7. Errors and error remedying
50
7.1.17 External error
Possible causes
Remedy
Error signal at the external error input of the IO
electronics board.
Alarm message of the frequency inverter.
For example:
Thermal contact of motor protection.
Find the cause of the external error and remedy it.
7.2 Undefinable activation of the switching outputs
Possible causes
Remedy
Improper installation of the search coil
See operational manual detector coil: "Mounting"
Conveyor belt systems:
Intermittent contacts on the conveyor frame for
example due to:
Loose guide plates
Loose screw connections on the frame parts
Changing contact resistance on the tension and
deflection roller bearings or on the drive roller
Certain parts of the conveyor belt are conductive:
Contaminated with metal (welding spatter,
me
tal chips, abraded material….).
Belt junction causing metal alarm to signal
even when no product on moving conveyor.
Check and tighten all screw connections
If necessary weld frame parts.
Insulate cross connections or tension and deflec-
tion rollers on one side.
Clean conveyor belt of all residue.
If necessary replace conveyor belt.
Circular coils:
Mechanical contact between scanning pipe and
detection coil.
Observe a minimum distance of 10mm between
pipe and coil. If necessary use a scanning pipe
with smaller diameter.
Sensitivity setting too high.
Repeat product teach-in procedure, if necessary
reduce sensitivity manually.
Metal particles hard to identify due to corrosion or
encapsulation.
Check processed material carefully, if necessary
pass through detector again.
Loose contact at the detector cables.
Check connections.
Material or conveyor statically charged (cracking
sound heard at the detection coil).
Prevent static by additional earthing (please con-
sult manufacturer) or by using ion spraying devic-
es.