ENGLISH
8.4 REFRIGERANT CHARGE
Additional charge of refrigerant
Although refrigerant has been charged into this unit, additional refrigerant charge is required according to piping length.
Determine the additional refrigerant quantity according to the following procedure, and charge it into the system.
Record the additional refrigerant quantity to facilitate maintenance and servicing activities thereafter.
Calculating Method of Additional Refrigerant Charge (W kg)
1
Additional refrigerant charge calculation for liquid piping
(W1 kg)
See example for model RAS-12FSNM, and fill in the
following table.
Outdoor unit-
W0 Outdoor Unit
Refriferant Charge (kg)
RAS-8FSNM
5.0
RAS-10FSNM
5.5
RAS-12FSNM
6.5
Note: W0 is outdoor unit ref. charge before shipment
2
Additional Refrigerant Charge Calculation for Indoor Unit
(W2 kg)
Additional refrigerant charge is 1kg/unit of 8HP and 10HP
indoor unit.
Additional refrigerant charge of less than 8HP indoor units is
not needed.
3
Calculation of additional charge (W kg)
Put weight W1 and W2 calculated in items 1 and 2 into the
beside formula.
Record of additional charge
Total refrigerant charge of this system is calculated in the
following formula.
Total refrigerant charge = W + W0
This system =
+
=
kg
?
N O T E
The additional refrigerant charge amount on site (for refrigerant
indoor unit) should not exceed the maximum additional charge amount.
8.5 CAUTION OF THE PRESSURE BY CHECK JOINT
When the pressure is measured, use the check joint of gas stop
valve ((A) in the figure below) and use the check joint of liquid
piping ((B) in the figure below).
At that time, connect the pressure gauge according to the
following table because of high pressure side and low pressure
side changes by operation mode.
Cooling Operation
Heating Operation
Check Joint for Gas
Stop Valve “A”
Low Pressure
High Pressure
Check Joint for Piping
“B”
High Pressure
Low Pressure
Check Joint for Liquid
Valve “C”
Exclusive for Vacuum Pump and
Refrigerant Charge
?
N O T E
Be careful that refrigerant and oil do not splash to the electrical parts at
removing the charge hoses.
When the cap is removed, obscure
sound may be heard because the
gas trapped at O-ring thread face is
released.
However, this is not gas leakage.
REFRIGERANT PIPING & REFRIGERANT CHARGE
PMML0390B REV.0 - 11/2015 - P5416649
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