Carrier 42NQ012N Service Manual page 39

8-5-3. Evacuating
After the piping has been connected to the indoor
unit, perform the air purge.
AIR PURGE
Evacuate the air in the connecting pipes and in
the indoor unit using a vacuum pump.
Do not use the refrigerant in the outdoor unit.
For details, see the vacuum pump manual.
<Use a vacuum pump>
Be sure to use a vacuum pump with counter-flow
prevention function so that oil inside the pump does
not flow back into the air conditioner pipes when the
pump stops. (If oil inside the vacuum pump enters
into the air conditioner circuit which uses R410A,
trouble with the refrigeration system may develop.)
1. Connect the charge hose from the manifold valve
to the service port of the gas side packed valve.
2. Connect the charge hose to the port of the
vacuum pump.
3. Open fully the low pressure side handle of the
gauge manifold valve.
4. Operate the vacuum pump to begin evacuating.
Perform evacuating for about 15 minutes if the
piping length is 20 meters (15 minutes for 20
meters) (assuming a pump capacity of 27 liters
per minute).
Confirm that the compound pressure gauge
reading is –101 kPa (76 cmHg).
5. Close the low pressure valve handle of gauge
manifold.
6. Open fully the valve stem of the packed valves
(both sides of Gas and Liquid).
7. Remove the charging hose from the service port.
8. Securely tighten the caps on the packed valves.
Compound pressure gauge
-101kPa (76cmHg)
Handle Lo
Charge hose (For R410A only)
Connecting pipe
Packed valve at gas side
Service port (Valve core (Setting pin))
Packed valve at liquid side
Fig. 8-5-8
Pressure gauge
Manifold valve
Handle Hi
(Keep full closed)
Charge hose
(For R410A only)
Vacuum pump adapter for
counter-fl ow prevention
(For R410A only)
Vacuum
pump
CAUTION
•
KEEP IMPORTANT 5 POINTS FOR PIPING WORK
1. Take away dust and moisture (inside of the
connecting pipes).
2. Tighten the connections (between pipes
and unit).
3. Evacuate the air in the connecting pipes
using a VACUUM PUMP .
4. Check gas leaks (connected points).
5. Be sure to fully open the packed valves before
before operation.
<Packed Valve handling precautions>
• Open the valve stem all the way; but do not try to
open it beyond the stopper.
• Securely tighten the valve stem cap with torque in
the following table:
Gas side (Ø12.7 mm)
Gas side (Ø9.52 mm)
Liquid side (Ø6.35 mm)
Service port
8-5-4. Wiring Connection
1. Remove the valve cover from the outdoor unit.
2. Connect the connecting cable to the terminal as
identified with their respective matched numbers
on the terminal block of indoor and outdoor unit.
3. When connecting the connecting cable to the
outdoor unit terminals,make a loop as shown in
the installation diagram of indoor and outdoor
unit to prevent water coming in the outdoor unit.
4. Insulate the unused cords (conductors) from any
water coming in the outdoor unit. Proceed them
so that they do not touch any electrical or
metal parts.
– –
38
FILE NO. SVM-10031
CAUTION
50 to 62 N•m (5.0 to 6.2 kgf•m)
30 to 42 N•m (3.0 to 4.2 kgf•m)
16 to 18 N•m (1.6 to 1.8 kgf•m)
9 to 10 N•m (0.9 to 1.0 kgf•m)
Hexagonal wrench is required.
Fig. 8-5-9