Important Information About Residential Knob and Tube Wiring; Part II

-Problems Associated with K&T Wiring-

•Unsafe modifications are far more common with K&T wiring than they are with Romex and other modern wiring systems. Part of the reason for this is that K&T is so old that more opportunity has existed for improper modifications.

•The insulation that envelopes the wiring is a fire hazard.

•It tends to stretch and sag over time.

•It lacks a grounding conductor. Grounding conductors reduce the chance of electrical fire and damage to sensitive equipment.

•In older systems, wiring is insulated with varnish and fiber materials that are susceptible to deterioration.

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Compared with modern wiring insulation, K&T wiring is less resistant to damage.  K&T wiring insulated with cambric and asbestos is not rated for moisture exposure. Older systems contained insulation with additives that may oxidize copper wire. Bending the wires may cause insulation to crack and peel away. 

K&T wiring is often spliced with modern wiring incorrectly by amateurs. This is perhaps due to the ease by which K&T wiring is accessed.

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-Building Insulation-

K&T wiring is designed to dissipate heat into free air, and insulation will disturb this process. Insulation around K&T wires will cause heat to build up, and this creates a fire hazard. The 2008 National Electrical Code (NEC) requires that this wiring system not be covered by insulation. Specifically, it states that this wiring system should not be in hollow spaces of walls, ceilings and attics where such spaces are insulated by loose, rolled or foamed-in-place insulating material that envelops the conductors.

Local jurisdictions may or may not adopt the NEC’s requirement. The California Electrical Code, for instance, allows insulation to be in contact with knob-and-tube wiring, provided that certain conditions are met, such as, but not limited to, the following:

•A licensed electrical contractor must certify that the system is safe.

•The certification must be filed with the local building department.

•Accessible areas where insulation covers the wiring must be posted with a warning sign. In some areas, this sign must be in Spanish and English.

•The insulation must be non-combustible and non-conductive.

•Normal requirements for insulation must be met.

-Knob and Tube Wiring on thermal insulation-

When K&T wiring was first introduced, common household electrical appliances were limited to little more than toasters, tea kettles, coffee percolators and clothes irons. The electrical requirements of mid- to late-20th century homes could not have been foreseen during the late 18th century, a time during which electricity was seen as a passing fad. Existing K&T systems are notorious for modifications made in an attempt to match the increasing amperage loads required by televisions, refrigerators, and a lot of other electric appliances. Many of these attempts were made by insufficiently trained handymen, rather than experienced electricians, whose work made the wiring system vulnerable to overloading.

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•Many homeowners adapted to the inadequate amperage of K&T wiring by installing fuses with resistances that were too high for the wiring. The result of this modification is that the fuses would not blow as often and the wiring would suffer heat damage due to excessive amperage loads.

•It is not uncommon for inspectors to find connections wrapped with masking tape or Scotch tape instead of electrical tape.

-K&T Wiring and Insurance-

Many insurance companies refuse to insure houses that have knob-and-tube wiring due to the risk of fire. Exceptions are sometimes made for houses where an electrical contractor has deemed the system to be safe.

-Advice for those with K&T wiring-

•Have the system evaluated by a qualified electrician. Only an expert can confirm that the system was installed and modified correctly.

•Do not run an excessive amount of appliances in the home, as this can cause a fire.

•Where the wiring is brittle or cracked, it should be replaced. Proper maintenance is crucial.

•K&T wiring should not be used in kitchens, bathrooms, laundry rooms or outdoors. Wiring must be grounded in order to be used safely in these locations.

•Rewiring a house can take weeks and cost thousands of dollars, but unsafe wiring can cause fires, complicate estate transactions, and make insurers skittish.

•Homeowners should carefully consider their options before deciding whether to rewire their house.

•The homeowner or an electrician should carefully remove any insulation that is found surrounding K&T wires.

•Prospective home buyers should get an estimate of the cost of replacing K&T wiring. They can use this amount to negotiate a cheaper price for the house.

In summary, knob-and-tube wiring is likely to be a safety hazard due to improper modifications and the addition of building insulation. Inspectors need to be wary of this old system and be prepared to inform their clients about its potential dangers.

Important Information About Residential Knob and Tube Wiring; Part 1

Knob-and-tube or K&T wiring was an early standardized method of electrical wiring in buildings in common use in North America from about 1880 up until the 1970s. The system is considered obsolete and can be a safety hazard, although some of the fear associated with it is undeserved.

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-Facts About Knob and Tube Wiring-

•It is not inherently dangerous. The dangers from this system arise from its age, improper modifications, and situations where building insulation envelops the wires.

•It has no ground wire and thus cannot service any three-pronged appliances.

•While it is considered obsolete, there is no code that requires its complete removal.

•It is treated differently in different jurisdictions. In some areas, it must be removed at all accessible locations, while others merely require that it not be installed in new construction.

