Results 1 to 9 of 9

Thread: Data Aire

  1. #1
    Join Date
    Nov 2006
    Location
    Iowa
    Posts
    86

    Data Aire

    Model DTAU-0532

    Called out on this unit about a month and a half ago and found it low on charge. Searched for a leak and nothing found. Average outdoor temp about 15 degrees at the time. Unit is remote air cooled condensor one fan. System has a headmaster and hot gas bypass. Added gas to system and it came around, checked over and found fan cycling on cond fan. called local rep and they said it should have a P66 speed contoller. Went back and installed P66 a couple of weeks ago. Called out today that unit is down. About 40 degrees out. Person on site said the fault was internal overload. They claimed to have reset it and it ran for a few minutes. I went to start unit up and found high pressure switch on discharge line tripped. I reset and unit ran. Pressures low and unit bypassing hot gas, LL sight glass empty and receiver glass empty. Added about 6lbs of 22 and things came around. Watched for about 45 min and all seems well. I am not sure if I am truly low on charge or if the headmaster had stuck. Going back tomorrow to check for a leak. Just seems very strange that hp switch was tripped. Any ideas??
    Bring back rotary phones so we dont have to press 1 to proceed in ENGLISH!!!!

  2. #2
    Join Date
    Jun 2006
    Location
    New Jersey
    Posts
    4,337
    Quote Originally Posted by hvacr man View Post
    Model DTAU-0532

    Called out on this unit about a month and a half ago and found it low on charge. Searched for a leak and nothing found. Average outdoor temp about 15 degrees at the time. Unit is remote air cooled condensor one fan. System has a headmaster and hot gas bypass. Added gas to system and it came around, checked over and found fan cycling on cond fan. called local rep and they said it should have a P66 speed contoller. Went back and installed P66 a couple of weeks ago. Called out today that unit is down. About 40 degrees out. Person on site said the fault was internal overload. They claimed to have reset it and it ran for a few minutes. I went to start unit up and found high pressure switch on discharge line tripped. I reset and unit ran. Pressures low and unit bypassing hot gas, LL sight glass empty and receiver glass empty. Added about 6lbs of 22 and things came around. Watched for about 45 min and all seems well. I am not sure if I am truly low on charge or if the headmaster had stuck. Going back tomorrow to check for a leak. Just seems very strange that hp switch was tripped. Any ideas??
    I believe that is a 5 ton with a single fan. If you are running a headmaster w/ receiver, you should have no fan cycle/speed controller on it.

    When checking the charge in cold weather, it's best to block your coil and get the head pressure up.

  3. #3
    Join Date
    Nov 2006
    Location
    Iowa
    Posts
    86
    Yes it is a 5 ton with a single fan with a headmaster and receiver. The first time I worked I it I saw the fan cycling and was going to remove it. Talking with the local rep they said it should have a speed controller. I have argued with them and could tell it never had a speed contoller because I had to change factory wiring to install it. I argued with my boss until I was blue in the face. I lost and he made me install it. I dont think it would cause the issue I am having though.
    Bring back rotary phones so we dont have to press 1 to proceed in ENGLISH!!!!

  4. #4
    Join Date
    Sep 2009
    Location
    Los Angeles
    Posts
    171

    Red face

    All of the Data Aires I've seen are metered by a TXV. Personally, I never use suction pressure to evaluate a TXV system. Was there flash gas in the sight glass? Did you check the subcooling? Are the filters & coils clean?

    I always evaluate a TXV system using a Fluke 52 II using two K-type thermistor pipe clamps, one for the liquid line & another on the suction. If the subcooling is greater than 15-20 degrees, I'll recover the excessive refrigerant. It's possible several guys have also added gas, stacking liquid in the condenser. If the condenser is half full of refrigerant, then you only have half of a coil to do any work. This will cause a high pressure safety or compressor overloads to trip after you get down the road.

    If the subcooling is OK, then I'll check for excessive superheat. You could have a TXV that isn't feeding properly or a restriction such as a plugged drier. Again using the two K-thermistors, hopscotch looking for a temperature drop.

    I apologize if you already knew this.

  5. #5
    Join Date
    Jan 2009
    Location
    Virginia
    Posts
    37
    Can you disable the hot gas bypass long enough to get head, suction, superheat and subcooling?

  6. #6
    Join Date
    Nov 2006
    Location
    Iowa
    Posts
    86
    Found out from data aire that this unit shouldnt have a fan speed controller. Just like I have argued all along. Going to go remove it tomorrow.
    Bring back rotary phones so we dont have to press 1 to proceed in ENGLISH!!!!

  7. #7
    Join Date
    Nov 2002
    Location
    NJ - WORK IN NYC AREA
    Posts
    1,455

    Cool

    As ASCJ said remove the speed control, your rep is misinformed. You never use a speed control with a headmaster as the instructions state.

    You may have to calculate your piping for a proper charge and weigh it in.
    "My hands are for sale"

  8. #8
    Join Date
    Nov 2001
    Posts
    9

    Cool Data Aire info

    Hvacr man,
    Data Aire has condensing unit head pressure is controled either by use of fan speed or flooded system. You are working with the latter.
    It sounds like the unit was installed with the summer charge, and never had the additional winter charge added. This would result in a low charge in the winter weather.
    I am including the link to the Data Temp Operation & Maintenance Manual. Please check out the charging info for flooded system on page 21. Also note that page 20 has seperate charging info for the fan speed control system.
    I am not sure on why the high pressure switch had tripped. But I suspect that it has something to do with trying to use two methods of head pressure control at the same time causing the pressure to hunt resulting in over shoot and under shoot.
    At this time I would first ensure that the unit has a proper charge.
    I would also ensure that the electric heater installed on the condensing unit receiver is wired in and working properly. This will help maintain head pressure as the ambient temperature goes down.

    Data Temp DX O&M Manual link: http://www.dataaire.com/downloads/Da...aTempIOM19.pdf

    I checked the wiring diagram for the Remote Condenser Flooded System and can't locate any P-66 or other fan speed controler.

    Condensing Unit link: http://www.dataaire.com/downloads/DRC-S-003_021203.pdf

    A link to good reading from Copeland on using air cooled DX equipment in low ambient environments: http://www.hvacrinfo.com/cope_ae_bulletins/TAE1234.PDF

  9. #9
    Join Date
    Nov 2006
    Location
    Iowa
    Posts
    86

    Talking

    Dave

    Thanks for the links. I have removed the speed controller and properly charged the unit. The cond diagram you show is the same one data aire gave me but not what the rep gave me or what is laying loose in the cond. Both of those show a controller. I had argued the controller with my boss and the rep and had lost. I should have stuck to my guns or called data aire direct earlier. Kinda funny I went out on another data aire today and found fan cycling and a headmaster on it. It was tripped on high head, so I checked charge and removed the fan cycling. I was about to leave and they came to me about another one that wasnt keeping up. Yep it was also tripped on high head. Did some digging and found out they had test run the generator this morning and the remote condensors are not wired into the generator.
    Bring back rotary phones so we dont have to press 1 to proceed in ENGLISH!!!!

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event