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HVAC experts Help!!!

Discussion in 'Off Topic Threads' started by ke4yyd, Jun 6, 2011.

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  1. ke4yyd

    ke4yyd Member

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    For 20 years I have been putting up with my inadequate  3 ton AC system.  It was too small for my home.  I replaced it in January with a 4 ton heat pump.   My first mistake was buying the equipment on line and having my local HVAC company install it.  I purchased a fairly complex 18 SEER Goodman unit that my HVAC technician was unfamiliar.  The equipment I purchased is as follows.

    1.DSZC180481A - 4 Ton 18 SEER Two Stage Compressor Goodman Heat Pump Condensing Unit, R410A Refrigerant
    2.Indoor modular unit. ( MBVC2000 )
    3. Cooling Coil ( CAPF4961D6 )
    4.Thermostatic Expansion valve. ( TX5N4 )
    5.1F95-1291 - White Rodgers Blue Multi Stage Programmable Universal Touchscreen Thermostat With Humidification & Dehumidification Function

    After installation in January it worked sporatically.  The HVAC guy could not determine the problem.  After a couple of weeks the compressor failed.  It shorted out and tripped the circuit breaker.   I could not get the HVAC guy to trouble shoot the system so I called in a second HVAC company who had a superior reputation.  They trouble shot the system and found the following problems which were corrected the last week in March.
    1.     Compressor grounded on all three legs – replaced compressor.
    2.     Wrong size R410A copper tubing – replaced with proper size and cleaned
    3.     Wrong size wiring to condenser unit – replaced with proper size
    4.     Inadequate return air duct size – replaced with larger size duct and added a second duct.
    The system worked great until last Friday when the compressor quit working although the condensing unit fan still ran.   The HVAC guy came out and  could not solve the problem.  He said the compressor was going to fail again..  It would come on for a few  moments and work fine then a loud metal on metal noise would start and then the compressor would cut out.  The control board had trouble shooting lights that indicated low voltage but the voltage was 247 volts.  The current on the compressor read 10 amps when it was running  but rose to over 40 amps when the noise started.   The HVAC guy said he felt the control board was bad.  He is going to call the factory rep today and get advice.
    This failure of the compressor is repeating the same process that occurred the first time.   Is there any HVAC techs on the board that might have suggestions on what could cause the compressor to fail again after the corrective procedures were done?
     
  2. burtona

    burtona Member

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    I've had somewhat similar experience with a Mini-Split unit for my shop I bought online and installed myself. Cooling cycle worked great for the first summer but would not change to heat cycle. I got a local HVAC guy I'd used for other things to help and we worked with the tech service rep to diagnose. They finally agreed to send a new outside unit but that didn't solve the problem. Then they sent a new control board and that didn't solve the problem either. Finally they sent a new inside unit which solved it. I've had a couple of other issues with it that the HVAC company that installed the main unit for my house worked on (relay, connector junction). Lucky they cover work on this unit under the same maintenance contract on the main unit. Buying online to save a few bucks has not been worth the problems and the replacement will a name brand sold by the HVAC company who installed and maintains my main house unit.
    Dave Burton
     
  3. GoldEx

    GoldEx Well-Known Member

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    I am by no means an expert here but do have some experience with this stuff. First of all, a bad control board does not normally create a 300% increase in amp draw. If it is asking for conflicting things to happen at once, it may be a control board issue. If you are supposed to be pulling 10 FLA and are pulling 40, something is very very wrong. A few things can make a compressor work too hard. Heat is the killer of a compressor. Trying to pump a liquid. A great way to snap things. If your unit is undercharged, the compressor is not getting adequate cooling from the cool returning refrigerant gas and could be causing the compressor to overheat. If the TXV is not operating properly and acting as a restriction, the refrigerant can begin to back up towards the compressor also causing problems. A heat pump has 2 TXV's depending on which mode it is in. There are check valves that may be functioning incorrectly too. It sounds like the guy who put it in did not have a clue what he was doing. Does the unit work in cooling mode but not heat? Do you have emergency electric strip heaters in your duct work before the indoor coil? Regardless if he is familiar with the unit or not, there are electrical codes that are standard regardless of what unit they are putting in. Undersize wire is a big no no. There is a lot to be said for saving a few bucks on line but if you are not doing the work yourself, it's hard to get any company to stand behind an install. It's like going to a restaurant and bringing your own eggs. He quoted you a price and did it as cheaply (and incorrectly it appears) as possible to maximize his profit as he was only quoting you labor and was making nothing on the equipment.

