Pump Down And Refrigerant Cycle - Carrier 42PQV...S Installation Manual

42PQV...S/38VBH...S

Pump Down and refrigerant cycle

Pump-down
Pump-down is an operation intended to collect all the
system refrigerant in the outdoor unit.
This operation must be carried out before disconnecting
the refrigerant tubing in order to avoid refrigerant loss to
the atmosphere, if it becomes necessary to disconnect the
refrigerant connections for unit repair, removal or disposal
in this case, after removal, unit must be delivered to an
appropriate disposal centre or the original dealer.
Legend:
Outdoor coil
Compressor
Check valve
Strainer
Vapor valve
Liquid valve
Service pressure port
GB - 18
Refrigerant Cycle
Heat pump unit
15
11
17
1
14
2
16
12 3
4 13 4
Cooling cycle
15
11
17
1
14
2
16
12 3
4 13
Heating cycle
Indoor until coil
Liquid distributor
Cooling + Heating expansion device
Heating expansion device
Additional suction acumulator
Reversing valve
Filter drier
Discharge muffler
Shut off the liquid valve with the Allen wrench.
Turn the system on in cooling with fan operating at high velocity.
(Compressor will immediately start, provided 3 minutes have
elapsed since the last stop).
After 2 minutes of operation, shut the suction valve with the
same wrench.
Turn the system off and switch mains supply off.
Disconnect tubing.
After disconnection, protect valves and tubing ends from dust.
7
5
a
6
7
5
4 6
10
10
Gas
Liquid + Gas
Liquid