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Continued 10.12 (b) (1)
your finger or a screwdriver. If the AC voltage now appears at that
disconnect, a simple bending of the micro switch arm with long-nosed
pliers to activate the micro switch when the arm is on the greater
diameter portion of the cam usually solves the problem.
(2) If the AC is present at both disconnects, the problem must lie with the
solenoid valve(s). Measure the resistance of each solenoid valve coil by
inserting meter probes into the female portion of disconnect leading to
the solenoid valve. The resistance of each coil should be ~440-ohms if
120V and ~1850-ohms if 220V. If other than this, valve coil is either
open or shorted. Replace the solenoid valves in pairs.
(c)
If the timer cams do not turn when the POWER switch is depressed to on
position, check the voltage coming from the RFI filter, Figure 5 (15).
(1)
If AC voltage is present between terminals 5 and 4 of TS-1 and not
present at the output of the RFI filter, the RFI filter is defective. Replace
RFI filter.
(2)
If voltage is present at both the input and output of the RFI filter, the
timer is defective. Replace timer.
10.13
If there is purge flow as detected at the DUMP fitting, Figure 2 (6), even though the
POWER switch is off, the problem lies with one of the solenoid valves experiencing
"blow-by" due to weakening of the spring within the coil housing. This spring holds
the spindle against its seat when the coil is not energized, closing the inlet side of
the valve at any pressure up to 100-psig. If the spring is defective, air is permitted
passage through the valve and because there is less restriction through the purge
valve and opposing column system rather than through the check valve, pressure
regulator, etc., this air appears at the DUMP fitting as purge air.
NOTE:
Because of the 100-psig limitation for the input air pressure (see Section
3.4), it is imperative that when connected to "house" air this 100-psig
limitation be observed. Otherwise, the greater pressure will cause
improper operation of the purification reactor and, consequently,
production of impure air.
10.14
Further confirmation of this condition can be made by removing the connecting
tubing from the bottoms of the solenoid valves; i.e., the common dump connection,
and determining which solenoid valve is leaking when its coil Is not energized.
Simply feel the air flow from the bottoms of the valves with the POWER switch off
and pressurized air is being applied to the inlets of the purification reactor. The
defective solenoid valve is that valve which does not evidence purge flow since its
22
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