The Electrical Code

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Whether we are dealing with the National Electrical Code (U.S.A.) or the Canadian Electrical Code, there is a common emphasis on “Consumer Safety”.

Both of these electrical codes have evolved over several decades into their present forms. Although the two electrical codes are not identical they share a common goal in keeping consumers safe. There are numerous local reasons (such as weather) why certain rules in the code are amended in a particular region. There is usually a sound reason based on practical experience for all of the content in the electrical code. Although the reason for a particular code rule may not be immediately obvious, we should remember that over several decades electrical contractors, electrical inspectors, fire departments, insurance companies, standards associations, engineers and others have provided input in an effort to enhance the safety of electrical wiring.

Considerable time is spent in selecting the correct wording for a code rule. An attempt is made to ensure that a new rule or an amended rule will be interpreted by electrical workers as the group intended.
In some cases, a “directive” is issued to electrical contractors in a particular area telling the contractor “how” to interpret a new rule or an amended rule. Once the directive has been issued, the local inspection authority can remove any ambiguity in the interpretation of the rule.

All of this process is done for your safety. It should, therefore, come as no surprise that the most important aspect of electrical safety is the compliance with your locally amended version of “the electrical code”.

The years of training and the ongoing upgrading of skilled electrical workers, together with the integrity of a reputable electrical contractor are your best chance of having a safe electrical installation.
Even on a small project, there may be some aspects that require skilled interpretation of the “code”. An electrical inspector may not catch a code violation, especially if there is concealed wiring or an attempt has been made to hide the violation from the inspector. You may have saved a little money on the installation only to find that it will need to be done again properly at a later date.

The cost of re-doing work is much higher than the cost of doing it correctly, to begin with. It may involve opening walls to expose the wiring and then re-decorating. In the cases where the defective installation causes a fire, the cost could be very high and may include injury or death.

If you have decided to tackle electrical work as a do-it-yourself project, you need to take the time to carefully read your code book.

Do’s and Do not’s

Don’t replace a fuse or circuit breaker with the next size to stop the circuit from tripping. (i.e. replacing a 15 Amp with a 20 Amp). If fuses are blowing or circuit breakers are tripping, this is for your protection. If the breaker or fuse trips or blows instantly, there is either a short circuit or a massive overload. If it takes several minutes in between each tripping or blowing episode, there is a circuit overload.

Don’t use an extension cord on a kitchen countertop. The cables on appliances are designed to be short so that they do not hang where a child can pull them. If you have an appliance placed where it cannot reach a receptacle, you should either move the appliance or have a new receptacle installed.

Don’t ever cut a ground pin from the cord cap of an extension cord or an appliance cord. This is done sometimes to allow the use of a 2-wire extension cord. If your appliance came with a ground pin, this means that it is required. Buy an extension cord that can accept the ground pin.

Don’t use defective or badly worn extension cords. Don’t jam extension cords in windows or doors when using outdoor items. If you have a use for electricity outdoors you should connect to an outdoor GFCI protected receptacle.

Don’t install “used” electrical materials, especially circuit breakers. You have no way of knowing how much wear there has been. The equipment will at best be unreliable and at worst very dangerous.

Do regularly test the GFCI breakers and/or receptacles to make sure that they are working properly.

Do regularly test smoke detectors and if they use batteries, replace the battery. Ensure that you have a sufficient number of detectors and check to make sure that existing detectors are not located in “dead” spots. If you have recently bought a previously owned older home, the smoke detectors will be an upgrade and may have been installed by an amateur. A smoke detector in the wrong location does not offer the intended degree of protection.

Do find the time to identify all of the receptacles, lights, heaters, etc. so that you have “up to date” information at the electrical panel when you need to switch a breaker off. This will also help you to prevent overloads.

Do call a reputable electrical contractor when adding new wiring unless you feel completely sure that you can handle the job.

Do immediately investigate the cause of flickering lights or any smell of burning. These are the early signs of problems and if left unattended could be a serious safety concern. Call your contractor.

Until the next information update, let’s be careful out there.

Popular Electrical Safety Myths

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Only a ground I have often heard electricians say “It’s only a ground wire” as if to imply that the wire was, therefore, unimportant. In North America, because the 3 wire system is used, there is often confusion about the neutral wire (white wire) in the system. Without adequate grounding there are no neutral wire and voltage fluctuations can occur.

