The maximum current that is legally allowed to be applied to a # 10 wire is 30 amps. The breaker required to protect this wire will be a 30 amp breaker
Number 10 thnn copper wire.
The wire is sized to the maximum overcurrent protection device (Max circuit breaker) ampacity. This is listed on the nameplate of the outdoor condensing unit. Size the wire to match the breaker.
The wire!! The breaker is there to protect the wiring not the device plugged into the circuit.
Read the literature for the ac condensing unit, or the tag on the outside of the unit. Minimum circuit ampacity= minimum breaker, wire and fuse size. Maximum circuit ampacity= the maximum size. Your circuit breaker, wire size and disconnect fuses should all be at or between those 2 numbers.
I think you mean either what is the correct size or minimum wire size needed when a branch circuit is protected by a 20 A breaker. The size is 12 American Wire gauge (AWG). 14 AWG is used for 15 A circuit and 10 AWG for a 30 A breaker. The lower the gauge the larger the cross-section of the wire.
using number 4 wire what is the maximun size breaker possible
Normally AWG #10 wire on a 30 amp breaker but it really depends on the size of the pump. The pump manufacture will specify the size wire and size breaker needed.
Most wires are in terms of gauges.
The correct wire size for a 15 amp breaker is a #14 wire.
No. Each conductor requires its own circuit breaker. Be sure to match the size of the breaker to the size of the wire. Ex.: 15 amp breaker for #14 gauge wire/ 20 amp breaker for #12 hauge wire.