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  1. #1
    Join Date
    Jun 2009
    Location
    DFW, TX
    Posts
    674

    Confused Training a supermarket tech

    Ok guys. I'm training / evaluating a new coworker who has more experience than me (I have about 3-4 years only). Our company does restaurant refrigeration - in other words, small reach-ins, walk-ins, and ice machines. HIS experience is primarily supermarket refrigeration and large air conditioning.

    Some of the things he says seem wrong, but he says that's how it is on big equipment. It doesn't make sense to me. Here it is:

    1. "Restricted drier will be very hot" I said no, a restriction in liquid line will have a temperature drop if anything. He says not on big AC units. He says the compressor is so big it pushes past the restriction and gets hot?

    2. "Low on charge will cause high suction and sometimes very high head, but only if a little low, not very low. Add refrigerant, and suction will drop and head will drop." I said totally backwards dude, flashing before TXV causes low suction. He says no, flashing due to low on charge causes the TXV to open up wide due to warm evaporator causing high suction. ??? I've never seen that, he said even ice machines will do it?

    Regarding high head due to low on refrigerant, I said maybe headmaster is bypassing due to low charge? He said no, this is how large AC units with no head pressure control work.

    If he's right I want to know, because I always thought refrigeration principles work the same regardless of application. He has about 8-9 years more experience than me, and I've never worked on a supermarket rack, and I've never worked on an AC unit other than a couple of residential ones for family members.

    What say you?
    Last edited by trippintl0; 06-21-2012 at 10:34 PM.

  2. #2
    Join Date
    Feb 2008
    Location
    California
    Posts
    2,066
    This guy is full of the stuff that come out of a bulls rear end.

    I too have tested many guys who have XX years experience, only to find out that they are full of it.

  3. #3
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    I do a lot of work on BIG AC units and a restricted drier will have a noticable temperature DROP across it. How do we get a temp drop with refrigerant ? Does his explanation mean TXVs on big equipment get hot ?

    Hi head and hi suction with low refrigerant ? seriously. The txv can open up all it wants. There is no solid column of liquid going to it. Low refrigerant causing hi head makes no sense either.

    Big AC units with no HP control act like little AC units with no head presszre control when they're low on charge. Hes full of it.

    Now some units with HGBP and a headmaster wont lose suction but WILL lose capacity.
    But he said no HP control.

    Humam reascources ought to take another look at the guy. Ppl do lie on their resumes.

  4. #4
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,758

  5. #5
    Join Date
    Jun 2009
    Location
    DFW, TX
    Posts
    674
    Wow, I was actually second guessing myself for a minute there...

    Keep in mind, I'm only mentioning the bad things... there are plenty of good things about him, and plus he has a great attitude and great work ethic. I just think he may have never had good training, not really sure. But he really listens to everything I tell him and says he is impressed with how much we know about these machines we service and is eager to learn more.

    I just wanted to make sure there wasn't something special about racks or big equipment that somehow negated the things I consider "fundamentals."

  6. #6
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,758
    Quote Originally Posted by trippintl0 View Post
    Wow, I was actually second guessing myself for a minute there...

    Keep in mind, I'm only mentioning the bad things... there are plenty of good things about him, and plus he has a great attitude and great work ethic. I just think he may have never had good training, not really sure. But he really listens to everything I tell him and says he is impressed with how much we know about these machines we service and is eager to learn more.

    I just wanted to make sure there wasn't something special about racks or big equipment that somehow negated the things I consider "fundamentals."
    The most important question here is "Is he willing to accept that he may be wrong?"

  7. #7
    Join Date
    May 2011
    Location
    Detroit, MI
    Posts
    27
    Maybe he is messing with your head? Maybe joking around with you?

  8. #8
    Join Date
    May 2011
    Location
    Detroit, MI
    Posts
    27
    Then again, my new service manager, who has "been doin' this since i was in diapers", told me that high super heat was caused by refrigerant stacking up in the evap. What do I know?...

  9. #9
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,758
    Quote Originally Posted by tek1
    Then again, my new service manager, who has "been doin' this since i was in diapers", told me that high super heat was caused by refrigerant stacking up in the evap. What do I know?...
    The lack of knowledge in this trade is both amazing and depressing at the same time.

  10. #10
    Join Date
    Jun 2012
    Location
    Semmes, AL
    Posts
    106
    Looks like you need to keep looking.

  11. #11
    Join Date
    Aug 2002
    Location
    Orange County CA
    Posts
    1,084
    In Bizarro World...he would be right.

    Just because people have driven for a long time , does not make them a good driver.

    The supermarket refrigeration trade usually weeds out the people who do not know what they are doing( in time ).....why is he a new guy with you?

  12. #12
    Join Date
    Mar 2009
    Location
    Mid-Mo
    Posts
    3,596
    Ya I wouldn't back down from him. Although jp has mentioned cases that he's seen high head pressure then after adding gas to it the pressure actually dropped. I'm sure it still is haunting him how that can happen. Otherwise the dude is off his rocker.

  13. #13
    Join Date
    Sep 2008
    Location
    Western PA
    Posts
    25,758
    Quote Originally Posted by ryan1088
    Ya I wouldn't back down from him. Although jp has mentioned cases that he's seen high head pressure then after adding gas to it the pressure actually dropped. I'm sure it still is haunting him how that can happen. Otherwise the dude is off his rocker.
    Doesn't haunt me.

    I figured out why I was wrong....

    It's possible, but not on the scale and magnitude that I was seeing.

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