Installation manual

Air Cooled Models
33
3.5 Lee-Temp/Flood Back Head Pressure Control Systems
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).
3.5.1 Piping
Be sure to install the valve with the refrigerant flow in the proper direction. When soldering or braz-
ing the valves, it is very important that the internal parts be protected by wrapping the valve with a
damp cloth to keep the valve temperature below 250°F (121°C).
3.5.2 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"x5/8")
• Terminal block for two-wire, 24V interlock connection between the unit and the condenser
• Condenser legs: four on one-fan models, six on two- and three-fan models, and eight on four-fan
models
• Lee-Temp system:
• Insulated storage receiver – one per circuit
• Head pressure control valve with integral check valve – one per circuit
• Adapter assembly – one per circuit
• Rotalock valve – one per circuit
• Pressure relief valve – one per circuit
• Liquid level sight glass – two per circuit
• Check valve – one per circuit.
• Bolts – six per receiver (3/8" x 1")
3.5.3 Dehydration
1. Open all disconnect switches.
2. Pull all fuses except transformer fuses. On units supplied with circuit breakers, open all breakers
except for the transformer.
3. Jumper Fan Safety Switch between Common and Normal Open. Turn disconnects ON.
4. Use the manual override switches to energize the solenoid valves.
5. Connect refrigeration gauges to the suction and discharge service valves of compressors 1 & 2.
6. Open all service valves.
7. Charge circuit #1 to 150 psig (1034 kPa) with dry nitrogen containing a tracer of Freon.
8. Check for pressure increase in circuit #2. This would indicate that the refrigeration circuits are
cross-circuited and must be re-piped.
9. If there is no pressure increase, charge circuit #2 to 150 psig (1034 kPa) with dry nitrogen
containing a tracer of Freon and leak-test both circuits.
10. After completion of leak testing, release test pressure and pull a vacuum on both circuits.
11. After 4 hours, check gauge readings and, if they have not changed, purge with Freon.
12. Pull a second and third vacuum of 250 microns (29.84 in. Hg), leave for 2 hours and recheck
gauges.
NOTE
Lee-Temp heater pads require a separate, continuous electrical source of
either 115 VAC or 200/208/230 VAC.
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