If the circuit breaker is off, the cause of the overload
may be shorted wiring, shorted motor windings; or a short in the
pressure sensitive switch.
Dehydrator stops and starts repeatedly before reaching preset
transmission line pressure:
Check for large leaks in the transmission line or connecting
line tubing.
Check the connecting line tubing for restrictions such as
kinks. Reroute the tubing to remove kinks.
Check to see if the transmission line is too restrictive for
the pressure delivered by the dehydrator; that is, the dehydrator
produces more pressure than the line can handle. If the line is
too restrictive, connect a pressure regulating tank between the
dehydrator and the line. The tank outlet pressure can then be
adjusted to suit the transmission line.
Dehydrator runs excessively - 30% to 50% more than normal:
Check the dehydrator running time and frequency of operation.
An antenna system incorporating an automatic dehydrator should be
designed so that the dehydrator runs no more than 72 minutes and no
less than 10 minutes during a 24-hour period. If the running time
is longer or operation occurs more frequently, there is major leakage
in the system.
Check for external or internal leakage. Disconnect the connecting
line tubing from the dehydrator outlet, block the outlet with your finger,
and run the dehydrator. The dehydrator should shut off at the preset
pressure of 8 psi within one minute. If it does, the leakage is either
in the connecting line or transmission line. If the dehydrator
continues to run after one minute, there is internal leakage.
Check the dehydrator for internal leaks. Cap the outlet, run
the dehydrator, and apply a soap solution at all fittings and
around components.
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Check components such as the back pressure valve, pressure
sensitive switch, humidity indicator, and the pressure gauge.
Bubbling indicates leakage. Tighten leaky fittings and replace
leaky components. Then recheck operation with the outlet capped;
it should shut off at 8 psi within one minute.
Dehydrator either does not start at pressure of 3 psi or
shut off at 8 psi:
Readjust the limits of or replace the pressure sensitive
switch.
System pressure does not increase when compressor runs:
Readjust or replace the back pressure regulator valve.
Replace the motor-compressor unit or rebuild the compressor
using compressor repair kit 40486.
Color of humidity indictor either pink, brown, or white:
Measure the delivery air flow rate. It should be at least
10 to 12 cubic feet per hour. A flow rate that is too low or
too high indicates that the back pressure regulator valve needs
readjustment or it is defective. If this adjustment or replacement
does not affect the flow rate, the compressor should be repaired
or replaced.
Check solenoid valve cycle time. Incorrect cycle timing
is caused by a defective solenoid timing motor or solenoid switch.
Run the dehydrator for 12 hours and check the humidity
indictor. If there is little or no color change, replace the
dryer assembly. (The dryer assembly includes the solenoid valves.)
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