York R-410A, Technical & Service Manual, Page: 261 / 385

Installation
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1) Install pressure modulation valve at the nitrogen cylinder. And the gas used must be
nitrogen. Carbon Dioxide will probably condense. And Oxygen will probably cause explosion.
2) Use charge pipe to connect pressure modulation valve and outdoor liquid pipe.
3) Jam well all the connection part in liquid side except indoor unit A.
4) Open the valve of nitrogen cylinder to 5kgf/cm2.
5) Check if there is nitrogen in liquid pipe of indoor unit A.
6) Flushing
♦
Use the insulating material in hand to resist the nozzle of gas main pipe of the indoor
unit.
♦
When the pressure can’t be resisted, release the insulating material quickly (flushing for
the first time), then use the insulating material to resist the nozzle again (flushing for the second
time).
♦
The dunghill can be checked by putting a piece of cloth in the nozzle loosely. Occasionally,
some dampness can be found, please dry the pipe thoroughly. Do as follows:
♦
Scouring the inner part of the pipes with nitrogen until no dampness.