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VRV in General
Si30-408
114
Cases for Examination
1.8
Malfunction Cooling Operation
Applicable
Models
VRV in general (Type K or later models)
Condition
Different systems are used to air-condition the 1st floor and the 2nd floor.
Compared with the 1st floor, 2nd floor is not cooled down well. (Though the system for the 2nd
floor operates normally, timing when its thermostat turns OFF is early compared with the one for
the 1st floor.)
Cause
Since the remote controller's thermostat has been set to disabled after the setting of remote
controller for the 2nd-floor system was changed during past inspection, ON/OFF switching is
made according to the body-thermostat.
(It is set to "enabled" at the factory. Change of setting may have been made in the past
inspection.)
Measure
Change the setting of remote controller's thermostat to enabled.
Point of
Diagnosis
1.9
Malfunction Heating Operation
Applicable
Models
VRV in general (Type K or later models)
Condition
If all thermostats are turned ON in heating operation, heating operation by the indoor units on
the lowest floor (2nd floor) is not good.
Cause
Due to less pressure loss of pipes, refrigerant tends to circulate in the upper floors and not to
flow to lower floors.
Measure
Make subcool adjustments for upper and lower floors, respectively. (Adjust to closing direction
for upper floors and opening direction for lower floors.)
Request to adjust the thermostat setting for the upper floors to the rising direction.
*
If needed, set to 0 PLS when the operation is stopped in the upper floors.
Point of
Diagnosis
Using long pipes may cause a slight drop of capability due to pressure loss even if the piping
length does not exceed the standard.
5m
5m
5m
OK
OK
Malfunction heating
4F
3F
2F
small
large
Subcool adjustment