What shall be installed at an approved location to shut off fans or blowers in flammable vapor or dust ventilation systems?

The installation of a manually operated remote control for shutting off fans or blowers in flammable vapor or dust ventilation systems is essential for ensuring safety in environments where hazardous materials may be present. This type of control allows for immediate operator intervention in case of an emergency, providing a rapid way to stop ventilation systems when necessary.

In environments with flammable vapors or dust, it is critical to have a reliable method of quickly shutting off equipment to mitigate risks associated with potential ignition sources. The manual remote control allows personnel to de-energize fans or blowers without entering potentially dangerous areas, enhancing safety and response time.

Other options, while they may serve useful purposes, do not prioritize the immediate and manual response needed in hazardous conditions. Automatic timer switches, for instance, proceed based on predetermined schedules rather than operator discretion, which could be detrimental in unexpected situations. Similarly, thermostatically controlled switches and wireless remote controls may not provide the quick access that a manual control does, thereby failing to ensure immediate action when facing the risk of flammable atmospheres.