Hitachi RAS-(2-6)HVNP1(E), Руководство по обслуживанию

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12 Maintenance notes
474
SMGB0087 rev.0 - 12/2013
12.1.5 Alarm code “03”
Question and answer for the field work
Example 4: Alarm code “03”
Phenomenon Alarm code “31” sometimes occurred and the system stopped.
Cause
The combination of the indoor units and the outdoor unit was the following.
ON
OFF ON ON ON ON
Power
Source
Power
source
This system was used in a tenant building. One of tenant’s customers turned off the main switch for the indoor
unit while other indoor units are running. This results in a different setting of the total indoor unit capacity in the
same refrigerant cycle.
Countermeasure All the main switches for the indoor units were always ON.
12.1.6 Not cooling well due to insufficient installation space for the outdoor unit
Question and answer for the field work
Example 5: Not cooling well due to insufficient installation space for outdoor unit
Phenomenon
Cooling operation was well performed through the intermediate season. However the cooling operation was
not well available when the outdoor temperature was higher than 35 °C.
Cause
As the outdoor units were installed without a sufficient installation space the hot discharge air from other out-
door units was circulated.
In this case though the outdoor temperature was 35 °C the actual suction air temperature was nearly 50 °C
and protection system from excessively high suction pressure was activated the frequency of the compressor
was decreased and the cooling capacity was also decreased accordingly.
As the outdoor units in-line were installed back to back with a distance of 600 mm (depending on model)
between each outdoor unit’s back the hot discharged air from other outdoor units was circulated.
Countermeasure Ensure that sufficient space should be secured for multi-row and multiple-installation.
Example
Keep a distance between other units and do not put obstacles on the right and left sides.
For detailed information please refer to “2. Unit Installation” chapter.