mensor PCS 400, Operation Manual

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Table 5.1 continued...
Continued on next page...
Symptoms and Clues Possible Cause Try This
4 SYSTEM DOES NOT CONTROL
AT COMMANDED SET POINT
CLUE: The PCS 400 requires an
input pressure higher than the
c o n t r o l o u t p u t s e t p o i n t , o r
pneumatics section is working
improperly.
The source pressure is not
high enough.
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The cable connecting the
e l e c t r i c a l m o d u l e t o t h e
regulator is disconnected.
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The solenoid valves are not
opening to let pressure into or
out of the control module.
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PCS 400 has a pneumatic
leak.
Apply source pressure 10 psi (or
10%) greater than the commanded
set point.
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Check the 9 pin connector
Å
on
the electrical module and the pcb
connector
Ã
o n t o p o f t h e
regulator. Make sure the regulator
connector is not shorted against
something.
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Run the solenoid valve test to verify
that all of the valves are working.
CAUTION: HIGH PRESSURES
COULD BE PRESENT AT THE
GAUGE OUTPUT DURING THE
TEST!
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See next section.
5 SYSTEM HAS A PNEUMATIC
LEAK
CLUE: Possible sources for leaks
are solenoids, plumbing, or relief
valves.
B e c a u s e o f t h e e x t r e m e
resolution of the PCS 400,
v e r y s m a l l t e m p e r a t u r e
changes on trapped volumes
of gas will appear as changes
in pressure. The PCS 400 will
control small leaks with no
e f f e c t
o n a n y c o n t r o l
parameters. The built-in leak
diagnostics are designed to
help troubleshoot problems
b u t n o t r e t u r n a b s o l u t e
numbers.
Run internal leak test and system
leak test to determine if leak is
inside unit or external. Most internal
leaks appear at solenoid valves,
relief valves and fittings.
6 SYSTEM DOES NOT RESPOND
F R O M T H E F R O N T P A N E L
KEYPAD
CLUE: Signals are not being
transferred from the front panel
keypad to the electrical module.
T h e k e y p a d c a b l e i s
disconnected at the front
panel
È
or at the electrical
module.
Re-connect the cable.
MAINTENANCE
PCS 400
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