Page 1 of 8 12345678 LastLast
Results 1 to 13 of 100
  1. #1
    Join Date
    Jul 2010
    Location
    NJ
    Posts
    394
    Post Likes

    Confused What causes compressor to trip on high pressure?

    Last week the fan on my Rheem compressor broke and the compressor tripped on high pressure - I assume because it got hot. The dreaded gas company came out and replaced the motor and fan assembly. Started unit up and it appeared to run fine. I asked them to check the R-22 levels while they were out there - said everything was fine.

    We did not need AC that day, so unit was shut down. Yesterday I ran system and noticed it was warm when I came home. Checked and unit had tripped on high pressure. Pushed the reset button and it came back on, but will only run about 15 to 20 minutes before tripping. When I place my hand on the unit it is very hot top deadcenter where the fan motor sits. The fan blades are about 1" wider than the old ones, don't know if that is an issue. Also at the top of the unit there is a circular shroud that the fan spins in. The fan blades are sitting about one inch below that, could it be that the fan should be higher to get correct air flow?

    Any clues based on what info I have as to what is going on? Thanks.

  2. #2
    Join Date
    Mar 2007
    Location
    NW AR
    Posts
    2,478
    Post Likes
    Why did the gas company get involved? Why did they replace the blade? Did they clean the condenser?

    My guess would be its either the wrong motor or blade, or both. Could also be wired wrong, weak high pressure switch, dirty condenser, overcharge. You need an hvac pro to check it out, not the gas company.

  3. #3
    Join Date
    Mar 2009
    Location
    Mount Holly, NC
    Posts
    7,115
    Post Likes
    why is the blade different? I've never replaced a blade with a fan motor unless the blade got damaged somehow.
    Rheem units need the blade to sit fairly high, and yes, if the blade is not correct, in both rotation, and pitch and depth, and speed, you can indeed get high pressure trip.
    also the coils could need cleaning. also the compressor itself could be damaged and cause a high pressure trip.
    the system needs to be checked out by a qualified HVAC service tech.
    oh, don't turn the system back on until it's serviced!
    The TRUE highest cost system is the system not installed properly...

    Find a HVAC-Talk Contractor by clicking here

    Do you go to a boat repairman with a sinking boat, and tell him to put in a bigger motor when he tells you to fix the holes?

    I am yourmrfixit

  4. #4
    Join Date
    Jul 2010
    Location
    NJ
    Posts
    394
    Post Likes
    Thread Starter
    The gas company is involved because I have a service contract with them for the equipment. The original problem was the shaft corroded on the old motor and broke about 1/2" down from the motor and the blade actually fell off which is why the unit tripped to start with. The replacement unit said it was for this system, but the blades while the same length and pitch are about an inch wider. I am thinking that the blade is sitting a little low and not giving correct air flow, but that is just a guess. The coils are clean, and when they put their gauges on the unit said the charge is correct.

  5. #5
    Join Date
    Mar 2007
    Location
    NW AR
    Posts
    2,478
    Post Likes
    The highest part of the blade should be a little higher than the shroud but Ive seen tons that were too low that would run without tripping HP. That may be a small part of your problem but I dont think think thats whats kicking it out on HP

  6. #6
    Join Date
    Jul 2010
    Location
    NJ
    Posts
    394
    Post Likes
    Thread Starter
    The highest part of the blade is about 3/4" BELOW the shroud. I assume this fan must be the problem as there were no issues with the unit before the fan fell off. The only thing that has changed is the new fan/motor.

  7. #7
    Join Date
    Dec 2010
    Location
    Woodbridge Twp, NJ
    Posts
    1,309
    Post Likes
    It's not the first time ive heard a "worryfree" horror story. Tell the orange and white vans to come out and fix what they messed up. It wouldn't hurt to clean the condenser coil while they have the fan out.
    Every customer you take for granted today will be someone else's tomorrow.

  8. #8
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    26,677
    Post Likes
    In general, a larger blade diameter will give more airflow, given the same number of wings and other characteristics.

    More airflow isn't likely to cause high head pressure problems.

    While positioning could be an issue, I don't think that's it.

    Get your contractor back out and tell them to get it right this time.



  9. #9
    Join Date
    Jul 2010
    Location
    NJ
    Posts
    394
    Post Likes
    Thread Starter
    Perhaps I did not correctly explain the difference on the blades. They are the same length (or diameter), it is the width of the blade that is larger by about an inch. Thus while there are the same three blades, there is less space between each blade.

  10. #10
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    26,677
    Post Likes
    I still don't think the blade is the biggest part of your problem.



  11. #11
    Join Date
    Jul 2010
    Location
    NJ
    Posts
    394
    Post Likes
    Thread Starter
    I have a big portable air mover and put it by the side of the compressor blowing through the coils on one side. When I did this the unit ran for about 35-40 minutes rather than the 15-20 with just the fan. That seems to imply an airflow problem I would think? If not airflow what else could be causing this all of a sudden?

    Note - I said three blades before, it only has two blades, which is what the old one had as well.

  12. #12
    Join Date
    Feb 2012
    Location
    Toronto Canada
    Posts
    1,090
    Post Likes
    Quote Originally Posted by kirbinster View Post
    I have a big portable air mover and put it by the side of the compressor blowing through the coils on one side. When I did this the unit ran for about 35-40 minutes rather than the 15-20 with just the fan. That seems to imply an airflow problem I would think? If not airflow what else could be causing this all of a sudden?

    Note - I said three blades before, it only has two blades, which is what the old one had as well.
    And if you busted out your garden hose and cooled the coil it would run longer but it is not the answer. Call back the Direct Morons and get them to fix it properly.

    Is the unit clean? Did anyone check the Head preasure?

  13. #13
    Join Date
    Jul 2010
    Location
    NJ
    Posts
    394
    Post Likes
    Thread Starter
    They are coming out tomorrow, between 8am and noon. I had them put a gauge on it when they did the fan and they said it was fine, but it had only been running about one minute at the time.

Page 1 of 8 12345678 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Related Forums

Plumbing Talks | Contractor MagazineThe place where Electrical professionals meet.