[ VII Control ]
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HWE0803A GB
-5- Bypass Control
Bypass solenoid valves (SV1a), which bypass the high- and low- pressure sides, perform the following functions.
(1) Bypass solenoid valve (SV1a) (ON = Open)
(2) Bypass solenoid valve (SV9) (ON = Open)
(3) Bypass solenoid valve (SV2) (ON = Open)
(4) Bypass solenoid valve (SV5b) (ON = Open)
Operation
SV1a
ON OFF
When each indoor unit compressor startup ON for 4 minutes.
After the restoration of thermo or 3 minutes
after restart
ON for 4 minutes.
During cooling or heating operation with the
compressor stopped
Always ON.
Exception: OFF when 63HS1-63LS is 0.2MPa[29psi] or less
After the operation has stopped ON for 3 minutes.
Exception: OFF when 63HS1-63LS is 0.2MPa[29psi] or less
During defrost operation ON
While the compressor is operating at the
minimum frequency and when the low pres-
sure (63LS) drops (3 or more minutes after
compressor startup)
When low pressure (63LS) drops
below 0.23MPa[33psi].
When low pressure (63LS) ex-
ceeds 0.38MPa[55psi].
When high pressure (63HS1) rises When 63HS1 exceeds
3.62MPa[525psi]
When 63HS1 is or below
3.43MPa[497psi] and 30 seconds
have passed
Operation
SV9
ON OFF
When high pressure (63HS1) rises during
the heating operation
When 63HS1 exceeds 3.50MPa
[507psi]
When SV5b is ON and the pressure
is 2.70MPa[391psi]or below
Others Always OFF
Operation
SV2
ON OFF
When high pressure (63HS1) rises during
the heating operation
When SV5b is OFF and the pres-
sure is 3.50MPa[507psi]or below
When 63HS1 exceeds 2.70MPa
[391psi]
When startup or resuming operation after a
defrost cycle
OFF
During defrost cycle ON
Others Always OFF
Operation
SV5b
ON OFF
When high pressure (63HS1) rises during
the heating operation
When SV2 is OFF and the pressure
is 2.70MPa[391psi]or below
When SV9 is ON and the pressure
is 3.50MPa[507psi]or below
At startup ON
During defrost cycle ON (open)
When returning to normal operation after
completion of the defrost cycle
ON for 5 minutes and goes OFF
Others Always OFF