Thermo King T-1000R, Maintenance Manual

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Refrigeration Maintenance 10-12
REFRIGERANT LEAKS
Use a reliable leak detector (e.g., electronic detector) to leak test the refrigeration system. Inspect for signs of oil leakage which
is the first sign of a leak in the refrigeration system.
It is normal for compressor shaft seals to have a slightly oily film.
REFRIGERANT CHARGE
Testing the Refrigerant Charge with an Empty Box (Controlled Check)
If the unit has an insufficient charge of refrigerant, the evaporator will be “starved” and the box temperature will rise even
though the unit is operating. The suction pressure will drop as the refrigerant charge decreases. The charge may be determined
by inspection of the refrigerant through the receiver tank sight glass with the following conditions established:
1. Close the truck box doors.
2. Install a gauge manifold. On units equipped with an ETV and a Premium HMI Control Panel the pressures may be viewed on
the screen.
3. Run the unit on high speed cool until the air in the box indicates 0 F (-18 C).
4. The discharge or head pressure gauge should read 290 to 310 psig (1999 to 2137 kPa).
If the pressure is below this, it can be raised by covering a portion of the condenser coil with a piece of cardboard.
5. The suction pressure gauge should be indicating 12 to 20 psig (83 to 138 kPa) gauge pressure.
6. Under these conditions, the ball in the receiver tank sight glass should be floating. If there is no indication of refrigerant in
the receiver tank sight glass, the unit is low on refrigerant.
Testing the Refrigerant Charge with a Loaded Box (Quick Check)
1. Install a gauge manifold (optional).
2. Run the unit on the Cool cycle.
3. Cover at least three quarters of the condenser to drive any excess refrigerant from the condenser into the receiver tank. Do not
cover the condenser for more than three minutes.
4. As the head pressure is rising, check the receiver tank sight glass. The ball should be floating. If there is no indication of
refrigerant in the receiver tank sight glass, the unit may be low on refrigerant. Perform a Controlled Check.
NOTE: If the ball floats, there is sufficient refrigerant in the unit for that load at that particular box temperature. This
test does not determine if the unit contains a full charge of refrigerant.
CHECKING COMPRESSOR OIL
The compressor oil should be checked when there is evidence of oil loss (oil leaks) or when components in the refrigeration
system have been removed for service or replacement. The oil level in the compressor oil sight glass should be 1/4 to 3/4 full.