Multiple Restaurant AC Issues Diagnosed



Eric Mele gets Multiple Restaurant AC Issues Diagnosed. He investigates several different issues with a restaurant’s HVAC/R equipment, including an inefficient A/C compressor and a failed fan motor on a refrigerator.

The readings indicate that the suction pressure is high, around 152 PSI, with an 80-degree return. The temperature split is only 10 degrees, and the unit is running too warm with low subcooling.

When Eric pumps the charge down, he notices that his meter stalls out a bit. Then, he shuts off the blower and checks the suction line temperature. The suction line temperature rises past 91 degrees, meaning that hot gas is leaking back through the compressor. The data affirms Eric’s suspicion of an inefficient compressor.

Upon further inspection, Eric notices that the unit has an aftermarket fan motor, which may have damaged the compressor and contributed to the inefficiency that Eric is currently investigating. When running the unit without the blower fan, the suction pressure fails to drop as quickly as usual. So, the compressor is the primary issue, and replacement is necessary.

Eric also inspects another small unit with filthy coils and a fan that won’t spin. However, the compressor appears to pump normally. In this case, Eric replaces the fan motor and cleans the system. (As always, he makes sure the motor spins in the correct direction.) None of the bolts fit, however, meaning that Eric must use a set of customized screws. He doesn’t put too many in all at once, as he wants to make sure the motor works and spins the right way first.

Once Eric was sure that the fan motor worked as it should, he used a Dremel to customize the remaining screws and mount the motor correctly. He also redoes some wiring and sees if the unit can make temperature. He runs the unit in defrost and checks the amperage as the unit comes out of defrost. The relay appears to draw high amperage; upon further inspection, the relay appears to be working, but Eric still takes the safe route and replaces the start gear.

The belt also has an issue; the belt is loose and runs counterclockwise. Eric replaces the belt, tightens it appropriately, and ensures that it spins in the proper direction. He props the motor up to get the correct belt tension, but the problem is bigger than that; the entire fixture will need replacement.

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41 Comments

  1. Dark

    Im in hvacr school rn and it’s really cool working on little things in class and seeing how it all comes together like in this vid

  2. wmiller295

    Run everything to failure and THEN want it all fixed in 1 day WHILE their kitchen is packed and busy. -0- maintenance. Typical dive…

  3. TennesseeHVAC

    !!!! Could you please tell me where Eric purchased his magnetic phone case holder. Or how he made the phone magnetic in order to place on the disconnect box to watch his Job Link app. ???!!! PLEASE HELP!!

  4. TennesseeHVAC

    PLEASE!!! Let me know where you got the magnetic phone case. Or how you are able to slap your phone up on the box like that. !!!!!!!

  5. jettelo

    When a compressor or fan has the paint off of it. It won't last much longer

  6. Eddie Gomez

    When you’re pumping it down are you pumping the refrigerant back into the condenser unit itself. Do you close the liquid line valve completely and hold the contact or button in so the Freon pumps into it through the suction side? I want to know because this is how I’m being taught.

  7. Ashton Lanier

    At least all your skids pulled out. It seems like every refrigeration call I get, they never do 😂

  8. ruben guzman

    Just curious on the temperature rise on the suction line your testing ,how do you know its not heat transfer from the compressor to the copper line causing the heat rise?

  9. Sparky Tech

    LOL I get jobs like this all the time. because they don't do any maintenance on anything they run everything to the ground.

  10. OthmanEmpire

    Thanks for the video =)

  11. Ronald Clark

    Musta had alota calls.
    Got everything running.
    Lots of follow up.

  12. HVAC1

    Run that motor before you mount it to check for rotation.

  13. Tom Walker

    I wouldn't want to eat there. NASTY, Nasty, Nasty.

  14. Ted Lahm

    Jumping around on the description.

  15. B. K. White

    Damn. I'm confused. So isn't that indicative of a failed metering device if the system doesn't pump down without the indoor fan running. Assuming it's a txv at the evaporator.. & what about a maintenance first?

  16. RJ_Make

    Tech. Life

  17. snapdragon 805

    Really good video. Please make more of these videos. I love how everything is straight to the point and not talking so much and going off track.

  18. Ron Toledo

    Great video ! I also found interesting the socket on your phone being magnetic, what brand is the socket you have on your phone ? I need one of those! Thanks

  19. Jerry Sarabia

    Im in hvacr school and it helps to watch these videos after a lab where I feel like watching these videos I can go back to the lab and slow things down and grasp more of an understanding Thxs man

  20. Jeff AlwaysDry

    3:15 rusted top of the scroll compressor normally means the compressor was running at low Freon situation for a very LONG time.

  21. gregmac19

    Did you really try to blame the issue on an aftermarket fan motor?

  22. Wayne Costanza

    Very good video, more please!

  23. raymond Moore

    As rusty as the top of that compressor is, the fan may very have caused this issue. That compressor head got very hot over time.

  24. 😃 I know the feeling of an over due replacement!
    Thanks for the video!
    🥃🥃🍺🍺🍺🍇🏌🏻‍♀️
    Stay safe.
    Retired (werk'n)keyboard super tech. Wear your safety glasses!

  25. Rick Rojas

    Right off the back the comp bad look at discoloration of the top of compressor mean been running high liquid line temps which could be early sign of valves going bad

  26. Paul Rozinski

    Gee I wonder how much spoiled food this restaurant served before calling for service. I’m sure techs all have horror (kitchen) stories to tell.🤢

  27. Philip Wall

    Great diagnosis on the first split system, you don't see in efficient compressors everyday.GREAT JOB!

  28. Mitchell Armyguy

    It's crazy how nasty hvac equipment gets in a restaurant. Cleaned some rtus the other day at a taco place all units were pretty close to the kitchen exhaust fans and all of them were completely caked in dust and oil vapor. Crazy shit is they only do maintenance once every 6 months. Evaps had oily residue all over them like you see on a kitchen hood. Of course the condensers had blankets on them. The worst unit had a brand new condenser next too it like they would rather buy units than increase the maintenance intervals.

  29. Joe Shearer

    Do you the 13a on the nameplate was for the defrost heaters? That's how it is on regular house refrigerator

  30. Jaime Gonzalez

    What about just cleaning the evaporator coil first before anything!?

  31. Mark Bell

    Everyone loves a good shit show.😂😂😂😂

  32. Durian Den

    What tool have ? Blootot gauge??

  33. Joe Shearer

    I don't think the temperature clamp test is a good one with a scroll. For one the motor windings very close proximity and there is a internal check valve that will work to stop the bypass in off cycle

  34. marty maness

    Does a scroll compressor have a discharge valve?

  35. James T

    Super tech, get it!

Comments are closed.