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Page 25
8. Troubleshooting
8.1 Instrument Function Troubleshooting
Symptom
Possible Causes
Remedy
No display
1. Mains power input not
switched on.
2. Mains power input
incorrectly connected.
3. Instrument is faulty.
Switch power ON.
Check connections (see
section 3.4.1).
Return to TPS for repair.
Alarm LED or
relay output do
not operate when
limit is exceeded.
1. Limit not set correctly for
“too high” or “too low”
alarm/control.
2. Hysteresis too large.
3. Fuse has blown.
4. Instrument is faulty.
Set the
J3
or
J4 Polarity
jumpers correctly (see
section 3.5.3 ).
Check and adjust the
Hysteresis trimmer (see
section 3.5.4). If in doubt,
set this to minimum level.
Check and replace fuse if
necessary (see section 7).
Return to TPS for repair.
Incorrect
analogue output
signal.
1.
Current/Voltage Output
jumpers incorrectly set
for required output.
2. 4-20mA loop resistance
too high.
3. Load on 0-1V DC output
is too low.
4. 4-20mA output is not
calibrated.
5. Instrument is faulty.
Check that the
Current/Voltage Output
jumpers are correctly set for
4-20mA or 0-1V, as per
requirements. Adjust if
necessary (see section 3.6).
Ensure loop resistance does
not exceed 500 Ohms.
Ensure load is 1000 Ohms
minimum.
Calibrate 4-20mA output
(see section 3.7).
Return to TPS for repair.