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On three phase 208 volts one leg does not have the potential of 208 volts. It takes two legs to provide the 208 volts. The potential is across AB, BC and CA. Voltage to the grounded neutral A-N, B-N and C-N will produce a potential of 120 volts. In a wye configured secondary three phase four wire you have the potential of 120/208 volts.

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Owing to the rapid development of newer and newer systems, often city codes and laws cannot keep up with the changes. Such a certificate is given when a certificate of occupancy is held up because the licensing board is unfamiliar with the newest electrical system, and to deny the c of o because of their ignorance is unfair to contractors who have enmbraced the technology. The cert. is usually temporary until such time as the board can know what it is dealing with. It is a stop-gap measure, but needed.

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Yes it can. It depends on the amount of voltage that you got shocked with.

Electric shock can put the heart into asystole (absence of heart contractions). The heart will often resume its rhythm, but the accomanying respiratory arrest lasts longer, and can then lead to a second cardiac arrest due to lack of oxygen.

Also, all electrical burns are considered to be worse than look externally (they can burn internally as well).

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Most places in Mexico adhere to the NEMA 1-15 (2 flat pins) standard. Some others use the American-adopted NEMA 5-15, which includes the third, ground pin. If you are from the U.S. you shouldn't have any trouble to plug your appliances/electronics, but in case your appliance has three pins, you should bring a converter just to be on the safe side.

If you have the European Standard or any other type of connector, you should buy a power converter, as the power grid uses a 110-120 Volt and most European appliances would not charge or work properly.

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It depends on the voltage on the circuit. If it is 24 volts or less and the circuit is protected by a current limiting device, it is considered Safety Extra Low Voltage, and one can use any insulating material desired. For voltages above 24 volts, only insulation materials approved by a safety testing agency such as Underwriters Laboratories (UL) or Canadian Standards Association (CSA) should be used. This may include friction tape, heat shrink tubing and "liquid tape" (a plastic that is painted on). Wire connections may be made with insulated terminal strips and terminal blocks or insulated wire nuts; no tape is needed for such connections.

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Typically the number of poles represents the number of sources being switched. In a normal household ON/OFF light switch the single pole is the HOT wire (Black). The most common single pole switch is also single throw. The ON/OFF switch described above. This switch is abbreviated SPST. You could also have a single pole double throw switch (SPDT). and other variants on the same theme. The term gang is usually used to describe multiple switches in the same electric box. For example, if you had 3 switches together with a single switch plate, the switch plate would be described as a 3-gang switch plate.

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This is also known as phantom power or vampire power. Even though an electric device is turned off, it is still drawing a small amount of power. A television, for example, continues to draw power so that it can sense the remote control to turn it on, or to keep the time.

Other examples are chargers left plugged in for telephones, video games, etc.

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Modern life as we know it would not be possible without magnetic energy. It is used to generate and distribute electrical power for our homes and factories (generators and transformers). It is used to perform work (motors). It is used in telecommunications (telephones, televisions). The computer you typed your question on could not function without it (switching power supply). It is used to diagnose medical problems (MRI). The ignition system in most cars uses magnetics to provide the spark to run the engine. There are literally hundreds of uses of magnetic energy, these are just a few! Earth's magnetic field allows us to navigate by compass, but more importantly protects us by deflecting harmful radiation. Oh, and how could we live without those handy little refrigerator magnets that we use to stick notes to the fridge?

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It may work but may be brighter than the rating stamped on the bulb or the filament may burn out very quickly, depends on what sort of bulb it is, wherhet is uses a ballast or some form of regulator etc.. its probably best not to try unless your positive it is designed to take double the voltage

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The dielectric stress is the stress placed upon a material when a voltage is placed across it.

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if electrical panel is labeled LT, usually means its a lighting panel

LT means "Low Tension" panel. Not lighting.

Lighting panels are normally known as LDB (lighting Distribution boards)

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If you were trying to obtain a 220 voltage from a 480 volt three phase system it can be done with a transformer. To take a 220 volt single phase system and change it into a 480 volt three phase system, it can not be done.

Depending on the amount of money you want to spend to make this happen there is a device on the market called a VFD ( Variable Frequency Drive). On the three phase input terminals you apply your single phase voltage. On the output terminals you connect your three phase motor. When run in this configuration there is an internal switch that has to be changed to let the VFD know that it should be looking for only two lines on the input to be hot. Other wise the VFD thinks that there is a line loss on the three phase input terminals and the unit will not start.

Actually, this is not true. You can go from 220 volt single phase to 480 volt three phase but in a rather cumbersome way. You would first need a phase converter - they have solid state VFD's that will go from single phase to three phase or you can build a simple rotary phase converter. After the phase converter, you will have 208/220 volt three phase power. From there you need a power transformer to step up the voltage.

Remember you have to know whether you want delta or wye configured transformers!

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A Megger is a device that will test the insulation of the circuit it is connected to. It produces a DC voltage to check for leakage current from the conductor to ground. It then will give you the value of insulation in Mega Ohms. Generally anything less than one Mega Ohm per thousand volts is poor insulation. Be careful when using this device because it does produce high DC voltages and it can give you an awakening jolt. It is most commonly used to test the insulation in motors and generators but can be used in many other applications.

Note that the word "Megger" is actually a trade name (hence capital M). The generic name for such an insturment is "high-voltage insulation tester".

Although Mega Ohms is strictly correct, you'll most often hear it pronounced rather more easily as "Meggohms".

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The terminology would typically reference a device such as a power supply, charger, diverter or transformer. The Input Voltage is the voltage supplied to the device to make it work. The Output Voltage is what the device supplies to an application.

For example, a power supply for a laptop might convert 120 VAC to a voltage like 19.5 volts (A Sony Laptop) for charging a laptop battery.

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Yes. There is a sign of Speaker/sound on a side DMM. Move the knob of DMM on that symbol. Now connect one prob of the DMM on one circuit element & one under that(If you are designing the circuit on PCB or plain board). If a sound come out of that then it means that your circuit element & the portion below that are properly connected.

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Are you going to use the 9-volt motor as a dynamo, and the 9-volt dynamo as a motor? Yes, the motor can rotate the dynamo because DC motors and DC generators are actually the same thing--they just apply power to the terminals of a motor to make it turn, and turn the shaft of a generator to make power appear at the terminals.

Having said that, if you're going to try to connect the shaft of a 9v motor to the shaft of a 9v dynamo, and use the dynamo to power the motor so as to create a perpetual motion machine...that won't work. The motor wastes a little bit of energy, as does the dynamo. It is possible to build a device that uses a motor to drive an alternator, which is the AC version of a dynamo. You power the motor from the AC grid, and power something that's very sensitive to noise on the line from the alternator. This is called a Motor Generator set, and it's how they powered Cray-1 supercomputers.

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daytime classes windows and skylights

not Microsoft windows btw that will increase energy consumption

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Ac current. Ac current is easily controlled for voltage and frequency. The diesel engine runs a generator that generates AC current for use in the electric drive motors on each drive wheel.