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There is missing information in the question, but I will make some assumptions and answer it...
Assumptions (and givens): (460V), (80 HP), three phase delta, power factor of 0.92, efficiency of 0.95...
One horsepower (electric motor) is 746 watts, so 80 HP is 60 KW. Divide by three and you get 20 KW per winding. Divide by 0.92 and divide by 0.95 and you get 23 KVA per winding. Divide by 460 and you get 49 A per winding. Multiply by 1.732 (square root of 3) and you get 86 A per phase.
Allowing for an 80% load factor on the breaker, per NEC, you need a 107 A three phase breaker. You also need a wye-delta starter, so as to minimize thermal damage to the motor on startup.
Now, 107 A is a lot, requiring large wires and subsequently large motor windings. I would consider a higher voltage motor, such as 4160V. Back-calculating all of that, gives a breaker rating of 12 A, a much more reasonable value. You still need a wye-delta starter.
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∙ 12y ago
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∙ 10y agoThere are two equations for amperage when horsepower is shown. One is for three phase motors and one for single phase. As it is not stated, both equations will be shown.
A standard motor's efficiency between 5 to 100 HP is .84 to .91.
A standard motor's power factor between 10 to 100 HP is .86 to .92.
Three phase; HP x 746/1.73 x Voltage x %eff x pf.
Single phase; HP x 746/Voltage x %eff X pf.
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∙ 11y ago34.5 fully loaded steady state, generally lower due to not fully loaded and several hundred for the first fraction of a second or seconds until it is up to speed.
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∙ 13y agoIt depends on the motor type, efficiency, and load on the motor. I found one example motor that draws ~100A at full load.
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∙ 11y agoTo answer this question the HP of the motor must be stated. For calculation purposed 1 HP is equal to 746 watts. The formula you need to use is I = W/E.
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∙ 10y ago52
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How many Amps for 3 horsepower at 208 volts?
For a single phase 3 HP motor at 208 volts the amperage is 18.7 amps. For a three phase 3 HP motor at 208 volts the amperage is 10.5 amps. This figure is derived at by taking the full load amps at 230 volts and adding 10%. As the voltage goes down the amperage goes up. For 200 volt motors 15% is added to the FLA of a 230 volt motor.
What is the start up amps on a 200 hp 3 phase 480 volt motor?
i have 200 hp motor what i need cable size in 100 feet distance
How many watts is 1 hp at 480volts?
A 1-HP motor is reckoned to draw 7 amps at 240 v single-phase. The same power of motor would draw 3.5 amps at 480 v single-phase, but a 480 v supply could most likely be a three-phase suppy, and the current in that case would be reckoned as 2 amps.
What size of wire and breaker do you need for a 10 KW electric furnace?
To answer this question, wire size is rated in the amount of amperage that it can legally carry. The formula to find amperage when the HP is known is I = HP x 746/1.73 x E x %eff x pf. A standard motor's efficiency between 5 to 100 HP is .84 to .91. A standard motor's power factor between 10 to 100 HP is .86 to .92. Amps = 10 x 746 = 7460 = 7460/1.73 x 220 x .84 x .86 = 7460/275 = 27.1 amps. The electrical code states that a motor conductor has to be rated at 125% of the motors full load amperage. 27.1 x 125% = 33.8 A #8 copper conductor with an insulation factor of 60, 75 or 90 degrees C is rated at 40, 50 and 55 amps respectively.
What is the full load amperage of a 500 HP motor at 4160 volts?
20.833 amps at 240volts equals 5000 watts. Wattage is volts times amps.
How many amps does a 15 hp motor draw?
To answer this question the voltage of the motor must be stated.
What is the full load amps for 2.4 hp motor at 460 volts?
what is the full load amps for 2.4 hp motor at 460 volts ?
How many amps does a 30HP motor use hooked to 480v 3 pH 60Hz line?
The electrical code states that a 30 HP induction motor at 460 volts three phase will draw 40 amps. <<>> I = 33.34 AMPS IF EFF.= 95% AND P.F.= 85%
How many amps does a 1 hp electric motor pull under a load?
T430.247 of the NEC shows that a 1 hp motor operating at full load on 115v will draw 16 amps, called Full Load Current (FLC). Conductors supplying this motor are required to be 125% of FLC which is 20 amps. Motor circuits are complicated things and do not follow the rules of other circuits. This motor, while drawing a maximum of 16 amps at full load and supplied with #12 AWG copper conductors can be protected by a breaker of 40 amps.
What size time delay fuse do you use on a 40 hp 230 volt 3 phase motor?
The electrical code book states that a 40 HP 230 volt three phase motor draws 104 amps. For that motor the wire must be rated for 131 amps, Non time delay fuses at 300 amps, time delay fuses at 175 amps or a 250 amp circuit breaker. When calculating wire sizes and motor protection the motor's full load amperage should be taken from the motor's nameplate.
Motor 1 hp equals how many amps?
hp= 745.699872so if the rated voltage is 220 so 745.699872 /220=3.389 A
Will a 10 hp 220 volt motor draw large amounts of electricity?
A single phase 10 HP motor will draw aproximately 50 amps. A three phase 10 HP motor will draw aproximately 28 amps.
How many amps does 1 phase 220volt 7.5 HP draw?
Look at the motor nameplate and it shoud have the amp draw on it. If the nameplate is missing, then the amp draw depends on what type of motor it is. The basic calculation to get you in the ball park would be as follows: 1 HP = 0.75 KW 7.5 HP = 5.63 KW Assume the efficiency of the motor is 80%, then the power supplied will need to be 5.63/0.8 = 7.04 KW amp draw = 7040/220 = 32 amps <<>> For calculation purposes the electrical code book states that a 7.5 HP motor draws 40 amps.
How many amps does a five horse power motor draw?
It depends on the voltage-- I think at 110v it's 4 amps per hp
How many amps does a 2 hp 210 volt single phase motor draw?
Then you are trying to get more HP out of the motor that it can supply. Back off on the load that the motor is driving or put a bigger motor onto the load.
How many ampere in one hp?
There are 746 watts in 1 HP. Watts = amps x volts. It depends on the voltage rating of the motor. Amps = 746/volts = ? need voltage.
How many amps does a 5 hp 208 volt 3 phase motor draw?
read the name plate on the motor
