Sahara -Pak HC-1260 Instruction Manual page 37

INSTRUCTION MANUAL
Model HC
3.0 Troubleshooting (continued)
Problem
Failure to Switch Towers
Dryer Fails to Repressurize
Primary Drain Failure
Secondary Drain Failure
Reference 219
Page 37 of 46
Probable Cause
No input power
Defective solenoid valves
Low pilot air caused by tubing
leakage
Two-way switching valve actuator
leakage causing switching valve
to malfunction. Low pilot pressure
due to leakage (or solenoid valve
failure) will cause fail-to-shift
alarm to activate.
Flow control valves misadjusted
Purge adjusting valve, V16, is
closed
Sediment plugging orifice or
impeding proper operation of float
Solenoid valve failure. When the
liquid level rises above the
primary float valve elevation and
contacts the liquid level probe, a
circuit is completed energizing the
3-way normally open solenoid
valve depressurizing the
secondary drain valve actuator.
The system pressure should open
the secondary drain valve.
Liquid level probe failure
Remedy
Check fuse
Check solenoid valves SV1;
electrical connection, coil, and
valve seat.
Check pilot air line, pilot air filter,
and system pressure
Check for leakage
Adjust flow control valves in
tubing so that mainstream valves
open fast and close slow
Check purge valve adjustment
Check drain trap for proper
operation. Disassemble, inspect,
and clean as necessary.
If the PRIMARY DRAIN FAILURE
ALARM activates, but the
secondary drain valve fails to
open, check the 3-way normally
open solenoid valve. Clean,
repair, or replace as necessary.
If the PRIMARY DRAIN FAILURE
ALARM does not activate after or
during failure of the float operated
drain, check the liquid level probe
for proper operation.
Rev 2
06/20/2013