Why doe the AFCI immediately trip?

by

cstarr

Last Updated August 05, 2017 05:21 AM

I recently installed some AFCI/GFCI circuit breakers. One of them kept tripping immediately, so I tracked down the problem to where a neutral and ground were joined. (There was just the one neutral in that box.) To confirm that this was the problem, I disconnected the neutral from the ground and ran a neutral wire to another nearby box in the same circuit and connected it to neutral there. Problem solved!

Almost.

S---------L

|

S3------S3

| |

O--------O

It looks like the above. The outlet (O) on the left is fed into from earlier in the circuit. It connects to the right, which connects up to a 3-way switch (S3), which connects left to the other 3-way switch, which then feeds a regular switch (S) to a light (L) (independent of the 3-ways). S3 on the right has an isolated neutral from O that is capped off. S3 on the left therefore has no neutral to contribute to the S and L...

Hi!

I have a problem I am hoping someone can help with.

The problem … Outlets and switches don’t work. I have a GFCI circuit breaker in the garage/at the panel. It tripped and won’t reset. I got it to reset once but then I flip the light switch and it immediately trips.

I bought a new GFCI breaker and installed it, same thing. At this point I assume it is not a faulty breaker but a problem.

The breaker runs on it two unused bedrooms (lights and outlets), the lights in an unused bathroom (but not the outlets) and one outlet in a hall (on the other side of the wall from the unused bathroom mentioned).

How the problem happened…I went to the room one day, turned on the light – it worked. A few hours later I went back to the room (to put back what I took out) and the light didn’t’ work. During those few hours we didn’t use any of the lights or outlets on that breaker.

What I have done….*Replaced the GFCI breaker, *Went through the house...

First, check the circuit breaker that’s tripping. Does it have a “TEST” button and the letters AFCI displayed on it?

First, check the circuit breaker that’s tripping. Does it have a “TEST” button and the letters AFCI displayed on it?

If so, what you have is an “Arc Fault Circuit Interrupter” circuit breaker. These breakers are specifically designed to protect your circuits from electrical “arcing” (more on what that is later).

Note: If you have a normal circuit breaker (not AFCI), you either have an overloaded circuit, an electrical short, or a worn out breaker. Here’s a helpful article that details what to do when you have a breaker that’s tripping.

So why is your AFCI breaker tripping when you run the vacuum? Well it depends on how often the breaker trips:

If your vacuum occasionally trips the breaker, the breaker is most likely just “nuisance tripping” (vacuums are notorious for causing AFCI nuisance trips).

If your vacuum always...

AFCI Frequently Asked Questions

The information in this article is from the Siemens web site www.siemens.com and was initially compiled by Tarry Baker of Broward County, Florida. Additional information was provided by Peter Spirito.

Click HERE for a direct link to Siemens complete information on AFCI’s

Click HERE for a direct link to UL Laboratories’ AFCI information

Overview

What is an arcing fault?

According to UL 1699, Standard for Arc Fault Circuit Interrupters, an arcing fault is an unintentional arcing condition in a circuit. Arcing is defined as a luminous discharge of electricity across an insulating medium, usually accompanied by the partial volatilization of electrodes.

There are 3 basic types of arcing faults: line-to-neutral, line-to-ground, and series arcing.

What causes an arc fault?

Arc faults may occur anywhere in the electrical system and may be a result of the following:

worn electrical...

The customary Electric Panel Box at the entrance to any building receives electricity from the government and distributes it evenly and safely to various portions of the building. Circuits are used to disburse electricity to various parts of the building. The often asked question of why circuit breakers keep tripping is simply because the circuit exists to prevent any damage. From saving you from shocks when a touch a switch or a wire, to preventing appliances from overheating and burning, circuits trip and cut current instantly.

Circuit breakers form a part of the panel box. In the past century or so, circuit breakers have replaced ceramic fuses which tended to catch fire and blow up instead of tripping. In other words, they ‘cut the power distribution’ to the house whenever there is an overload on one or more circuits. It is easy to reset a circuit breaker. Unlike Fuses, they do not have to be replaced. Once the problem is rectified, it can be reset...

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An arc-fault circuit interrupter (AFCI) is a circuit breaker* located in your electrical panel that serves the functions of a normal breaker but also senses hazardous arcing on its circuit and will trip off for this. It can be identified by the special colored test-button near its handle. (Ground-fault breakers also have a button, so read with a magnifying glass to be sure which kind your breaker is.)

*A different device is now allowed away from your breaker panel. It resembles the familiar GFCI receptacles. (Its installation is more strict, however.) It is called an "outlet/ branch-circuit type of AFCI" or simply AFCI outlet or AFCI receptacle.

AFCI breakers began to be required by Code in 2002 for new wiring supplying bedrooms. The areas to be protected were expanded in 2008 (where that national Code has been adopted locally) to most rooms of the home. The areas left out of the requirement were garage, bathroom, kitchen, and laundry; these were already...

