62-11785 8–10
3. Ensure that the operator message panel displays “RECOVER/LEAK CHK/EVAC MODE” during the pressurizing
and leak checking procedures. (Refer to
Section 5.2.5
.) If the control system switches to Charge Mode during
the process, switch it back to the “RECOVER/LEAK CHK/EVAC MODE”.
4. Pressurize the low side of the system 5 to 10 psig (0.3 to 0.7 bar) with refrigerant from the high side by turning
the liquid line service valve off frontseat for a few seconds and then returning to frontseat.
Do not use a nitrogen cylinder without a pressure regulator. Cylinder pressure is approxi-
mately 2350 psig (159.9 bar). Do not use oxygen in or near a refrigerant system as an explosion
may occur. (See
Figure 8.15
)
5. Connect a cylinder of dry nitrogen. Use the nitrogen to increase the low side pressure 20 to 150 psig (1.4 to
10.2 bar) to detect the leak. The larger the leak the less pressure is required. The smaller the leak, the greater
the pressure required.
6. The recommended procedure for finding leaks from a system is with an electronic leak detector. Checking joints
with soapsuds is satisfactory only for locating large leaks, or pinpointing small leaks once a general area has
been located.
7. Once leak checking is complete, remove the refrigerant/nitrogen vapor from the low side of the system.
8. If no leaks are found the low side of the system is ready for evacuation. (Skip to Step 11.)
9. If any leaks are found they must be repaired before proceeding.
10. Repeat steps 4 through 9 as necessary.
11. Disconnect the nitrogen cylinder. Evacuate the low side of the system after all leaks are repaired. (Refer to
Section 8.5.4
.)
d. Leak Checking Compressor
The compressor connections, suction, discharge, and economizer, must be leak checked once the compressor is
closed and all repairs complete.
1. Ensure the unit will not start automatically by disabling any two way communication and placing the START/
RUN-OFF switch in the OFF position. Disconnect the high voltage source and lockout/tagout the receptacle.
2. Connect refrigerant system service equipment to the suction and discharge service valves, if not already
connected. Refer to
Figure 8.4
.
Only a refrigerant cylinder containing R404A should be connected to this refrigeration unit in
order to pressurize the system. However, dry nitrogen may be used to increase pressure. Any
other gas or vapor will contaminate the system and require additional removal and evacuation.
Do not vapor charge R404A. Only liquid charging through the liquid line service valve is
acceptable.
3. Pressurize the compressor 5 to 10 psig (0.3 to 0.7 bar) by opening the suction service valve for a few seconds,
then closing (front-seating) it again.
Do not use a nitrogen cylinder without a pressure regulator. Cylinder pressure is approxi-
mately 2350 psig (159.9 bar). Do not use oxygen in or near a refrigerant system as an explosion
may occur. (See
Figure 8.15
.)
To Next Page
Loading...
Need help?
General
