Did you know that arc welding on the frame rails or other frame-mounted components of an apparatus can damage electronic control units for the chassis multiplex electrical system and other devices?

Electronic control systems are usually grounded through the frame rails. Electrical arc welding can send dangerous current spikes through the rails and into these devices. Different systems have different methods of grounding and electrical isolation, so service personnel should always check the warning labels and warning notices published in maintenance manuals before arc welding any part of the frame. In some cases, temporarily disconnecting the ground connection to the electronics may be sufficient to avoid damage.

This feature offers a variety of short tips and facts about apparatus maintenance and testing. Look for it every month. Submissions of 150 words or less are welcome from our readers, subject to editing. Send them to Senior Editor Chris Cavette at cavettes@ix.netcom.com