2014 National Electrical Code

AFCIs – What You Need to Know

Arc Fault Circuit Interrupters (AFCIs) are an important electrical fire prevention and safety requirement of the National Electrical Code. With the changes to the NEC in 2017 there still seems to be questions regarding the use of AFCIs. This primer will address these questions.

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Feeders Part 1: What is a Feeder?

In order to understand what a feeder is, it is best to start with what a feeder is not. The conductors between the utility service point and the service disconnecting means are service conductors, not feeder conductors. Special service conductor rules apply because these conductors do not have short-circuit or […]

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Feeder Conductor Ampacity

Feeders Part 3 Feeder Conductor Ampacity. The conditions of use must be considered when determining the minimum size of a feeder conductor. A continuous load, such as the lighting load in a store building, generates heat in the feeder conductor that must be compensated for. Ambient temperatures above 86oF or more than […]

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Feeders Part 2: Overcurrent Protection

The general rule in 215.3 is that a feeder overcurrent device shall have a rating not less than the noncontinuous load plus 125% of any continuous loads supplied by the feeder. Unless permitted for specific applications, such as motor circuits, the rating of the feeder overcurrent device is selected as […]

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210.23(A)(1)&(2) Permissible Loads, Multiple-Outlet Branch Circuits.

A multiple-outlet branch circuit is a branch circuit that supplies two or more outlets. With the exception of the required small appliance, laundry, and bathroom receptacle circuits in dwelling units, those outlets may be a combination of lighting outlets for luminaires, receptacle outlets for cord and plug connected utilization equipment […]

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Recently in 2014 National Electrical Code

Replacing Two-Wire Receptacles

Upgrading wiring in older homes usually includes replacing old two-wire, non-grounding type receptacles. Replacing a two-wire receptacle with a grounding-type receptacle and not providing an equipment ground or GFCI protection is a serious NEC violation. Extending a two-wire circuit without an equipment ground is also prohibited, even if protected by […]

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GFCI Protection for Health Care Receptacles

Most exam tables at the dentist or doctor’s office are not “patient sleeping beds”. A patient sleeping bed is usually found in a health care facility’s patient room rather than in an exam room. Typically, these beds have sheets and pillows, rather than paper covering over vinyl. In an exam […]

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Pool and Spa Wiring Part II

Here is a list of the most common electrical mistakes made when installing a hot tub outdoors

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Pool and Spa Wiring Part I

Here are some common items that can cause the electrical inspection to fail at swimming pools.

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PV System: Marking and Labeling

There are many PV system marking and labeling requirements in the NEC. Some markings will be factory applied as required by the product listing and others must be field applied by the installer

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PV Systems: Point of Interconnection

A PV system is useless until it gets connected into the premises wiring system. NEC section 690.64 states that the point of connection for a PV system shall be in accordance with section 705.12. Article 705 provides the rules on how an electric power production source, such as a PV […]

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PV Systems: Grounding

In the past few blog posts we have discussed some of the more important issues related to the PV system including PV modules, PV source circuits, PV output circuits, and inverters. Now let’s talk about PV grounding. Equipment Grounding In most PV installations, the PV modules are fastened to […]

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PV Systems: The Inverter

An inverter takes the DC current produced by the PV modules and converts it to AC current for connection to the utility grid.

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PV Systems: Starting with the Modules

When wiring PV modules in series (to create a series string of modules), voltage is additive while current remains the same. Series = Adds Voltage. When wiring several strings in parallel, the result is the opposite; voltage remains the same while current is additive.

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Field Applied Hazard Markings

Section 110.21(B) states that if caution, warning, danger signs or labels are required by the NEC, the labels shall “adequately” warn of the hazard using effective words and/or colors and/or symbols.

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