Hitachi Highly WHP05600VUK, Installation Manual

Page: 16 / 31

HEAT PUMP WATER HEATER COMPRESSOR CRITERIA FOR LONG LIFE
SYSTEM
PAGE:15/29
25.3 Eliminate all system contaminants such as trichlorethylene, alkalies,
soap, acid, oil & washing fluid used at machining the heat exchanger tubes.
25.4 Purge parts with dry nitrogen or dry air to remove remains in parts
(dust, detergent
，
etc.) before assembly of system.. Time for purging :over one
second for pipe ;over three seconds for heat exchanger . Purging pressure:
0.9±0.1MpaG.Dew point of dry air: Below -20°C
。
Dry nitrogen should be charged in compressor before assembly of system.
Welding should be finished within one minute after charge of ni
trogen. Dry nitrogen needs to be
charged again and weld if over one minute. Always purge the compressor with dry nitrogen during
assembly of system .
25.5 The motor winding temperatures should be less than 149
℃
in process of
manufacturing the refrigerating system. The temperature of the hermetic
terminal body should be less than 177
℃
.
25.6 The compressor should be operated for more than 20 seconds within 15
minutes after charging refrigerant into the system so proper lubrication results.