Electrical Wiring

Suppression of harmonics

Earth wire is meant to protect the user in case there is earth fault in the device or circuit. Only earth wire alone is not sufficient. It needs to be provided with suitable circuit breaker that breaks the circuit automatically.

A C dry cell battery has a voltage of 1.5 volts. The amperage produced by the battery is dependant upon what the load current is of the connected device. The higher the load current the quicker the battery will discharge, shortening the life of the battery. Rechargeable C cells will have to be recharged at this point in time. Four cells in parallel will produce a total of 1.5 volts. Four cells in series will produce a voltage of 6 volts.

Wiring the DC outputs of the 2 converters in series would double the DC output voltage but not the current (amperage). The maximum safe output current would just be the same as the rating of the convertor which has been designed for the least current output. So be sure to check the rating plates of the two convertors to see which one has the lowest output current: that is the maximum current your load device should take. Yes you can do them in series. You take the positive of one and connect it to the negative of the other, then the other positive and negative are still pos. and neg.,,,,,,,,,,,,,,, This will double the VOLTAGE but keep the AMPERAGE the same. ,,,,,,,,,,,,,,, I do not know if it will actually work or not on A transformer though. For parallel : You connect the pos. to pos. and neg. to neg., This will keep the VOLTAGE the same, and double the AMPERAGE.,,,,,,,,,,,,,,,, I don't know if this will work or not either. This will work on BATTERIES, I am not sure about transformers. Re the parallel case mentioned above, that is a very well-worded answer because it is cautious about saying what is likely to happen! To illustrate that case: you have a 12 volt DC car light bulb which is rated at 60 Watts so it takes a current of 5 Amps. You want to power-up the bulb from the mains using two AC to DC converters which each have a 12 volt DC output voltage but a rated output current of only 2.5 Amps each. Wiring the DC outputs in parallel could work to allow double the current output of a single converter to be produced BUT ONLY IF THE TWO CONVERTERS WERE CAREFULLY WIRED with their DC + terminals (or wires) connected together and their DC - terminals (or wires) connected together. *** (See note below.) However, whilst the resulting output voltage might be close to the output voltage of one of the converters, that cannot just be assumed! Particularly if the converters were not identical (if they were of different makes and/or power outputs, say) then the different slew rates of the convertors could cause the final output voltage to hunt around as the two converters tried to control each other. This voltage hunting would be accompanied (or caused by!) a current circulating between the two converters that was much higher than they were designed to handle. If they were badly matched such an unstable situation could lead to serious overheating and maybe a burnout of one of the convertors, if not both, even if there was no actual visible smoke and/or fire. (However this is not likely to be as bad as the situation described in the Note *** below.) Such voltage hunting and higher than normal output current circulating between the converters (please note this does not involve the attached load - say a light bulb - at all!) might not be visible using normal test meters but, if present, would be seen on an oscilloscope. To be safe - and to help avoid any overheating or burning-out of one or both of the converters - if you wished to try using them in parallel it would be very wise to wire a proper lab-type variometer into the AC mains feed and, whilst everything is switched off, attach your desired load to the parallel-connected outputs of the two AC to DC converters. Then do this test: very slowly bring up the AC supply voltage from zero, measuring both the DC output current and voltage of each converter all the time. You should also watch and feel the adapters throughout the test to be able to detect any signs of overheating well before the full mains voltage is tried. If you don't have the right kinds of controllers and instruments to measure what is really happening it would be best not even to try to do the above parallel-connecting "blind" at all. ("Blind" meaning "without instruments".) Instead the best plan would be to obtain a single AC to DC converter which has been designed to give the desired output current at the desired voltage. *** Note : IF THE CONVERTERS WERE WRONGLY WIRED with the DC + terminals (or wires) of one connected to the DC - terminals (or wires) of the other THERE WOULD BE A MASSIVE CURRENT CIRCULATING BETWEEN THE TWO CONVERTORS AND, IF FULL MAINS VOLTAGE WERE SUPPLIED, BURNOUT IS PRETTY MUCH GUARANTEED!

Standard is 48" to the top of the switch box.

I'm guessing this is in reference to a restricted earth fault, and you want to know what the opposite is? Restricted earth fault protection is designed to operate for earth faults within a specific zone. Unrestricted protection will operate for faults "anywhere", as long as the pickup can be satisfied.

