Visible notification appliances must not have a candela rating less than ____ when installed in a corridor.

Visible notification appliances must not have a candela rating less than ____ when installed in a corridor.

• A. 10
• B. 15
• C. 20
• D. 25

Answer: (B)

The key idea is that visual notification appliances along escape routes must meet a minimum light intensity so occupants can see them clearly while moving through a corridor. The required minimum in corridors is fifteen candela. This level helps ensure the strobe is visible at typical corridor distances and mounting heights even with normal background lighting and some smoke. A lower rating, like ten candela, could fail to be seen promptly in many corridor setups, while higher ratings (twenty or twenty-five candela) may be used in certain installations or by code exceptions, but the requirement specifies the minimum as fifteen candela.

The key idea is that visual notification appliances along escape routes must meet a minimum light intensity so occupants can see them clearly while moving through a corridor. The required minimum in corridors is fifteen candela. This level helps ensure the strobe is visible at typical corridor distances and mounting heights even with normal background lighting and some smoke. A lower rating, like ten candela, could fail to be seen promptly in many corridor setups, while higher ratings (twenty or twenty-five candela) may be used in certain installations or by code exceptions, but the requirement specifies the minimum as fifteen candela.