Hitachi RAS-(4-6)HVRNS2E - Insufficient Cooling Performance When a Long Piping Is Applied

12 Maintenace notes
464
SMGB0064 rev.0 - 08/2011
12.3 Insufcient cooling performance when a long piping is applied
Question and answer for the eld work
Example 2: Insufcient cooling performance when a long piping is applied
Phenomenon Sufcient cooling was not available for an indoor unit that was located at the farthest position.
Cause
If the location of an outdoor unit is 20 meters lower than the location of the indoor units resetting of the DIP switch DSW3
is required.
However no setting was performed. Therefore the largest discharge pressure was not increased. This resulted in an in-
sufcient cooling performance for the indoor unit.
Outdoor unit
Indoor units
Insucient cooling
Countermeasure The setting of the DSW2 was changed.
Remarks Pay special attention to the size of liquid pipe. Refer to “piping work in TC” for details.