Quincy Compressor QPHT 20, Operator'S Manual

6

July 2004

OPERATING INSTRUCTIONS

1.

Start the air dryer system by turning the switch to the 
ON position. At this time the compressor and 
cooling fans will start.

2.

After the unit is running, the suction pressure will 
begin to drop into the appropriate pressure range 
for the particular dryer model. Normal operating 
suction pressure ranges are as follows:

Model QPHT-20: 25 to 33 PSIG (Blue Range)

Model QPHT-40: 52 to 64 PSIG (Green Range)

Model QPHT-60: 25 to 33 PSIG (Blue Range)

Model QPHT-80: 25 to 33 PSIG (Blue Range)

Model QPHT-100: 25 to 33 PSIG (Blue Range)

3.

Once the suction pressure stabilizes and is 
maintained in the proper operating pressure range, 
compressed air can be allowed to flow through the 
air dryer system. At this point the air dryer system is 
delivering dry air to your process.

4.

If the refrigerant suction pressure is not in the proper 
operating range, a hot gas bypass adjustment may 
be required. See Page 9 for hot gas bypass valve 
adjustment instructions.

5.

Hold the PUSH-TO-TEST button on the drain controls 
open for several seconds. This procedure should be 
repeated 3 or 4 times in every 8 hour period of 
operation.

6.

The moisture drain valve operates automatically and 
is controlled with the two CYCLE TIME and DRAIN 
TIME knobs. Initially both knobs should be turned 
counterclockwise to the seven o’clock position. 
When using the unit after shipment, check both 
knobs and turn to the seven o’clock position if they 
have been moved. The controls are now set so that 
the unit opens the drain every 1 minute (cycle time) 
for a 2 second period (drain time).

After the unit has been running and the suction pressure 
indicator arrow is in the blue/green zone, check the 
moisture drain line. The line should drain moisture without 
expelling air. After the unit has been operating, recheck 
the line for proper drainage. If needed, slowly increase 
the cycle and drain timings to adjust for an increased load 
and to compensate for humid air conditions. Adjust cycle 
and drain time if needed for proper drainage without the 
loss of any compressed air.

Press the PUSH-TO-TEST button for manual override, and 
to periodically clear the moisture drain of sediments or 
foreign material.

7.

Manually turn the coalescing oil filter drain stem 
once every 8 hours of operation, or when the sight 
of glass is half full of liquid. Failure to drain may 
cause reentrainment.

SPECIFICATIONS 

Model QPHT-20

1.

Unit Dimensions:

Length: 17.50”
Width: 18.75”
Height: 17.75”

2.

Flow:

20 SCFM

3.

Inlet Pressure:

175 PSIG (200 PSIG Maximum)

4.

Ambient Temperature:

Minimum 40°F (4°C)
Maximum 100°F (38°C)

5.

Inlet Temperature:

180°F (82°C) Maximum

6.

Dew Pt. Temperature:

40°F±2° (4°C±1°)

7.

Refrigerant H.P.:

1/4

8.

Heat Exchanger Material:

Copper

9.

Automatic Drain:

Installed

10.

Refrigerant:

R-134A

11.

Electrical Power Supply:

115V, 60HZ, 1 phase

12.

Instrumentation:

ON/OFF switch
Power-on light
High temperature light
Refrigerant suction pressure gauge
Drain test button
Drain adjustment controls (2)