AT&T D-10,000, D-320 operating instructions Start-Up

I. START-UP

After the installation of your air dryer at a suitable location, the following checks should be made:

a)Bypass piping installed and valves set to bypass the dryer.

b)Before start-up, the refrigerant analyzer gauge should indicate a dryer shutdown pressure of 125-175 PSIG for R-22 or 74-108 PSIG for R-134a for Models D-320-A through D-10000-A. If analyzer pressure is above or below normal shutdown pressure, do not start the dryer.

Pressure may vary with ambient temperature.

c)The operational switch must be in the "OFF" position.

d)The main electrical disconnect energized.

UNITS THAT DO NOT REQUIRE A CRANKCASE HEATER CAN BE STARTED IMMEDIATELY AFTER STEP D (ABOVE) BY SIMPLY TURNING THE OPERATIONAL SWITCH TO "ON". The red high-temperature Light may remain on for a short time after the unit is started and the Refrigerant Analyzer Pressure will drop to its normal range to indicate 55-65 PSIG for R-22 or 26-33 for R-134a. When the Red High Temperature Light goes out, the dryer is ready to assume full load operation.

ON UNITS SUPPLIED WITH CRANKCASE HEATERS, THE CRANKCASE HEATERS MUST BE ENERGIZED 24 HOURS BEFORE INITIAL START-UP OR AFTER ANY PROLONGED SHUT DOWN. After the 24 hour period, the dryer may be started. The Refrigerant Analyzer pressure will drop and bring itself to the normal running pressure of 55-65 PSIG for R-22 or 26-33 for R-134a. When the red high temperature light goes out, the dryer is ready to assume full load operation.

e)When the operational switch is turned to the “on” position, the amber dryer running light should be “on”.

Dryers having dual condenser fans will have one (1) fan which may start when the operational switch is turned on. The cycling of the fan(s) is controlled by the low ambient fan control which is factory preset to maintain the proper head pressure within the refrigerant system.

Dryers with scroll compressor(s) need to be checked for proper rotation by making sure the discharge pressure is greater than the suction pressure. To change rotation, switch inlet power leads L1 and L3. Any questions or problems, consult factory.

f). Open water supply valve (water-cooled units only).

g). Adjust solenoid drain valves for appropriate “open” time.

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