There is insufficient information. If this is question about a dryer or stove, please specify.
The typical rating of a hot wire relay contacts is 35 amp
A #3 copper wire with an insulation rating of 75 or 90 degrees C is rated at 100 and 110 amps consecutively.
A #4 copper conductor with an insulation factor of 75 or 90 degrees C is rated at 85 amps.
You never, ever mix wire sizes within a circuit. However you can wire a 30 amp circuit using AWG # 8/3 wire, although that is overkill and AWG #10 wire is what you would normally use on a 30 amp circuit.
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.
That is 10 amp wire.
10
The ampacity or amp rating of all wire is rated by the size of the wire. NM (non-metallic sheathing) wire is no different. In household wiring 14 gauge wire must go on a 15 amp breaker/ 12 gauge goes on a 20 A and 10 gauge goes on a 30 Amp.
The typical rating of a hot wire relay contacts is 35 amp
The typical rating of a hot wire relay contacts is 35 amp
80 amps
A #3 copper wire with an insulation rating of 75 or 90 degrees C is rated at 100 and 110 amps consecutively.
Yes you can. That being said the different wire size that is to be used can not have a smaller current capacity than the breaker that is supplying that circuit. In other words the wire size that is added to the circuit has to be larger not smaller. For example a 20 amp breaker can have a #12 at 20 amp rating, #10 at 30 amp rating or a #8 at 40 amp rating added to the circuit but not a #14 which is only rated at 15 amps. Using 15 amp wire on a 20 amp breaker could overload the capacity of the #14 wire which is rated for a maximum of 15 amps.
250 amps maximum.
Wire size is rated by Amperes of current. You did not mention the wire size of the aluminum wire, so there is no way to answer your question. The voltage rating is more a rating of how good the insulation around the wire is.
A 3/0 copper conductor with an insulation rating of 90 degrees C is rated at 225 amps.
The amperage rating of any wire or conductor is determined by its size or gauge. It has nothing to do with whether it is a two, three or four conductor wire. For example, in basic residential wiring, a 14 gauge wire is rated at 15 amps, a 12 gauge wire is rated at 20 amps, a # 10 is rated for 30A and so forth.