McQuay MCM 020 D, Manual

Page: 74 / 94

(6) Additional Charge
•
The refrigerant gas has already charged into the outdoor unit. For the piping length of 5m. Additional
refrigerant charge after vacuuming is not necessary.
•
When the piping length is more than 5m, please use the table below (unit in gram).
MODEL 7m 10m 15m 20m 35m
020D/ 020DR 30/50 75/125 150/250 225/375 -
025D/ 025DR 76/100 190/250 380/500 570/750 -
030D/ 030DR 100 250 500 750 1500
040D/ 040DR 100 250 500 750 1500
050D/ 050DR 100 250 500 750 1500
061C/CR 220 550 1100 1650 3300
Diagram shows typical charging method.
CAUTION FOR R407C
Avoid prolong exposure of an opened compressor, or the internal part of refrigerant piping to moist air.
The POE oil in the compressor and piping can absorb moisture
from air.
(7) Overall Checking
•
•
•
•
Ensure the following, in particular :
1) The unit is mounted solidly and rigid in position.
2) Piping and connections are leak proof after charging.
3) Proper wiring has been done.
Drainage check - pour some water into drain pan.
Test
run
1) Conduct a test run after water drainage test and gas leakage test.
2) Watch out for the following :
a) Is the electric plug firmly inserted into the socket?
b) Is there any abnormal sound from unit?
c) Is there any abnormal vibration with regard to unit itself or piping?
d) Is there smooth drainage of water?
Check that :
1) Outdoor fan is running, with warm air blowing off the outdoor unit (cooling cycle).
2) Indoor blower is running and discharge cool air (cooling cycle).
3) Suction (low side) pressure is as per recommendations.
4) The remote controller has incorporated a 3 minutes delay in the circuit. Thus, it requires about 3
minutes before the outdoor unit can start up.
Page 73