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  1. #14
    Join Date
    Jan 2007
    Posts
    60
    I've messed with those head pressure controllers before. Id scrap it and go with the Johnson Controls one that John Dalton mentioned, they even have t's that screw on to the liquid line port so you can cap one for your guages and have another spot to hook up the pressure port for the controller. Good luck and post your final results.

  2. #15
    Join Date
    Dec 2006
    Location
    In a Mess
    Posts
    1,029
    Thanks Mr Berg and Mr. Dalton I appreciate your input on this situation! This 'situation' was handed to me initially froma co-worker who didn't go further with this job.

    Initially the problem was The Condensing Unit was locking out due to low pressure on start up, I watched the unit and the suction would drop below 20psi after the fan shut off and after the 90 second grace period the controller gives for low pressure after start up.

    THe low pressure switch that I changed out earlier seemed to have "cure" my locking out issues, it has not locked out since!

    There is still the humidity issue. It is lower than what is wanted. The room is (rough estimate) 30'W X 70'L X 20'H

    The equipment there:

    York 7.5 ton condensing unit M# h5ced090a58a

    trane air handler, M# twe090aw00ab

    Thermolec electric heat M# sc-ctpx 2 stage @ 12.5KW each

    Nortec Humidifier , (NHB 030 maybe) can't find model number but i think it's out put is 30lbs/hr


    controls are Johnson Controls system 350, 6 all together

    A350 A/B
    S350C, one for York one for Nortec
    W351
    D350 & D351
    Sig removed by mod. G-Rated site

  3. #16
    Join Date
    Dec 2006
    Location
    In a Mess
    Posts
    1,029
    Quote Originally Posted by partsonorder View Post
    I've messed with those head pressure controllers before. Id scrap it and go with the Johnson Controls one that John Dalton mentioned, they even have t's that screw on to the liquid line port so you can cap one for your guages and have another spot to hook up the pressure port for the controller. Good luck and post your final results.

    aah I just looked up the Johnson P66 Electronic Fan Speed Control, I have never used one of those before, looks like it may be a better item for control. although I think The fan motor on the York unit has sleeve bearings which may not be sutible for such a control, Would I need a ball bearing equipped motor for this unit?

    What is the approx cost ofa P66 would ya know?

    Thanks
    Mike
    Sig removed by mod. G-Rated site

  4. #17
    Join Date
    Jan 2007
    Posts
    60
    Actually i haven't used a P66 either, I guess the one I was referring to was the P70 type controller. As far as cost i'm not sure they always been on the shelves at the shops I've worked at and usually I'd be putting them in a start up type situation or warranty. Hope this helps.

  5. #18
    Join Date
    May 2004
    Location
    Los Angeles, CA
    Posts
    1,560
    Dear MikeSq,

    You’re correct in that you need to replace the existing condensing motor with a ball bearing type that will stand up to the added heat of the Johnson Control #P66 controller….but it is worth the investment in the system. The company I work for has installed over 150 of these setups to counter the fickle weather that we have in the Los Angeles area (OSA: 28 to 115 degrees F).

    Approximate cost of the Johnson Control #P66 is 55 pounds of #R-22 (remember we’re not to post prices at this forum, but now you can calculate the approximate cost of the controller).

    We use a lot of Armstrong and Nortec electric steam generators at our company, and I too like the convenience of the replaceable or cleanable tanks, that are available from both manufacturers.

    Hope this helps…….

    Respectfully Submitted,
    John J. Dalton CM

  6. #19
    Join Date
    Nov 2005
    Location
    Shreveport, Louisiana
    Posts
    2,338
    Quote Originally Posted by MikeySq View Post
    Thanks Mr Berg and Mr. Dalton I appreciate your input on this situation! This 'situation' was handed to me initially froma co-worker who didn't go further with this job.

    Initially the problem was The Condensing Unit was locking out due to low pressure on start up, I watched the unit and the suction would drop below 20psi after the fan shut off and after the 90 second grace period the controller gives for low pressure after start up.

    THe low pressure switch that I changed out earlier seemed to have "cure" my locking out issues, it has not locked out since!

    There is still the humidity issue. It is lower than what is wanted. The room is (rough estimate) 30'W X 70'L X 20'H

    The equipment there:

    York 7.5 ton condensing unit M# h5ced090a58a

    trane air handler, M# twe090aw00ab

    Thermolec electric heat M# sc-ctpx 2 stage @ 12.5KW each

    Nortec Humidifier , (NHB 030 maybe) can't find model number but i think it's out put is 30lbs/hr


    controls are Johnson Controls system 350, 6 all together

    A350 A/B
    S350C, one for York one for Nortec
    W351
    D350 & D351
    The nortec humidifier has a capacity control pot on the control board, but you must be sure the container is still good.

    When you run the huimidifer and it looks like a "lighting storm " inside the bottle then it MUST be replaced. We have tried to clean out the bottle but that did not work it gets full and degrades the elements.

    You can also add a teaspoon of salt to the bottle to get it started.

    Check the nortec website and get the manual for the unit. It will detail the change out and capacity control settings on the board....

  7. #20
    Join Date
    Dec 2006
    Location
    In a Mess
    Posts
    1,029
    As far as the Norteec is concerned it has a display of the current output of the unit. how is that output on the display achieved? If it reads 30lbs/hr is it actually doing it or could the reading be false? It is usually reading in the Vaxcinity of 30lbs/hr

    The Cylinder was Replaced in Dec 2006, I'm sure that salt was not added to it when it was changed, I have not done that myself either I was unaware of it and can't remember reading that in the instructions.

    The Water here in this City is really Hard so frequent chanvgers of the Nortec cell are common, You should see the condition of the Ice makers I work on haah you wanna see mineral/scale build up? haah I sewar it builds up on your teeth if ya drink too much tap water!
    Sig removed by mod. G-Rated site

  8. #21
    Join Date
    Feb 2007
    Location
    Springfield, MA
    Posts
    1
    Instead of the cost of a P66 controller, couldnt you go with a cheaper Ranco HP controller? We cover a lot of computer / server rooms and thats something Ive installed or other techs have installed to solve the issue.

  9. #22
    Join Date
    May 2004
    Location
    Los Angeles, CA
    Posts
    1,560
    Dear BrianEnglish,

    Although a typical condensing fan cycling control (Ranco) is the easiest and cheapest of all condensing capacity controls to install, it is also the worst way to do so for many reasons.

    First of all the condensing motor is constantly being turned on and off most of the time to maintain the desired liquid line temperature, this not only reduces the life expediency of the motor, but it also reduces the reliability of the system should this motor fail, or go off on internal temperature overload. Second, if you were to monitor the liquid line temperature (the value you are trying to maintain) you would find that the temperature, as well as the pressure, would be fluctuating tremendously over a broad range. While this might appear to be satisfactory to an inexperienced service technician, an experienced one would know that any refrigeration system is extremely dynamic in nature, and subject to ALL of it’s reading being affected by just one, in this case the liquid line temperature. The large oscillations in the liquid line temperature will directly affect the pressure differential across the metering device (remember most metering devices have to have a minimum of 100 PSI difference across the valve to operate properly and efficiently).

    All in all, these condensing fan controls should not be used on any cooling system that is guarding an expensive or important load (ie. server or data room).

    Just my option based on the above outlined information………………

    Respectfully Submitted,
    John J. Dalton CM

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