Appliances shall be installed in accordance with the manufacturer's installation instructions. [NFPA 54:220.127.116.11]
Appliances shall be installed on a well-drained surface of the roof. At least 6 feet (1829 mm) of clearance shall be available between any part of the appliance, and the edge of a roof or similar hazard, or rigidly fixed rails, guards, parapets, or other building structures at least 42 inches (1067 mm) in height shall be provided on the exposed side. [NFPA 54:18.104.22.168]
All appliances requiring an external source of electrical power for its operation shall be provided with the following:
- A readily accessible electrical disconnecting means within sight of the appliance that completely de-energizes the appliance.
- A 120 V-ac grounding-type receptacle outlet on the roof adjacent to the appliance on the supply side of the disconnect switch. [NFPA 54:22.214.171.124]
Where water stands on the roof at the appliance or in the passageways to the appliance, or where the roof is of a design having a water seal, a suitable platform, walkway, or both shall be provided above the waterline. Such platform(s) or walkway(s) shall be located adjacent to the appliance and control panels so that the appliance can be safely serviced where water stands on the roof. [NFPA 54:126.96.36.199)]