Outline of Control (Outdoor Unit) < Symbols using in this manual > Si33-105
94 Function R407C PLUS Series Heat Recovery System
3.6.4 Heating Pump-Down Residual Operation (Heating & Simultaneous
Cooling / Heating Operation)
Conduct an operation during stop mode to discharge refrigerant from the low pressure side,
since liquid refrigerant remaining in the accumulator can be sucked into the compressor during
startup and dilutes the refrigerating machine oil in the compressor and lowers the lubricating
performance.
"
1
Pump down residual operation starting condition
Compressor ON
→
OFF
"
2
Pump down residual operation ending condition
Compressor OFF
Conducts residual operation by
the condition
H
1
PI control
INV
SVP
Outdoor EV
Indoor EV
(Thermostat
ON unit)
Outdoor fan
Indoor fan
SVRVG
PI control
SC control
0←→200
Normal control
Normal control
Controls SH
with
H
3
All indoor units in
heating EV 500pls
H+ON+(ON+ON)
/ON+ON
Thermostat OFF unit
Stopping unit
Accumulator
discharge operation
Restart standby
(5 minutes)
H
4
60 seconds
Stop
0pls
LL
OFF
In case of condition
H
1 is not met
67Hz+OFF
Residual operation ending
condition
H
2
(V2595)
&
OR
Compressor ON → OFF
DSHi<20˚C
Th7-Te<10
(V2597)
OR
DSHi>90
Th7-Te>10
LP<0.07MPa
Tc>48.6˚C
Retry·fault
10 minutes
(V2598)