For example, REF (restricted earth fault) transformer protection looks for a small amount of neutral current, and if this exists, and the relay identifies this current as being within the zone of protection, the relay will trip. If it were unrestricted, the small amount of neutral current alone would be enough to cause a trip.

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Single phasing occurs when one or two of the fuses protecting the load fault open. This is likened to using two legs from a three phase source to provide two single phase feeds, hence the name.

This is how an induction motor normally works, hence the name. The supply voltage is connected to the stator winding(s) and a current is induced in the rotor. A synchronous motor, on the other hand, will have current supplied to the rotor through slip rings and brushes. The rotor current is generally supplied as DC though, or else rectified in the rotor.

Single phase power from a L-L voltage of 208 volts is calc'd:

P = V(phase to phase) * I (individual phase current) / sqrt(3)

Total power from all three legs is the above P * 3.

P is in watts; continuous sampling will result in watt hour measurements; 1000 x this is kWh's.

I "think" it stands for Wiring Harness It means WEATHER CONDITION - WET OR WATER Please refer to this link:http://database.ul.com/cgi-bin/XYV/template/LISEXT/1FRAME/showpage.html?name=ZLGR.GuideInfo&ccnshorttitle=Thermoplastic-insulated+Wire&objid=1074134071&cfgid=1073741824&version=versionless&parent_id=1073996426&sequence=1

Armored electrical cable contains insulated electrical service wires protected by a flexible steel covering. Unarmored electrical cable has no protective flexible steel covering, its covering is made of plastic.

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Armored cable (BX) is the older version of Metal Clad cable (MC). It was flexible steel covered wire that used the steel as it's Ground. BX was a poor grounding system so it was replaced with MC which looks similar but has a separate Grounding conductor. MC is most often made with aluminum as its cover.

Armored cable if used today will refer to MC type wiring.

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Some kinds of armored cable are in fact made to a tougher standard than the ordinary soft wire strand types of shielded cable that are used for hooking-up antennas. The 'armor' is actually a thin flexible metal film that better protects the wire or wires inside from damage in high use or high traffic areas. Such kinds of armored cable are also used in radio frequency assemblies in electronic equipment.

LM stands for "NATIONAL SEMICONDUCTORS". i.e, that particular ic has been manufactured by "NATIONAL SEMICONDUCTORS".

infact on any ic two letters indicate the manufacturing company's name,eg MC stands for Motorola(now freescale),SN for Texas instruments,NS for signetics, CM for California microelectronics and so on...

Probably because Egypt came under the British sphere of influence, whereas KSA came under the US sphere of influence.

Sometime you may have a switching requirement where you have a white wire you want to use as a "Hot" connection. Depending on your local inspector you can often get away by using black electrical tape at each end of the circuit to indicate it is a "Hot" wire. On new construction this wouldn't typically be accepted.

ponypomp--

12ga wire is 12ga wire,the color is used to indicate what it is.

House wire is romex, so you have the color already inside.

For the most part, wire that is run in conduit is single strand and does not have a sheathing.

Ex- I buy a 500ft spool of thhn/thhw- I do not buy a spool of black,red,white,green.

I only buy black,and color code all other wires.

I wrap the other ends with red,white,green, electric tape,and and inch below the top wrap with another wrap, to indicate that the wire is used for hot,neutral and ground.

As the person said above,about new, but anyway,when dealing with romex,there is no reason you should have to use a different color, unless you have say 12/2wgr but needed 12/3wgr, do not run a single strand with the rest to make up for the missing wire.

Some switches are installed as a break,that is, hot does not run to switch, there is only one set of wire(12/2wgr) from switch to fixture, so the hot goes to light box, but then runs to switch then back to light, so inside the box or fixture I connect the black to black then the white coming up from switch,wrap with black tape and attach to light because it is now a hot wire.

I am not sure whether I am answering your question or if I have missunderstood how you have written it, but I am assuming you mean why do pigeons not get electrocuted when sitting on power lines.

