CSLB C-27 Landscaping ContractorHardscape and FeaturesMedium
A landscape contractor is installing a new automatic gate opener system for a residential driveway. To comply with safety regulations and prevent entrapment, which type of safety device is explicitly required at both the leading edge of the gate (in the direction of travel) and at potential crushing points?
- AAudible alarms
- BPhotoelectric sensors
- CMotion sensors
- DPressure-sensitive edge sensors
Show answer & explanationAnswer & explanation
Correct answer: D. Pressure-sensitive edge sensors
UL 325 safety standards, adopted by many building codes, specifically require pressure-sensitive edge sensors (or equivalent non-contact sensors) at leading edges and potential crushing points of automatic gates. These devices detect contact and reverse the gate's movement to prevent entrapment or injury.
Why the other options are wrong
- A. Audible alarms warn of gate movement but do not prevent physical entrapment or crushing.
- B. Photoelectric sensors (safety beams) detect objects crossing a path but may not cover all crushing points or activate upon contact.
- C. Motion sensors detect movement near the gate but don't provide direct entrapment protection at the pinch points.
Automatic Gate Safety Devices
Automatic gates must incorporate safety devices to prevent entrapment and injury. Key devices include photoelectric sensors (safety beams) and pressure-sensitive edge sensors to detect obstructions and reverse gate movement.
- UL 325 is the primary safety standard for gate operators.
- Pressure-sensitive edges are often required at leading edges and pinch points.
- Safety beams (photoelectric sensors) are also critical for detecting objects in the gate's path.
Memory trick: Gate Safety: Don't Get Pinched, Get Edged!