EXHAUST FAN INSTALLATION CONSIDERATIONS BASIC INFORMATION AND TUTORIALS

To turn the exhaust fan on and off, an ac general use, single-pole snap (toggle) switch is installed on the wall below the fan. The electrician will install an outlet box approximately 1 ft from the ceiling (see the electrical plan), from which he will run a short length of flexible metal conduit to the junction box
on the fan.

The fan exhausts the air from the Bakery. The fan is installed through the wall, approximately 18 in. below the ceiling.

Some occupancies will have a roof-mounted exhaust fan that is ducted to a supply grill on the ceiling of the facility or to hoods located above cooking equipment. NEC 430.111 permits this switch to serve as both
the controller and the required disconnecting means.

Important: As you study the following motor branch circuit information, be sure to clearly understand that 430.6(A)(1) tells us to select motor branch-circuit conductors, disconnecting means, controllers, and the branchcircuit short-circuit and ground-fault protection based on the current values found in Tables 430.247, 430.248, 430.249, and 430.250 rather than on the motor nameplate. NEC 430.6(A)(2) instructs us to use the actual motor nameplate current rating to determine the motor’s overload protection.