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Thread: out of ideas

  1. #14
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    Sep 2008
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    586
    for kicks I would wire it directly to the panel on another breaker. rule out any wiring issues.

  2. #15
    Join Date
    Mar 2008
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    NY NY
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    3200 cfm on a two hp motor is extremely high. Is it 1600 cfm on two separate fans, or parallel fans on a common discharge duct?

    The current on initial start up seems high; typically, manufactures select a motor, which runs at 80% Fla for the selected airflow and tsp. By doing so, it provides latitude in the event a speed increase will be required due to unexpected duct friction losses, air leakage etc.

    I would reach out to the manufacture and ask for the fan curve on the selected unit. Then ask the designer for the selected airflow and tsp. I think you are going to find the fan is moving more air, exceeding the bhp of the motors.

    Motor current runs up the cube of the flow increase that is the key here.
    Local 30 New York, New York Operating Engineer

  3. #16
    Join Date
    Jul 2007
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    south bay california
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    132
    Try pulling wires straight from disconect to motor, then fire it up. if it runs fine, you'll see it in the amps.

  4. #17
    Join Date
    Dec 2009
    Location
    Buffalo, N.Y
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    101
    thanks to all for the replies.


    I've checked that it is wired right about twenty times.


    I haven't wired it directly to the panel, but its in the same room, less than ten feet of #6 wire to the unit, into a terminal block, through the contactor and to the motor. All short runs, all exposed, no voltage drop on the contactor.

    I agree that 3200 cfm is high for 2hp. There is only one fan. I have had this blower running at 10 and 11 amps in the past. I know I'm pushing it but I did call the manufacturer originally due to condensation issues in the pool room and was told to set up the sheave for FLA.

    Again, thanks. I'm hoping to have one of those AH-HA moments at some point. Maybe I'm getting the same run of junk motors out of the factory?

  5. #18
    Join Date
    Jun 2001
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    Michigan
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    12,077
    being at 11 amps with no load on that baby is flat out a problem. So.

    what about wire size?

  6. #19
    Join Date
    Nov 2001
    Location
    Seattle, WA
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    7,814
    If this pool room dehumidification systems also has an air reheat coil, the switchover valve or its controls could not be working.

    What can happen is that the new motor, set-up and running correctly, ends up getting a higher air over temp that will eventually heat the motor up to thermal overload. If this happens over and over it can ruin the motor permanetly yet there seems to be no problem with the motor it self.

    Check the entire operation of the dehumidifier/heat pump portion of the system to make sure that the system is working correctly in all of its desiged stages. And this includes: pool water temperature heating and controls; dehumidification cycle and its controls; air temperature cycle and its controls; and, especially, make sure the fan runs 24/7 and the bearing are good.

    Sometimes on larger blowers the pool room conditions start to ruin the bearing where they will start to freeze up thereby producing an extra and unsustaniable load on those bearing.

    All of this needs to be checked with all the inspection/service panels in place and the pool water, air temp and humidity at normal levels.

    One more thing, check the simple things such as all the air vents are open. Just had a customer with repeated safety trips on one system only to find out his kids were closing off all the supply air registers.
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  7. #20
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    Dec 2009
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    Quote Originally Posted by Dowadudda View Post
    being at 11 amps with no load on that baby is flat out a problem. So.

    what about wire size?
    wire size is adequate. 244.9 measured at terminals inside motor junction box while in operation.

  8. #21
    Join Date
    Dec 2009
    Location
    Buffalo, N.Y
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    101
    DeltaT, I have already performed a start-up and checked unit in all modes of operation. De-hum is not a problem, my excess heat is rejected into the pool as it was designed. This unit is also a geothermal heat pump. The belt drive blower is downstream of the coils, so in heating mode the motor's ambient reaches 115 F. Motor nameplate states max. ambient 40 C. (104 F). I questioned the manufacturer and got the stuttering, backtalking mumbo-jumbo I expected, with their best defense being, noone else has this problem.
    They will not admit a design flaw. My customer has an automatic pool cover and sets back room temp while covered. Upon recovery of room temp, the heat cycle can last for hours. This is the only heat pump I have ever seen with the blower downstream of the coils.
    My problem now is that a brand new motor, never seen a heating cycle, exhibits the exact same chartacteristics as its overheated predecessor.

