4
INSTRUMENTATION
ON/OFF Switch
The dryer is equipped with an ON/OFF switch on the front panel.
A light signals when the dryer is on.
Color Indicator
All dryers are equipped with a color indicator which indicates
dryer conditions as follows:
It is normal for the indicator color to be in the red zone when
the dryer is first turned on and then move to the green zone
when the dryer reaches its normal operating temperature. If this
indicator is in the red zone during normal operation, turn the
dryer off to avoid compressor damage. Refer to the Field Service
Guide for additional information, or call your local distributor.
DRAIN VALVES
An electronic drain valve is supplied to automatically discharge
condensate from the dryer. The drain valve and its controls are
accessible from the rear of the dryer. The electronic drain valve
has two indicators and a test button to help verify operation.
Pushing the test button causes the drain port to click open. If
either indicator fails to turn on at the proper time, refer to the
maintenance section of this manual. Drain valve operation is
controlled by an electronic timer. The drain opening can be
set from 0.5 sec to 10 sec. The drain cycle can be set from
0.5 min to 45 min.
Drain Valve Adjustment
To minimize air losses, the drain timer should be adjusted to
open the drain port just long enough to discharge accumulated
condensate. Set the timer so that only air discharges at the end
of the open period.
Recommended Drain Settings
Time
Model
Open (Sec)
Closed (Min)
HPR25
2
10
HPR35
2
10
HPR50
2
10
NOTE: If liquid discharges as the port is closing, set the timer for a
shorter cycle or a longer opening. The amount of condensate will
vary as ambient conditions and inlet flow rates change.
START-UP/OPERATION
Follow the procedure below to start your dryer. Failure to follow
the prescribed start-up procedure will invalidate the warranty. If
problems arise during start-up, call your distributor.
Refer to Serial Number Tag for dryer operating
capacity. Do not exceed recommended capacity.
Drain connections must be made before the dryer can be op
-
erated. The dryers are fully automatic and require no auxiliary
controls.
1. Connect inlet and outlet lines to the dryer. Reference dryer
indentations and instruction tag for appropriate inlet and
outlet connections.
2. Route drain connections to a condensate separator or ap-
proved collection point.
3. Turn the on/off switch to on. Double check connections.
4. After the dryer has been running for 30 minutes:
a. Check that on/off lighted switch is glowing. If light
is not glowing, unplug unit and refer to Field Service
Guide for additional information or call your local dis
-
tributor.
b. Check the Color Indicator. If the Indicator is in the red
zone, unplug the dryer. Refer to the Field Service Guide
for additional information, or call your local distributor.
c. Confirm that condensate is discharging from the drain.
This can only be done when there is air flow through
the dryer.
Reference Serial Number Tag for appropriate
power requirement/connection rating. Make other dryer con
-
nections prior to connecting power source.
The dryer is designed to run continuously. Let the dryer run
even when the demand for compressed air is interrupted; the
dryer will not freeze up.
Operating Check Points
1. Power light is on, light is illuminated.
2. Condensate is discharging properly.
3. Color Indicator is in the Green Zone.
SHUTDOWN
When the dryer must be shutdown for maintenance or other
reasons, use the following procedure:
1. Turn the power on/off switch to off.
2. Disconnect the main power supply.
If mechanical repairs are to be made or service is performed,
vent the internal pressure of the dryer to atmospheric pressure.
Restart the dryer according to the start-up instructions.
Disconnect power supply and depressurize dryer
before servicing. Dismantling or working on any component of
the compressed air system under pressure may cause equip-
ment failure and serious personal injury.
