Top 10 Most Common
Light Curtain Issues

As an authorised distributor of ABB products and safety items, we at Rowse have seen and installed many systems that use light curtains. While these are now quite widely used, there still seem to be several misconceptions about how light curtains are supposed to function. We have therefore reviewed a selection of the common problems encountered with light curtain applications, and list below the top ten most frequent issues.

1. Too Close To The Safety Hazard

The basic requirement for a safety light curtain circuit is that it must halt the hazardous process before anyone can reach it. The best method of checking whether a light curtain is effective is to monitor the stop times via a video feed. On many systems, we find that the hazard does not halt quickly enough to prevent a safety threat. In order to remedy this situation, we t

ypically recommend several solutions. These include simply moving the light curtain to a safer distance, and/or implementing minor changes to the drives and controls.

2. Inconsistent Halting Of The Safety Hazard

This example of the top ten most common issues with light curtains is most frequently found in pneumatic systems. Calculating the right stop distance for a light curtain can be difficult, if the worst case scenario stop time can't be pinned down. Pneumatic systems are subject to problems with trapped air, but issues can also arise from a totally vented cylinder; for example, causing a quick initial movement.

3. Guard Gaps

A safety light curtain wont be able to protect your workers if the guards surrounding the unit have openings that allow them to reach under or around it. Any potential gap in protection may tempt people to do things that they shouldnt be doing!