In this post I hope to answer the burning question of, why doesn't the UK include the

Arc Fault Circuit Interrupter

(AFCI) in their regulations? Actually following the UK naming conventions, I assume they would call them, Arc Fault Circuit Breakers (AFCB) when located within the consumer unit or generically they would be called, Arc Fault Detection Device (AFDD).

Contents

AFCI are common in North America but are not required in the UK, why?

AFCI are common in North America but are not required in the UK, why?

This is a very good question and one that I will have to take an educated guess at. As I am not privy to the discussions that happen in the UK standards bodies I cannot give a definitive answer but I will attempt to guess at the logic behind the decision in this following post. If you're not familiar with what an Arc Fault Circuit Interrupter (AFCI) is, then take a look at the video or read the previous post. For a longer more...

I can think of a couple scenarios
First, the switch may be causing a small arc as the contacts separate, and that is tripping a GFCI/AFCI breaker in the panel. The switch may also be worn to the point where it can cause a short from hot to ground; this would be unlikely to trip a breaker, but it could happen. Lastly, there may be exposed wiring in the switch box, coupled with a loosened mounting of the switch int the box, causing a short between wires when the switch is flipped.
In all cases, the most likely culprit is the switch. Single-pole 120V15A switches are a buck-fifty a pop, so it can't hurt to just replace it. Make sure there's no bare wire that can short against a ground; I've found it helpful to give the switch or outlet I'm installing a wrap of electrical tape, which covers the terminals and other energized metal around the switch body and helps prevent shorts. Make sure no bare metal can touch any other bare metal when you put the new switch back in the...

FAQ

1. What is a GFCI (Ground Fault Circuit Interrupter) & why it is necessary in my home?
a. Commonly known as the outlet with the “buttons”, it is necessary in your home as it is specifically designed to protect from shock by monitoring if low current is leaking out of the circuit to the ground. If it senses leakage, it will de-energize the circuit. The GFCI is necessary in wet locations such as bathrooms, kitchen, outdoor receptacles and more.

2. What is an AFCI?
a. The AFCI is a breaker that recognizes any sparks in the circuit that could cause a fire. In case of any spark, the AFCI will trip and de-energize the circuit. Today, by code, it is required to the use of the AFCI breaker in your new home or when rewiring your electrical system.

3. Why do I need Smoke and Carbon Monoxide Detectors in my home?
a. Smoke detectors will alert you and your family of any danger caused by smoke. Carbon Monoxide detector monitors the toxic “silent killer”...

[Summary]AFCI Circuit Breaker AFCI Circuit Breaker Troubleshooting An arc-fault circuit interrupter (AFCI) is a circuit breaker* located in your electrical panel that serves the functions of a normal breaker but also senses hazardous arcing on its circuit and

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AFCI Circuit Breaker

AFCI Circuit Breaker Troubleshooting

An arc-fault circuit interrupter (AFCI) is a circuit breaker* located in your electrical panel that serves the functions of a normal breaker but also senses hazardous arcing on its circuit and will trip off for this. It can be identified by the special colored test-button near its handle. (Ground-fault breakers also have a button, so read with a magnifying glass to be sure which kind your breaker is.)

AFCI circuit breakers and the problem of 'nuisance tripping'

The main problem that homeowners experience with AFCI circuit breakers is nuisance tripping. It's what we call it when an AFCI...

Photo © david.asch - Fotolia.com

Arc-Fault Circuit-Interrupters were the new kid on the block when they first appeared in the 1999 National Electrical Code (NEC). Since then, we have seen the technology advance to a new generation of devices, along with incremental expansion of the requirements for AFCIs in each new code edition. The next (2014) edition will continue that trend.

Why AFCIs?

An arc results from an electrical current propagated through air. A common example of the discharge of electricity between electrodes is the spark plug in a car engine. Snap switches sometimes will cause an arc as the contacts make or break continuity, although arcs are momentary and rarely damaging. A sustained arc can occur at a loose connection or between conductors that have damaged insulation. These electrical arcs can produce temperatures of several thousand degrees while still drawing less current than is necessary to trip a conventional breaker...

AFCI Questions and Answers - Mike Holt

AFCI Questions and Answers

By Mike Holt
Would it be possible for you to give more information on how the tests were conducted?
A typical receptacle installed in a metal and nonmetallic box mounted on wood studs with drywall. The hot wire just touching the screw on the receptacle, it was move around so that it began a very small arc when the 1,500W heater load was on. In less than one hour the receptacle and the wiring in the box would melt. The AFCI opened because of an arc fault (line-to-neutral) on one case (when the peak current of a half-cycle exceeded 50A, three times in a row) and it was the Ground Fault Interrupter (GFI) that opened in the other. In both of these examples, the arc energy was as low as could be detected.
What are the characteristics of an arc on the electrical circuit? I teach an apprenticeship class and I would like to be able to explain the theory to the class.
What makes the AFCI protection...