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  1. #14
    Join Date
    Apr 2007
    Location
    Kaufman county, Texas
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    Quote Originally Posted by benatwhodotnet View Post
    Most of the systems I see in AZ are builder installed. I call them "contractor specials" because they have no start cap, no pressure limit switches, no delay-on-break timer, no fan run detection, and will sit there for days popping the thermal check in the compressor every minute when they can't start. It is sad but these units burn up the compressor when the outdoor fan motor run capacitor fails. If there were factory start capacitors on these I would repair them with matching parts.
    You can still get the start kit by the compressor #. I am surprised if the condenser model does not list a start kit as an 'accessory item', but I have used the compressor number.

    FWIW I always sized my own potential relays at 75% pickup voltage and used the reasonably smallest start cap it took to make it happen. [thinking less shock to the start winding maybe]
    "You boys are really making this thing harder than it has to be". Me


    I like having infraction points, it makes me feel like 'one of the guys'.

    "I am not here to rescue you, I am bringing you along for emergency rations" Quark.

    Service calls submitted after 3PM will be posted the next business day.

    I give free estimates [Wild Ass Guesses] over the phone.

    My front door is locked. For your personal protection.

  2. #15
    Join Date
    Mar 2015
    Location
    Medford, N.Y.
    Posts
    4,623
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    Way back,when! A 1hp comp AC was = to 1t of cooling= to 12,000 BTU.
    A 1 hp comp,med temp R was = to 9000btu.
    A 1 HP freezer was = to 6000btu.

    Now adays , if the box needs 36k btu,then you go hunting for a comp that gives 36k btu at the choosen/required SST. You can have SEVERAL different HP comps producing the necessary 36K btu.

  3. #16
    Join Date
    Jan 2013
    Location
    Glendale, AZ
    Posts
    33
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    1992 unit... 12 SEER York

    Quote Originally Posted by Tool-Slinger View Post
    You can still get the start kit by the compressor #. I am surprised if the condenser model does not list a start kit as an 'accessory item', but I have used the compressor number.

    FWIW I always sized my own potential relays at 75% pickup voltage and used the reasonably smallest start cap it took to make it happen. [thinking less shock to the start winding maybe]
    I install start kits regardless, but I'd like to be more scientific about it. It can be difficult to track down specs on 24 year old equipment that pre-dates internet usage by manufacturers.

    The 39,000 BTU (3.25T) York single package unit was installed in 1992 with a panel label stating 12 S.E.E.R. and 18.2 max RLA which I consider to be the same as FLA. The unit was tripping a thermal sensor in series with the control wiring on the compressor run lead (Y) from the thermostat. That series included a high pressure cut-out switch too. It was only tripping when the sun was shining on the black anodized coil in the mid afternoon with ambient air about 110F or higher and exhaust air above the fan at 125-130F. The homeowner hoped to make it through the summer to September and get a new unit installed in the off-season or pre-season when there are better deals.

    The unit is limping through a very hot week and the replacement will be done on Tuesday.
    "We are what we repeatedly do, excellence then is not an act, but a habit." -Aristotle

  4. #17
    Join Date
    Feb 2013
    Posts
    1,792
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    I was told R22 AC was 1TR to 1HP. R12 MTR was 1/2TR to 1HP. R502 LTR was 1/3TR to 1HP. Or something like that.

  5. #18
    Join Date
    Apr 2007
    Location
    Kaufman county, Texas
    Posts
    13,746
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    Quote Originally Posted by MechTech2013 View Post
    I was told R22 AC was 1TR to 1HP. R12 MTR was 1/2TR to 1HP. R502 LTR was 1/3TR to 1HP. Or something like that.
    Me too, I ran across the specs many years ago. 3 ton = 3HP. IF AC. Same compressor was rated about 80% for that at medium temp and 60% for low temp. Copeland specs, I was working on a walk-in, a long time ago in a galaxy far, far away.
    "You boys are really making this thing harder than it has to be". Me


    I like having infraction points, it makes me feel like 'one of the guys'.

    "I am not here to rescue you, I am bringing you along for emergency rations" Quark.

    Service calls submitted after 3PM will be posted the next business day.

    I give free estimates [Wild Ass Guesses] over the phone.

    My front door is locked. For your personal protection.

  6. #19
    Join Date
    Oct 2013
    Location
    Pacific Northwest
    Posts
    54
    Post Likes
    I think the rating of compressor tonnage and hp changes with application is due to 1hp=746w electrical energy not cooling energy. The compressor hp would also change with different operating conditions as it will use more/less electrical energy depending on load.

  7. #20
    Join Date
    Feb 2007
    Location
    Fremont, Indiana
    Posts
    3,273
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    Quote Originally Posted by TechmanTerry View Post
    Way back,when! A 1hp comp AC was = to 1t of cooling= to 12,000 BTU.
    A 1 hp comp,med temp R was = to 9000btu.
    A 1 HP freezer was = to 6000btu.

    Now adays , if the box needs 36k btu,then you go hunting for a comp that gives 36k btu at the choosen/required SST. You can have SEVERAL different HP comps producing the necessary 36K btu.
    I thought it was
    12 high temp
    8 med temp
    4 low temp
    I thought that was what dan wrote in his book as ROT only.
    Member of the "Work Exchange Program"
    "Will work for knowledge"

    "Everyone is a genius. But if you judge a fish on its ability to climb a tree, it will live its whole life believing that it is stupid"
    A Einstein

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  9. #21
    Join Date
    Feb 2007
    Location
    Fremont, Indiana
    Posts
    3,273
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    Quote Originally Posted by kamersoutdoor View Post
    I thought it was
    12 high temp
    8 med temp
    4 low temp
    I thought that was what dan wrote in his book as ROT only.
    Dick wirz....... not Dan
    Member of the "Work Exchange Program"
    "Will work for knowledge"

    "Everyone is a genius. But if you judge a fish on its ability to climb a tree, it will live its whole life believing that it is stupid"
    A Einstein

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