TK 56701-1-IM-EN
89
System Evacuation
IIm
mp
po
orrtta
an
ntt:: Do not evacuate unit until it is leak free. Unit with less than a full refrigerant charge should be leak checked
and all leaks must be repaired.
N
No
otte
e:: Use of Thermo King Evacuation Station (P/N 2040725) and Evacuation Station Operation and Field Application
Instructions (TK-40612-2) is required.
Refer to the illustration on the following page.
1. Recover any refrigerant to 0 psig. (Regulations may require recovery machine to pull system pressure lower than 0
psig).
2. Before connecting refrigerant hoses to unit, close valves V1 and V4 on the evacuation system and turn micron
gauge ON.
3. Back seat suction and receiver tank service valves. Attach evacuation hoses to these two valves as well as the
discharge service port (check condition of hose seals).
4. With service valves fully back seated, turn evacuation pump ON and open valve V1 (V2 and V3 should also be open).
Micron gauge should move to a deep vacuum.
5. Open valve V4. Micron reading will rise. If micron gauge returns to reading less than 500 microns, proceed to step 6.
If micron reading remains high, a leak exists at hose fittings or packing glands. Locate and correct problem. Packing
glands that do not seal can be corrected by installing valve stem covers (see step 6).
6. If step 5 was successful, close valve V2 to isolate thermistor. Open suction, discharge and receiver service valves to
port. Install brass and steel valve stem covers (with sealing washers) on service valves and tighten. Let vacuum
pump continue to operate
7. After 5 minutes of evacuation, open valve V2 to access thermistor and micron gauge. Micron reading now shows
system pressure.
8. Evacuate system to 500 microns or lowest achievable level between 500 and 1000 microns. Multi-Temp units should
be evacuated for an additional hour once 500 microns is reached.
9. When acceptable micron level is achieved (500 to 1000 microns plus on hour for Multi-Temp units), close valve V1 to
isolate pump. Turn pump OFF.
10. Observe reading on micron gauge after 5 minutes have elapsed. If vacuum level exceeds 2000 microns after 5
minutes, leak is present or additional evacuation time is required.
11. If vacuum level is acceptable, start pump and open valve V1 to evacuate pressure rise (5 minutes).
12. With vacuum pump running, back seat suction service valve. Observe micron gauge and continue to operate
vacuum pump until an acceptable micron level is achieved.
13. Close valve V1 and stop pump. Observe micron gauge to confirm that system remains in a deep vacuum. Close
valve V4. Unit is ready to charge.
