LRA (locked rotor amps) is not used to calculate the breaker size. Breaker's are used to protect the size of the conductor that is connected to it. Motor calculations are based on the motor's FLA (full load amps).Conductor size is 125% of the motor's FLA.Breaker size is 250% of the motor's FLA.This is the only occasion when the breaker is sized larger that the conductors maximum amperage rating. This is due to the motor drawing up to 300 to 600% of its FLA when starting.If you state the motor's wattage, voltage or amperage this calculation can be calculated here.
running wire 12-2 300ft w/9ea. 27watt lights what size breaker should be used
This is determined by the size motor and the amount of amps the motor draws, be on the safe side and consult the owners manual or an Electrician. <<>> The sizing of the breaker and feeder wire is based on the amperage of the compressor. Look on the name plate and find the amperage. The amperage on the nameplate then has to be multiplied by the motors full load amperage and that value is used for the wire size. Because the load is a motor the FLA is again multiplied by 250% to size the breaker. This takes into allowance the high starting current of a motor from 0 to 100% RPM.
A breaker is based on the amount of current that the motor draws. This amperage should be taken off of the motors nameplate. In motors of a specific horsepower the amperage is proportional to the voltage the motor uses. Without the motors voltage this question can not be answered.
50 amp breaker wired with AWG # 6 wire.
A breaker is sized indirectly by the load current. The breaker is used to protect the wire from being overloaded by amperage. Wire is sized by the load amperage. The procedure is, use the load amperage to find the correct wire size that will carry that amperage safely. Size the breaker so that the amperage on the wire doesn't exceed the rated capacity of the sized wire. The only time a breaker is over sized above the wire's rating is when a motor is connected into the circuit. Then the breaker is over sized by 250% of the motors full load amperage. This is to compensate for the starting current of the motor which can get as high as 300% above the motor's run current.
The size breaker you use is determined by the size wire used in the circuit. If you use AWG #12/2 wire then use a 20 amp breaker. If you use AWG # 14/2 then use a 15 amp breaker.
The breaker sizing will be governed by the size of the motor's full load amps. The wire used to feed the motor is based on the voltage of the motors full load amperage. Either the motor's full load amps or the motor's voltage have to be stated to calculate an answer this question.
MPCB is motor protection circuit breaker. It is used as feeder to a motor
Minimally 30 AMPS