Abort switches, where provided, have which key features?

• A. Located within the protected area near the means of egress; require constant manual pressure; override by normal manual control and manual emergency control; audible and visual indication of impairment.
• B. Located outside the protected area; remote operation; no override requirement.
• C. Not required for protection; optional.
• D. Located at the control panel; hand-operated but not near egress.

Answer: (A)

Abort switches are designed to give people inside the protected area a deliberate way to stop a discharge if someone is still present or a discharge was started in error. The best practice places these switches inside the protected area, near the means of egress, so they’re reachable without having to evacuate through the danger zone. They must be held with constant manual pressure to keep the abort active, ensuring the action is intentional and not the result of a momentary touch. There is an override path so that the normal manual discharge control and manual emergency control can still initiate discharge when needed. Finally, there’s audible and visual indication if the abort circuit is impaired, so operators are aware of any fault that could prevent safe operation. This combination of location, hold-to-act operation, override capability, and impairment signaling aligns with how abort functionality is intended to support safety in the system.