Hitachi RAM-10MQ Installation & Maintenance Manual Download Page 20

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(

註

無論是大室、中室、小室、極小室對於洩漏冷媒量皆以 2

0kg

來計算。

≦

Maximum permissible concentration (kg / m

)

R410A(

(0.3k /

)

1) Fully open the gas line stop valve.
2) After cooling operation starts, connect the gauge manifold

using charging hoses with a refrigerant charging cylinder
to the check joints of the liquid line stop valve to charge
refrigerant. (Refrigerant charging quantity error tolerance:
±0.5kg around.) In the meantime, the liquid line stop valve

is slightly open.
3) Fully open the liquid line stop valve after completing

refrigerant charge.

4) Please be sure to perform the air-tight test.

5) The check joints on the accumulator is used to fill

refrigeration oil, do not use for other purposes.

(10) Caution of The Refrigerant Leakage

When an air conditioner is installed in a room, in case of refrigerant leakage, refrigerant concentration must not exceed the
maximum permissible concentration.

●

The products use non-flammable, non-toxic safe refrigerant R410A. If leakage occurs and gas fills a room, it may cause
suffocation. Especially for multiple indoor units and outdoor units with long-distance piping connection, the amount of
refrigerant is more than individual air-conditioner. So make sure the indoor unit installed in the room,

even in case of

refrigerant leakage, the refrigerant concentration should never exceed the maximum permissible concentration.

●

Please calculate the refrigerant concentration by the following formula

：

The total amount of charged refrigerant (kg)

Room space for each indoor unit (m

)

●

If a room’s refrigerant concentration is more than the maximum permissible concentration and the air conditioner still need
to be installed, please choose a treatment method according to the following

：

1.Set refrigerant leakage detector alarm and link it to mechanical ventilation devices. (See below) (Cooling capacity per ton

should be more than 0.4 m

/min ventilation capacity. Cooling capacity is shown in following table according to the outdoor

unit capacity.)

2.Set the effective ventilation outlet between adjacent rooms (The outlet area need to be more than 0.15% floor area on the

upper and lower of the door), so that the leakage of refrigerant concentration can drop less than the maximum permissible
concentration.

●

New refrigerant R410A product notes

Since R410A is a non-azeotropic refrigerant, when leakage occurs, the proportion of
mixture will change. Do not charge new refrigerant directly; the whole system must
be re-processed.

Outdoor

Unit

Cooling

Capacity

R410A

冷媒配管作業要領圖

Outdoor Unit

Gas Piping

Liquid Piping

Branch Pipe

Refrigerant

Piping Work Diagram

Indoor Unit

Pipe connection part
union and flare nut, be
sure to do insulation
process.

Nitrogen Bottle (Use
for Brazing and
Air-Tight Test)

(Note

：

1) Whether it is a large room, medium room, small room or tiny small room,

the amount of refrigerant leakage is all 30kg.

(Note

：

2) The concentration must not exceed the maximum permissible concentration

0.3kg / m

The total amount of refrigerant within the system: 30kg

Example

Indoor

Outdoor

Large Room

Medium Room

Small Room

Ventilation
Outlet

Refrigerant Pipe

mechanical ventilation devices

＋

refrigerant

leakage detector alarms devices

Excess or insufficient additional refrigerant will result in
compressor failure or other abnormal conditions, be sure
to charge refrigerant according to the calculated values.

Liquid piping must be insulated. (To prevent poor
performance and low pressure pipe surfaces condensation.)

Be sure to check the refrigerant leakage. If a large amount of
refrigerant leaks, it will cause the following phenomena

：

1. Lack of oxygen.
2. Harmful gases would occur if a fire was being used in the

room.

Liquid Line Stop Valve

Gas Line Stop Valve

Manifold Gauge

Vacuum Pump

Refrigerant
Cylinder (R410A)

Weight Scale

Thermal Insulation
Material Wrapping

Outdoor Unit