Brooks Instrument 5866M - Manual (Page 24)

5-1
Troubleshooting
Troubleshooting
5-1 General
It is important that this controller be serviced only by properly
trained and qualified personnel.
CAUTION
A. System Checks
The Model 5866 is generally used as a component in gas handling
systems which can be quite complex. This can make the task of isolating a
malfunction in the system a difficult one. An incorrectly diagnosed
malfunction can cause many hours of unnecessary down time. If possible,
make the following system checks before removing a suspected defective
pressure controller for bench troubleshooting or return to the factory,
especially if the system is new.
1. Verify a low resistance common connection and that the correct power
supply voltage and signals are reaching and leaving the controller. The
Break-out Board (P/N S-273-Z-649-AAA) will make this job much
easier.
2. Verify that the process gas connections have been correctly terminated
and leak checked.
3. If the pressure controller appears to be functioning but cannot achieve
set-point, verify that sufficient inlet pressure and pressure drop are
available at the controller to provide the required flow.
4. Verify that all user selectable jumpers are in their desired positions
(refer to Figure 2-1).
WARNING
If it becomes necessary to remove the controller from the system
after exposure to toxic, pyrophoric, flammable or corrosive gas,
purge the controller thoroughly with a dry inert gas such as nitrogen
before disconnecting the gas connections. Failure to correctly purge
the controller could result in fire, explosion or death. Corrosion or
contamination of the pressure controller upon exposure to air may
also occur.
5-2 Troubleshooting
A. Bench Troubleshooting (Table 5-1)
1. Connect the pressure controller to a ±15 Vdc power supply, and a
command voltage source. Connect an output signal readout device (a
4-1/2 digit voltmeter is recommended) to Terminals 2 and 10 (refer to
Table 2-1).
2. Apply power to the controller, close the valve using the valve override
closed input and allow it to warm up for fifteen minutes. Do not connect
the controller to a gas source at this time.
5
Section