Surge Suppression Devices
Sep 9, 2009, By Mike Holt, NEC Consultant
Avoid transient voltage problems by understanding how to correctly apply Art. 285 of the National Electrical Code (NEC)...
Refrigeration Systems and the Electrician
Sep 1, 2009, By David Herres, Master Electrician
One of the great inventions of our time in terms of its social impact and influence on the health care and food preservation industries refrigeration...
Code Quandaries
Sep 1, 2009, By Mike Holt, NEC Consultant
Q. What are the NEC grounding requirements for satellite dishes?...
Air-Conditioning and Refrigeration Equipment
Sep 1, 2009, By Mike Holt, NEC Consultant
Article 430, the largest Article in the NEC, is commonly understood to be the “motor” Article...
Illustrated Catastrophes
Sep 1, 2009, By Brian J. McPartland, NEC Consultant
These two installation photos were contributed by Pierre Belarge, president of Electrical Training Solutions in Elmsford, N.Y. Belarge, who is an International...
The Changing Power Needs of Nursing Homes
Sep 1, 2009, By Burton Klein, P.E., Burton Klein Associates
In the 1960s, a group of surgeons and anesthesiologists in Arizona came up with a revolutionary concept that would forever change the face of medicine:...
Pools and Spas — Part 3 of 3
Jun 1, 2009, By Mike Holt, NEC Consultant
How to meet Art. 680 requirements for wiring fountains, pools, and spas per the National Electrical Code (NEC)...
Pools and Spas — Part 2 of 3
May 1, 2009, By Mike Holt, NEC Consultant
How to meet Art. 680 requirements for wiring pools and spas per the National Electrical Code (NEC)...
The Evolution of Solar Photovoltaic Systems
May 1, 2009, By Ron Slade, P.E., Solar Consultant
Although NEC rules for photovoltaic (PV) systems haven’t changed much over the years, confusion still surround some portions of Art. 690...
Stumped by the Code
Apr 1, 2009, By Mike Holt, NEC Consultant
Q. We have a 400A, 3-phase feeder that we want to wire with two parallel sets of 3/0 AWG conductors in the same raceway. Is this acceptable?...
Pools and Spas — Part 1 of 3
Apr 1, 2009, By Mike Holt, NEC Consultant
If Art. 680 of the National Electrical Code (NEC) has one overriding concern, it's to keep people and water separated from electricity. Article 680 applies to pools, spas, hot tubs, fountains, and similar bodies of water....
Electrical Services — Part 2
Mar 1, 2009, By Mike Holt, NEC Consultant
Looking at Fig. 230.1 in the NEC, we can see that the second and third major areas of Art. 230 provide requirements for service entrance conductors (Part...
680.26 Equipotential Bonding for Swimming Pools, Spas and Hot Tubs
Feb 19, 2009, By Mike Holt
Electrical Services — Part 1
Feb 1, 2009, By Mike Holt, NEC Consultant
If you look at Fig. 230.1 in the NEC, you'll see that Art. 230 divides neatly into three general of coverage. The first includes general requirements,...
How Much Working Space Is Enough?
Jan 1, 2009, By Mike Holt, NEC Consultant
In order to create safe working conditions, OSHA and the NEC [110.26] provide working space requirements that vary according to the hazards involved with...
Box Fill Calculations
Nov 1, 2008, By Mike Holt, NEC Consultant
Box fill isn't just the number of wires in the box — it's the total volume of the conductors, devices, and fittings in a box....
Illustrated Catastrophes
Nov 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)....
What's Wrong Here?
Oct 1, 2008, By Joe Tedesco, NEC Columnist
How well do you know the Code? Think you can spot violations the original installer either ignored or couldn't identify? Here's your chance to moonlight...
Stumped by the Code?
Oct 1, 2008, By Mike Holt, NEC Consultant
Q. I have a 1,200A, 480V panel that has a working space of 3½ feet. The engineer says 7 feet is required. Is he correct?...
