ICC Residential Electrical Inspectors Practice Exam

What must be installed on the disconnecting means for heating equipment containing motors rated over 1/8 hp?

1. a permanent tag

2. a warning sign

3. a lock

4. a circuit identifier

The correct answer is: a lock

For heating equipment that contains motors rated over 1/8 horsepower, it is essential to install a lock on the disconnecting means. This requirement is grounded in safety protocols designed to prevent accidental energization of the equipment while maintenance or repair work is being carried out. The use of a lock ensures that only authorized personnel can access and operate the disconnecting means, thereby reducing the risk of electrical shock or injury. By securely locking the disconnect, it provides a clear indication that work is being performed and prevents unauthorized or accidental reactivation of the equipment. The other options, while they may have their own purposes in electrical installations, do not provide the same level of safety assurance as a lock. For example, a permanent tag would communicate information but would not physically prevent operation, and a warning sign may alert individuals to potential hazards but lacks the physical security necessary in a maintenance context. A circuit identifier could assist in identification but does not enhance safety during maintenance tasks. Therefore, the installation of a lock is the most appropriate requirement in this scenario, aligning with safety standards and practices.