Arrow Pneumatics RH203, Instruction & Maintenance Manual

Page: 6 / 23

6
3. OPERATION
A. START-UP
After all piping and electrical connections are made, proceed as follows:
1. SLOWLY pressurize the dryer. When the dryer reaches full operating pressure, check
the system for air leaks. Soap test all joints and fittings. To maintain desired dewpoint,
any leaks detected must be fixed, especially those on the outlet side of the dryer.
2. Adjust purge adjustment valve so that purge pressure gauge reads appropriate pressure
(see attached purge pressure chart).
3. Energize electrical circuit.
4. When electrical circuit has been energized, the control circuit board or mechanical timer-
will start to operate and automatically initiate dryer operation. The timer is factory set, so
that no field adjustment is necessary.
NOTE
AT INITIAL START-UP, CHECK THE DRYER OPERATION FOR ONE OR TWO
CYCLES, ESPECIALLY AT THE TIME OF THE TOWER SHIFT. VERIFY THAT
ALL SYSTEMS ARE OPERATING IN THEIR PROPER ORDER AND
SEQUENCE. IF THE DRYER IS NOT FUNCTIONING PROPERLY, CONTACT
YOU ARROW REPRESENTATIVE.
B. DRYER OPERATION
The dryer is fully automatic in operation and will now operate with a minimum of
maintenance and care. Each sequence of operations is programmed by a central circuit
board or mechanical timer. Dryer programs may differ slightly, but all perform similar
functions.
Standard dryers operate on a 10 minute NEMA cycle with 5 minutes drying and 5 minutes
regenerating.
At tower switchover, a 20 second time interval is allowed to bring both towers to full line
pressure before switchover, thus preventing rapid pressurization which would agitate the
desiccant bed. A special repressurization circuit is energized when the purge valve closes
to maintain a 30 second repressurization.