Obstruction threshold during installation?

• A. 15 lbs
• B. 5 lbs
• C. 50 lbs
• D. 100 lbs

Answer: (A)

Obstruction threshold during installation is the force on the safety sensing device that makes the escalator or moving walk stop when something blocks it. This setting is chosen to detect real obstructions promptly without being overly sensitive to normal contact from installers and tools.

The 15-pound threshold hits a practical balance: it’s light enough to trigger a stop for small obstructions or accidental contact, which protects workers and the equipment during installation, but not so light that every brush or light touch causes an unnecessary shutdown. If the threshold were much lower, minor contact could cause frequent stops, slowing work and causing nuisance resets. If it were much higher, larger obstructions could pass through before the system responds, increasing the risk of injury or damage. So, 15 pounds is selected to provide reliable protection during installation while avoiding excessive interruptions.