Liebert DS user manual Lee-Temp Piping, Lee-Temp Controlled Materials Supplied

Piping

8.3.2Air-Cooled Condenser with Lee-Temp “Flooded Condenser” Head Pressure Control System

The Lee-Temp system consists of a modulating type head pressure control valve and insulated receiv- ers with heater pads to ensure operation at ambient temperatures as low as -30°F (-34.4°C).

Lee-Temp Piping

Two discharge lines and two liquid lines must be field-installed between the indoor unit and the out- door condenser. See Figures 57 and 59 for details.

Lee-Temp Controlled Materials Supplied

•Built-in, pre-wired condenser control box

•Air-Cooled condenser

•Piping access cover to be reinstalled when piping is complete

•Bolts—four per leg (3/8" x 5/8")

•Terminal block for two-wire, 24V interlock connection between unit and condenser

•Condensate legs—four with 1-fan, six on two-and three-fan models and eight on four-fan models

•Bolts—six per receiver (3/8" x 1")

•Lee-Temp system:

•Insulated storage receiver—one per circuit

•Head pressure control valve with integral check valve - one per circuit

•Service valve—one per circuit

•Pressure relief valve—one per circuit

•Liquid level sight glass—two per circuit

•Check valve—one per circuit

NOTE

Lee-Temp heater pads require a separate, continuous electrical source. See nameplate on unit for proper voltage.

Lee-Temp Leak Check and Evacuation Procedure

Proper leak check and evacuation can be accomplished only with all system solenoid valves open and check valves accounted for.

NOTE

Systems with scroll or digital scroll compressors include a factory-installed check valve and an additional downstream Schrader valve with core in the compressor discharge line. Proper evacuation of the condenser side of the compressor can be accomplished only using the downstream Schrader valve. See piping schematic (Figure 59).

1.If unit power is available, open the unit liquid line solenoid valves using the evacuation function for System #1 and System #2 in the diagnostic section of the iCOM control. If unit power is not available, a field-supplied 24VAC / 75VA power source must be directly connected to each of the unit solenoid valves.

2.Attach a jumper hose from the service valve fitting on the outlet of the receiver and the Schrader fitting on the discharge header of the condenser. Front-seat the service valve approximately two (2) turns.

3.For semi-hermetic compressors, connect refrigeration gauges to the suction and discharge service valves of both compressors.

4.For scroll and digital scroll compressors, connect refrigerant gauges to the suction rotalock valves and discharge line Schrader valves (see Note above) on both compressors.

5.Starting with Circuit #1, open the service valves and place a 150 PSIG (1034 kPa) of dry nitrogen with a tracer of refrigerant. Check system for leaks with a suitable leak detector.

6.With pressure still in Circuit #1, open the compressor service valves in Circuit #2. If pressure increases in Circuit #2, the system is cross-circuited and must be rechecked for proper piping. If there is no pressure increase, repeat the leak check procedure for Circuit #2.

7.After completion of leak testing, release the test pressure (per local code) and pull an initial deep vacuum on the system with a suitable pump.

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