The oldest residential wiring is called knob and tube wiring. Ceramic knobs support individual strands of wire along their run and ceramic tubes protect the wire where it passes through wall studs or floor joists. Knob and tube wiring was state-of-the-art up until around 1950. If not abused or tampered with, knob and tube wiring is still capable of carrying electricity throughout your home.

Knob and Tube Wiring Problems

Knob and tube wiring is generally safe except in the following circumstances:

•  Brittle insulation – the insulation on the wire cannot handle high temperature environments, such as those found in modern ceiling-mounted light fixtures. If the wire has been inappropriately used for such an application, the insulation around the knob and tube wire will become brittle and break off, leaving exposed wire.
•  Improper splices – splicing into knob and tube wiring is not a straightforward process. While an electrician can do a proper splice, Pillar To Post® inspectors often find inappropriately splices which create a serious safety hazard.
•  Not a grounded system – the ungrounded aspect of this kind of wiring is not a defect but knob and tube cannot be used to wire modern electrical outlets. It is only appropriate for ungrounded applications.

Do You have Knob and Tube Wiring?

If your home was built prior to 1950, you may have knob and tube wiring and not know it. Most homes with knob and tube wiring have been at least partly upgraded. It is not unusual to find all new wiring at the breaker panel and old knob and tube wiring for the lighting circuits on the top floor of the home.

Is it Safe?

Knob and tube wiring is not inherently unsafe. Installations have to be evaluated on a caseby-case basis. Safety usually depends on the history of modifications and upgrades

Home Insurance

Most home insurance companies will not write new policies on homes with knob and tube wiring. If you are already living in the home and have a policy, you can simply have an electrician evaluate the system and correct any deficiencies. If you are buying a home, you will probably have to replace all the knob and tube wiring. The insurance company will insure you through the transaction but will require you to upgrade within a defined period of time.

This situation sometimes creates conflict during a home inspection. The inspector informs the buyer of a likely wiring upgrade to satisfy the insurance company. But the seller does not understand the fuss because they have home insurance already. The insurance will not likely chase down existing policies for upgrades, but they will take the opportunity with a new policy to request an electrical upgrade.

Updating the Wiring

If you only have a few knob and tube circuits to replace it will not be expensive. But if the home has knob and tube wiring throughout, an upgrade may involve more than just replacing existing circuits, and thus may present a greater expense. In an upgrade, the wiring will be replaced to today’s standards. For example, in the era of knob and tube wiring, a living room might have had only a single electrical outlet. Today, outlets are installed within six feet of any point along the wall. This probably also means you will need to upgrade the breaker panel to accommodate the additional circuits. In the end, it is generally well worth the expense to upgrade to a modern electrical system.

Information that is being provide is for Educational Purpose, Any electric work that is needing to be done, should be done by a Licensed Electrician.

Source: Pillar To Post Information Series

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The electrical outlet not only provides vital access to the electrical current that makes your house hum, but it also warrants deeper consideration for reasons of comfort and safety.  But before we discuss safety measures, let’s start with a quick tour of this component and its mate, the plug.

Have you ever wondered why your electrical outlets have holes of different sizes and shape? To accommodate the plug is the obvious answer. But there is more to this relationship than meets the eye. Hidden behind the outlet is a series of wires that must be properly connected for the outlet’s safe functioning. On a modern electrical outlet that accommodates a three-pronged plug, each hole serves a specific purpose: the round hole is for the ground pin on the plug; the small slot takes the small blade on the plug and connects to the “hot” wire in the outlet (the wire that can cause a shock); the large slot takes the large blade and connects to the “neutral” wire in the outlet.

Specific wires have to be connected to the proper terminals for an outlet’s safe function. Correct installation is so important that our Pillar To Post® inspectors spot-check outlets with an outlet tester during every inspection.

Reverse Polarity

The large slot and small slot on an electrical outlet, and the different-sized blades on a plug, designate their respective polarizations, and ensure that the plug goes in the outlet only one way, a safety feature that reduces the chances of shock. For instance, a light-bulb socket has exposed electrical connections, the threads being the most exposed part. But polarized socket threads are attached to the neutral wire to prevent someone from getting a shock when changing a light bulb.

If the electrical outlet itself is mis-wired with reverse polarity, the lamp socket threads described above will become “hot”. If you touch the threads in the socket, or on the bulb as you screw it into the socket, you may get a shock.

Outlet Not Grounded

Pillar To Post® inspectors have also discovered outlets with the circular ground holes but with no ground wire connected. In older homes, sometimes the cable leading to the outlet does not have a ground wire, yet the outlet has nonetheless been upgraded to a modern grounded type. Some plug-in electrical devices need this ground connection for their built-in safety features. If the outlet appears to be grounded but is not, the device’s safety features will not work.

Old Outlets

In older homes some outlets may have no ground slot at all. This does not represent a defect or safety concern, but you will not be able to plug in an electrical appliance that has a ground pin on the plug. Today, most plug-in appliances are not the grounded style and, therefore, do not use or have a ground pin on the plug because they are a double insulated design. In these cases, the old ungrounded outlet will work fine.

If you think it might be a good idea to simply cut off the ground pin to accommodate an outlet without a ground hole, think again. This procedure is doubly unsafe because it not only bypasses the grounding safety feature, but also it bypasses the polarizing feature since a de-pinned plug can be inserted into the outlet either way.

Easy to Fix

An electrician can fix these outlet problems. Though your outlets may appear as minor considerations in the grand scheme of your home, your understanding and the safe installation of your outlets can prevent serious safety hazards.

 

 

 

 

 

 

 

 

 

 

 

Information that is being provide is for Educational Purpose, Any electric work that is needing to be done, should be done by a Licensed Electrician.

