Detcon TP-700 - Manual (Page 36)

Model TP-700
TP-700 Instruction Manual Rev. 3.5 Page 32 of 38
Nuisance Alarms
 Check condulet for accumulated water and abnormal corrosion on terminal blocks.
 If nuisance alarms are happening at night, suspect condensation in condulet. Add or replace Detcon’s
Condensation Prevention Packet P/N 960-202200-000.
 Investigate the presence of other target gases that are causing cross-interference signals.
 Determine if cause is RFI induced.
Processor and/or Memory Faults
 Recycle power in attempt to clear problem
 Restore Factory Defaults - This will clear the processor’s memory and may correct problem.
Remember to re-enter all customer settings for range and cal gas level after Restore Factory Defaults.
 If problem persists, replace the Intelligent Sensor Module.
Unreadable Display
 If due to excessive sunlight, install a sunshade to reduce glare.
Nothing Displayed – Transmitter not Responding
 Verify condulet has no accumulated water or abnormal corrosion.
 Verify required DC power is applied to correct terminals.
 Swap with a known-good ITM to determine if ITM is faulty.
Faulty 4-20mA Output
If Sensor has a normal reading with no Faults displayed, and the 4-20 mA signal output is 0mA….
 Check that wiring is properly connected at terminal blocks and through to controller inputs.
 The 4-20mA output loop must be closed to avoid a Loop Fault. If the 4-20mA output is not being
used the green wire from the sensor must be connected to the (-) terminal on the Transient Protection
Module to ensure that it does not create a 4-20mA Fault. (section 2.6 Field Wiring)
 Perform a “Signal Output Check” sequence via Section 3.5.7 and verify 4-20mA output with Current
Meter.
 Swap with new ITM to determine if the ITM’s 4-20mA output circuit is faulty.
 If the 4-20mA current loop is still out of tolerance, contact Detcon at
[email protected] , or contact
Detcon customer service.
No Communication - RS-485 Modbus™
If sensor has a normal reading with no Faults displayed and the Modbus™ is not communicating….
 Verify that the correct (and non-duplicated) serial address is entered (per Section 0).
 Check that the wiring is properly connected at terminal blocks, and the serial loop is wired correctly.
 Perform a “Signal Output Check” per Section 3.5.7 and troubleshoot wiring.
 Consider adding a Modbus™ repeater if the distance from the nearest distribution drop is excessive.
 Swap with new ITM to determine if the ITM’s serial output circuit is faulty.
 Refer to Detcon’s “Guide to Proper Modbus™ Communications” Application Note.