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Answer for USA, Canada and countries running a 60 Hz supply service.
The motor's amperage has to be found to answer this question.
The formula to use 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 = 746 x 1.5/1.73 x 480 x .84 x .86 = 1119/200 = 5.6 amps
The breaker has to be sizes to 250% of the motors full load amps. 5.6 x 250% = 14 amps.
A three pole 15 amp breaker connected to three conductor 600 volt rated cable will be needed.
As for overload protection without knowing the brand of contactor it is hard to say what the proper number of the heaters will be.
To obtain the proper overload protection base the overload heaters on the 5.6 amps or the motors full load amps that will be on the motor's nameplate.
As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.
Before you do any work yourself,
on electrical circuits, equipment or appliances
always use a test meter to ensure the circuit is, in fact, de-energized.
IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB
SAFELY AND COMPETENTLY
REFER THIS WORK TO QUALIFIED PROFESSIONALS.
What else can I help you with?
What size breaker for a locked rotor motor rated at 54 amps?
For a locked rotor motor rated at 54 amps, it's generally recommended to use a breaker rated at 250% of the full-load current for starting protection. Therefore, you would calculate 250% of 54 amps, which equals 135 amps. However, to comply with electrical code and ensure proper protection, you might choose a breaker size typically available, such as a 150-amp breaker. Always consult local codes and regulations for the final decision.
What size main breaker feeding 480v 75 kva transformer?
An exact breaker size can not be given because the voltage, and hence the calculation for current, is not given. A transformer shall be protected by an over current device that is not rated at more that 150% of the primary current.
What size breaker for a 20 horse power motor with 3 phase 208 volts?
The question is impossib;e to answer without knowing the supply voltage. <<>> What ever the motors full load amperage is, the breaker has to be sized to 250% of that FLA.
How do you find out how big your main breaker box is?
Simple. Your main electrical panel will have a "main breaker". This will be a two pole breaker, usually at the top of the panel. It will have a number on the breaker "handle" such as 150 or 200. This is the maximum number of amps your panel can supply. Most newer homes, 1975 and newer have a 200 amp service.
What size run and start capacitors do you need for 3450 rpm 240 Volt 23.5 Amp k56a46b23 ao smith compressor motor?
For a 3450 RPM, 240 Volt, 23.5 Amp A.O. Smith K56A46B23 compressor motor, a typical run capacitor size would be around 30-35 µF, while a start capacitor might be in the range of 100-150 µF. It's important to ensure that the voltage rating of both capacitors is at least 250 volts to handle the electrical load safely. Always verify the specific requirements in the motor's manual or consult with a professional for precise specifications.
What is the Largest amperage single phase 120 volt breaker made?
6000amps <<>> The above answer must have big lugs to accommodate 6000 amp capacity wire. In my breaker catalogue the largest 120 volt single pole breaker is 70 amps, 277 volt single pole is 150 amps and 347 volt single pole is 100 amps. The 120 volt single pole breaker occupies two opposed slots because of its length.
What is the recommended size for the main breaker in a residential electrical panel, specifically for a 125 amp main breaker?
The recommended size for a main breaker in a residential electrical panel with a 125 amp main breaker is typically 150 amps.
What size breaker for a locked rotor motor rated at 54 amps?
For a locked rotor motor rated at 54 amps, it's generally recommended to use a breaker rated at 250% of the full-load current for starting protection. Therefore, you would calculate 250% of 54 amps, which equals 135 amps. However, to comply with electrical code and ensure proper protection, you might choose a breaker size typically available, such as a 150-amp breaker. Always consult local codes and regulations for the final decision.
What size wire and breaker for a 3 hp 240 volt 3 phase motor?
Wire sizing is based on the amperage needed by the load. The equation used to find amperage when the HP is shown is; A = HP x 746/1.73 x V x %eff x pf. Amps = 25 x 746 = 18650/1.73 x 240 x .87 x .87 = 18650/314 = 60 amps. 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. Motor feeders have to be rated at 125% of the motors full load amperage. 60 x 125% = 75 amps. A #4 copper conductor with an insulation rating of 75 or 90 degrees C are both rated at 85 amps. The breaker has to be 250% of the motors full load amperage 60 x 250% = 150 amps The breaker will be a three pole 150 amp breaker connected to three #4 copper conductors to operate a 25 HP 240 volt three phase motor.
What wire size 240 volt 21 amps 150 foot run?
A #10 copper conductor will limit the voltage drop to 3% or less when supplying 21 amps for 150 feet on a 240 volt system.
What is the maximum current capacity of a 150 amp breaker?
The maximum current capacity of a 150 amp breaker is 150 amps.
What size of outboard motor for a 19 ft dusky?
175/150
What size breaker for a 3 phase 460 volt 50 hp motor?
Breakers are sized by the conductors that are connected to them. Conductors are sized by the amperage that the load draws. The electrical code states that a 50 HP 460 volt three phase motor draws 65 amps. The ideal amperage would be taken from the motors nameplate as different motors of the same horsepower will have different amperage's depending on what they are designed to do. The feeders for this motor have to be sized at 125% of the motors full load amperage. 65 x 125% = 81 amps. A #4 copper conductor with and insulation rating of 75 or 90 degrees C is rated at 85 amps. The breaker for this motor is 150 amp or 175 amp fusing or 110 amp time delay fusing.
What size wire would you need for 150 amp breaker?
# 1 awg if in Canada not sure about us codes
What size main breaker feeding 480v 75 kva transformer?
An exact breaker size can not be given because the voltage, and hence the calculation for current, is not given. A transformer shall be protected by an over current device that is not rated at more that 150% of the primary current.
What is the maximum amperage capacity of a 150 amp circuit breaker?
The maximum amperage capacity of a 150 amp circuit breaker is 150 amps.
What is the maximum amperage capacity of the main breaker in the electrical panel, specifically looking for a 150 amp main breaker?
The maximum amperage capacity of a 150 amp main breaker in an electrical panel is 150 amps.
