Page 4 of 4 FirstFirst 1234
Results 40 to 45 of 45
  1. #40
    Join Date
    Mar 2008
    Location
    West Monroe, LA
    Posts
    69
    I was a little worried with the amp draw at 12.5 and still getting into the hottest part of the day. The FLA was 14.4

  2. #41
    Join Date
    Jul 2009
    Location
    South Carolina
    Posts
    3,261
    Quote Originally Posted by daviddsims View Post
    SP=82
    DP=255
    SL temp=65
    LL temp=110

    Still not completely happy with the results.
    Those numbers look pretty good if it was 103 outside.
    If your TD across the evaporator was 15 or so you may be O.K. depending on the inside coinditions. What about your indoor DB & WB?
    Gary
    -----------
    http://www.oceanhvac.com
    An engineer designs what he would never work on.
    A technician works on what he would never design.

  3. #42
    Join Date
    Jul 2005
    Posts
    5,576
    Quote Originally Posted by daviddsims View Post
    I was a little worried with the amp draw at 12.5 and still getting into the hottest part of the day. The FLA was 14.4
    The amp draw could be normal. The compressor in the pdf file below has an RLA of 14.4. It may not be the compressor in your unit, but yours should have a similar amp draw profile. The RLA is for sizing the circuit/protectors feeding the unit, and isn't equivalent in function to the FLA of a fan motor. Compressors are actively cooled by returning refrigerant and can run all day long at higher than RLA. A fan motor OTOH, will generally trip out on thermal overload if it runs very long at higher than FLA.

    BTW, looks like the high suction pressure isn't really high in this case. There's a huge difference between a cap tube system and a high efficiency TXV system.
    Attached Images Attached Images
    Last edited by hvacrmedic; 07-29-2012 at 10:55 PM.

  4. #43
    Join Date
    Jan 2012
    Location
    WEST COLUMBIA S.C.
    Posts
    285
    With103 outside system seems to be okay.Remember design conditions are 95 od 75 id with 50% humidity

  5. #44
    Join Date
    Jul 2005
    Posts
    5,576
    Quote Originally Posted by hewitt View Post
    With103 outside system seems to be okay.Remember design conditions are 95 od 75 id with 50% humidity
    There are so many standards for different purposes it's difficult to keep them straight. The rated capacity of a condensing unit is from these conditions.

    Cooling Standard: 80F (27C) db 67F (19C) wb indoor entering air temperature and 95F (35C) db air entering outdoor unit.

    I cut and pasted that to make sure I got it right.

    Design conditions (Manual J) depend upon the location and local codes. Maybe that's what you were referring to? Yep, they don't tend to keep up when design conditions are exceeded, unless they're over-sized like mine. It stays 75 in my house even when it's 110 out. In my book it's sized just about right, and it wasn't by accident either.
    Last edited by hvacrmedic; 07-30-2012 at 12:20 AM.

  6. #45
    Join Date
    Jul 2000
    Location
    NW IL.
    Posts
    3,935
    Lennox uses the approach method in conjunction with subcooling for charging. Their approach temperatures are below 10 degrees. Check the installation instructions for Lennox AC units.
    Aircraft Mechanical Accessories Technician. The Air Force changed the job title to Air Craft Environmental Systems Technician. But I've decided I'll always be a Mech Acc.

Page 4 of 4 FirstFirst 1234

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