Refrigerant Lines; System Evacuation And Charging - Carrier 40MPHA Service Manual

REFRIGERANT LINES

IMPORTANT: Both refrigerant lines must be insulated separately.
Table 2 on page 3 lists the pipe sizes for the indoor unit. Refer to the outdoor unit installation instructions for other allowed piping lengths and
refrigerant information.
SYSTEM EVACUATION AND
CHARGING
CAUTION
UNIT DAMAGE HAZARD
Failure to follow this caution may result in equipment damage
or improper operation.
Never use the system compressor as a vacuum pump.
Refrigerant tubes and indoor coil should be evacuated using the
recommended deep vacuum method of 500 microns. The alternate
triple evacuation method may be used if the following procedure is
followed. Always break a vacuum with dry nitrogen.
System Vacuum and Charge
Using Vacuum Pump
1. Completely tighten flare nuts on the line set at both the indoor and
outdoor units. DO NOT open the service valves on the outdoor unit
for the new installation or the replacement unit. Open the service
valves on the outdoor unit if repairs have been made to the
refrigerant sealed system. Connect the manifold gauge low pressure
hose to the charge port of the gas side service valve (see Fig. 8).
2. Connect the charge hose to the vacuum pump.
3. Fully open the low pressure valve of manifold gage (see Fig. 9).
4. Start the vacuum pump.
5. Evacuate using deep vacuum or triple evacuation method.
6. After evacuation is complete, fully close the pressure valve side of
manifold gage and stop the vacuum pump operation.
7. The factory charge contained in the outdoor unit is good for up to
25ft. (8 m) of line length. If vacuum is complete per Fig. 10 or 11,
open service valves to release factory charge into the system.
8. Disconnect the charge hose from the charge connection of the gas
side service valve.
9. Securely tighten the service valve caps.
Outdoor Unit
A
B
Service Valve
Fig. 8 — Service Valve
Manifold Gage
500 microns
Low pressure valve
Low pressure hose
Gas side valve
Fig. 9 — Manifold
12
Indoor Unit
Refrigerant
Gas Side C
D
Liquid Side
High side valve
Charge hose
Vacuum pump
Specifications subject to change without notice.
Deep Vacuum Method
The deep vacuum method requires a vacuum pump capable of pulling
a vacuum of 500 microns and a vacuum gage capable of accurately
measuring this vacuum depth. The deep vacuum method is the most
positive way of assuring a system is free of air and liquid water (see
Fig. 10).
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0 1 2
Fig. 10 — Deep Vacuum Graph
Triple Vacuum Method
The triple evacuation method should be used. Refer to Fig. 9 and
proceed as follows:
1. Pump the system down to 1500 microns and allow the pump to
continue operating for an additional 15 minutes.
2. Close the service valves and shut off the vacuum pump.
3. Connect a dry nitrogen cylinder and regulator to the system and
break vacuum until the system reaches 2 psig.
4. Close the service valve and allow the system to stand for 1hr.
During this time, the dry nitrogen can diffuse throughout the system
absorbing moisture.
5. Pump the system down to 1000 microns.
6. Break the vacuum with dry nitrogen (2 psig).
7. Pump the system down to 500 microns.
8. Perform the hold test for 30 minutes.
EVACUATE TO 1500 MICRONS
BREAK VACUUM WITH DRY NITROGEN TO 2 PSIG
EVACUATE TO 1000 MICRONS
BREAK VACUUM WITH DRY NITROGEN TO 2 PSIG
EVACUATE TO 500 MICRONS MINIMUM (HOLD FOR 30 MINUTES)
CHECK FOR TIGHT, DRY SYSTEM
(IF IT HOLDS DEEP VACUUM)
RELEASE CHARGE INTO SYSTEM BY OPENING VALVES COMPLETELY
Fig. 11 — Triple Evacuation Method
Final Tubing Check
IMPORTANT: Check to be certain factory tubing on both
indoor and outdoor unit has not shifted during shipment.
Ensure tubes are not rubbing against each other or any
sheet metal. Pay close attention to feeder tubes, making
sure wire ties on feeder tubes are secure and tight.
LEAK IN
SYSTEM
VACUUM TIGHT
TOO WET
TIGHT
DRY SYSTEM
3 4 5 6 7
40MPHA-03SM