Q. Does the Code permit a circuit breaker to be installed horizontally?
A. Enclosures that contain overcurrent protection devices must be mounted in a vertical position unless this isn’t practical (240.33). However, where circuit breaker handles are operated vertically, the “up” position of the handle must be in the “on” position (240.81). So in effect, an enclosure that contains one circuit breaker can be mounted horizontally, but an enclosure that contains a panelboard/load center with multiple circuit breakers would have to be mounted vertically.
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