•It is not permitted in any new construction.

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-How Knob and Tube Wiring Works-           

K&T wiring consists of insulated copper conductors passing through lumber framing drill-holes via protective porcelain insulating tubes. They are supported along their length by nailed-down porcelain knobs. Where wires enter a wiring device, such as a lamp or switch, or were pulled into a wall, they are protected by flexible cloth or rubber insulation called “loom.”

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-Advantages of Knob-and-Tube Wiring-

•K&T wiring has a higher ampacity than wiring systems of the same gauge. The reason for this is that the hot and neutral wires are separated from one another, usually by 4 to 6 inches, which allows the wires to readily dissipate heat into free air.

•K&T wires are less likely than Romex cables to be punctured by nails because K&T wires are held away from the framing.

•The porcelain components have an almost unlimited lifespan.

•The original installation of knob-and-tube wiring is often superior to that of modern Romex wiring. K&T wiring installation requires more skill to install than Romex and, for this reason, unskilled people rarely ever installed it.

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Eastlake Business Park Exterior Painting

B&G’s painting division recently finished painting the Eastlake Business Park located on Redmond – Fall City Road.   The old colors were dated and faded and no longer fit the scheme of the growing commercial look of the area.  The new arrangement is more complex and lends itself to the natural surroundings.  Tenants include Laura’s Gourmet Bakery , and Anali Fine Linens.   Please contact Rosen Properties for leasing information. IMG_2387 IMG_2388 IMG_2390 IMG_2391

Electrical Safety Tips – NFPA.org

U.S. fire departments responded to an estimated annual average of 47,820 reported home structure fires involving electrical failure or malfunction in 2007-2011. These fires resulted in 455 civilian deaths, 1,518 civilian injuries and $1.5 billion in direct property damage.
Replace or repair damaged or loose electrical cords. Avoid running extension cords across doorways or under carpets. In homes with small children, make sure your home has tamper-resistant (TR) receptacles. Consider having additional circuits or outlets added by a qualified electrician so you do not have to use extension cords. Follow the manufacturer’s instructions for plugging an appliance into a receptacle outlet. Avoid overloading outlets. Plug only one high-wattage appliance into each receptacle outlet at a time. If outlets or switches feel warm, frequent problems with blowing fuses or tripping circuits, or flickering or dimming lights, call a qualified electrician. Place lamps on level surfaces, away from things that can burn and use bulbs that match the lamp’s recommended wattage. Make sure your home has ground fault circuit interrupters (GFCIs) in the kitchen bathroom(s), laundry, basement, and outdoor areas. Arc-fault circuit interrupters (AFCIs) should be installed in your home to protect electrical outlets.

The Benefits of Using Thermography and Thermal Imaging

Benefits of using Thermal Imaging

  • You can conduct inspections more efficiently
  • You can improve equipment maintenance and pinpoint problems quickly
  • Increase panel and system reliability
  • Less costly to maintain vacant spaces, landlord covered utilities and general property power needs.
  • Reduces environmental impact

Many common electrical and mechanical problems begin as an increase in temperature.  A thermal imager lets you easily detect them, without interruption to building or tenant operations.   By locating problems prior to failure, unscheduled outages and unplanned downtime is greatly reduced.

Thermal Imaging Cameras

Thermal imaging cameras detect radiation in the infrared range of the electromagnetic spectrum and produce images of that radiation, called thermograms.   The product B&G Electrical Contracting uses is from Fluke.

Applications

Thermal Imagers are most commonly used for inspecting the integrity of electrical systems because the test procedures are non-contact and can be performed quickly.  Electrical Thermography and Thermodynamics is qualitative which means it compares values to known conditions.  It is a very straightforward approach to discerning three phase systems, typical in all commercial properties, due to easily understood thermal signatures.    Our trained electrical technicians can inspect panel and power protection as preventive maintenance for any application in office, flex and retail properties. Our technicians will be able to see thermal signatures that indicate heat leaks in faulty thermal insulation and windows, and can use the results to improve the efficiency of heating and air-conditioning units as well.

Utility and Cost Savings

Utilities worldwide use infrared cameras to locate problems or to detect hot spots and other problems before they turn into costly failures and production downtime or dangerous electrical fires.   Poor or inadequate insulation, moisture, building envelope leaks, and substandard work are costly to residential and commercial building owners.   Electrical panel malfunctions and areas of high resistance can be both troublesome and destructive.   An infrared camera can help you quickly see where energy efficiency can be improved with utility cost savings as a direct result.

