Use general safety precautions for troubleshooting.
If a component must be replaced, perform the proper power down procedures. Use
standard electrical safety procedures for troubleshooting hot circuits for voltage
tests. Beware of pinch points on the machine.
PROCEDURE:
- Locate the proximity switch in question.
- The LED on the proximity switch must be on if the object to be sensed is
present at the switch. The proximity switch is detecting the object and operating
normally if the switch LED is "on". If the LED is off, check the
proximity switch plug to see if it is tightly connected. If the proximity
switch LED is on and the object to be sensed is not near it, make sure the
end of the switch is not touching a metal surface and that it's clean.
- If neither light is on and the object is not sensed by the proximity switch,
use a metallic object to check the sensing of the switch. Do this by placing
a metallic object such as a tip of a screwdriver no more than 3/16" [5
mm] away from the proximity switch. This should cause the LED to turn on.
If the LED does turn on, make sure the sensing part is in the correct location
and reposition the proximity switch so the sensing part can make the proximity
switch.
- To adjust the proximity sensor, remove the sensor wire attached to the
proximity switch. Loosen the jam nut on the proximity switch. Turn the proximity
switch so that the sensing face of the switch moves closer to the object it
senses. Reconnect the sensor wire (This should cause the LED to light).
Never place
LockTite on the jam nuts to prevent them from loosening. Proximity switches
do fail over time and having LockTite on the jam nuts will make removal extremely difficult and time consuming.
- With the proximity switch repositioned, test the station to check the new
position. If the sensing object is actuating but the light is not on, then
the proximity switch is functional but the LED is burned out. Check all connections
at the proximity switch and Main Electrical Panel. If all connections are
good then replace the proximity switch.
- If the proximity switch still does not work, remove it and replace it with
a new one.
- If the fault still exists, check the corresponding input LED in the Main
Electrical Cabinet.
If the input is ON, the LED on the proximity switch may have burned out, but
the switch is still operational. If the input is OFF, replace the proximity
switch plug with a new one.
- If the fault still exists, check the wiring and electrical circuit.