Arcing Parts, Markings, & Disconnecting Devices

Parts of electrical equipment that produce arcs, sparks, flames, or molten metal must be enclosed or separated and isolated from all combustible material.

Electrical equipment cannot be used unless the manufacturer's name, trademark, or other identification and other markings providing voltage, current, wattage, or other ratings have been placed on the equipment. These markings must be durable enough to withstand the environment in which the equipment is located.

OSHA regulations set forth the following requirements to ensure that the disconnection equipment is installed properly and that circuits can be disconnected safely:

• Motors and appliances: Each disconnecting device required for motors and appliances must be legibly marked to indicate its purpose, unless located and arranged so that the purpose is evident.
• Services, feeders, and branch circuits: Each service, feeder, and branch circuit, at its disconnecting means or overcurrent device, must be legibly marked to indicate its purpose, unless located and arranged so that the purpose is evident.
• Capable of accepting a lock: Disconnecting devices must be capable of being locked in the open position.
• Marking for series combination ratings: Where circuit breakers or fuses are applied in compliance with the series combination ratings marked on the equipment by the manufacturer, the equipment enclosures must be legibly marked to indicate that the equipment has been applied with a series combination rating. This marking must be readily visible and state "Caution-Series Combination System Rated __ Amperes. Identified Replacement Component Requirement."

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