TSI Instruments SUREFLOW 8635-M, Operation And Service Manual

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34 Part Two
Troubleshooting Chart
Symptom Possible Cause Corrective Action
Display is blank. Fuse is blown.
No power to DIM.
DIM is defective. Measure voltage at pins 1 and 2 on DIM.
The voltage should nominally be 24 to 30 VAC.
If correct voltage is measured, internal DIM fuse is
probably blown. Unplug 14-pin connector from DIM for 2
minutes. The internal fuse will automatically reset. Plug
unit back in and check display. If display is still blank,
check all wiring, etc. If no problems are found, replace
DIM.
If zero volts are measured, see
No power to DIM .
Verify circuit breaker is on.
Verify transformer primary measures 110 VAC.
Verify transformer secondary measures 24 to 30 VAC.
If proper voltage is found between pins 1 and 2 of the
DIM, all wiring has been checked, fuses have been
reset, and screen is still blank, the DIM is probably
defective. Replace DIM.
Sensor does not
calibrate.
Incorrect pressure
sensor address.
Pressure sensor must have address of 1. Check
pressure sensor dip switches 5 & 6 and verify address 1
is correct (7 to12 must be OFF).
Figure 8: Pressure sensor DIP switch
Sensor
communications
not working. Check SENSOR STAT item in diagnostics menu. If
NORMAL is displayed, sensor is okay, if COMM
ERROR is displayed, check wiring, pressure sensor
address, and that dip switch 1 & 2 are ON (Figure 8).