A rooftop exhaust system for exhausting air from a building, comprising a housing including one or more sides; a motor mounted in the housing; a fan rotatively mounted in the housing and driven by the motor; a support disposed generally underneath the housing for supporting the housing the housing having the motor and the fan being pivotally connected to the support and moveable between a closed position where exhaust air moves upwardly through the support and through the housing and an open position where the housing is tilted with respect to the support and access car be gained to the fan and the motor; a motor disconnect switch mounted on the side of the housing and moveable back and forth from an on position to an off position; the motor disconnect switch being operatively connected to the motor or to a source of electricity for the motor and configured to prevent the motor from being energized when the motor disconnect switch is in the off position; and a mechanical motor lockout being stationary mounted adjacent to and aligned with the motor disconnect switch and configured to: (a) engage the motor disconnect switch when the switch is in the on position and to move the motor disconnect switch to the off position in response to the housing pivoting from the closed position to the open position, and (b) lie in the path of the motor disconnect switch when the housing assumes the open position, preventing the motor disconnect switch from moving from the off position to the on position. a housing including one or more sides; a motor mounted in the housing; a fan rotatively mounted in the housing and driven by the motor; a support disposed generally underneath the housing for supporting the housing the housing having the motor and the fan being pivotally connected to the support and moveable between a closed position where exhaust air moves upwardly through the support and through the housing and an open position where the housing is tilted with respect to the support and access car be gained to the fan and the motor; a motor disconnect switch mounted on the side of the housing and moveable back and forth from an on position to an off position; the motor disconnect switch being operatively connected to the motor or to a source of electricity for the motor and configured to prevent the motor from being energized when the motor disconnect switch is in the off position; and a mechanical motor lockout being stationary mounted adjacent to and aligned with the motor disconnect switch and configured to: (a) engage the motor disconnect switch when the switch is in the on position and to move the motor disconnect switch to the off position in response to the housing pivoting from the closed position to the open position, and (b) lie in the path of the motor disconnect switch when the housing assumes the open position, preventing the motor disconnect switch from moving from the off position to the on position. (a) engage the motor disconnect switch when the switch is in the on position and to move the motor disconnect switch to the off position in response to the housing pivoting from the closed position to the open position, and (b) lie in the path of the motor disconnect switch when the housing assumes the open position, preventing the motor disconnect switch from moving from the off position to the on position.