- Identify the types of entrapment protection devices required under CSA standards
- Explain photoelectric sensor mounting and testing requirements
- Describe sensing edge operation and monitored safety systems
- Differentiate constant-pressure controls from automatic operation
- Apply the correct entrapment protection for residential and commercial applications
Lesson 1
Entrapment Device Types & Classifications
What Is Entrapment Protection
Entrapment protection prevents a closing garage door from trapping a person, animal, or object. Canadian standards require that every power-operated garage door have at least one entrapment protection device. The specific requirements depend on the type of door, its application, and the control system used.
Primary Devices
Photoelectric sensors - infrared beam across the opening
Sensing edges - pressure-sensitive strip on door bottom
Constant-pressure controls - door moves only while button is held
Secondary Device
Auto-reverse mechanism - built-in force-sensing reversal
Required on all residential openers as a secondary backup
Must reverse door within 2 seconds of obstruction contact
Classification Under CSA C260
CSA C260 classifies entrapment protection devices into categories:
- Type A - External entrapment protection that detects an obstruction before the door contacts it (photo eyes, light curtains)
- Type B - Contact-type protection that detects an obstruction when the door touches it (sensing edges, auto-reverse)
- Constant-pressure - Not a detection device per se, but a control method that requires continuous operator input
Monitored vs. Non-Monitored Systems
Monitored entrapment protection systems continuously verify that the safety device is connected and functional. If a wire is cut or a sensor fails, the system detects the fault and prevents automatic door operation. CSA standards increasingly require monitored systems for new installations.
Exam Distinction
The exam will test whether you understand the difference between monitored and non-monitored systems. A monitored system detects sensor failure and prevents operation; a non-monitored system may continue operating even if a sensor is disconnected.
CSA C260 requires entrapment protection on all power-operated garage doors. Type A devices (photo eyes) detect obstructions before contact; Type B devices (sensing edges) detect on contact. Monitored systems verify sensor integrity and prevent operation if a sensor fails.