What is NOT a characteristic of the emergency stop control as per NFPA 160?

The correct answer indicates that an emergency stop control, as per NFPA 160, should not be overridden by the main show control system. This is because the primary function of an emergency stop control is to ensure safety during the use of flame effects in performances.

If such a control could be overridden, it poses a significant safety risk because it may prevent the emergency stop from functioning effectively when needed, undermining the purpose of having a fail-safe mechanism. Emergency stop controls are designed to be immediate and reliable, allowing operators to quickly halt flame effects if a hazardous situation arises. Therefore, maintaining the integrity of the emergency stop control as completely independent from the main show control system is critical for ensuring audience and performer safety.

In contrast, the other characteristics listed in the question affirm the purpose and reliability expected from an emergency stop system, such as being fail-safe, activating automatically in unsafe conditions, and requiring a manual reset, which are essential for maintaining operational safety standards as outlined in NFPA 160.