A 750 MCM wire with an insulation factor of 90 degrees C is rated at 500 amps. De rated to 80% will allow 400 amps on the wire. A 900 MCM wire with an insulation factor of 75 degrees C is rated at 520 amps. A 1500 MCM wire with an insulation factor of 60 degrees C is rated at 520 amps. Parallel 250 MCM will give you the same usage. A 250 MCM wire with an insulation factor of 75 or 90 degrees C are rated at 255 and 265 respectively. 255 x 2 = 510 x 80% = 408 amps. 265 x 2 = 530 x 80% = 424 amps.
It depends on the length of the run
For a 200 amp service, it is recommended to use 3/0 copper or 4/0 aluminum wire. These wire sizes are suitable for handling the electrical load of a 200 amp service with the appropriate safety margin. It is important to consult with a qualified electrician and adhere to local electrical codes when determining the wire size for a 200 amp service.
For a 70 amp service at 240 volts, you would typically use a wire size of 4 AWG copper wire. This wire size is suitable for carrying 70 amps of current safely over a 240 volt circuit. Be sure to consult local electrical codes and regulations to ensure compliance with requirements in your area.
For a 1200 amp service, you should use a copper ground wire of at least 3/0 AWG or an aluminum wire of at least 250 kcmil to meet the National Electrical Code requirements. It's always recommended to consult with a licensed electrician to ensure the proper sizing and installation of the ground wire.
Yes, but at every reduction in wire size there has to be a breaker sized to the smaller wire size. The wire size for 100 amp panels is recommended at #3 copper conductor. From the 200 amp feeder panel you will require a 100 amp two pole breaker for each of the two 100 amp services. Keep in mind that if you run the 100 amp services close to maximum this will take away the capacity of the 200 amp service for other branch circuits coming off of it. Also keep in mind that if the panels are located, not in the same building as the 200 amp service that the 100 amp panels will be treated as separate services and will have to be constructed like a 100 amp service. This includes ground rods. Also the bonding screw will have to be removed that connects the neutral buss to the panel enclosure.
It depends on the length of the run
You need to look at the regulations that apply in your country. If in doubt, use a neutral wire of the same size as the live wire or wires.
A 100 amp residential service requires a size #8 copper wire, it should be insulated in green.
4 inch rigid conduit
2AWG.
2 copper
A 200 amp service panel with a 60 amp sub-panel.
10 guage
Yes, the wire size has to be increased. The existing 100 amp service will now probably have a #3 conductor with an insulation factor of 75 or 90 degrees C which is rated for 100 and 105 amps respectively. Increasing to a 150 amp service will use a #1/0 wire size. If you are thinking of an upgrade, skip the 150 amp service and go to a 200 amp panel. New homes are installing 200 amp 42 circuit panels. The extra cost is only reflected in the materials as the labour costs will be the same regardless whether a 150 amp or a 200 amp panel is installed. The wire size for a 200 amp panel is #3/0. With an insulation factor of 75 or 90 degrees C the rating is 200 or 210 amps respectively.
For Service Entrance Cable 600 kcmill (Thousands of circular mils).
#10 wire is used on a 30 amp service.
AWG 12 will suffice.