  9. #22
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    Mar 2007
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    What kind of motors are they giving you, china special? If your drawing almost RLA with no load on it and wiring is fine, that's a real problem. If it were me, I would cross ref to another namebrand motor.

  10. #23
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    Nov 2001
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    Seattle, WA
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    Quote Originally Posted by fruecrue View Post
    DeltaT, I have already performed a start-up and checked unit in all modes of operation. De-hum is not a problem, my excess heat is rejected into the pool as it was designed. This unit is also a geothermal heat pump. The belt drive blower is downstream of the coils, so in heating mode the motor's ambient reaches 115 F. Motor nameplate states max. ambient 40 C. (104 F). I questioned the manufacturer and got the stuttering, backtalking mumbo-jumbo I expected, with their best defense being, noone else has this problem.
    They will not admit a design flaw. My customer has an automatic pool cover and sets back room temp while covered. Upon recovery of room temp, the heat cycle can last for hours. This is the only heat pump I have ever seen with the blower downstream of the coils.
    My problem now is that a brand new motor, never seen a heating cycle, exhibits the exact same chartacteristics as its overheated predecessor.
    What's the make and model of this unit? Something doesn't add up.

    I think on your first post you mentioned too much humidity? You can't reset the air temp back if this is a typical pool dehumidification system as on reset the running of the compressor will overheat the pool water resulting in too much humidity and loss of the envelope control of the room.

    Make and model of the unit to see the original design concept would be of great help.
    "The American Republic will endure until the day Congress discovers it can bribe the public with the public's own money.
    - Alexis de Toqueville, 1835

  11. #24
    Join Date
    Sep 2006
    Location
    Ohio
    Posts
    494
    Try switching the wires on the capacitor and see if the amp draw goes down. You may need to go with a higher HP motor with the same RPM's.

  12. #25
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    Sep 2009
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    Arnold mo
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    Quote Originally Posted by fruecrue View Post
    thanks to all for the replies.


    I've checked that it is wired right about twenty times.


    I haven't wired it directly to the panel, but its in the same room, less than ten feet of #6 wire to the unit, into a terminal block, through the contactor and to the motor. All short runs, all exposed, no voltage drop on the contactor.

    I agree that 3200 cfm is high for 2hp. There is only one fan. I have had this blower running at 10 and 11 amps in the past. I know I'm pushing it but I did call the manufacturer originally due to condensation issues in the pool room and was told to set up the sheave for FLA.

    Again, thanks. I'm hoping to have one of those AH-HA moments at some point. Maybe I'm getting the same run of junk motors out of the factory?
    Ten ft of wire, a terminal block and a contactor-plenty enough room for something going to ground causing high amps, but not enough to cause a voltage drop. Get a virgin supply of 240 going to it that motor-preferably at your shop for peace of mind-and if amps are normal go back and find that grounding issue. I'm no where near some of these other guys, or you probably, in experience. I do know that when something just don't make sense it's because something you're assuming to be right is not.

  13. #26
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    Dec 2009
    Location
    Buffalo, N.Y
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    Quote Originally Posted by maxpower View Post
    What kind of motors are they giving you, china special? If your drawing almost RLA with no load on it and wiring is fine, that's a real problem. If it were me, I would cross ref to another namebrand motor.
    first two were emerson electric, most recent was G.E. side by side there is no difference between them besides the name on the nameplate. Probably supplied by one source(lowest chinese bidder) to both companies. Another name brand would be an option, but until I know for sure that I'm dealing with defective motors, I can't buy another. Thinking about bringing them home and wiring them into the disconnect for my welder. For now just trying to put it off until after the holidays. This whole job has dragged on for long enough. He can wait a couple more days.

    Oh, and by the way, I just found out that the motor for the hydraulic pool cover burnt out as well. Has only been in two weeks and is used rarely for 30 seconds at a time. Coincidence, I think not. Okay, maybe- maybe not, just sounded good.

    Thanks again for all the help and suggestions. still waiting for the Ah-HA moment and open to any Ideas or brainstorms to get there. Hope everyone has a good time over the next couple days. Happy holidays.

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