Trane 2007 heat pump RTU piping understanding wanted

[mccann]

I'm trying to understand the refrigeration flow of a 2007, Trane heat pump RTU, model WSC060A3R..
It has a one direction drier, so the drier is only operative in heat. The check valve branches off the distributor and looks like it goes back into the condenser. What is the logic of this? I would like to find a diagram of the flow.
I recently had a unit with a failed compressor and check valve. I have heard it is good to replace the check valve with the compressor, I think I will do that from now on, so I don't have to recover twice. Alas.

[rundawg]

I'm trying to understand the refrigeration flow of a 2007, Trane heat pump RTU, model WSC060A3R..
It has a one direction drier, so the drier is only operative in heat. The check valve branches off the distributor and looks like it goes back into the condenser. What is the logic of this? I would like to find a diagram of the flow.
I recently had a unit with a failed compressor and check valve. I have heard it is good to replace the check valve with the compressor, I think I will do that from now on, so I don't have to recover twice. Alas.

Check your email.

[mccann]

Interesting. That the check valve takes the liquid into the condenser for one more loop. Do they do that to subcool it, or just to confuse me? So it looks like in cooling, the check valve screen is the filter. The drier is just for in heating. hmmm.

[BALloyd]

Not sure about your particular unit but lots of different condensers have sub cooling loops on them.

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[rundawg]

Do they do that to subcool it, or just to confuse me?

The answer to that question is above my pay grade - sorry.

[BALloyd]

Do they do that to subcool it, or just to confuse me?

The answer to that question is above my pay grade - sorry.

Little bit of this, little bit of that maybe?

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[CHAINIK]

Interesting. That the check valve takes the liquid into the condenser for one more loop. Do they do that to subcool it, or just to confuse me? So it looks like in cooling, the check valve screen is the filter. The drier is just for in heating. hmmm.

Its been a while since I worked on one of these, but as I recall...the extra loop used for subcooling also gives the extra refrigerant that's not needed in heating mode somewhere to go, like a charge compensator. Its subcooled in cooling mode, and isolated from the circuit in heating mode. I think that's what I remember, anyway.

I used to work on these fairly often when I did national accounts, and I was thrown by the layout for a few times at first. One stumped me for a long time trying to find the cause of low suction pressure. Of course the drier dutifully had been changed. I knew there was a check valve there, but I didn't know it had a strainer in there, too. Couple of days of frustration until I figured that one out, screen was almost completely blocked. Later I realized you could reach up in there behind the electrical panel and feel that check valve, and if there was a problem, it'd be cold right there.