Hitachi UTOPIA RAS-4HVRP2E - Page 154

7 Commissioning
Refrigerant cycle checklist
SMGB0136 rev.0 - 07/2021
152
b. Datasamples(cooling/heating,indoortemperature21–30°C)
No. Check item Result
1 Check the operating data after it has been operating for 20 minutes.
2 Check Pd and Td. Is Td-SH between 15 and 55 ºC?
3 Is Ps between 0.15 and 1.3 MPa?
4 Is Pd between 1.0 and 3.6 MPa? (If the outdoor temperature is high, Pd becomes high).
? NOTE
Underlined indicates a checking item.
3 Check item after the data sample
a. Cooling operation (this applies when the outside temperature is above 15 °C).
No. Check item Standard Causes Result
1
IsthefancurrentlyoperatingwhenFo(airow
rate of outdoor unit fan) is not "0"?
—
• Fan motor failure
• PCB1 failure
• Condenser failure
2
Is TL (indoor unit heat exchanger liquid pipe
temperature) lower than Ti (Indoor unit air inlet
temperature)?
It is normal when TL-Ti
< -5 °C.
• TL thermistor failure
• Indoor unit expansion valve
fully closed
• Short-circuit
3
Is TG (indoor unit heat exchanger gas pipe
temperature) lower than Ti (indoor unit inlet air
temperature)?
(This is applicable when the inlet air
temperature is 3 °C higher than setting
temperature).
It is normal whenTG-Ti
< -5 °C.
• TL thermistor failure
• Indoor unit expansion valve
fully closed or partially open
• Short-circuit
4
Is there any excessive difference between
indoor unit at SH (TG - TL) of indoor unit heat
exchangers?
(This is applicable when the inlet air
temperature is 3 °C higher than setting).
It is normal if the
difference between
units is within 7 °C.
• TL/TGthermistorfailure
• Indoor unit expansion valve
fully open, partially open or
completely closed
5
Is there any indoor unit with a heat exchanger
value of SH (TG - TL) excessively different
from the value of other units and is iE (opening
of the indoor unit expansion valve) less than
"5"?
It is normal if SH is
within 3 °C lower than
other units.
• Indoor unit expansion valve
locked when fully open
• Mismatched wiring and piping
6
Is there any indoor unit with a heat exchanger
value of SH (TG - TL) excessively different
from the value of other units and is iE (opening
of the indoor unit expansion valve) less than
"100"?
It is normal if SH is
within 3 °C higher than
other units.
• Indoor unit expansion valve
locked when partially open or
closed
• Mismatched cabling and
piping
7
Is the temperature difference between indoor
units* more than 7 °C?
* The difference in temperature between
indoor units means the following:
b3 (discharge air temperature) - b2 (air inlet
temperature) indicated on the remote control
by the check mode.
7 ºC and over —