Table of Contents

  1. My light bulbs burn out prematurely, what can be the problem ?
  2. My lights dim when my refrigerator cycles on, is there a problem?
  3. Should I exercise my main breaker?
  4. I am getting a new electric range and dryer do I need a three wire plugs or four wire?
  5. What is the Code?
  6. What is a Ground Fault Circuit Interrupter?
  7. I do not have enough places to plug in my computer and electronics can I safely use a plug strip?
  8. What is an Arc Fault Circuit Interrupter ?
  9. I have some Knob & Tube wires in my house; are they safe?
  10. I have glass fuses should I upgrade to circuit breakers?
  11. My dimmer gets hot is there a problem?

  12. I have an old house and I have bought new replacement light fixtures is there a problem installing them?

     

 

 

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My light bulbs burn out prematurely, what can be the problem ?

Incandescent lamps that burn out prematurely may be subject to vibration. Vibration caused by doors slamming and sudden pounding on floors will burn out lamps very quickly. Today 120 volt lamps are now subject to higher voltage supplied by the power companies. Nominal voltage can be 130 volts or more. When purchasing new lamps consider buying 130 volt rated lamps (available at electrical supply stores) for extended service.

The government has now banned the sale of the traditional type incandescent lamp in certain wattages. Newly available products like LED lamps are a great replacement for incandescent lamps. Remember this when going out to purchase lamps. Incandescent lamps are nineteenth century technology, fluorescent lamps are twentieth century and LED lamps are twenty first century.

 

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My lights dim when my refrigerator cycles on, is there a problem?

A very slight dimming of lights for brief moment such as a refrigerator or other appliance starting may be normal. Dimming may be caused by the circuit for the lights are also sharing the load of the appliance. Dimming to a larger degree may be indicative of a loose connection somewhere in the system. A loose connection maybe spotted a non-coincidental dimming and flickering of lights. If this is the case there is a problem which should be checked out with out delay.

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Should I exercise my main breaker?

In a perfect world exercising a main breaker by turning it off then turning it on would not be a problem. However, this is not a perfect world electrical parts are subject to heat, moisture, dust, wear and abuse. It is possible that simply turning off the breaker and turning it back on it just might fail to reset. If this is the case replacement is the only option. Some older equipment may be difficult to locate and expensive to replace. Keep this in mind when ever turning off a main breaker.

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I am getting a new electric range and dryer do I need a three wire plugs or four wire?

If you live in a condo, mobile home or a newer house the answer is definitely four wire. If you live in an older house the answer might be three wire for a preexisting circuit only. If a new circuit is installed it should be a four wire circuit.

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What is the Code?

The National Electrical Code is the general rule book that explains electrical  installations and materials in minimum standards written every three years and published by the National Fire Protection Association, it is adopted by the State of Vermont with certain exceptions, these exceptions are listed in the Vermont Electrical Safety Rules. See our link section for Department of Public Safety which has jurisdiction on electrical issues.

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What is a Ground Fault Circuit Interrupter?

The GFCI is a device that can be in a form of a circuit breaker in your panel or a  receptacle outlet on your wall. Its primary function is to protect someone from a fatal electrocution. When a GFCI is tripped it is reset by resetting the breaker or pushing in the reset button on the receptacle type. If the device does not reset then there could be a fault present, troubleshooting will be necessary to clear the problem. There are specific locations where GFCI is required to be installed for example: all kitchen and bathroom receptacle outlets. Do not confuse GFCI with AFCI. See: What is a Arc Fault Circuit Interrupter ?

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I do not have enough places to plug in my computer and electronics can I safely use a plug strip?

In the case of plug strips it is important to read the label, not all plug strips are surge suppressors. If on the strip it has the word "temporary" do not use it. A temporary power tap is nothing more than an extension cord. I have personally seen several of these "temporary" devices fail and could have started a major fire. For computers use an Uninterruptible Power Supply, for other electronics use a good listed surge suppressor.

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What is an Arc Fault Circuit Interrupter ?

The AFCI is a relatively new circuit breaker that not only provides overcurrent and short circuit protection it also is design to detect faults in a circuit such as loose connection or splice that will create an arc and abnormal heating condition which may cause a fire. For Example: a table lamp loose plug might be heating to a point that a fire may start. The AFCI circuit breaker is design to detect this condition before it gets out of hand. AFCI breakers are now required for all new branch circuits that serve  outlets in the main living quarters in a dwelling. Do not confuse the AFCI with a GFCI a GFCI is design to save a life by preventing electrocution.

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I have some Knob & Tube wires in my house; are they safe?

Knob & Tube circuits should be replaced for several reasons. First: is these wires and associated devices are at least seventy-five to one hundred years old, the splices and connection as well as the rubber insulation are now beyond there designed life span. Second reason: is it is a code violation to have any type of insulation or combustibles in contact with Knob & Tube conductors. Third reason: is Knob & Tube circuits do not provide an equipment ground necessary for safely grounding of fixtures, appliances and electronics. Fourth reason: is today homeowners insurance companies will not cover houses with Knob & Tube wires.

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I have glass fuses should I upgrade to circuit breakers?

Insurance companies today will not cover homes with the glass Edison type fuses. These fuses are no long acceptable for new circuits because they do not support AFCI and GFCI protection. Also, the size of the fuses can be unwisely increased or circumvented beyond the capacity of the conductors to safely carry the current; remember the proverbial penny behind the fuse? Almost all old main fuse boxes I have seen are now overfilled beyond there designed capacity creating an un-safe condition. Most service entrances on houses with Edison fuses are still only sixty amperes, way too small for today's life style.

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My dimmer gets hot is there a problem?

Dimmers are a device that electronically modifies the power to a light fixture by changing the duty cycle of the AC sine wave. The dimmer actually shuts off the power to the lamps for a fraction of a second. The lower you set the dimmer control the longer the period of time it shuts off the power. The power is actually shut off 120 times a second once every half cycle. This happens so fast you see the result as a lower output of light. The dimmer device has inductive, capacitive and resistive elements to it and will get hotter the more wattage you try to control. The dimmer is constructed to dissipate some of the heat with an aluminum yoke heat sink. Mounting dimmers adjacent one another in the same box require breaking off some of the heat sink. Dimmers mounted in this arrangement are reduced to 80% of their rated wattage. For example: a 600 watt incandescent dimmer should now only control up to 480 watts or overheating can occur.

Dimmers are now made in all types of styles and uses. Not only are there incandescent but there are fluorescent and LED dimmers. Care must be taken when changing the lamps in a fixture especially from incandescent to fluorescent or LED. If the fixture is controlled by a dimmer make sure that everything is compatible. A note to remember on fluorescent and LED, not all lamps are dimmable so read the label.

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I have an old house and I have bought new replacement light fixtures is there a problem installing them?

Maybe, since the mid 1980’s wire and cables in dwellings have been required to have a 90 degree Celsius rating which greatly improves the conductor’s longevity as far as the insulation retaining its resiliency. Older wires installed before then were rated for not much more than 60 degree C. Heat from ballast and lamps and other environmental reasons has heated the conductors where the insulation has become brittle. Dwellings wired new or rewired since then should have had the better cables installed. When purchasing a new light fixture check to see if the manufacturer has stipulated that the fixture is only to be installed with 90 degree C conductors.   When checking the cables in your home, look for NM-B (new) rating not just the NM (old). The older styles of cables that have the cambric and the spiral metal sheaving (BX) also knob and tube conductors are not rated for modern light fixtures

 

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Peter M. Crosby; Master Electrician.
Copyright © 2009  Williamson Electrical Service, Inc. All rights reserved.
Revised: 03/16/15.