Acson A4MC 100ER, Manual, Page: 18 / 67

(3) Refrigerant Piping
Field Piping
To ensure satisfactory operation and performance, the following points should be noted for the field piping
arrangements of the complete refrigerant cycle.
a) Liquid loops or oil traps must be provided according to the position of the outdoor and indoor units (depend-
ing on whether the indoor unit is above or below the outdoor unit).
b) Field supplied filter dryer should be provided as close to the expansion valve(s) of the indoor unit
(evaporator) as possible.
c) Field supplied sight glass must be assembled and mounted next to filter dryer.
Maximum Piping Length and Maximum Number of Bends
When the pipe length becomes too long, both the capacity and reliability drop. As the number of bends
increases, system piping resistance to the refrigerant flow increases, thus lowering the cooling capacity,
and as the result the compressor may become defective. Always choose the shortest path and follow the
recommendation as tabulated below:
Model
Indoor
Outdoor
ACC 7/00 D/DR
AMC/AMC
7/00 D/DE
Maximum Length, m
Maximum Elevation, m 0
Maximum No. of Bends
CAUTION:
1) Our guarantee on the performance of our air-conditioners is strictly revoked if the height, length
and/or the number of bends of the refrigerant piping system installed is beyond the limit above.
2) Bendings must be carefully made so as not to crush the pipe. Use a pipe bender to bend a pipe as
far possible.
(4) Vacuuming and Charging
The pre-charged outdoor unit does not need any vacuuming or charging. However once it is connected, the
connecting pipe line and the indoor unit need to be vacuumed before releasing the R/R07C from the out-
door unit.
. Open the service port core cap.
. Connect pressure gauge to the service port.
. Connect the line to vacuum pump. Open the charging manifold valve and turn the pump on. Vacuum to -0.
MPa (-70mmHg) or lower. (Evacuation time varies by the pump but averagely in hour).
CAUTION FOR R407C
Do not top-up when servicing leak, as this will reduce the unit performance. Vacuum the unit
thoroughly and then charge the unit with fresh R407C according to the amount recommended
in the specification.