5. Recharge of Refrigerant

When recharge of the refrigerant is required, charge the new refrigerant with the specified amount in the procedure as described below.

Recover the refrigerant and check there is no refrigerant in the equipment.

Connect the charge hose to the packed valve service ports at gas side, liquid side, and balance side of the outdoor unit.

Connect the charge hose to vacuum pump adaptor.

Open the packed valves of the balance pipe fully at liquid and gas sides, and then return the valve at gas side a little to the closed side.

Open fully PMV of the outdoor unit.

Turn on power of the outdoor unit.

Short CN30 on I/F P.C. board of the outdoor unit.

Turn off power of the outdoor unit within 2 minutes after shorting CN30.

Open fully the handle on the Low side of the gauge manifold, and then turn on the power of vacuum pump for vacuuming.

When the pressure has lowered until indication of the compound gauge pointed –0.1MPa (–76cmHg), open fully the handle Low and turn off the power of vacuum pump.

QNever charge the refrigerant over the specified amount. R Do not charge the additional refrigerant.

If charging refrigerant additionally when refrigerant gas leaks, the refrigerant composition in the refrigerating cycle changes resulted in change of air conditioner characteris- tics or refrigerant over the specified standard amount is charged and an abnormal high pressure is applied to the inside of the refrigerating cycle resulted in cause of breakage or injury.

Leave it as it is for 1 to 2 minutes and check the indicator of the compound gauge does not return.

Set the refrigerant cylinder on the electronic balance, connect the charge hose to connecting ports of the cylinder and the electronic gauge, and then charge the liquid refrigerant from the service port at liquid side. (Shield with the gauge manifold so that refrigerant does not flow to gas side.)

(Charge the refrigerant as below.)

 

 

 

Low-

High-

 

 

pressure gauge

pressure gauge

Connected to

Valve fully closed

 

 

indoor unit

VL

VH Gauge

(gas side)

Main

 

manifold

 

Center unit

 

 

 

 

pipe

 

 

 

 

 

 

 

Brazed

 

Service

 

Reducing

 

 

 

 

 

port

Ø6.4

valve

Fully

 

Copper pipe

 

tightened

 

 

 

 

 

Service port

 

 

 

Valve fully closed

 

 

Fully

 

(liquid side)

 

Nitrogen

tightened

 

 

 

 

gas

 

 

 

 

 

 

 

Ø6.4

 

 

 

Copper pipe

 

 

Valve fully closed

 

 

 

 

(balance)

 

 

Connected to other

 

 

 

terminal units

 

 

 

 

4mm-hexagonal wrench is required.

QSet the equipment so that liquid refrigerant can be charged.

RWhen using a cylinder with siphon pipe, liquid can be charged without inverting the cylinder.

[ Cylinder with siphon ]

[ Cylinder without siphon ]

 

Gauge manifold

Gauge manifold

Siphon

OUTDOOR unit

OUTDOOR unit

 

Refrigerant

cylinder

cylinder Refrigerant

Electronic

Electronic

balance

balance

6. Environmental concern

R410A refrigerant is consisted with HFC mixed refrigerant. Therefore if the refrigerant gas is charged, the composition of the charged refrigerant changes and characteristics of the equipment changes.

Use “Vacuum pump method” for an air purge (Discharge of air in the connecting pipe) in installation time.

Do not discharge flon gas into the air to protect the earth environment.

Using the vacuum pump method, clear the remaining air (Nitrogen, etc.) in the unit. If the air remains, the pressure in the refrigerating cycle becomes abnormally high and an injury could occur through failure of the product.

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Toshiba MMU-AP0091H service manual Recharge of Refrigerant, Environmental concern, 4mm-hexagonal wrench is required