Electrical Wiring

Three phase means just that- three phases in the windings of the motor. Therefore three leads (outputs) are used to supply power. A lot depends on the number of wires coming out of the motor. In large industrial motors, you can have 9 leads. The wiring of the motor depends on the application- the motor will either be wired in series (leads 1-4-7, 2-5-8 & 3-6-9 combination) or parallel (4-7, 5-8 & 6-9 with the first three leads connected separate).
To change the direction of the output shaft, simply reverse any two of the three leads.

I assume that by two-phase, you really are talking about a supply with two hot wires and a neutral, such as 120/240 volt. This is single phase power, it just has power taps on both ends of the transformer winding, the neutral is the center tap.

I don't think it is possible to convert or rewire your motor. A large 3 phase motor must be run on a 3 phase electrical supply. It will not run and will overheat if you try to connect it to a single phase supply. The only way to make a 3 phase supply from a single phase supply is to use a converter like a motor-generator set. That would be way more expensive than getting a new motor.

a traditional rcd wont work as it uses the difference between the incoming active and neutral to detect current loss it has to read 0.

In particular, an RCD alone will not detect overload conditions, phase to neutral short circuits or phase to short circuits. Over-current protection must be provided.

The normal phase of an element is:

What form it is (liquid ,solid ,gas)

what the classification is (nonmetal ,metal ,metalloid)

Yes because the total load is only 18 amps. It would be more usual to allow three 9-amp circuits on a 20-amp breaker because the total current would probably not exceed 20 amps at any one time.

As close to zero ohms as makes no difference.
Zero, or close to it. It should be nearly the same as if you touch the probes together.

Wire size is based on the amperage that the load requires. For an accurate answer the motor amperage is needed. That said you can get an approximate figure by this method. 1 HP = 746 watts. This formula for amperage when HP is known. HP x 746/1.73 x Voltage x %Eff x pf. Use a Efficiency % at 90 and a power factor of .85. A horse power of 5 x 746 = 3730/1.73 x 220 x 90% x .85 = 12.81 amps. Code states that motor supply conductors have to be 125% of the full load amps = 16 amps. Code also states that conductors can only be loaded to 80% on continuous load which a motor falls into. A #12 copper wire 90 degree insulation is rated at 20 amps x 80% = 16 amps. A #12 wire will do the job. It will need a 40 amp three pole breaker, 50 amp non time delay fuse or a 30 amp time delay fuse to feed the motor.

Any where between 220 and 240 volts are a nominal figure in the same voltage range. It is brought about by the power company, as they have a responsibility to keep voltages within a certain 10% range. The load will only notice a difference of 1% on the load current. eg. Wattage load of 2400. Amps = watts/volts. 2400/240V = 10 amps. 2400/220V = 10.9 amps.

It depends on the country you're in (what codes apply), local utility standards, land being crossed (is it hilly?), type of structure/configuration of wires, and the distance between towers. At its' lowest point, the conductor could hang ~25 feet off the ground.

A single-phase transformer works with a single-phase supply, while a 3-phase transformer is used with a 3-phase supply.

A single-phase transformer has 2 wires on the primary and secondary (ignoring taps) while a 3-phase tansformer has 3 or 4 wires on the primary and secondary.

A short circuit is a low resistance connection where one is unexpected. It causes a diversion of current from the intended load, and, since it is usually a higher than expected current, it often causes the protective device (fuse, circuit breaker, or relay control logic) to trip.

The simplest answer is that the electric utility uses a transformer across 2 of the 3 hot leads to develop a single hot lead with an earth reference. What follows below is frequently edited by both amateurs and professionals, with mixed results. Wikipedia is a better source of more detailed information on this subject, in part because the article on three phase power has pictures.

Verify wiring layouts by making measurements, before connecting and/or energizing equipment. A 120V single phase 2 wire should have one hot wire, a 230V single phase 2 wire should be assumed to have two hot wires, and a 230V single phase 3 wire also should have two hot wires.

You cannot build a power tube amplifier without bias. At minimum, you need some kind of negative bias on the control grid, and you might need positive bias on the screen grid as well as cathode voltage on the suppressor grid.

Depending on who does the work it could be less expensive than getting a different air conditioner. The compressor will also need a capacitor and some rewiring. The old unit could have a 3 phase blower motor also which could run the price up even more. Although the changes can be made, the warranty at best will probably be a one year warranty and a new unit could have a 5-10 year warranty.

Wow that is hugely dangerous and a risk of fire. They get hot because you are running a large amperage through them, melting cause it is overloaded.

For example. If you had a 20 amp breaker, and 12 gauge wire (20A), and a 15 amp recepticle. Then the most you would want to run on that recepticle is 12 amps continuously, 15 amp peak non continuous. If you replaced the recepticle with a 20 amp recepticle you could run 20 amp peak, or 16 amps continiously. You could not go with a higher amp outlet as the circuit only has 12 gauge wire, and a 20A breaker.

If you plugged something with a 30 amp draw into said outlet you would get the outlet hot.

find out how many amps you are drawing off the outlet in question, then check the gauge of the wire in the wall, and the rating of the outlet and breaker that outlet is off of. Then we could decide what to do next.

Well,Being a Electrician, my advice is if you have to ask question about that call a Electrician IMMEDIATLY!!!!It could be a number of things.A loose wire in the back of plug in,worse yet a broken wire that keeps rubbing together ,(EXTREME FIRE HAZARD)Electricity is nothing to fool with if you are not trained.BE SAFE<SMART.Turn circut breaker OFF.CALL ELECTRICIAN

Really,cmon. Residential pulling that much power off ! outlet.....look outside the box!!how old is house would be first question

As well as motors, contactors also have kW and Ampere ratings. Have a look on the name plate of your motor and you will see its maximum current draw (amps). Select a contactor with a current rating greater than this.

Current = (Voltage across the circuit) divided by (Total resistance of the circuit).

The current is the same at every point in the series circuit.

Higher capacity (higher KW rating) motors take huge starting current to get over the starting torque. To avoid the high inrush of current, star delta starter is used. When started, the motor gets connected in star for few seconds and switches over to Delta and continues to run in delta. In this case motor is designed to run in Delta.

It depends on how many amps it was designed for. A 12.5kV/600v 10kVA 3 phase transformer can handle ~.5 amps on the primary and ~10A on the secondary. A 600/120V 10kVA 3 phase transformer can handle ~10A on the primary and ~50 on the secondary.