User's Manual

30 Rockwell Automation Publication 440G-UM004C-EN-P - August 2020
Chapter 6 Device Status and Troubleshooting
Troubleshooting
Mounting Holes of the Switch Body Cracked or Broken
The mounting hole of the switch body can crack when washers are used to
mount the switch or when an incompatible thread locking compound is used
to secure the mounting hardware. Three M5 fasteners are required to mount
the switch body properly. Do not over torque the screws.
Check the manufacturer specifications of any thread-locking compound used
to secure the screws. It is recommended to use a cyanoacrylate-type
compound. Other compounds can cause stress cracks in the plastic feet of the
switch.
IMPORTANT Do not use a washer with the screw at the base of the switch body. Using a
washer causes the plastic to crack.
Loctite 242 thread-locking adhesive is known to cause stress cracks in the
plastic housing of the 440G-MZ safety switch and should not be used. Lab tests
have determined that Loctite 425, a cyanoacrylate adhesive, does not cause
cracking and can be considered if the faster cure time is acceptable in the
application.