Troubleshooting; Intermittent False Trips - Advanced Detection Systems 1200E Series Installation Manual And Owner's Manual

TROUBLESHOOTING

WARNING: Whenever wiring is to be done to the terminal stop of the
detector, make sure ALL sources of power have been disconnected. Terminals
3 through 9 may be powered from sources other than those supplying the
metal detector. Caution should be used when working on machinery as
components may stop and start automatically without warning.
Most faults found with metal detector installations occur in the external
system or in the surroundings of the machine. As a result, the best way to
troubleshoot a detector is to go through the mechanical and electrical
installation sections.
Remember:
There should be one ground to the detector, conveyor, and reject.
The metal detector should be installed away from pulleys and motors.
All support feet should be firmly on the floor to prevent rocking.
There should be no fixed or moving metal within the metal-free zone.
Nothing should be in contact with the inside of the metal detector
aperture.
Voltage sags or surges greater than 10% can cause false triggers.
Two pieces of metal making intermittent contact in the vicinity of the
detector will cause false triggers. Check for loose nuts and bolts.

INTERMITTENT FALSE TRIPS

Observe the surroundings.
When the detector trips, try to figure out what could be causing it.
Look for two pieces of metal making intermittent contact in the vicinity
of the metal detector.
Look for starting/stopping of nearby machinery.
Verify that the electrical ground to the detector is making solid
connection.
Check for static electricity around the metal detector. Control static by
using an antistatic spray or by grounding the support frame and pipe.
If the detector has a remote mounted control cabinet, make sure that the
connecting cable is securely fastened to prevent movement.
Check to see if the rejection device is binding when it moves, causing
excessive vibration.
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