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It depends on what the amperage of the motor is. The motors amperage depends on the voltage of the motor. The higher the voltage the motor operates on the lower the amperage. So unless the amperage from the motor's nameplate is stated an answer can not be given.
Just remember that the feeder capacity to the motor has to be 125% of the motors full load amperage and the breaker protecting the conductors to the motor has to be rated at 250% of the motors FLA. This higher breaker size allows the motor to start without tripping a normal size breaker that is rated for the lower conductor size.
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LRA is 134 AMPS. what size breaker should be used?
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.
Why do you need a 125 amp breaker for a 83 amp furnace?
If you put a 85 amp breaker in there it will overheat from the starting and stopping of the motor. The extra size of the breaker insures that the furnace will run without interruption and without overheating the breaker. And electric motor can draw three times the amperage rated on start up momentarily. This is why there is need of extra amperage ratings.
What size breaker do you need for 9000W at 440V 3phase?
This formula will give you the amperage I = kw x 1000/1.73 x E x pf (pf = power factor). Take the amperage and multiply it by 125%. This will give you the breaker size that you need.
How do you wire a 277 to 120 volt transformer?
The voltage 277 volts is a three phase line to neutral voltage of a 480 volt system. What is needed for the protection of the transformer is a two pole breaker from the 480 volt CDP (Central Distribution Panel). The breaker will be sized to the KVA of the transformer. The wire will be sized to the breaker plus 25%. The electrical code requires that on motor and transformer feeders, they be sized to 125% of the total current capacity of the equipment.
What size underground feeder wire is needed from a 400 amp breaker to a 125 amp panel box. The total distance is 100 feet?
1/0 <<>> This is a voltage drop question. A voltage and whether it is a single or three phase system must be provided to give an answer.
LRA is 134 AMPS. what size breaker should be used?
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.
How do you calculate breaker capacity of 10 hp three phase induction motor?
The first thing you have to do is find the full load amps of the motor. The wire size feeding the motor has to be 125% of the full load current. The breaker is usually 250% of the full load current. If the voltage and amperage had been added to the question the exact breaker size could have been calculated.
What size breaker do you need for a well pump?
A breaker is based on the amperage that is drawn by the pump motor load. Find the full load amperage of the motor. The wire fed from the breaker has to be rated at 125% of the motors full load amperage. The breaker for motors have to be over sized, usually 250% of the motors full load amps.
Why do you need a 125 amp breaker for a 83 amp furnace?
If you put a 85 amp breaker in there it will overheat from the starting and stopping of the motor. The extra size of the breaker insures that the furnace will run without interruption and without overheating the breaker. And electric motor can draw three times the amperage rated on start up momentarily. This is why there is need of extra amperage ratings.
What size wire and breaker for 125hp 240 volts 3 phase motor?
The wire size and the circuit breaker for a 125 hp motor must consider the length of lead wire to the motor (essentially the distance of the motor from the supply). 125 hp is a VERY large motor and would be used only in industrial applications. You will need to consult a technician for proper advice, but the general answer to your question follows: The current draw on such a large motor would be approximately 300 amps. That is very large, and would require a wire size of 0000 AWG or 750M. 0000 AWG is 0.46 inches (11.68 mm) in diameter. As you can see, the wire is very large. It is not something you could install yourself.
What is the circuit breaker rating required for a motor with a 250 Ampere full load current?
A motor that is rated at 250 full load amps will need 400 amp time delay fuses or a 500 amp frame breaker with adjustable amperage trips. The wire size for this motor has to be 125% of the motors FLA. 250 x 125% = 312 amps. A 350 MCM copper conductor with an insulation factor of 90 degrees C is rated at 325 amps.
What size circuit breaker is used for a 10000 watt single phase cooler with 240 volts?
The equation for amperage is Amps = Watts/Volts = 10000/240 = 41.6 amps. It is not stated if this is a motor load or not. If it is a motor load then the feeder has to be rated at 125% x 41.6 = 52 amp wire. Also if it is a motor load then the breaker will have to be 250% x 41.6 = 104 amps. A 100 amp breaker will work and still be within the electrical code ruling. Otherwise for 41.6 amps a 50 amp breaker will be sufficient.
What size circuit breaker should be used on 125 feet of 4 AWG power feed?
The circuit breaker is used to protect the conductor that is connected to it from an overload condition. On a motor load the breaker has to be sized 250% of the motors full load amperage. Some circuits can be only loaded to 80% capacity and this is governed by the sizing of the breaker. Without knowing what the load amperage is, this question can not be answered.
What amp breaker do you use for a three fourths horse garage door opener?
A 15 amp should be fine, provided that #14 wire is used for the outlet. If #12 is used, then use a 20 amp breaker. Depending on what the motor voltage is makes a difference on what the wire size is. A 3/4 HP motor draws 13.8 amps at 115 volts and 6.9 amps at 230 volts. The motor feeder conductor must have an ampacity at least equal to 125% of the full load current rating of the motor. 13.8 x 125% = 17.25 amps. The conductor required on a motor using 120 volts is #12 rated at 20 amps. The breaker for this motor needs to be rated at 30 amps.
How big of a breaker for a 26 amp motor?
Sizing circuit breakers for motors falls into a different category. Because of the inrush of current when the motor is in the stopped position, the breaker has to be sized to allow for this. Breakers usually are 250% of the nameplate full load amp rating. The wires that feed the motor are sized to 125% of the full load amps of the motor.
What size breaker do you need for 9000W at 440V 3phase?
This formula will give you the amperage I = kw x 1000/1.73 x E x pf (pf = power factor). Take the amperage and multiply it by 125%. This will give you the breaker size that you need.
What size breaker is needed for feeding 10 kva transformer at 460 v single phase?
One horsepower (electric motor) is 746 watts, so ten horsepower is 7460 watts. Divide that by a power factor (assumed) of 0.8 and you get 9325 volt-amps. Divide that by a voltage (again, assumed) of 240 and you get 39 amperes. For calculation purposes the electrical code book states that a 10 horsepower motor at 240 volts will draw 50 amps. The motor's nameplate amperage that is driving the rotary phase converter should all ways be used first. The electrical code requires a breaker for a motor to be 250% of the motor's operating full load current. 250% of 39 amperes is 97 amperes. I would use a 100 ampere breaker for a 10 horsepower motor. If the motor rating is used from the code book values, then 50 x 250% would equal 125 amps and that is the size of the breaker that must be used. This is the reason that the motor's exact name plate amperage rating should be used. In the long run feeder wire costs could make a saving in the overall projected costs.
