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  1. #1
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    Old carrier packaged unit tonnage?

    This is an old carrier water cooled packaged unit. Its straight cool with no reversing valve for heat. I am trying to find the tonnage? But also does anyone know if this unit is supposed to have 3@ 12 ton compressors in it? Or 3@ 15 ton compressors? So the unit data plate shows 3 with all the same specs for the compressors. All of the compressors have been replaced at one point. There are 2 @ 12 ton (06D337) compressors and 1 @ 15 ton (06D537) compressor.
    This cant be right. I looked in the carrier Carlyle compressor book. If I read it right the 12 ton compressor has an RLA 23, while the 15 ton comp has an RLA of 28. This will tell me the unit should have 3 12 ton compressors. Now the catch here is someone installed 3 @ 15 ton Sporlan txvs. 1 valve per circuit. Each circuit is separate from each other. These compressors are NOT in tandem. The txvs are flooding the compressors. Running about 1.8 degrees superheat on r-22. I closed one of the txvs all the way in/closed but the super heat stayed the exact same 1.8. Could be the valve is bad or since its oversized the valve is just over feeding extremely this is likely being its a 15 ton txv on a 12 ton comp. I am planning /thinking of putting a 12 ton txv in. I might try one first to see how it turns out.
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  2. #2
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    Quote Originally Posted by anthonyac1 View Post
    This is an old carrier water cooled packaged unit. Its straight cool with no reversing valve for heat. I am trying to find the tonnage? But also does anyone know if this unit is supposed to have 3@ 12 ton compressors in it? Or 3@ 15 ton compressors?
    Check your inbox. I don't post manuals in this "OPEN" forum.
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  3. #3
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    Thread Starter
    Thank you. Those manuals show exactly the 337 compressor with additional good information.
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  4. #4
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    Quote Originally Posted by anthonyac1 View Post
    Thank you. Those manuals show exactly the 337 compressor with additional good information.
    Instead of learning the tricks of the trade, learn the trade.

  5. #5
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    You can always count the distributor tubes and measure their lengths to check on the evaporator capacity.

    I doubt that 15 ton TXV's would flood a 12 ton circuit - except on startup. And as most valves will over feed to some extent - the originals may have been 10's. <g>. And being water cooled may have induced Carrier to be uuhhhhh . . . . 'generous' when rating the 'tonnage' of this unit. <g>

    If the distributors appear to be originals - I'd start there and work outward to the compressors. And I would do all my 'cypherin' in BTU's rather than in tons.


    PHM
    ---------



    Quote Originally Posted by anthonyac1 View Post
    This is an old carrier water cooled packaged unit. It’s straight cool with no reversing valve for heat. I am trying to find the tonnage? But also does anyone know if this unit is supposed to have 3@ 12 ton compressors in it? Or 3@ 15 ton compressors? So the unit data plate shows 3 with all the same specs for the compressors. All of the compressors have been replaced at one point. There are 2 @ 12 ton (06D337) compressors and 1 @ 15 ton (06D537) compressor.
    This can’t be right. I looked in the carrier Carlyle compressor book. If I read it right the 12 ton compressor has an RLA 23, while the 15 ton comp has an RLA of 28. This will tell me the unit should have 3 12 ton compressors. Now the catch here is someone installed 3 @ 15 ton Sporlan txv’s. 1 valve per circuit. Each circuit is separate from each other. These compressors are NOT in tandem. The txv’s are flooding the compressors. Running about 1.8 degrees superheat on r-22. I closed one of the txv’s all the way in/closed but the super heat stayed the exact same 1.8. Could be the valve is bad or since it’s oversized the valve is just over feeding extremely this is likely being it’s a 15 ton txv on a 12 ton comp. I am planning /thinking of putting a 12 ton txv in. I might try one first to see how it turns out.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  6. #6
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    Quote Originally Posted by Poodle Head Mikey View Post
    You can always count the distributor tubes and measure their lengths to check on the evaporator capacity.

    I doubt that 15 ton TXV's would flood a 12 ton circuit - except on startup. And as most valves will over feed to some extent - the originals may have been 10's. <g>. And being water cooled may have induced Carrier to be uuhhhhh . . . . 'generous' when rating the 'tonnage' of this unit. <g>

    If the distributors appear to be originals - I'd start there and work outward to the compressors. And I would do all my 'cypherin' in BTU's rather than in tons.


    PHM
    ---------
    My local distributor has an 11 ton txv in stock. With a 5/8 inlet and 7/8 outlet. The 15 ton txv was 1 1/8 outlet. So for this 11 ton valve I will need to Busch it down to 7/8. But that is straight forward. Do you think the 11 ton will be close enough or I should look for a 12 ton valve?

    Also this unit is short on air flow. I think there might be some vav boxes closed off possibly.
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  7. #7
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    The 11 ton valve will probably be OK - BUT you don't have to rely on me: check the manufacturer's literature and you can see the actual BTU flow rates all spelled out by pressure drop, sub cooling factor, and so forth.

    BTW: be sure to check for closed fire dampers! <g>

    And again: I would start by verifying the evaporator capacity by working out the distributor tube capacities First. Diameter and length times the number of holes in the distributor = evaporator capacity. Then out to specifying the correct TXV. And then out to a compressor which pumps that number of BTU's for the refrigerant and operating conditions. I would probably take the TXV out there with me - along with the capacity charts for it - Justin Case it was correct. But I would want more verification than me guessing that the valve would probably be OK - Before starting into the unit rebuild.

    The hacks have already had their way with it - let's get back to technical prowess. <g>

    PHM
    -------


    Quote Originally Posted by anthonyac1 View Post
    My local distributor has an 11 ton txv in stock. With a 5/8” inlet and 7/8” outlet. The 15 ton txv was 1 1/8” outlet. So for this 11 ton valve I will need to Busch it down to 7/8”. But that is straight forward. Do you think the 11 ton will be close enough or I should look for a 12 ton valve?

    Also this unit is short on air flow. I think there might be some vav boxes closed off possibly.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  8. #8
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    running a slightly smaller txv was once common. Yeah at 100% load you could starve some, but the units never really run at 100% unless totally sized wrong. it allows better throttling.
    Make sure the pins in the txv are not stuck. Make sure the cap tube off the power head bulb is at the highest spot ( very important)

    Id bet that unit is rated at 54 tons. water cooled units dont need as large of a compressor to get the same rated capacity due to the lower cop.

    Someone could have put 12 tons due to availability or to reduce capacity to bandaide a poor heat transfer in a clogged evaporator.

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