The answer to this is simply that if they are sitting on one wire (one phase) and not touching any other wire (whether is be another phase, earth or neutral). They will not be electrocuted due to the fact that current needs a path to travel. Voltage (otherwise known as potential difference) is the difference in potetnial between two conductive materials. Now a Pigeon would carry current (just like humans) and be electrocuted IF it was to touch two wires at the same time, as it is making itself a part of a circuit (in this case it would be a short circuit.) But if it is only touching a wire that is, for example, 11,000 volts, and is not touching any other conductor of another phase, or earth potential. then the Pigeon itself would be at the same potential as the 11,000 volt line and be perfectly fine.

I hope this answers your question.

It is very rare to have three-phase electricity coming into a residence. One of the wires is probably the neutral (It will be white or black with white stripes.) The ground comes in from a ground rod near the main, and connects to the ground coming from the meter, AND (If the main fuse box is the first disconnecting means,) the neutral and ground bars have to be bonded together in the box.

Any ground wire has to be connected to an independent ground wire that returns directly to the distribution panel and not to the neutral of the circuit.

XLR refers, not to the cable (wire) per se, but actually to the type of connector used. An XLR connector has 3-pins and is used primarily in audio. Professional microphones and other audio equipment use it. Of the three pins, two are for the balanced signal, and one is for the shield. The wire used then is a two conductor shielded cable using a braided wire or a foil shield. So, an "XLR cable" refers to a two conductor, shielded cable with XLR connectors on each end.

There are two reasons one cares about polarity in AC circuits: safety and phasing.

In a common household circuit, we are concerned with safety. One side of the AC line, called the "neutral", is at the same voltage as ground. This side of a common outlet is identified by the wider slot and plugs have a wider blade. In the wiring, the neutral is white. On wiring devices, the neutral wire connects to a silver colored screw. On appliance cords, especially flat, two-wire "zip" cord, the neutral side usually has a rib or ribs to identify it. Sometimes this rib is very subtle, like a square corner on the neutral lead where the hot lead is completely round.

The other side of the line is the "line" or "hot" wire. In household wiring, this side is black or red. It corresponds to the narrow slot in an outlet and connects to a brass colored screw.

Circuit breakers and switches are supposed to be wired in the hot lead so if they are turned off, both sides of the connected receptacle or light socket are at neutral potential. If this were not the case, you could get a shock from a light socket which is turned off, if you were also touching a grounded contact of some kind. For further safety, the larger annular threaded contact in a light socket is supposed to be connected to the neutral and the smaller button contact to the line side.

Years ago, this was even more important because household electrical appliances were often made of metal. Plastic wasn't as common. The metal would sometimes be connected to the neutral wire. If the polarity was reversed, the metal case would be "hot". Many old tube-type radios had no transformer in their power supply and the chassis was connected directly to the wide blade of the plug. If the receptacle was wired wrong, the whole radio would be "hot".

The second reason we care, phase, relates to more complex wiring such as three-phase circuits and in electronics. AC voltages are really DC voltages at any particular instant in time and thus have polarity. The polarity of these instantaneous DC voltages is just as important, and for the same reasons, as constant DC voltages.

"Phase" refers to the relative polarity of these instantaneous DC voltages among a related group of AC voltages. If you wire two AC sources in series and they are "in phase" then the voltages add as expected. If one source is reversed, then the voltages subtract. Similarly, paralleling two AC sources which are out of phase, will have the same result as paralleling two DC sources with opposite polarity - a fire.

The proper terminology is L1,L2,N. N is for neutral and it is this wire that is grounded. The voltage measurement from the L1 to N will give you 120 volts. Also from L2 to N will give you 120 volts and as you know from L1 to L2 will give you 240 volts. Single pole breakers in the panel board starting at the top, alternate between L1 and L2 all the way down to the bottom. These breakers all have 120 volt outputs. If you plug a 2 pole breaker into two slots then you get 240 outputs because L1 and L2 are adjacent to one another.

Current on neutral in a multi phase system is caused by imbalance between the phases.

Question: Are you talking about neutral or ground? The two are very different. Although neutral is grounded, it is expected to be a current carrying conductor, so current on neutral is normal, so to speak. Ground, on the other hand is a protective circuit that is not supposed to have any current on it at all.

Usually a centrifugal switch. When the rotor reaches proper speed, the weights fly out and move a set of contacts so they are disconnected, thereby disconnecting the starting circuit.

The black wire is the hot wire through which the electrical current flows to the appliance. The left over voltage which is usually zero flows back to the main circuit panel through the white neutral wire where it flows to ground.