Sizing Junction Boxes
Oct 1, 2008, By Mike Holt, NEC Consultant
The sizing requirements for pull boxes, junction boxes, handhole enclosures, and conduit bodies exist to prevent conductor insulation damage. Those requirements...
Illustrated Catastrophes
Oct 1, 2008, By Joe Tedesco, NEC Columnist
As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC). Without...
Motor Calculations
Sep 1, 2008, By Mike Holt, NEC Consultant
To prevent a motor from burning up, you must provide a means of protecting it from overcurrent (overload, short circuit, or ground fault). If you can remember not to confuse motor protection with circuit protection, you’ll eliminate a major point of confusion in motor calculations....
Illustrated Catastrophes
Sep 1, 2008, By Joe Tedesco, NEC Columnist
As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC)....
Fill 'Er Up
Aug 14, 2008, By Mike Holt, NEC Consultant
Raceways must be large enough to hold conductors without overheating and avoid insulation damage during conductor pulls. Therefore, we must determine the maximum number and size of conductors to put in a given raceway. That limit is what we mean by raceway fill....
Conductor Size Matters
Aug 1, 2008, By Mike Holt, NEC Consultant
The NEC provides minimum size requirements for conductors to prevent overheating and fire....
Illustrated Catastrophes
Aug 1, 2008, By Joe Tedesco, NEC Columnist
Alan Christofk, a superintendent with Gephart Electrical Construction in Stillwater, Minn., found this unique installation at a gas station...
UL 1449 and the 2008 NEC
Jun 1, 2008, By Joseph DeGregoria, Underwriters Laboratories
The use of surge protective devices (SPDs) within residential, commercial, and industrial applications has sharply increased over the last decade...
Article 600: Electric Signs and Outline Lighting
Jun 1, 2008, By Mike Holt, NEC Consultant
Every commercial occupancy needs a form of identification, the standard method of which is typically the electric sign. This is one reason why you'll be working with Art. 600 if you do much commercial or industrial work....
Cathodic Protection Systems and the NEC
Jun 1, 2008, By Whitt L. Trimble and Eddie Guidry, Fluor Enterprises, Inc.
During the 2005 National Electrical Code (NEC) review cycle, a relatively simple revision was made that created a significant change on the cathodic protection (CP) systems of petroleum and chemical facilities (plants)....
Illustrated Catastrophes
Jun 1, 2008, By Joe Tedesco, NEC Columnist
Gary Parker, P.E., Burns & McDonnell, Centennial, Colo., found a circuit breaker panel installation that's gone through a few changes that do not comply with the NEC....
Ohio Home Builders Fight 2008 NEC Adoption
Jun 1, 2008,
The purpose of the National Electric Code (NEC) is the practical safeguarding of persons and property from the hazards arising from the use of electricity....
Illustrated Catastrophes
May 1, 2008, By Joe Tedesco, NEC Columnist
As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC). Without...
Article 450: Transformers and Transformer Vaults
May 1, 2008, By Mike Holt, NEC Consultant
The operation of any facility depends on power distribution, which, in turn, depends on transformers. Safe and reliable operation of transformers is crucial...
Illustrated Catastrophes
Apr 1, 2008, By Joe Tedesco, NEC Columnist
As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC). Without...
Article 424: Fixed Electric Space Heating
Apr 1, 2008, By Mike Holt, NEC Consultant
Considering the fact that it has nine parts, at first glance, Art. 424 might seem like overkill for a device as simple as a heater. Walk into any hardware...
Can You Hear Me Now?
Mar 1, 2008,
Despite protestations from the International Association of Electrical Inspectors (IAEI) Michigan Chapter, on Nov. 23, 2007, the 2005 Michigan Electrical...
Grounding and Bonding of Separately Derived Systems
Mar 1, 2008, Mike Holt, NEC Consultant
Separately derived systems (SDSs) include most transformers as well as any generator or UPS supplying a transfer switch that opens the neutral conductor....
Illustrated Catastrophes
Feb 1, 2008, By Joe Tedesco, NEC Columnist
As usual, never consider the following commentary associated with these photos as a formal interpretation of the National Electrical Code (NEC). Without...
Transformer Secondary Conductors
Feb 1, 2008, By Mike Holt, NEC Consultant
Similar to feeder taps, covered in the last issue, transformer secondary conductors can be every bit as confusing. Let's take a closer look at 240.21(C)...