Tips to Get the Most from Your Home Electrical Inspection

Electrical panels and circuitry in Puget Sound Region homes tend to be ignored throughout the year.  A homeowner might only address electrical concerns after they are subject to short-circuits, blown fuses, failed lighting or even electrical burning smells.  A Whole Home Electrical Inspection is a must for any new home purchase as well as something any home could use after renovation, lighting or appliance upgrades or even updating an entertainment system.  As a homeowner, you may not be required by Washington State law to know the intricacies of your home’s electrical circuitry, but there are still some things that you should ask your electrical inspector when an inspection is being carried out.

Factors to keep in mind during an electrical inspection:

First, regardless of whether you are simply changing old electrical paneling, or conducting extensive renovations on your property, the first question you should ask your electrical inspector is whether your home’s electrical fittings are in compliance with building codes and regulations. If circuitry is in violation of these codes, you run the risk of getting into legal trouble.

Secondly, you should ensure that your electrical inspector pays close attention to safety.  Electrical panels and circuitry need to be properly insulated to reduce the risk of shocks. Moreover, paneling must never be placed next to areas that are damp or wet.  A good inspector will locate this condition instantly.

Understanding the current and voltage that flows through your electrical circuitry is also important.  Electrical appliances like air conditioners, washing machines and televisions consume significant amounts of electricity.  It falls under the homeowners responsibility to connect them to the right circuitry in order to avoid short-circuits, flipped breakers and constant voltage fluctuations.

 

Finally, once an electrical inspection has been carried out and repairs have been made, make sure to double-check that all of the home’s panels are working efficiently.  B&G Electrical Contracting can complete this process through Thermography by scanning the panel with a thermal imager. Our blog on Thermography, Emissivity, Infrared and General Thermal Imaging will be coming soon.   Once the inspection is complete, make sure that your inspector provides you with a comprehensive report of checks made, and any and all recommended repairs.

Is Installing A Backup Generator Cost Effective?

How much does it cost to install a backup generator?

Most modern households rely heavily upon electrical energy supply. The installation of a backup generator can deliver whole-house energy during a loss of power due to storms, general power outages and natural disasters.  It can also be designed to supply only necessary systems, like a refrigerator or electric heat, until electrical service is restored.

There are small, mid-sized and large generators available, and they work in the following ways:

  • Small to Mid-Sized will deliver 7-10 kW, and will be able to run a few basic household systems, but cannot sustain the needs of the entire home. These tend to need manual start and will average from $500 to $2500.
  • Mid-Sized to Large will deliver 12-20 kW, and will be able to function more effectively than a small system, but will not deliver the power needed for the entire home. This is a good option for those who need heating during cold weather situations. These will cost from $2000 to $4500.
  • Large Sized or ‘Whole Home’ will deliver 22-45 KW, and will be able to operate the entire home. These will usually be permanently in position and contained in protective “cases”. They are usually liquid cooled and can be permanently connected to the home. Many will come with installation fees of a few thousand dollars. These will cost from $5000 to $15000 and up.

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Cost breakdown

Installation of a backup generator is not considered a “DIY” project and it is not recommended that anyone but a licensed electrician perform the work. Typical installation can include:

  • Assessment of home energy needs to select suitable equipment (unless whole-house supplies are the goal). To understand the needs of the building the homeowner must do simple math that totals all appliances and household systems, and use the total kW figure to select the proper equipment;
  • Selection of equipment and list of installation requirements from contractor or supplier
  • Preparing site nearest to current electrical meter and power panel
  • Pouring of suitably sized concrete pad
  • Installation of fuel tank to feed generator throughout use. This must be done by a utility company and can rely on propane or diesel. The tank can be buried or positioned next to equipment, and professional connection is also usually required
  • new subpanel must be installed near the original electrical panel and an automatic transfer switch should be included as well
  • detailed plan of which appliances and electronic devices should be disconnected during use is necessary as well. Usually only the installer can indicate items such as televisions and computers that will be damaged by the fluctuating energy of the generator.
  • Provide electrical wiring and lighting to code – This is going to depend upon the amount of work required.  If the generator is located near the house panel with a suitable foundation, installation can be as little as $499 + tax.  This will include the transfer switch and attachment of any circuit(s) the need to be energized through the generator.

B&G Electrical Contracting is the Puget Sound’s best option for installing Backup Generators for residential use.  For more information or to set up a Free Estimate, please visit the Contact Us page at our website, www.bgmaintenance.com.

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Incandescent vs CFL vs LED Part II

Let’s examine the three most popular light bulb options: Incandescent, Compact Fluorescent and LED.   We will look at the advantages and disadvantages, starting with Incandescent.

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Incandescent Light Bulb

An incandescent light bulb or lamp is an electric light which produces light with a wire filament heated to a high temperature by an electric current passing through it, until it glows.  The hot filament is protected from oxidation with a glass bulb that is filled with inert gas.  The light bulb is supplied with electric current by terminals or wires embedded in the glass. Most bulbs are used in a socket which provides mechanical support and electrical connections.

