Oklahoma Electrical Practice Exam

What is the minimum fire rating of a vault door that has an automatic sprinkler system for fire protection?

1. 30 minutes

2. 1 hour

3. 2 hours

4. 3 hours

The correct answer is: 1 hour

A vault door equipped with an automatic sprinkler system is required to meet specific fire safety standards to minimize the risk of fire damage. In this case, a fire rating of 1 hour is considered the minimum acceptable level of protection. This is based on codes that recognize that automatic sprinklers effectively reduce the spread of fire and heat, allowing for a slightly lower fire rating compared to vaults without such systems. The rationale is that while a 1-hour fire rating provides adequate protection in conjunction with the sprinkler system to manage potential fires, it effectively balances safety requirements with practicality for storage spaces like vaults. A higher fire rating, such as 2 or 3 hours, may be necessary for certain structures or materials that do not benefit from sprinkler protection, but in environments with automatic systems, a 1-hour rating suffices for general fire safety compliance.