Brooks Instrument SLA5840 - Manual (Page 24)

4-2
Brooks ® Model SLA5840
Section 4 Maintenance
& Troubleshooting Installation and Operation Manual
X-PR-SLA5800-RT-eng
Part Number: 541B120AAG
August, 2009
4-2 Troubleshooting
This section contains suggestions to help diagnose simple RT related
problems in the gas distribution system and answers commonly asked
questions.
Brooks part #S273Z668AAA can be used as an accuracy for diagnosing
electrical problems.
a. Problem: No response to input commands/No output status signal.
1. The unit may not be receiving power. Check that module status
LED is green.
2. Connections may not be secure. Check all cable connections.
b. Problem: Flow/flow signal doesn't reach setpoint. (MFC Only)
Failure of the flow rate or flow signal to achieve setpoint could be caused
by a number of factors:
1. Insufficient pressure drop across the MFC (low or no pressure).
If there is not enough pressure differential across the MFC, it is
impossible for the MFC's valve orifice to pass the full scale flow
rate. To check for this condition, compare the actual inlet/outlet
pressure drop as read from pressure gauges with that specified
on the order (shown in Figure 4-1). Increase the pressure if
necessary.