What is the minimum depth of a working platform required for each rooftop appliance when the slope of the roof pitch is three inches?

The minimum depth of a working platform required for rooftop appliances on pitched roofs is determined by the slope of the roof. In this case, with a pitch of three inches, the establishment of a safe and practical working area is essential.

A dimension of 30 inches provides sufficient space for technicians to maneuver around the equipment safely while performing maintenance or repairs. This depth ensures that the platform allows for adequate accessibility to the rooftop appliance without the risk of slipping or falling due to the incline of the roof.

As for the other depth options, they either exceed the minimal requirements or may not provide practical considerations for routine inspection and servicing tasks. The focus is on achieving both safety and functionality for those working on rooftop units, making 30 inches the most appropriate choice in this scenario.