Modification of Old Electrical Work

For a 300 amp three phase circuit breaker, you should use wire that is rated for at least 300 amps. The wire gauge needed will depend on the material (copper or aluminum) and the installation method (conduit or cable), so it's recommended to consult with the National Electrical Code (NEC) or a qualified electrician for the specific wire size required. Using the correct wire size is crucial to ensure safety and prevent overheating.

P = E^2 / R

P = (240 x 240)/ 8 = 7200 watts

If this is coninuously energized for 24 hours:

7.2 kw/hr x 24 = 172.8 kw/hrs

Don't overload it.

Your circuit may not be large enough. If it is 15 amps at 110 volts I'd bet that's it. If it shares a circuit with lights or other equipment that may be a major factor also.

It actually is called a three way switch. The reason you use them is so you can turn on lights from two locations like two entries to the room that may be far apart

To check if you have 240 volts on a 30 amp two pole breaker, you can use a digital multimeter set to measure voltage. Turn off the breaker, then test between the two breaker terminals and ground. If you read around 240 volts, it indicates that the breaker is providing the right voltage. If not, there may be an issue with the breaker or the wiring.

I'd try to stay about 16 amps to prevent the breaker from nuisance tripping.

That is as many as 32 - 60 watt incandescent (normal) lights or 83 - 23 watt CFLs. In practical terms it is hard to overload a single circuit with lights or other small loads (just about anything using a receptacle except the obvious AC unit or vacuum cleaner).

Yes, a relay with a 40 amp rating can be used in a circuit with a 30 amp fuse. The fuse is designed to protect the circuit from overcurrent, while the relay's rating indicates the maximum load it can handle. As long as the total current drawn by the circuit does not exceed the fuse rating, the relay should function properly.

Yes but it is not compliant with the NEC you can use a 240 volt circuit, (Ground, Hot, Hot) you would use a (either) hot wire with a ground wire and that will be a 120 volt circuit.

I strongly advise you not to do this though because a ground wire is not trully meant to carry current and it will not be approved by any inspector.

To calculate the number of receptacles on a 20 amp circuit with a 120V supply, you need to consider the total circuit capacity. A 20 amp circuit can typically support around 10 receptacles. However, always consult local building codes and regulations to ensure compliance and safety.

If the load is not grounded and has no connection to neutral then nothing should happen. This begs the question of why you would do such a thing. If you touch any metal part on the load you will likely get a shock.

It is NEVER a good idea to use a higher value fuse. The reason for the 10 Amp fuse is that it blows at 10 amps which the wire and device being protected is designed to handle. If you substitute 15 amps and that amount of current flows in your device, it may destroy the device and other things in the path of the current.

The resistance for 400 ft. of 10 AWG copper is .4 ohms. This would be a voltage drop of (.4 x 20) or 8 volts. For 120 VAC service this is a 6% which is a bit high. At 240 volts it is 3%. At 8 AWG the resistance is .251 ohms which will give you better performance.

For a 200 amp service running 120 feet, you would typically need 2/0 gauge copper wire. This size wire is capable of handling the current without significant voltage drop over that distance. It's always recommended to consult with a licensed electrician for a specific project to ensure compliance with local electrical codes and safety standards.

A black and white single wire in a ceiling fan is typically used for connecting the fan's light kit. The black wire is for connecting the live/hot wire, which powers the light, while the white wire is for the neutral wire, completing the electrical circuit. It's important to follow the manufacturer's instructions when connecting the wires to ensure proper installation and safe operation.

Yes you can put a 4 prong plug on a 3 prong appliance. A 4 prong plug is designed for 3 phase wiring. a 3 prong appliance is designed for single phase wiring. In the United States, going across two of the hot wires in three phase wiring will give you 208 volts instead of the 240 volts you would get with single phase wiring. Going across one of the wires will give you 104 volts instead of the 120 volts you would get with single phase wiring. Your stove will not be as hot.

On the other hand, if you are trying to run an appliance with a motor, you could burn up the motor. The motor is designed so the wire from one side will be on when the wire from the other side is off. That will not work when they are out of phase. Hopefully, your circuit breakers and fire extinguishers are in good condition. ( The answer above is incorrect and that's why I am leaving it alone, the correct answer follows.) your question probably applies to a residential dryer or cooking unit. Past codes only required three wire cords. The bare wire on this cord acted as ground and neutral. Now the code requires that the metal enclosure of these appliances have a separate grounding conductor and neutral. To convert a dryer to four wire, remove the wiring terminal cover, you will see a terminal block with three wires on it. the center wire is the neutral/grounding conductor, it should also have a copper bonding strap from this block to the frame of the dryer. Remove this strap and discard. Remove the two outside wires and complete removal of old cord. Install the new cord and connect the white wire to the center terminal, the green wire to the dryer frame. Connect the two hot wires to the outside terminals and reinstall the terminal cover. Do not put to much confidence in the original answer as part of his answer reveals to me he is an amateur electrician and shouldn't answer questions he knows nothing about.

You are correct that I knew nothing about that!. On the other hand, I have seen licensed electricians really mess up 3 phase in industrial settings!

At least 000 AWG copper or better yet, 0000 AWG copper. Another consideration is how far the 200 Amps are to be carried. Wire has resistance and 0000 copper has a resistance of .04901 Ohms per thousand feet. At 200 Amps, this means that over one thousand feet the voltage will be 9.8 Volts lower than at the starting point.

The question can't be answered without knowing what the voltage is. That is because the allowed voltage drop is 5% of the supply voltage, so you need to know the supply voltage. Then the wire calculation aims to find out what the minimum size of wire is that produces that voltage drop or less.

Yes you can use a 60 amp breaker to feed a 100 amp sub panel. The wire from the 60 amp breaker must be #6 or larger. You will not be able to draw the maximum 100 amps from the panel you will be limited to 60 amps.

no it won't, it will only effect your circuit breakers........your bill depends on how much electricity u use.................

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Conductors that are too small will actually reduce your electric bill, but for bad reasons. Smaller conductors have higher resistance which reduce how many amps can flow. But at the same time can produce more heat and provide less voltage than you need to equipment.

Smaller conductors consume more power in themselves, limiting how much power gets to equipment.

Yes. I know of no limits to how many regular receptacles (outlets) you can "piggy back" onto one GFCI receptacle.

However, in commercial and industrial construction there are limits to how many receptacles can be placed on any one circuit. These limits in the United States and according to the NEC are: 10 receptacles on a 15 amp circuit and 13 receptacles on a 20 amp circuit.

To wire a three-prong twist lock receptacle to a four-prong male connector for 220V, you will need to connect the two hots, neutral, and ground wires from the male connector to the appropriate terminals on the receptacle. Make sure to follow the specific wiring diagram for your receptacle and connector to ensure proper installation and safety. If you are unsure or unfamiliar with electrical wiring, it is recommended to seek the assistance of a licensed electrician.

The pilot light in a GFCI is an indication that the receptacle is hot, maybe they should add a red pilot light to indicate that no power is coming out of the outlet and green when power is available.

No, typically the black wire goes on the dark-colored screw (usually black) and the gold screw is reserved for the traveler wire in a three-way switch setup. Make sure to follow the specific wiring instructions provided with your particular light switch.