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  1. #14
    Join Date
    Jun 2010
    Location
    Miami
    Posts
    257
    I'm going to have to get up there and see what all I have. It turns out both evaporators are hard wired 208. Best I can remember, when I installed A419's in them, one had to be wired for 208 but the other was just 120 (to the LL solenoid).

    I know I could do a lot of things, like involving the time clock and removing the X terminal so the fans don't start once it warms up. However I'm not crazy about that. Plus one freezer has the time clock and contactor back at the mechanical room and one has it on the outside door of the freezer.

    Whatever I do needs to be fairly quick as I doubt I can get them to shut down and empty the box. It is looking like anything I do needs to be waterproof. For safety reasons I'm leaning more and more to a stainless NEMA 3R/4X safety switch and killing ALL power. Gonna suck if I have one 208 circuit for the fans, another for the defrost heaters, and another 120 circuit for the LL solenoid. Mostly piped in ridgid and aluminum bell boxes from the 70's and the stuff doesn't come apart easy! At that point changing the breakers to shunt trips and hoping I can pull a pair of wires in the existing conduits is probably easier.

    Does seems a little strange that the fire department is requesting it. This is someone who comes by once a year and typically makes sure fire doors are positive latching and such. Must be some new OSHA requirement or something. I know a boiler inspector recently made me install such a switch outside the boiler room door. Like this stuff is really going to help if you are locked in a freezer overnight or the boiler blows up

    Anyhow, just thought maybe some of you guys had dealt with this already and knew a nice quick, cheap, and easy way to do it.

  2. #15
    Join Date
    Apr 2003
    Location
    Maple Grove, MN
    Posts
    1,139
    Maybe you could mount 24v contactors and a transformer in a box in the mechanical room near the breaker panels and wire them up to break power before it goes to the time clocks. Then you could run thermostat wire to a single pole switch in the freezers.

    If one of your solenoids is 110v, that might throw a wrench in things, though.

    I can appreciate what you mean by in needs to be done quickly when you have a 0 degree box to work in, and you are from Miami.

    By the way, Removing the "x" terminal wont do anything, except make the defrost cycle take longer. Good luck!

  3. #16
    Join Date
    Jul 2012
    Location
    Western KY
    Posts
    1,221
    There is a difference between "should" and "must". Should means he thinks its a good idea, not really up to him though. Must means there is a code or regulation on it. Get clarification before you spend money. 24 years in this trade and 11 years in the fire service, 5 of those as a chief, and I have never heard this. Code requires the door safety and that's all I know of.

  4. #17
    Join Date
    Jun 2010
    Location
    Miami
    Posts
    257
    Yes, I am debating fighting it. But we have a great relationhip with the inspector and I'd like to keep it like that.

    A switch in series with the "4" terminal and the loads is the quick and dirty way. However it has me running a couple hundred feet of conduit and might make someone think it is safe to work on the evaporator....which it wouldn't be!!!

  5. #18
    Join Date
    Jan 2006
    Location
    DFW Metroplex
    Posts
    4,910
    Quote Originally Posted by trippintl0 View Post
    Just put a single pole switch to break the "4" terminal coming from the timer to the evaporator. That should kill fans and solenoid.
    Quote Originally Posted by ammoniadog View Post
    Please don't do the above advice if you have a 230v device. You really need to break both hots, otherwise you could hurt or kill someone.
    If the 230V power was supplied via contactors at the outdoor unit (fans/defrost heaters) - and depending upon how, exactly, the control wiring is configured.....I wouldn't have a problem breaking one leg of the control power via a single pole fan switch. Should kill one side of both contactors as well as one leg to the LLSV.
    "The problem is the average person isnt tuned in to lifelong learning, or going to seminars and so forth. If the information is not on television, and its not in the movies they watch, and its not in the few books that they buy, they dont get it" - Jack Canfield

  6. #19
    Join Date
    Jun 2009
    Posts
    92
    What is needed is a either a push rod or if the door is locked an internal way of forcing it open

    I know when i go into a beer cooler especially that has a padlock I take the padlock with me inside

    shutting the fans off or solenoid does nothing for the person locked inside

    how many cases, outside of hollywood, has this happened

  7. #20
    Join Date
    Jul 2011
    Location
    St. Louis
    Posts
    118
    I think that just shutting off fans may not be a good thing for the system. The compressor is bound to be very unhappy sooner or later! Of course, once the compressor breaks, the room will get warmer and the person locked inside will be OK!

    There are modern evaporator controls out there that will shut the entire system down with a simple dry contact switch. The fans, heaters AND compressor will all shut down. The same switch input can also cause an alarm (light, siren) locally and an email or text sent out. Safety, alarm and notification all in one package.
    In an infinite universe, not only are all things possible, all things are necessary

  8. #21
    Join Date
    May 2013
    Location
    Utah
    Posts
    57
    When dealing with some odd combinations such as 240V fan bank and 115v solenoid...I have seen worse. You can use a 2 or 3 pole switch as necessary to break fans and solenoid together. Having pumpdown and fan bank shutdown is helping yourself when you need to quickly clean the evaporator. Every install should be cleaned up and streamlined whenever possible.

  9. #22
    Join Date
    Aug 2009
    Location
    Maine
    Posts
    2,638
    So unless he is brain dead he would use a 2 pole switch
    Quote Originally Posted by ammoniadog View Post
    Please don't do the above advice if you have a 230v device. You really need to break both hots, otherwise you could hurt or kill someone.

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