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IAEI Magazine | Author: Daniel R. Neeser
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Daniel R. Neeser

Dan Neeser is a field application engineer with Cooper Bussmann. He has been associated with Cooper Bussmann since 1996 and specializes in training on the design and application of overcurrent protective devices in electrical distribution systems in accordance with the National Electrical Code®, and equipment in accordance with the various product standards. He participates in IEEE, NEMA, NFPA, and IAEI activities. Prior to his position with Cooper Bussmann, he was a sales engineer for a large electrical manufacturer focusing on construction project sales. He received his B.S.M.E. from the University of North Dakota, and is a committee member of NFPA 79.


Manual Motor Controllers and Self-Protected Combination Motor Controllers Used in Industrial Control Panels

Some of the most commonly used, but often misunderstood and misapplied devices in industrial control panels are manual motor controllers and self-protected combination motor controllers. The advantage of these devices is the reduced cost and size when compared to traditional motor controllers and combination motor starters.

NEC Requirements for Short-Circuit Current Ratings

Overcurrent protective device interrupting rating (IR) and equipment short-circuit current rating (SCCR) are key considerations for the safety of commercial and industrial electrical systems. If inadequate overcurrent protective device IR or equipment SCCR is present, a serious potential safety hazard exists.

How to Determine Short-Circuit Current Ratings

Caveat emptor: buyer beware! That designer watch or handbag might not hurt you but buy that discounted holiday light string or off-brand electrical equipment and you may live to regret it. Or worse yet, you may not.

Marking of Available Short-Circuit Current

In the 2011 National Electrical Code® (NEC) Report on Proposals (ROP) process, two proposals were submitted and accepted that required the marking of the amount of available fault current on service equipment or enclosures that contain service or feeder overcurrent protective devices. The intent of the proposals was to provide a marking of the maximum available fault current to assist owners, designers, engineers, installers, inspectors and others concerned with the proper selection and application of equipment in accordance with the requirements of NEC 110.9 and 110.10. Section 110.9 covers the requirements for interrupting rating (IR) of equipment, such as overcurrent protective devices.

Selection of Arc-Fault Circuit Interrupters

The 2002 National Electrical Code (NEC) requires that the branch circuits supplying outlets of dwelling unit bedrooms, as well as mobile homes and manufactured home bedrooms, be protected by arc-fault circuit interrupters (AFCIs). Rules 210.12 and 550.25 are clear in this requirement. However there is considerable confusion as to which type of AFCI meets the intent of the Code.