Hitachi RAS-FSNM Serie Manual De Instrucciones página 25

REFRIGERANT PIPING & REFRIGERANT CHARGE
8.4 REFRIGERANT CHARGE
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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.
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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-
RAS-8FSNM
RAS-10FSNM
RAS-12FSNM
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.
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
Check Joint for Gas
Low Pressure
Stop Valve "A"
Check Joint for Piping
High Pressure
"B"
Check Joint for Liquid
Valve "C"
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N O T E
Be careful that refrigerant and oil do not splash to the electrical parts at
removing the charge hoses.
15 PMML0390B REV.0 - 11/2015 - P5416649
W0 Outdoor Unit
Refriferant Charge (kg)
5.0
5.5
6.5
Heating Operation
High Pressure
Low Pressure
Exclusive for Vacuum Pump and
Refrigerant Charge
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 = +
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N O T E
The additional refrigerant charge amount on site (for refrigerant piping +
indoor unit) should not exceed the maximum additional charge amount.
When the cap is removed, obscure
gas trapped at O-ring thread face is
= kg
sound may be heard because the
released.
However, this is not gas leakage.