    JK
     
  4. Catpower

    Catpower Molon Labe

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    I love it, I've been in the business for about 36 yrs, it's great to see you save money, and try to hose the local guys that you need to bail your ass out

    Keep buying on line and getting advise on line it's the internet, it knows everything

    Gold ex, a circuit board couldn't cause a high amp draw? Read what he bought a 2 stage, guess what shifts the compressor from high to low speed, or vice versa, a circuit board, it might be trying to run in high and low at the same time

    I know times are tough and you want to save money, but there are a/c companies for a reason, and yes it may seem like we are high priced, but it costs alot to be able to stay up on top of the technology that keeps coming out ever day

    There is no way that you can trouble shoot a poorly installed system online, unless you are able to give the vital statistics on the unit, and a two speed is going to make it a lot harder
     
  5. ke4yyd

    ke4yyd Member

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    Thanks to those who replied. I have been properly chastised for buying on line. FWIW, I talked with my local HVAC guy before buying and he told me about the savings on line and suggested I consider the savings.


    The first failure was almost identical to the second except the first failed while operating in the heat cycle. The second occurred while operating in the cooling cycle. During the cooling cycle, the unit operated exceptionally well while it was working. I never saw it go into the second stage. It maintained the set temperature exactly no matter how hot it was and it has been very hot lately.

    The compressor certainly overheated as the tech took the cover off and cooled it off with the water hose in order to get it to run.
     
  6. GoldEx

    GoldEx Well-Known Member

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    Catpower - I covered that possibility which is why I said "If it is asking for conflicting things to happen at once, it could be a control board issue." That would cover the running on stage 1 and stage 2 at the same time. Like I said, I'm no expert. Just know enough to be a little dangerous. lol.

    JK
     
  7. Catpower

    Catpower Molon Labe

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    I'm sorry for coming off as a ahole, it's been tough for everybody out there and the people that sell on the internet won't warranty anything, and alot of the manufacturers won't warranty it if it is sold out of territory, they will check the serial numbers, and on top of that Goodman is the worst there is about honoring warranty, the OP might find that out if there is another warranty compressor in such a short time

    It could be something simple like a shorted or open run capacitor, like all things that used to last forever they have figured out how to make them wear out in as short of time as possible

    I can trouble shoot a lot of stuff on line or over the phone, but a two speed you almost have to be there or have a quite capable tech there to give the right numbers
     
  8. ke4yyd

    ke4yyd Member

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    My HVAC guy called today and will be back Wed morning with the Goodman tech rep on the phone to walk him through the trouble shooting steps.

    Thanks again guys.
     
  9. Youffer

    Youffer TS Member

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    I tend to agree with CATPOWER. I have been in the business for 28 years. Systems today are much more "delicate" than the old 6-8 SEER systems of old. We undergo training updates at least once a year for our license. Probably more than that for factory upgrades. If you are not up to date on a particular system, or brand, you can be in the dark, and not know it. You really have to be on-site to really know what is happening.
     
  10. ke4yyd

    ke4yyd Member

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    "did they put a filter line dryer on it"

    Yes
     
  11. GoldEx

    GoldEx Well-Known Member

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    So what is the updated diagnosis on your unit?

    JK
     
  12. slic lee

    slic lee Active Member

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    Are you looking for sympathy on A/C on a shotgun forum?
    You say, the 3 ton unit YOU choose was inadequate, you chose a 4 ton to replace it,Im not a A/C engineer but the 4 ton cant be right either. Buddy,its you.
     
  13. Duck Head

    Duck Head TS Member

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    Hey, Lay off of him. So he's cheap. You KNOW he's cheap because he's a Trapshooter.If he'd have bought from a local expert and even paid more he would be able to concentrate on his trap game.
     
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