Brooks Instrument 4800 Series - Manual (Page 24)

4-2
Brooks ® 4800 Series
Section 4 Maintenance and Troubleshooting Installation and Operation Manual
X-TMF-4800-MFC-eng
Part Number: 541B072AAG
September, 2013
Trouble Possible Cause Check/Corrective Action
Output stays at zero (regardless of
Setpoint) and there is flow through the
meter/controller Incorrect calibration coefficients
Defective electronic board
Defective restrictor seal Contact Brooks Instrument
Valve leaks or is stuck open (applicable
to MFC) Contact Brooks Instrument
Maximum voltage applied to the valve
override input (applicable to MFC) Check the valve override terminal (pin 12)
Output signal stays at approx. 5.5 Vdc or
22 mA (regardless of Setpoint) and there
is flow through the meter/controller
Defective electronic board Contact Brooks Instrument
Output signal follows Setpoint at higher
Setpoints but will not go below 2% Control valve leaks or is stuck open
Contact Brooks Instrument
Insufficient inlet pressure or pressure
drop Adjust pressures, inspect in-line filters and
clean/replace as necessary
Clogged inlet filter Replace inlet fitting
Partially clogged valve (applicable to
MFC) Contact Brooks Instrument
Valve out of adjustment (applicable to
MFC) Contact Brooks Instrument
Valve guide spring failure (applicable to
MFC) Contact Brooks Instrument
Output signal follows Setpoint at lower
Setpoints, but does not reach full scale
OR
Flow cannot be achieved regardless of
Setpoint (applicable to MFC)
Defective electronic board Contact Brooks Instrument
Instrument grossly out of calibration. Flow
is lower than desired. Partially clogged restrictor Contact Brooks Instrument
Pressure drop or inlet pressure deviates
from calibrated values Adjust pressures to original specifications
PID out of adjustment Adjust PID settings or contact Brooks Instrument
Valve out of adjustment Contact Brooks Instrument
Unstable inlet pressure Check external pressure regulator
Controller oscillates (applicable to MFC)
Defective electronic board Contact Brooks Instrument
This instrument contains electronic components that are
susceptible to damage by static electricity. Proper handling
procedures must be observed during the removal, installation, or
other handling of internal circuit boards or devices.
CAUTION !
4-2 Troubleshooting
This section contains suggestions to help diagnose simple MFC/MFM
related problems in the gas distribution system and answers commonly
asked questions.
4-2-1 Troubleshooting Table
Table 4-1 Troubleshooting