Mike Holt

Articles by Mike Holt
Code Q&A
Q. I heard that the Code only permits one equipment grounding (bonding) conductor to terminate on a grounding block screw terminal. Is this true? A. No. The number of equipment grounding (bonding) conductors permitted to terminate on a grounding ...
Code Q&A
Q. I have a panel that contains a circuit breaker for air-conditioning equipment. If the circuit breaker in the panel is within sight of the equipment, am I required to install another disconnect near the air-conditioning equipment? A. Not if you comply ...
Understanding The Basics of Wye Transformer Calculations
Add this information to what you know about delta transformers and you may be ready to solve power quality problems
Code Quandaries
Stumped by the Code?
Code Q&A
Q. Is there a section in the Code that restricts the use of power strips? A. No. The NEC is an installation standard, not a product standard. The use of listed relocatable power taps (power strips) should be in accordance with the instructions provided ...
Code Q&A
Q. When is an insulating bushing required on raceway fittings? A. Where raceways containing conductors 4 AWG and larger enter an enclosure, the conductors must be protected from abrasion during and after installation by a fitting that provides a smooth, ...
Everything You Need to Know About Switches, and More
Just like the receptacle, which was covered in this column last month, switches are a common element in everyday life. You can find them at work, in public,
Understanding the Basics of Delta Transformer Calculations 1
Transformer configuration names like and derive from the way the windings are connected inside the transformer. These connections determine the way the
Service Your Customers With the Proper Feed
How can you correctly and efficiently follow service installation requirements?
Code Q&A
Q. Does the Code permit installation of nonmetallic-sheathed cable in a three-story hotel building? A. Yes, as long as the structure is built of Type III, IV, or V construction and the cable is concealed within walls, floors, or ceilings that provide a ...
Code Q&A
Q. When does the NEC require a main breaker in a load center? A. Each lighting and appliance branch-circuit panelboard must be protected on the supply side . The overcurrent protection device can be located within the panelboard, or the panelboard’s ...
Article 406: Receptacles
You might be surprised to learn just how many rules are associated with these simple devices
Commercial Electrical Load Calculations 5
Knowing how to correctly size loads in commercial applications is an essential skill for electricians
Code Quandaries
Stumped by the Code?
Code Calculations
According to the U.S. Census Bureau, there are more than 3,500 recreational and vacation camps in this country. That's a lot of supply facility sites for recreational vehicles. Although the work may not be performed on a regular basis, do you know the ...
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