Incandescent bulbs are manufactured in a wide range of sizes, light output, and voltage ratings, from 1.5 volts to about 300 volts. They require no external regulating equipment, have low manufacturing costs, and work equally well on either alternating current or direct current. As a result, the incandescent lamp is widely used in household and commercial lighting, for portable lighting such as table lamps, car headlamps, and flashlights, and for decorative, holiday and advertising lighting.

Incandescent bulbs are much less efficient than most other types of electric lighting; incandescent bulbs convert less than 5% of the energy they use into visible light, with standard light bulbs averaging about 2.2%. The remaining energy is converted into heat. The luminous efficacy of a typical incandescent bulb is 16 lumens per watt, compared with 60 lm/W for a compact fluorescent bulb or 150 lm/W for some white LED lamps.  Incandescent bulbs typically have short lifetimes compared with other types of lighting; around 1,000 hours for home light bulbs versus typically 10,000 hours for compact fluorescents and 30,000 hours for lighting LEDs.

Incandescent bulbs are gradually being replaced in many applications by other types of electric light, such as fluorescent lampscompact fluorescent lamps (CFL), cold cathode fluorescent lamps (CCFL), high-intensity discharge lamps, and light-emitting diode lamps (LED). Some jurisdictions, such as the European UnionChinaCanada and United States, are in the process of phasing out the use of incandescent light bulbs while others, including  Colombia,[6]MexicoCubaArgentinaBrazil or Australia,[7] have prohibited them already.

 

CFLs: Compact Fluorescent Lights

According to EnergyStar.gov, CFLs work differently than incandescent bulbs in that, instead of running an electric current through a wire filament, they drive an electric current through a tube that contains argon and mercury vapor. This process creates ultraviolet light that quickly translates into visible light, unlike incandescent lights which put off a warm glow.

The big difference between CFLs and incandescent bulbs is how much energy it takes to use them over time. CFLs use about 70% less energy than incandescent bulbs. They also last years longer than traditional bulbs, and only cost about a dollar more per bulb.

However, one of the biggest drawbacks of CFLs is that it takes a few moments for them to warm up and reach full brightness. That means they’re not ideal in spots where you want lots of light as soon as you flip the switch, such as a dark, steep basement stairway. They also cannot be used with a dimmer switch.

Plus, modern CFLs contain a small amount of mercury, which is very harmful to both your health and the environment. That means it’s bad news to break one (here’s how to clean it up safely if you do), and they shouldn’t be disposed of in your regular household trash (here’s how to recycle them).

LEDs: Light-Emitting Diodes

Light-emitting diodes, or LEDs, were for years most commonly found in small electronic displays, such as the clock on your cable box. Because the light emitted by each tiny LED is directional and fairly weak, household LED bulbs were on the fringe of mainstream technology just a few years ago.

According to the Lighting Research Center, LED light bulbs work by bringing together currents with a positive and negative charge to create energy released in the form of light. The result is a fast source of light that is reliable, instantaneous, and able to be dimmed.

What sets LEDs apart from incandescent bulbs and CFLs is just how long they can last.According to Consumer Reports, LED light bulbs can last anywhere from 20,000 to 50,000 hours, or up to five times longer than any comparable bulb on the market.

But that combination of efficiency and durability has historically come at a cost. LEDs cost more money than CFLs and incandescent bulbs. The good news, however, is that their price has dropped considerably over the years.

Where once it was common to pay $50 or even $100 for an LED light bulb, they’re now available for about $8 a bulb on Amazon. IKEA sells its own 60W-equivalent LED light bulbs for just $5, and Home Depot is reportedly running a promotion in May that will discount Philips LED light bulbs to as low as $2.50 per bulb.

Despite concerns over mercury content and contamination issues, policy makers, manufacturers, and scientists are in agreement over the greater environmental and economic benefits of CFLs. When recycled properly, nearly every component of a fluorescent bulb can be separated and reused – even the mercury.

According to the EPA, electricity from coal-fired power plants is the main source of U.S. mercury emissions. By using CFL bulbs in place of incandescent, we can decrease the demand for coal-fired power and in doing so, significantly reduce the amount of mercury released into the environment.

Gymnasium Lighting Upgrade

B&G Electrical Contracting recently upgraded the lighting in a local Bellevue school’s gym from 250w Metal Halide lamps, to more energy efficient LED lamps.   The old Metal Halide lamps not only used 18,290 less kilowatt hours per year saving an estimated $1657.39 in utility costs, it also created a brighter sport court, assembly space and meeting area.   A feature the maintenance staff appreciates is that the lights turn on and off immediately and do not have the warm up time and constant hum of the Metal Halide fixture.   A project like this typically takes 4-5 years to pay for itself through energy savings, averaging around 18-20% ROI per year.

 

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