Mitsubishi Electric PUHY-HP144TSHMU-A Service Handbook page 94

[ VII Control ]
(3) Bypass solenoid valve (SV6) (ON = Open)
Operation
During cooling operation
During heating operation (outdoor tempera-
ture (TH7) is 5°C[41°F] and above)
During heating operation (outdoor tempera-
ture (TH7) is 3°C[37°F] or below)
If outdoor temperature (TH7) during heating operation is between 3°C[37°F] and 5°C[41°F] , ON or OFF.
(4) Bypass solenoid valve (SV9) (ON = Open)
Operation
After resuming operation after the comple-
tion of the defrost cycle
At NO1 compressor startup (outdoor tem-
perature: -15°C[5°F] or lower) or after re-
suming operation after the completion of the
defrost cycle(outdoor temperature:
-15°C[5°F] or lower)
When the compressor stops at cooling/heat-
ing mode
During heating operation, during compres-
sor frequency Fmin operation, and when
high pressure (63HS1 or 2) rises
HWE0716A
ON
Always ON except for the defrost cycle.
OFF when 1 minute has passed since compressor startup.
ON
ON for 5 minutes.
ON when 5 minutes or less have
passed and 63HS1 or 2 < 1.76MPa
[255 psi].
ON for only 5 minutes in 1 hour.
When 63HS1, 63HS2 exceeds
3.43 MPa [497 psi].
- 85 -
SV6
OFF
ON
SV9
OFF
OFF when 5 minutes or more have
passed or 63HS1 or 2 1.76MPa
[255 psi].
When 30 seconds have passed,
compressor frequency Fmin +10 or
more, and 2.65MPa [384 psi] or
less.
GB