Heat Controller DMH24DB-1 - Manual (Page 32)

32 Multi type Air Conditioner
Checking the Drainage, Forming the Pipings and Long Pipe Setting
1. Connect the charge hose end described in the preceding
steps to the vacuum pump to evacuate the tubing and
indoor unit.
Confirm the "Lo" knob of the manifold valve is open. Then,
run the vacuum pump.
The operation time for evacuation varies with tubing length
and capacity of the pump. The following table shows the
time required for evacuation.
2. When the desired vacuum is reached, close the "Lo" knob
of the manifold valve and stop the vacuum pump.
Finishing the job
1. With a service valve wrench, turn the valve stem of liquid
side valve counter-clockwise to fully open the valve.
2. Turn the valve stem of gas side valve counter-clockwise to
fully open the valve.
3. Loosen the charge hose connected to the gas side service
port slightly to release the pressure, then remove the hose.
4. Replace the flare nut and its bonnet on the gas side ser-
vice port and fasten the flare nut securely with an
adjustable wrench. This process is very important to pre-
vent leakage from the system.
5. Replace the valve caps at both gas and liquid side service
valves and fasten them tight.
This completes air purging with a vacuum pump.
The air conditioner is now ready for test running.
: Repeat evacuation procedure for each indoor
unit.
NOTICE
Required time for evacuation when 4 CFM vacuum
pump is used
10 min. or more 15 min. or more
If tubing length is less
than 10m (33 ft)
If tubing length is longer
than 10m (33 ft)
Indoor unit
Outdoor unit
Lo Hi
Manifold valve
Vacuum pump
Pressure
gauge
Open Close
Evacuation