From the safety point of view, the ground wire is the most important wire. You should always ensure that grounding is done to the requirements of the electrical code.

Can’t get a shock from the neutral This one is a potential killer. I have seen several electricians fall victim to this myth. In some North American homes, two circuits are run using a 3 conductor cable. The third wire is supposed to be a common neutral and each circuit is supposed to be on a different “live leg”. When this is looped from box to box in the home, there are splices made in the neutral wire. As long as the splice in a box is secure, it is true that you could touch the white wire and the box without receiving a shock.

However, after being drawn into a false sense of security, many electricians undo the splice (maybe to add a wire) and get a big surprise to find 240 Volts across the white wires.This is how it happens. In the home, you have 240 Volts across the Red and Black wires (two live legs) and 120 Volts from either live leg to neutral (white). In circuit 1, the current goes from the Red, through the load, back on the white (back to the ground). In circuit 2, the current goes from the Black, through the load, back on the white (back to the ground). When the splice is opened there is no path back to the ground. There is no current flow so there is no Voltage Drop. If there is no Voltage Drop, all of the voltage (240 Volts) appears across the two white wires. When the electrician touches these wires it comes as a complete shock in every sense of the word because he/she had just moments before assured his/

This is how it happens. In the home, you have 240 Volts across the Red and Black wires (two live legs) and 120 Volts from either live leg to neutral (white). In circuit 1, the current goes from the Red, through the load, back on the white (back to the ground). In circuit 2, the current goes from the Black, through the load, back on the white (back to the ground). When the splice is opened there is no path back to the ground. There is no current flow so there is no Voltage Drop. If there is no Voltage Drop, all of the voltage (240 Volts) appears across the two white wires. When the electrician touches these wires it comes as a complete shock in every sense of the word because he/she had just moments before assured his/herself that the white wire was safe to touch.
In a commercial building with a 3 Phase system, the voltage present may be 600 Volts (347 Volts to ground) and this could be lethal.

Can’t get a shock at a plastic switch box.┬áThis one has caught a few electricians off guard. Because the box is plastic, it seems that touching between a live terminal on the switch and the box will not result in a shock. I should mention here that plastic switch boxes in Canada have a grounding terminal on them, whereas the U.S. boxes made by the same company do not. This is one of those examples where a manufacturer won’t spend the extra few cents unless required to do so.

Electricians take care at metal switch boxes, knowing that there might be a loud bang if the switch terminals touch the box. With a plastic box, they drop their guard because they don’t get a bang if the terminals touch the box. They forget that the logic of the previous situation also applies in this case. If the switch is open (off), there is no current flow. If there is no current flow, there is no Voltage Drop. If there is no Voltage Drop, all of the voltage (120 Volts for a switch But 240 Volts at a thermostat) appears across the switch terminals or thermostat terminals. A careless moment is all it takes to get a shock.

Some areas do not allow the use of plastic boxes. Personally, I do not think that the U.S. plastic boxes should be allowed as switch boxes because the switch does not have a ground terminal to attach a wire to. There is a potential danger that is well understood by inspectors, manufacturers, standards agencies, etc. but it seems that nobody will require a change until there is an accident (hopefully not fatal). You will notice that a receptacle does have a ground terminal to attach a wire so I believe that the U.S. plastic boxes should only be allowed for receptacles. As an alternative, switch manufacturers who are already aware of this situation should add a ground terminal to their switches (but this may cost one or two cents).

Fluorescent Lighting Problems

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Fluorescent lighting of the standard tube type is popular in the garage, the hobby room and in kitchens with “sunshine” ceilings. Compact fluorescent bulbs are becoming popular in table lamps and for general lighting.

Cold weather causes problems with fluorescent tubes. This can be overcome by installing a ballast that is rated for outdoor use. So if you have an unheated garage or workshop and you notice that the lights seem dim and flickering (barely on) you have three choices. You can provide some heat or you can use outdoor style ballasts or you can install normal incandescent bulbs. There are some common complaints about fluorescent lights. The noise from the ballast can be very annoying (a humming noise). Since the ballast is sealed and filled with tar-like insulation, all you can do is replace the ballast with a new one. You might want to use an electronic ballast as the replacement. This has several advantages over the older design, but

