Which description applies to Type B1 Monitored Non-Contact Sensor Entrapment Protection?

Which description applies to Type B1 Monitored Non-Contact Sensor Entrapment Protection?

• A. An external mechanical edge device
• B. A photo eye beam or infrared beam mounted within 5 inches of moving gate panel and 21 to 27.5 inches above grade
• C. An inherent force limiting device
• D. Only used on swing gates

Answer: (B)

Monitored non-contact entrapment protection uses safety beams to detect any obstacle in the gate’s path without touching it, and the system stops or reverses to prevent injury. This approach relies on a beam network that is continuously monitored by the control system, so if a beam is interrupted or its circuit fails, the gate halts immediately. The described mounting—a photo eye or infrared beam placed very close to the moving gate panel (within 5 inches) and at a height between about 21 and 27.5 inches above grade—is exactly how this protection is implemented. Positioning the beams near the edge where entrapment could occur ensures that a person or object is detected before a limb or body gets trapped, and the specific height targets the common entrapment zone while staying out of normal reach for most small animals and debris. The term “monitored” is key: the safety logic constantly checks that the beams are clear and functioning. If the beam path is broken without a valid command to move, or if a transmitter/receiver fault happens, the gate responds by stopping, protecting anyone nearby. In contrast, an external mechanical edge device relies on physical contact to detect contact, which is a different, less ideal solution for entrapment. An inherent force limiting device reduces closing force but does not detect entrapment. And safety beams like this are not limited to swing gates; they’re used on various gate types where entrapment protection is needed.

Monitored non-contact entrapment protection uses safety beams to detect any obstacle in the gate’s path without touching it, and the system stops or reverses to prevent injury. This approach relies on a beam network that is continuously monitored by the control system, so if a beam is interrupted or its circuit fails, the gate halts immediately.

The described mounting—a photo eye or infrared beam placed very close to the moving gate panel (within 5 inches) and at a height between about 21 and 27.5 inches above grade—is exactly how this protection is implemented. Positioning the beams near the edge where entrapment could occur ensures that a person or object is detected before a limb or body gets trapped, and the specific height targets the common entrapment zone while staying out of normal reach for most small animals and debris.

The term “monitored” is key: the safety logic constantly checks that the beams are clear and functioning. If the beam path is broken without a valid command to move, or if a transmitter/receiver fault happens, the gate responds by stopping, protecting anyone nearby.

In contrast, an external mechanical edge device relies on physical contact to detect contact, which is a different, less ideal solution for entrapment. An inherent force limiting device reduces closing force but does not detect entrapment. And safety beams like this are not limited to swing gates; they’re used on various gate types where entrapment protection is needed.