Toshiba MMU-AP0091H service manual Recharge of Refrigerant, Environmental concern

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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