There are some common complaints about fluorescent lights. The noise from the ballast can be very annoying (a humming noise). Since the ballast is sealed and filled with tar-like insulation, all you can do is replace the ballast with a new one. You might want to use an electronic ballast as the replacement. This has several advantages over the older design, but the cost isn’t one of them. Replacing a ballast is pretty easy to do. Make sure the supply of electricity to the light fixture is off. The wires are colour coded in pairs so that it is hard to make a mistake. Cut the wires close to the ballast so that you leave plenty of wire. Remove the screws (or nuts) holding the ballast in place, then remove the ballast. NOTE: You must dispose of the old ballast in a safe manner as toxic waste. Some very old ballasts had PCBs in them. Attach the new ballast to the fixture using the screws (or nuts) that you removed. Makes sure that it is positioned so that the colours match the wires that you cut. Splice the wires one pair at a time. In a two lamp

Make sure that it is positioned so that the colours match the wires that you cut. Splice the wires one pair at a time. In a two lamp ballast, you should see 2 red, 2 blue, 2 yellow, 1 black and 1 white wire. The two reds connect to the two reds that were cut. These go to a lamp holder. Repeat this for the blue wires. Repeat this for the yellow wires. The black wire connects to the incoming live wire (which might not be black). The white wire connects to the incoming neutral wire (which should be white). Use approved wire connectors for the connections. Remember that both lamps need to be in for testing. The pair of lamps is part of the circuit so an individual lamp will not go on.

Another problem with fluorescent lighting is a very bad smell (like the smell of burning oil) that comes from an overheated ballast. Again, replacing the ballast is the solution.Another problem is blackening of the ends of the lamps (tubes). This happens as the lamps age and can also happen if there are ballast problems. Usually, you will notice that the lamps take longer to reach full brightness and over time the ends darken. The solution is to replace the lamps. If the lamps do not reach full brightness quickly there may be a problem with the ballast. The only other parts (in North America) are the

Another problem is blackening of the ends of the lamps (tubes). This happens as the lamps age and can also happen if there are ballast problems. Usually, you will notice that the lamps take longer to reach full brightness and over time the ends darken. The solution is to replace the lamps. If the lamps do not reach full brightness quickly there may be a problem with the ballast. The only other parts (in North America) are the lamp holders. These are usually made from plastic that (in my opinion) is too brittle for the job. Too often, the lamp holders are broken while a lamp is being replaced. If you notice that a part of the lamp holder is broken off, this may cause the lamp pins to have poor contact with the lamp holder. This can cause some strange behaviour with the light fixture, including humming, flickering or darkening of lamp ends. Replacing a lamp holder is a simple task.

Make sure that the supply of electricity is off. Slide the lamp holder out from the lighting fixture (it usually slides into a groove). Cut the pair of wires off as close as possible to the lamp holder. Strip the ends of the wires to about half of one inch (12.5mm). The wires push into holes provided on the new lamp holder and are gripped by the contacts. That’s all it takes. In a two lamp fixture, one end of the fixture will have a pair of wires looping between two lamp holders (this is usually the yellow wires). One of the lamp holders will, therefore, have 4 wires attached to it. Just make sure that you don’t put both wires of the pair into the same contact. Doing this will create a short-circuit.

If you have the tee-bar type fixtures with 4 lamps, this is just like a pair of 2-lamp fixtures in one common enclosure. So you have two ballasts. One ballast controls the two outermost lamps while the other ballast controls the two innermost lamps. When testing these you should remember that the lamps work in pairs, so you need both outermost lamps for one test and both innermost lamps for the other test. Sometimes people think that the adjacent lamps should be on together and assume that they have a problem that really doesn’t exist.

Another common problem with fluorescent lighting is with circuit overloading. When a home is built, the electrician uses the electrical code as a guide. If the electrician knows in advance that a particular lighting outlet will have multiple bulbs (such as a chandelier or track lighting), he/she will allow for this and put fewer outlets on that circuit. In the case of fluorescent lighting, the electrician will allow for the ballast current and not the lamp current. This is roughly twice what you might expect. If you had two 40 Watt lamps you would expect the current to be 0.66 Amps (at 120 volts). In fact, the current will be about 1.2 Amps.

When there is no information about the light fixture type, the electrician makes an allowance of 1 Amp. The 15 Amp circuit breaker is only loaded to 80% so it has a maximum load of 12 Amps when used in a lighting circuit. This is where the “rule of thumb” that you put 12 outlets on a circuit comes from. You should actually have 12 as the Maximum number of outlets. The true number could be as low as one or two, especially when track lighting is installed.