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  1. #40
    Join Date
    Jun 2012
    Location
    Northeast
    Posts
    234
    I would most certainly hook it up if it had it OEM. I will let one of the more experienced guys on here help you with the set up but they will need to know if it is electric or pressure. If it is electric I would not trust that is is already set up right either.

    Did you check the oil level again. If you had oil stuck in the evap cause of the failed compressor you will be over charge once it comes back. I would check for acid also due to they way you described the oil color. A high acid drier might of helped you out here also.

  2. #41
    Join Date
    May 2008
    Posts
    356
    I did install a new LL dryer. Also performed double evac. Didn't get back to check on it today.
    td55

  3. #42
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    Quote Originally Posted by tonydykes55 View Post
    The old one had unloader. I wasn't sure if there was a problem with the old one or not so I called manufacturer. He explained that depending on how the system was set up determined whether it was needed it or not. He said if the suction ever ran low the unloader would keep the pressure up. That's what I understood. I haven't hooked it up. It came width a sleeve that holds the valve open, if I'm correct, in the event that an unloader is not installed. That is how I left it. I'm glad you brought this up. Can you tell me more about it? Should I install it and if so how do I check it's operation? There is a low pressure switch.
    It depends on whether it was a "mechanical" unloader or electric unloader. Obviously the electric unloader will have a solenoid attached to it.

    It's purpose is to "unload" the head under a light load and "load " the head under a heavy load. It's a capcity control. 2 ways to unload a head internally on a 06 compressor.

    Either "Hot Gas By Pass" or "Suction Cut Off". You can tell the difference by the way the head is shaped. If it's smooth it is HGBP if it's suction cut off will have a four bolt plate mounted to the bottom of it. FYI carrier doesn't use HGBP any more to unload heads.

    If it's a mechanical unloader it needs to be checked when the compressor is running for correct load and unload set points.

    The way I've done it over the years is to throttle the suction king valve (slowly close but not all the way) to lower suction pressure and watch my gauges and my amp clamp for compressor load and unload.

    A mechanical unloader for R22 should be set to unload at around 65 PSI and load at around 75.

    The " nut " on the unloader cranked all the way down means that the compressor will run constantly unloaded.......( not good)

    Turn nut counter clockwise to adjust LOAD setpoint. Each FULL turn = 7.5 psi.

    Once your load set point is adjusted you can check differential. There should be a small cap on the side of the unloader.
    Remove cap and adjust differential with a flat head screw driver while your watching you gauges.

    Differential is adjustable up to about 20 psi and down to about 5 psi. I try to shoot for 10.

    IF ITS ELECTRIC.......some of those carrier RTU's have the unloader wired into Y2.

    You will have to use a relay to reverse the action since it's UNLOADED when it's energized.

    I HATE that.......

    Running a compressor continuously unloaded will kill it.

    This is what I do.....ancient chinese secret and has served me well.

    IF its electric put a delay on make timer and let it start unloaded. Let the delay on make wired through a relay to revers the action of the coil load the compressor up by de-energizing it after about 5 minutes.

    Works like a charm'

    A company called us out of the blue because they kept losing their 06Ds during the cooler months. I think they were on compressor number 5. Carrier 15 ton RTU loaded/unloaded through the Y2 output from the thermostat.

    I put in my little fix and that was 5 years ago. No problems.

    Make sure you clock the unloader correctly and remove the steel piston shipped with the 06D.

    Good luck and if you have an unloader I would use it.

  4. #43
    Join Date
    May 2008
    Posts
    356
    Electric. Has solenoid. So I will follow through and finish the job. Owner of the business is one of my biggest customers. He's been in this building for over a year (one of three furniture stores, plus warehouses). I can see where this is not the first compressor put in ( mounting springs, bolts, etc). So we don't know the history much more than a year. This has been very interesting and educational.
    td55

  5. #44
    Join Date
    May 2008
    Posts
    356
    Am I understanding correctly - if it's wired through y2. Then its unloaded on start up. So I should feed the solenoid through n.c. contacts, the coil being wired through a delay on make, via Y2. Therefore it starts unloaded (energized). Whe the delay on make closes, it unloads (de-energizes). And where should I pick up the signal for the n.c. relay contacts - from Y2 also?
    td55

  6. #45
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    If it has an electric unloader there should be a relay circuit already there from the factory. If yes just move the factory input from Y2 to Y1 and then wire the make on delay in series with that relay signal.

    If not pick up the signal from Y1 through the delay on make relay and then to the relay coil. Small jumper from relay coil to n/c side of contacts for unloader solenoid power.

    Ignore Y2 altogether. Chances are if he's using a 2 stage stat its cost him more than one compressor.

  7. #46
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    Y2 is being used as the units second stage but under the right conditions ( unit oversized or mild conditions) a Carlyse comp wired like that can run unloaded for an excessive amount of time.

    Take Y2 out of the picture and that replacement will live a long life.

  8. #47
    Join Date
    May 2008
    Posts
    356
    I see. I will keep you posted.
    td55

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