Walchem W600 Series Instruction Manual page 92

The chemical supply has run out.
The pump or valve or supply line is faulty.
Wrong chemical is being controlled.
The sensor is not responding to changes.
The pump is siphoning, valve leaking.
Control output has been left in "HAND" mode.
It may be a normal part of the process.
DI STATE CUSTOM MESSAGE
A digital input that is a DI State type can be set such that either the open or closed state generates an alarm. The alarm message may
be customized. The most common use for this will be a Flow Switch.
Possible Cause
No flow
Faulty flow switch/cable
Faulty controller
TOTAL ALARM
Occurs if the flow meter or feed monitor totalizer alarm limit is exceeded.
Possible Cause
Normal operation
AC coupled onto flow meter cable
Noise coupled onto flow meter cable
RANGE ALARM (for flow meter or feed monitor type digital inputs)
Occurs if the flow meter or feed monitor accumulated total is too large. The maximum total is 1 trillion times the increment of the
device. For example, if the increment is one gallon per pulse the maximum total is 1 trillion gallons.
Possible Cause
Normal operation
FLOW VERIFY
Occurs if the feed monitor digital input does not register any contacts while the control output for that pump has been active for longer
than the Flow Alarm Delay time.
Possible Cause
Metering pump has lost prime
Faulty metering pump
Incorrect feed monitoring device wiring
Faulty feed monitoring sensor
Blown fuse
Faulty output relay
Faulty digital input
OUTPUT TIMEOUT
This error condition will stop control. It is caused by the output (either relay or analog) being activated for longer than the programmed
Time Limit.
Possible Cause
The process went further out of control than normal.
The chemical supply has run out.
The pump or valve or supply line is faulty.
Wrong chemical is being controlled.
The sensor is not responding to changes.
Replenish the chemical supply.
Repair or replace the control device.
Replace with correct chemical.
Repair or replace sensor. Evaluate mixing or recirculation.
Repair or replace the control device or re-route tubing.
Switch back to "AUTO".
None required.
Corrective Action
Check piping for closed valves, blockage, etc. Check recirculation
pump.
Check with ohmmeter.
Check by shorting digital input in controller.
Corrective Action
Reset the total to clear alarm, or wait for the automatic total reset to occur.
Route cable at least 6 inches (150 mm) away from any AC voltage
Shield cable
Corrective Action
Reset the total to clear alarm, or wait for the automatic total reset to occur.
Corrective Action
Re-prime metering pump
Repair or replace metering pump
Correct wiring. Make sure that digital input that the feed monitoring
device is connected to has been assigned to the correct relay
Replace feed monitoring sensor
Verify the pump is getting power. Replace fuse
Replace relay board
Verify that feed monitoring device is making contact closures using
an ohmmeter. If OK, and connected properly, replace the controller
circuit board.
Corrective Action
Increase time limit or reset timer.
Replenish the chemical supply.
Repair or replace the control device.
Replace with correct chemical.
Replace sensor. Evaluate mixing or recirculation.
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