovens on back to back walls with one common exhaust and Ansul system. The hood installers are telling me that I have to do the following in the event of an Ansul dump:
  • Make the exhaust fan come on (irrespective of whether it was running or not)
  • Shut down the make-up air system
  • Shut off the lights in each hood
  • Trigger the fire alarm system
I'm going to verify this with the bldg. dept. today but based on what has been posted here so far I'm thinking they're right on the $$.
 

sparkyrick

Senior Member
Location
Appleton, Wi
I wound up using a RIB relay for the make up air and a 50 amp contactor for the pressure cooker both with 120 volt coils coming off the Ansul micro switches .Are you sure about the exhaust fan turning on if it is off? The way it's wired now is both make up and exhaust come on together and make up shuts down with the Ansul. If for some reason they didn't turn the hood on, were using the pressure cooker or even not using it, if the Ansul activated the pressure cooker power would be killed but the exhaust fan would not come on.

The exhaust fan turns on to draw the fire suppression agent into the ductwork to reduce the possibility of a duct fire sparked by a cooking appliance fire.
 

sparkyrick

Senior Member
Location
Appleton, Wi
As luck would have it I just picked up a job for almost the exact same system. I have (2) electric ovens on back to back walls with one common exhaust and Ansul system. The hood installers are telling me that I have to do the following in the event of an Ansul dump:
  • Make the exhaust fan come on (irrespective of whether it was running or not)
  • Shut down the make-up air system
  • Shut off the lights in each hood
  • Trigger the fire alarm system
I'm going to verify this with the bldg. dept. today but based on what has been posted here so far I'm thinking they're right on the $$.

Plus you have to kill both electric ovens and any other electric cooking appliance under the hood.
 

sparkyrick

Senior Member
Location
Appleton, Wi
Trying to think how I would do that if I had to. I'm thinking another relay after the one I have now on the NO mico switch.

Most ansul systems have two sets of micro switches. One can be used to trigger the exhaust fan and the other can be used to either activate shunt trip breakers or drop out contactors/lights, etc.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
Most ansul systems have two sets of micro switches. One can be used to trigger the exhaust fan and the other can be used to either activate shunt trip breakers or drop out contactors/lights, etc.

The AUTOMAN control head can accommodate up to four (4) micro switches.
 

goldstar

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Plus you have to kill both electric ovens and any other electric cooking appliance under the hood.
That's an interesting point and one that my bldg. dept. didn't tell me about. I'll ask and get back and post what I find. Usually with a gas system the Ansul shuts down the gas with a gas solenoid. Both ovens/ranges in my case are electric.
 

kwired

Electron manager
Location
NE Nebraska
That's an interesting point and one that my bldg. dept. didn't tell me about. I'll ask and get back and post what I find. Usually with a gas system the Ansul shuts down the gas with a gas solenoid. Both ovens/ranges in my case are electric.
Gas valves may be mechanically interlocked by the suppression system instead of electrically shut down, but the basic concept is the heating sources (gas or electric) need to shut down when the suppression system is discharged.
 

GerryB

Senior Member
Most ansul systems have two sets of micro switches. One can be used to trigger the exhaust fan and the other can be used to either activate shunt trip breakers or drop out contactors/lights, etc.
That is what I have, two micro switches. I am using one NC for a relay for the 240 volt make up air, the other one is for a contactor for the pressure cooker. Can I use one of the NO wires off of the micro switches to control another contactor to turn the exhaust on if it isn't already on? So my question is can you use both the NO wire and the NC wire of the same micro switch to control two different things?
 

kwired

Electron manager
Location
NE Nebraska
That is what I have, two micro switches. I am using one NC for a relay for the 240 volt make up air, the other one is for a contactor for the pressure cooker. Can I use one of the NO wires off of the micro switches to control another contactor to turn the exhaust on if it isn't already on? So my question is can you use both the NO wire and the NC wire of the same micro switch to control two different things?
I don't see why not, even if there is a contactor connected to NC and a shunt trip breaker connected to the NO - both will result in removal of power to the respective circuits under the hood when the switch changes state.

You can supply more then one contactor or one shunt trip breaker from the individual switch, multiple switches make it easier to have more then one control circuit - say one is 240 volts and another is only 120 volts. Mixing 240 and 120 in same control scheme sometimes gives undesired results because of backfeed from the unswitched 240 volt line if only breaking one line.
 
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