Electrical Engineering

Step Potential is the potential Difference between two points on the earth's surface, separated by distance of one pace, that will be assumed to be one meter in the direction of maximum potential gradient (IS 3043) Touch Potential is the potential difference between a grounded metallic structure and a point on the earth's surface separated by a distance equal to the normal maximum horizontal reach, approximately one meter. (IS 3043)

If your meter is running with no load connected, meaning your main breaker is off, call your utility company and notify them of the problem. There is no reason a meter should be turning with all loads disconnected. Some people suggest to get video evidence of the meter running with your main breaker disconnected. Supposedly this may make getting reimbursed from your utility company easier.

http://en.wikipedia.org/wiki/Electricity_meter

dont-know

Clamp the meter around the energized conductor that is connected to the load to be measured and read the amperage off of the dial face of the meter.

Power interfacing unit

Impedance = √(Resistance2 + Reactance2 )

= √(22 + 42)

= √(20)

= 4.47213595

the fuse protection feature should be adapted to overload characteristics of protected objects, considering the possible short-circuit current, choose corresponding fuse breaking capacity;
2, fuse to be adapted to line voltage level, the rated voltage of rated current of the fuse is greater than or equal to the rated current melt;
3, line fuse melts at all levels in the rated current to the corresponding coordination, keeping the level of the melt must be greater than the rated current level of the melt under the rated electric current;
4, fuse melts to use combination according to the requirement of the melt, not allowed to increase the melt or other conductor instead of the melt.

The interpolation factor is simply the ratio of the output rate to the input

8x65x1.8/240=

The fuse rating is inherently tied to the current flow through the fuse, not necessarily the voltage.

The fuse has a small internal "wire" that has a specific resistance; when enough current flows through it, the power dissipated by this "wire" will melt. This power can be expressed P = I^2 x R.

For isolation purposes, fuses are also specified with a voltage rating. This rating is spec'd based on the distance between the (internal) terminals of the fuse that don't melt. For higher voltages, this distance must be increased to prevent power from "jumping across" the small area where the "wire" has melted (this is called arcing).

So when picking a fuse, you must pick a fuse that is rated for the voltage you are using (or higher - you can use 250 volt fuses on 120 volt equipment), and rated for the current you want to allow to flow (specified in amps).

The equations you list in your question are not inherently tied to fusing, but are power fomulas:

P = watts = voltage * current; ohm's law states V = I / R, so

P = V * I = V^2 / R = I^2 * R

V*R does not equal power.

In a shorted circuit, the temperature of the wires increases. This is because the wires are not perfect conductors - they have resistance - so the large fault current that flows generates a voltage across the wires, which then generates power, generating heat.

Pole mounted

Outdoor

A machine that runs on an alternating current.

Electrical resistance is measured in Ohms.

Once apon a time in a galaxy far far away locked in a tower was e.t. and the scary door....they thought it would be great to invent a device with which the potential differnce of the world could be controlled. this was known as thor's hammer

The Decepticons.

In open circuit, find the ratio of voltages across the slip rings in rotor side to the applied stator voltage.

There is none. There is a relationship between voltage and current and turns ratios in a transformer. But this rule remains - power in = power out. You don't get anything for free.

Horsepower is a unit of energy delivery rate, while KWH is a unit of total energy. The two units are not convertible. It is true that, for an electric motor, 1 horsepower is defined as 746 watts, or 0.746 KW, but KWH is an entirely different thing.

rotor speed = 0

The device described here goes under a few different names, and one is a motor-generator set. The motor-generator set (MG set) already exists, and one example might be the ones in submarines. Let's look at the setup.

The electrical bus in the modern submarine is AC, and the storage batteries are DC. This MG set has a DC end connected to the batteries, and an AC end connected to the electrical bus. By sticking that MG set between the batteries and the AC bus, the AC power, delivered normally by steam turbine generators, charges the batteries and keeps the lights and everything else powered up. If the turbine generator goes down, the MG set, which has been acting as an AC motor and a DC generator, will switch functions. In its new configuration, the MG set's DC end becomes a motor (taking battery power), and the AC end becomes a generator, which then powers up the ship's AC electrical bus.

There may be some small MG sets out there, and a bit of searching may reveal a source or sources. Certainly as this equipment already exists, it is just a matter of finding it in the right size. Note, however, that banks of storage batteries can be set up, an AC charging system can keep them up, and a big inverter can convert the stored DC to a usable AC voltage for delivering power to any AC device (with load limits, of course). The advantage here would be that you can buy all the batteries you need, a small emergency generator, a battery charger, and a handful of inverters right now. All of those things are common, readily available, and fairly inexpensive compared to what you'd have to shell out for a little MG set.

Slow blow

Fuse that can withstand a heavy current (up to ten times its rated value) for a small period of time before it opens. Normally used for inductive loads like fans, transformers, etc.

Fast blow

Fast-acting fuses have no intentional built in slow-blow and are used in circuits without transient inrush currents. Fast-acting fuse opens on overload and short-circuits very quickly. This type of fuse is not designed to withstand temporary overload currents associated with some electrical loads.

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