Installation and Operation Manual
X-CM-QmB-eng
Part Number: 541B029AAG
June, 2017
QmB Series IP40, IP66, IP66XP
Observation
Cause
Resolution
No Flow or unable to
stability could suffer).
Chemical deposits.
Valve out of adjustment
Contact Brooks Instrument.
(applicable to Controller).
Valve out of adjustment
Valve guide spring failure
Contact Brooks Instrument.
(applicable to Controller).
Valve override input is grounded
Check the valve override input.
(Pin12).
Defective electronic board
Contact Brooks Instrument.
Output signal follows Setpoint
Control valve leaks or is stuck open.
Exercise the control valve
at higher Setpoints but not
alternating between valve override
at lower Setpoint
s
"open" and closed. If problem
a solvent or purge gas with valve
override "open".
If the device has an external
control valve you can replace or
disassemble and clean the valve.
(See Section 4-3)
Output signal stays in approx.
Valve leaks or is stuck open
5.5 Vdc or 22 mA
(applicable to Controller).
a solvent or purge gas with valve
(regardless of setpoint) and
override "open".
If the device has an external
meter/controlle
r
control valve you can replace or
disassemble and clean the valve.
(See Section 4-3)
+15 Vdc applied to the valve
Check the valve override terminal
overrride input
(Pin 12).
(applicable to Controller).
Defective PC board.
Contact Brooks Instrument.
T
able 4-1 Maintenance &
Tr
oubleshooting (continued)
If the device has an external contro
l
valve you can replace or disassembl
e
and clean the valve.
(See Section 4-3)
No secondary output signal
Not all models have a secondary output.
Check calibration sheet and/or other
documentation to confirm if device
should have a secondary output.
If yes, contact Brooks Instrument.
Particulates in the flow stream.
4-4
