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Thread: ansul system

  1. #11
    Join Date
    May 2005
    Location
    Richmond, Virginia
    Posts
    21,838
    All these responses have covered the main requirements. Every system is different. There are new installs and up-fitting of existing systems. The rules have changed over the years.

    New systems can be either self-contained Ansul-type with a pre-wired control box and switches, or can be just fans mounted on ducts, and we have to wire everything together from scratch.

    Sometines, there's already one or more shunt-trip breakers, sometimes a whole kitchen panel controlled by a shunt-trip. Often, only the exhaust fan was connected to the micros.

    In existing systems, I use contactors; shunt-trips are expensive and require running a cable back to the panel. Contactors are easy, cheap, and can be mounted where needed.

    Here's a few pics from a new church kitchen I didn't wire, but I installed the system:







    The box contains four contactors. There were four 120v receptacles, so I used two 2p contactors for those. The three cables with the tape (a 12/3 and two 12/2's), are those feeds.

    The fan supplies and loads (controlled by two 3p contactors), plus the circuit/light supply, enter and exit the top. From the bottom are the cables to the gas valve and the lights.

    The 1/2" flex goes in the wall to the switches, and the 1/2" EMT to the horn-strobe, to the extinguisher box which contains the microswitches, and then on to the gas reset box.

    Here's a pic of the wiring diagram:



    Both of these circuits were fed by the same supply; I just showed them separated them for ease of tracing. (Big! Sorry.)

    Now, under-hood lights must also shut off. Appliances under the hood that must shut down, whether their supply is under the hood or not. Unused receptacles can be blanked off.

    We also have to install a horn/strobe unless there's a building alarm system tie-in, and a gas valve w/reset box that must shut down the gas even upon manual exhaust shutdown.

    That means every morning starts with turning on the exhaust, pressing the button on the reset box, and then lighting each standing pilot. The owners and cooks HATE this requirement.
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

  2. #12
    Join Date
    Feb 2003
    Location
    NE Arkansas
    Posts
    2,222
    Opinions, opinions, opinions.

    I finally got tired of all the "they want" folklore. No one ever seemed willing to come up with a print, a sequence of operation, etc. Just what is 'make up air,' anyway?

    Here's a secret ..... the only standard I've been able to find that relates to this is NFPA 96; NFPA 17A also repeats much. GET the standard. READ it. You WILL be surprised.

  3. #13
    Join Date
    Feb 2004
    Location
    federal way,washington
    Posts
    1,240
    I use the no contact on the ansul to activate a contactor to turn off any receptacles or lites under the hood. much less expensive than shunt trips. the nc contact runs your make up air fan either with or without a relay or cantactor. that way when the ansul is activated the make up stops ,the devices turn off, and the exhaust continues to run.

  4. #14
    Join Date
    Aug 2007
    Posts
    2,754
    what larry said works for around here too -shunt trip, contactors, mish mash -as long as it works properly its ok by fire marshal, so we just make it work. I feel better when the job has the money to have one single logistics panel, though, so that people in future can easily trouble shoot the system.

    in my area the following has to occur for it to be compliant:
    -all equip under hood goes off (sometimes gas valves are required also
    -exhaust has to go on and run for at least 45 min (some prewired ansuls have a 45 min timer module)
    -FA has to activate
    -any AC or heat unit moving air has to go off (we never use thermostatic controls for this, not sure if that is allowed or not)
    -general lights in room usually stay on, sometimes lights under hood are required to go off, sometimes not
    -any other exhaust fans in the room have to go off (example - a dishwasher with its own hood exhaust)

  5. #15
    Join Date
    Jan 2007
    Location
    New Jersey
    Posts
    846
    The system requires a manual reset. It must shut off make up air and all gas and electric under the hood that would provide heat to the protected appliances. The lights do not have to shut down. This is based on the IBC and IFC which will direct you to 2009 NFPA 17 and 17a. In 17 look at sections 9.3 to 9.7. In 17A section 5.3.3 and other sections.
    Last edited by RICK NAPIER; 03-03-09 at 09:47 AM.
    Rick Napier
    Inspector and Instructor

  6. #16
    Join Date
    May 2005
    Location
    Richmond, Virginia
    Posts
    21,838
    I want to add that, in the upper half of my drawing, the gas-valve reset box would be connected to the same NC terminal as the intake fan, so it can be set (or reset) only when the exhaust fan is on, except for when the system has tripped.
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

  7. #17
    Join Date
    Feb 2003
    Location
    Massachusetts
    Posts
    49,051
    Quote Originally Posted by ultramegabob View Post
    the lights under hood must turn off, all power under hood off,
    I believe that to be one of those trade myths, as I understand it only the circuits that control the sources of ignition must be shut down.

  8. #18
    Join Date
    Jan 2007
    Location
    New Jersey
    Posts
    846
    As I noted in the code sections above the combustion air feed as well as the sources of heat protected by the ansul system must be disconnected. The idea is to end the heat sources for the fire and the air being fed into it. The exhaust can continue and usually does.
    Rick Napier
    Inspector and Instructor

  9. #19
    Join Date
    May 2005
    Location
    Richmond, Virginia
    Posts
    21,838
    Quote Originally Posted by iwire View Post
    I believe that to be one of those trade myths, as I understand it only the circuits that control the sources of ignition must be shut down.
    Not necessarily true. Here, lights must extinguish, too.
    Code references based on 2005 NEC
    Larry B. Fine
    Master Electrician
    Electrical Contractor
    Richmond, VA

  10. #20
    Join Date
    Dec 2006
    Location
    Chapel Hill, NC
    Posts
    26,454
    I was just told by the Ansul installer that the lights under the hood where fine as long as they were explosion proof fixtures. ???

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