Home » Electrical Wiring Directory

« Electrical Question from Gary about Ceiling Fan Wiring

How to Solve the Problem of Tripping Circuit Breakers »

Identifying The Cause Of a Dimming Light Circuit

	©Copyright Dave Rongey - About Me - Summary: How Dimming Lights may be a Indication of an Electrical Problem: Dimming lights may in fact be a sign of a bad electrical connection or a malfunctioning electrical device.

Dimming Lights and Electrical Problems

Sponsored Links

Electrical Question: There is one circuit in my home that dims than regains power several times in a row.

• It’s not a flicker and at times everything seems normal, plus it doesn’t matter if one rooms’ electricity is being used or several.
• I have replaced the circuit breaker for that line, but still the problem exist.
• There has not been any reconstruction on this 55 year old house for over ten years and any new upgrades utilize their own separate circuit.
• I have considered there may be a bad rheostat (dimmer) switch in the line, but I’m not sure how to make an accurate meter check.
• Aside from the frustration, I am concerned that there may be a short or bad wiring that could cause a fire.

Please reply ASAP.

Thank you
Background: Greg, from Massapequa, New York

Additional Comments: Mr. Rongey,
As an IT Professional and Multimedia Designer,  I find your pages conducive to the content.

Dave’s Reply:

Thanks for your electrical question and complement about this website Greg.

How Dimming Lights may be a Indication of an Electrical Problem

• Dimming lights may in fact be a sign of a bad electrical connection or a malfunctioning electrical device.
• You mention that this happens with one circuit only, so that will be our focus. The possibility of a bad dimmer switch can be easily tested by simply replacing the dimmer switch with another dimmer or a standard light switch just to see if the problem still exists.
• If a dimmer switch is not the problem then electrical junction boxes will need to be opened so that the wiring splices may be inspected. This is done by starting with electrical junction or device boxes that are up-stream or close to the incoming power source.
• This is a process of elimination which will eventually reveal the problem. Typically a bad splice is found which is identified by discolored or burnt insulation on the wiring and or the splice connection itself.
• Upon discovery the affected wiring must be repaired in such a way to ensure that the new splice and affected wiring are re-spliced properly to prevent a repeat occurrence.
• Understand that the problem with this circuit may be with the hot or the neutral, in fact often it is a neutral connection that is faulty.
  • That being said, here is another consideration:
    • At the electrical panel identify the affected circuit neutral wire and follow it to the position on the neutral terminal block.
    • Check that the screw is firmly holding the neutral wire in place. Often a loose neutral wire can produce a similar problem.
    • If this is the case, the neutral wire may be discolored due to a loose connection.

Yes, this could be a fire hazard so I would encourage you to have this taken care of asap.

RESOURCES

Circuit Wiring

Electrical Circuit Wiring

This article looks at common 120 volt and 240 volt house wiring circuits and the circuit breakers that are installed identifying the types and amperage sizes used in most homes.
Electrical Panel Circuit Listing

Electrical Circuit Breakers

Home Electrical Circuit Breakers

A guide to home electrical circuit breakers and how they work to protect your electrical wiring. When properly installed, your home electrical wiring is protected by a circuit protection device.

Using Testers to Identify Electrical Problems

Testers to Help Solve Electrical Problems

Troubleshooting Electrical Wiring
Types of Electrical Testers
Using Electrical Testers

Using Electrical Testers and Voltage Meters

Understanding Digital Volt Meters

When working on home electrical wiring using voltage meter can play an important part in electrical safety. Electrical testers and voltage meters enable you to identify electrical circuits and help prevent the possibility of accidental electrical shock.