Branch Circuits - Part One
Apr 1, 2007, By Mike Holt, NEC Consultant
Article 210 contains the requirements for conductor sizing, conductor identification, overcurrent protection, and GFCI and AFCI protection of branch circuits....
Article 820: Community Antenna TV and Radio Distribution Systems
Mar 1, 2007, By Mike Holt, NEC Consultant
Article 820 covers the distribution of television and radio signals via cable. This is in contrast to Art. 810, which covers the distribution of television...
Article 810: Radio and Television Equipment
Feb 1, 2007, By Mike Holt, NEC Consultant
Article 810 provides installation requirements for transmitter and receiver equipment as well as the associated wiring and cabling (Fig. 1). Article 810...
Article 800: Communications Circuits
Jan 1, 2007, By Mike Holt, NEC Consultant
Because Art. 800 has its roots in telephone technology, it addresses telephone and related systems that use twisted-pair wiring. The telephone utility...
The Ins and Outs of Optical Fiber Cable Installation
Dec 1, 2006, By Mike Holt, NEC Consultant
Several factors are driving the popularity of optical fiber cabling. Chief among those is the growth of high-tech applications that require the massive...
Fire Alarm System Facts
Nov 1, 2006, By Mike Holt, NEC Consultant
Article 760 tells us how to install wiring and equipment for fire alarm systems, including all circuits these devices control and provide power to. What...
Article 725: Around the Circuit Part 2
Oct 1, 2006, By Mike Holt, NEC Consultant
In last month's Code Basics article, starting on page 56 of the September issue, we spent most of our time discussing Class 1 circuits. Now, it's time...
Article 725: Around the Circuit Part 1
Sep 1, 2006, By Mike Holt, NEC Consultant
Any time you are working with burglar alarm, access control, sound, nurse call, or intercom systems, as well as computer networks, lighting dimmer controls,...
Legally Required and Optional Standby Systems
Aug 1, 2006, By Mike Holt, NEC Consultant
Emergency power systems (Art. 700) are at the top of the hierarchy of backup power systems. Legally required standby systems, which fall under Art. 701,...
Article 700: Emergency Systems
Jun 1, 2006, By Mike Holt, NEC Consultant
Essentially, emergency systems are lifelines for people, and Art. 700 is all about keeping those lifelines from breaking. The Article's main goal is to...
Power to the Pump
May 1, 2006, By Mike Holt, NEC Consultant
One of the principal NEC requirements for circuit protection is that you shut down the equipment rather than let supply conductors melt from overload....
Exploring Requirements for Information Technology Equipment
Apr 1, 2006, By Mike Holt, NEC Consultant
If you've ever seen a shutoff switch located just outside an information technology (IT) room, you may have wondered who in their right mind would install...
Applying Article 525 in Amusement Venues
Mar 1, 2006, By Mike Holt, NEC Consultant
If you do electrical work with temporary events, you obviously need to understand Article 525, which covers the installation of portable wiring and equipment...
Class and Division: Don't Break Rank on Your Next Installation
Feb 1, 2006, By Mike Holt, NEC Consultant
What exactly is a Class I location? Can you define it, or better yet, easily identify it in the field? You have a Class I location any time enough flammable...
An Inside Look at Hazardous (Classified) Locations
Jan 1, 2006, By Mike Holt, NEC Consultant
When you're looking for answers on hazardous (classified) location questions, where should you turn? Think of Articles 500 through 517 as a mini codebook...
Article 406: Receptacles
Oct 1, 2004, By Mike Holt, NEC Consultant
You might be surprised to learn just how many rules are associated with these simple devices...
Clearing Up Multi-Family Dwelling Unit Calculations
Sep 1, 2004, By Mike Holt, NEC Consultant
Calculating multi-family dwelling unit service sizes needn’t be a difficult process, but it can be if you don’t follow the right steps...
Dwelling Unit Feeder/Service Conductor Calculations
Aug 1, 2004, By Mike Holt, NEC Consultant
How do you size conductors for residential services and feeders?...
A change to 338.10 of the 2002 NEC
Jul 8, 2004, By Mike Holt
A change to 338.10 of the 2002 NEC is meant to clarify that when Type SE service-entrance cable is used for interior wiring...
Don't Get Your Signals Crossed When Installing Radio and TV Equipment
Jul 1, 2004, By Mike Holt, NEC Consultant
Whether it’s professional transmitting equipment or local ham radio, grounding is the key to a safe system...
Don't Let Voltage Drop Get Your System Down
Jun 1, 2004, By Mike Holt, NEC Consultant
Contrary to common belief, the NEC generally doesn't require you to size conductors to accommodate voltage drop. It merely suggests in the Fine Print...
Motors, Motor Circuits, and Controllers, Oh My!
May 1, 2004, By Mike Holt, NEC Consultant
Don’t be intimidated by the largest chapter of the NEC...
Installation and operation of optional standby systems
Apr 23, 2004, By Mike Holt
With last year’s blackout still lingering on the minds of many, the use of optional standby power systems is worth a closer look. ...
Cords and Fixture Wires
Apr 1, 2004, By Mike Holt, NEC Consultant
Correctly applying the requirements of Art. 400 and 402 can prevent serious problems...
Art. 300: Wiring Methods
Mar 1, 2004, By Mike Holt, NEC Consultant
After a small engine plant began experiencing severe power quality problems and the subsequent investigation showed the wireways weren't electrically...
