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Instrument does not
light.
Instrument lights but
does not show anything
on the display.
Light on sensor does
not light but instrument
powers up.
Light on sensor lights
but instrument doesn't
respond to chlorine
exposure.
Checking sensor wiring.
Verify indicator
operation.
Instrument shows high or
drifting readings when first
powered up but settles to a
stable reading within a
minute or two.
GAS SENSOR INTERNAL WIRING (REF. ONLY)
BASIC SYSTEM TROUBLESHOOTING
Check that 115 VAC (230VAC if used) is reaching TB5.
•
Check that the ribbon cable to the display is plugged in at both ends and fully seated.
•
Make sure power is disconnected and then remove fuse and check for continuity.
•
Check "V SELECT" switch is set for the input voltage in use. Never change this switch
•
with the power on!
Check everything but the fuse in the "Instrument does not light" section.
•
Check the "CONTRAST" pot on display board. Turn to both ends of it's travel while
•
watching the display. It's usually turned clockwise from factory.
Check instrument wiring. See "Normal wiring" for TB3 in the diagram section.
•
Measure between "24V (TB3-1) and PV1 –(TB3-3)". It should be between 22 & 24 VDC.
•
Go to "Checking sensor wiring"
•
Remove any cap seals from the sensor.
•
Remove the calibration plug for faster response time. See the sensor data sheet for
•
details.
Check instrument wiring(see above). The black wire from the sensor must be on PV1 (or
•
PV2) "+". If it's on a "-" terminal this problem will result.
Go to "Checking sensor wiring"
•
Open sensor box (4 screws). The circuit board mounts to the sensor on three gold pins.
•
Be sure the board is on all three pins and fully seated.
Check that the orange plug has not pulled loose from the sensor.
•
The sensor has a two-pin orange header but has a three-pin plug. From left to right with
•
the screws facing you the wires are red, black, then red & white twisted together. The
terminal with the red & white is the one not connected to the two-pin header (see GAS
SENSOR INTERNAL WIRING above).
Check for broken wires on the L.E.D. The side of the L.E.D. with the flat is the one that
•
goes to the leftmost terminal on the three-pin plug.
If no problems were found go to "Verify indicator operation".
•
Disconnect the sensor. Wire a 4-20mA generator as shown under "4-20mA POWERED
•
(ACTIVE) CALIBRATOR WIRING" in the diagram section.
Injecting 4mA will give a 0ppm reading and 20mA will give a 30ppm (or full-scale)
•
reading if the unit was setup for a standard Cl
This is not a problem. The sensors need to stabilize when first powered up. The alarms
•
are disabled until the stabilize delay timer disappears from the screen. This takes about
two minutes.
sensor.
2
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