Source: Pillar To Post Information Series

A ground fault circuit interrupter, or GFCI, is an inexpensive electrical safety device that can protect you and your family members from a serious electric shock.

Have you ever had an electric shock? While it is an unpleasant experience, it is not usually fatal. However, given the right conditions, the same shock could be fatal! If your body makes a solid connection to the ground, the shock could easily kill you. Here are two examples of a solid ground connection:

• If you are physically standing or touching the ground outside

• If you touch something conductive, such as any part of the plumbing system in your house, that is also touching the ground outside

In other words, if you decide to operate your hedge trimmer in your bare feet and you get a shock, you may not survive it.

How Can a GFCI Help?

A GFCI is a special electrical outlet that prevents electric shocks in situations such as the ones described above. The GFCI monitors the electrical current leaving from and returning to the outlet. The current leaving the outlet should be the same amount as the returning current. If the current returning is less than that which leaves, the missing current could be passing through somebody’s body to the ground. The GFCI detects the mismatch and shuts off the electrical outlet in a split second.

Where Should GFCI Outlets Be Located?

GFCI outlets should be installed in any area that presents a risk of an electric shock with a direct path to the ground. In other words, anywhere you might directly touch the ground outside or anywhere where you might touch a part of the plumbing system. Some smart GFCIs locations are:

• Exterior outlets
• Kitchen counter outlets (not common in Canada)
• Bathroom outlets
• Garage outlets
• Outlets in unfinished basements

This is not a complete list. Areas near swimming pools, hot tubs, and so on should also include this type of outlet.

GFCIs are not perfect, however, and have been known to “nuisance trip” when connected to certain types of electrical equipment. For this reason, exceptions to the suggested (or required) locations for GFCIs exist. For example, a regular outlet would be a better choice for a freezer in your garage since the potential for nuisance tripping of the GCFI is high and might go undetected for days, leading to spoiled food in the shut-off freezer.

Remote GFCI

Several electrical outlets usually connect to a single circuit in an average home. A single GFCI outlet will protect all of the outlets in the circuit, even if the other outlets are not GFCIs. But the GFCI outlet must be the first outlet in the string in order for it to properly protect the other outlets, and, of course the connections have to be properly made.

Remote GFCIs sometimes cause confusion for home owners in the following ways:

• A home owner thinks the bathroom does not have a GFCI because the outlet looks like a standard one. The standard outlet under the protection of a remote GFCI should have a sticker indicating its GFCI protection. The problem is, the sticker does not stick forever. A Pillar To Post® inspector can test this for you.

• A standard outlet that does not appear to work in a bathroom or kitchen may actually be attached to a remote GFCI outlet that has nuisance tripped. Before calling an electrician, check the GFCI outlets in other bathrooms and in other locations around the house.

Testing

GFCIs are easy to test and should be tested every month. Simply press the test button on the outlet. You should hear a pop as the reset button pops out a little. To reset, just press the reset button. If the GFCI fails to trip, or if you are unable to reset it, it is time for an electrician to replace it.

Special breakers also provide GFCI protection to the entire circuit. These breakers can be installed instead of GFCI outlets. The GFCI breaker should also be tested monthly. You will recognize this breaker from the test and reset button.

GFCIs can help prevent injury and death from electric shock. It is a small device worth having to ensure the safety of your family members.

 

 

 

 

 

 

 

 

Information that is being provide is for Educational Purpose, Any electric work that is needing to be done, should be done by a Licensed Electrician.

Source: Pillar To Post Information Series

A 40 amp breaker, standard ranges have a three conductor #8 copper wire installed, terminating in a three pole four wire grounding receptacle. NEMA number 14-50R.

 

Information that is being provide is for Educational Purpose, Any electric work that is needing to be done, should be done by a Licensed Electrician.

The most common type of cable used in houses is technically known as NMD 90 (Non-Metallic Dry service cable rated at maximum of 90 degrees Celsius).

It is usually a plastic white covered cable.

How is Wire Sized?

In Canada and the United States there is a standard by which we measure wire. This standard is the A.W.G. (American Wire Gauge).

The most common size of wire that you will be dealing with is a #14.

Wire sizes start at higher numbers such as #24 (small wire) and as the number decreases in value the wire increases in size. The largest wire you will likely need is a #3 gauge. This would be for your incoming service.

The following chart identifies wire/amperage/breaker sizes:

Wire Size	Rating (Amperage)	Breaker Size (Amps)
#14	15 A.	15 A.
#12	20 A.	20 A.
#10	30 A.	30 A.
#8	45 A.	40 A.
#6	65 A.	60 A.
#3	105 A.	100 A.

*All sizes are a maximum value and in accordance with the Canadian Electrical Code.

Types of Wire

Wire can be either solid of stranded. Most wiring you do in your home will be with solid wire.

Solid wire is easier to work with and takes less time to install. You will find stranded wire in extension cords and any wire gauge over a #10.

Most Commonly Used Cables and Their Uses

2-conductor #14

Plugs, Switched, Lights ,( approx 70 % of your house wiring)

3-conductor #14

3- way Switches, Split Receptacles

2-conductor #12

Selected Heaters , Air Compressors, etc. (anything that uses a maximum of 20 amps)

Kitchen Receptacles circuits (as per the new provisions in the Canadian Electrical Code)

3-conductor #10

- any device that requires a maximum of 30 amps (the most common application would be your electric dryer)

3-conductor #8

- maximum of 40 amps (the most common application would be your electric range)

Information that is being provide is for Educational Purpose, Any electric work that is needing to be done, should be done by a Licensed Electrician.