Walchem WebMaster ONE Instruction Manual page 172

Rate High Alarm
The rate for a flow meter input or counter input has exceeded its programmed maximum limit.
Possible Causes
The system has experienced too high a rate
The rate high alarm point is too low
You are getting false contacts.
Rate Low Alarm
The rate for a flow meter input or counter input is less than its programmed minimum limit.
Possible Causes
The system has experienced too high a rate
The rate low alarm limit is too high
The input is no longer connected
Faulty device
Faulty digital input
Sensor calibration time
Normal condition; programmed calibration reminder time has elapsed
4-20 mA Input Sensor Error
This error message is caused by a 4-20 mA input signal that is less than 3.9 mA or greater than 21
mA.
Possible Causes
Faulty transmitter.
Faulty wiring between transmitter and
analog input option circuit board.
Faulty analog input option circuit board.
Corrective Actions
Evaluate system
Go to the input page and reset the limit
Go to the appropriate Input Page and verify
that the total is increasing even when the
solution is not flowing.
Disconnect the input cable from the
controller and verify that the flow total stops
increasing. Route the input cable away
from any AC voltage and make sure that the
cable is shielded.
Corrective Actions
Evaluate system
Go to the input page and reset the alarm limit
Check the wiring. Short the cable at the device
end to verify that it is OK.
Repair or replace the device.
If shorting the input does not yield a count,
replace the input circuit board.
Corrective Actions
Make sure that the transmitter is functioning
by measuring the output using an ammeter. If
the output directly from the transmitter is less
than 4 mA, the transmitter is the problem.
Repeat the measurement of the transmitter
output at the 4-20 mA input option board
terminal strip. If this is less than 4 mA, then
the wiring is faulty. Also make sure that the
wires are attached to the correct terminals as
defined in the 4-20 mA Input Page.
Replace the 4-20 mA input option board.
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