Hitachi Highly WHP05600VUK, Installation Manual

Page: 10 / 31

HEAT PUMP WATER HEATER COMPRESSOR CRITERIA FOR LONG LIFE
SYSTEM
PAGE:8/29
5 Current limitation
Current peak among motor terminals
（
include instantaneous current peak
）
should be below
21.6A(at130
℃
) in order to prevent magnet in motor from demagnetization.
6 Pressure difference between suction and discharge
In all allowable rotational speed range, the difference of pressure should be more than
0.39MPa{4kgf/cm
2
}. But if there is no problem of noise when assembled in air conditioner,
it can also below this value.
7 Discharge pipe temperature
Discharge pipe temperature is measured at a distance 300mm from the surface of compressor
and should be less than 110
℃
. The tip of the thermocouple is fixed by soldering when
measuring discharge pipe temperature .Furthermore, soldering point is covered with urethane
foam to prevent the effect of wind.
8 Air leakage test pressure
The pressure should be less than 2.847MPa{28kgf/cm
2
G}.
9.Oil Back and height of the oil level
The oil should be returned continuously to the compressor and the structure of the refrigerating
system should not make oil stay in the system. The oil level in compressor should be satisfied
with chart 2.If not keep the oil level, the shortage will occur, and influence the reliability of the compressor.(please
check the oil level in the compressor with the sight glass which supplied form SHEC.
10 Dust of compressor hermetic terminals
Compressor hermetic terminals should be mounted with specified cover in right way to prevent
dust entering, and should be used in direction which dust is hard to enter in.
11 Lead wire of compressor hermetic terminals
Measuring the temperature of hermetic terminals , lead wire should be resist to the temperature
and be clamped so as not in touch with the surface of compressor and pipe.