I am disconnecting a residential R410a system for about 3 months. I have evacuated and recovered the refrigerant. System is down to about 500 microns. Before I pinch off the lines and disconnect should I put a charge of dry nitrogen on the system? If so, what pressure?
Residential R410a Temporarily Disconnecting, Charge with Nitrogen?
erschwartz80
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I am disconnecting a residential R410a system for about 3 months. I have evacuated and recovered the refrigerant. System is down to about 500 microns. Before I pinch off the lines and disconnect should I put a charge of dry nitrogen on the system? If so, what pressure?
Personally I would never have recovered any refrigerant from a split system at all unless needed major work. Turning off the power would have done just fine. R410a is bad about moisture and contaminants and such. Nitrogen at this point might save the system.
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The refrigerant lines need to be disconnected and rerouted for a major renovation in this house. I just figured it would be better not to leave a vacuum on the condenser and evaporator if the lines I am pinching off leak a little. Does that yellow jacket pinch tool really close up the line? Do I also need to braze the end? Thanks, I'm new to working on refrigeration so I'm trying to learn best practices. The unit is a 2 ton trane, 15xi I think, from about 2010.
If you are isolating condenser and evaporator then yes you need to leave stubs and they need to be welded shut. I would leave them with a 50 to 100 psig charge of nitrogen.
You will probably have to weld a Schrader port on the evaporator.
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And save $$ in the long run. Are you qualified to do this?
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Why do I need a new line set? If the system has been evacuated and charged with dry nitrogen, what has been done to compromise the lines? When I commission the system I will just cut the pinched/brazed ends, then braze a short splice in the liquid and suction lines, right?
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Pumping down would've been fine.
Otherwise, anything that you are going to re-use should never see the air you breathe. Everything needs to be sealed with nitrogen inside. And all you need is a few psig above zero.
Otherwise, anything that you are going to re-use should never see the air you breathe. Everything needs to be sealed with nitrogen inside. And all you need is a few psig above zero.
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Post #4 you stated "Rerouted" have you ever tried to remove an insulated line set, unbend and reinstall? Run new!
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I would have ran new lineset, but I've pumped a system down, pressurized a sealed lineset, pressurized a sealed coil, that was leaking by the time I went to reuse.
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See reply # 12 and also the less brazed joints the better. Would you re-use a condom??
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There's nothing wrong with what you did, or plan to do...
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New drier will remove the moisture from the oil after a sub 500 micron evac.
That why I like PVE oil.
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I have a Danfoss scroll in my Goodman Hp. I installed it. The new Goodman GPD1448 started life as 4 tons. I didn't need 4 tons so I changed the compressor to a pve oil filled Danfoss 2 ton scroll and installed txvs on both coils. Works great. Slowed the ecm motor down to proper flow.
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