Gardner Denver Air Dryer RDS250A-3

Blow entire unit out with compressed air.

Blow condenser coils out with compressed air.

Inspect refrigeration compressor for overheating.

Clean air filter on the condenser.

NOTE: Filters that are running in dirtier than normal environments will need to be inspected and changed more often.

Sign off on the air dryer inspection

Warning: Ensure the machine is powered off before starting the procedure.

Thermistor removed from the well or refrigerant line

Control wires plug removed from CN3 on the control board

Thermistor terminal location verified

Resistance measured with a resistance meter

Resistance reading compared to the value at ambient conditions

Probe placed in a bottle of ice water

Did the resistance change in value?

Tighten all electrical connections. Look for broken, cracked, or bare wires.

Measure and record amperage. Verify that readings are within acceptable parameters as listed in specification table.

Clean the condenser coil with a mild detergent mixture and brush.

Sign off on the air dryer maintenance

Inspect entire assembly for loose connections, screws, panels etc.

Inspect refrigeration circuit for signs of oil and refrigerant leakage.

Clean fan blades, casing, motors and internal components.

Use light mixture of detergent. No oil based cleaning solvents should be used for cleaning the unit.

Sign off on the air dryer maintenance

Slide control panel out of the grooves in the extruded aluminum rails. Set the panel on top of the dryer

Slide the front panel out of the grooves in the extruded aluminum rails. Set the panel aside

Locate the drain solenoid valve on the lower righthand side of the heat exchanger assembly. Remove the retainer screw on the top of the solenoid coil

Lift the coil off of the valve and set it to the side

Locate and remove the two (2) screws that hold the valve core in place. The screws are located on either side of the solenoid stem in the brass retainer plate. NOTE: some of the fiberglass insulation on the heat exchanger may need to be cleared away to gain access to the screws

Carefully remove the core from the valve assembly. CAUTION: This assembly contains a plunger, seat, and a small spring. Be careful to not lose any of the small parts during di-assembly

Inspect the valve seat for signs of wear. Inspect the orifice of the valve for signs of dirt, oil, or other contaminants. If any contaminants exist, remove them with needle nosed pliers or a cotton swab soaked with alcohol. Be careful not to push any contaminants back into the valve

When the valve is clean, reassemble in reverse order