Motors

Horsepower Calculation

Horsepower (HP) is a unit of power commonly used to measure the output power of motors.

Formula:

HP = (Volts * Amps * Efficiency * Power Factor) / 746

Formula Breakdown:

Volts: Volts represents the voltage supplied to the motor or electrical device. It measures the electrical potential difference across the system, typically measured in volts (V).
Amps: Amps refers to the current flowing through the motor or electrical device. It measures the rate of flow of electric charge, typically measured in amperes (A).
Efficiency: Efficiency is the ratio of output power to input power, representing the effectiveness of converting electrical energy into mechanical work. It is typically expressed as a decimal or percentage.
Power Factor: Power Factor is a dimensionless quantity that measures the ratio of real power (in watts) to apparent power (in volt-amperes) in an AC electrical system. It indicates how effectively the electrical power is being utilized.
Constant (746): The constant 746 is derived from the conversion factor between units of power (horsepower) and units of electrical power (watts). It accounts for the relationship between electrical power and mechanical power.
To calculate horsepower, you multiply the volts by the amps by the efficiency by the power factor, and then divide the result by 746.

The motor speed calculation is based on the following formula:

Formula:

Motor Speed (RPM) = (Frequency (Hz) * 60) / Number of Poles

Formula Breakdown:

Frequency (Hz): The frequency of the alternating current (AC) input to the motor.
Number of Poles: The total number of poles in the motor.

kVA (kilovolt-ampere) is a unit of apparent power commonly used to size electrical equipment.

Formula:

kVA = (Volts * Amps) / 1000

Formula Breakdown:

Volts: Volts represents the voltage supplied to the system or electrical device. It measures the electrical potential difference across the circuit, typically measured in volts (V).
Amps: Amps refers to the current flowing through the system or electrical device. It measures the rate of flow of electric charge, typically measured in amperes (A).
Constant (1000): The constant 1000 is used to convert the result of the multiplication from VA (volt-amperes) to kVA (kilovolt-amperes). It accounts for the unit conversion from watts to kilowatts.
To calculate kVA, you multiply the volts by the amps, and then divide the result by 1000.

kW (kilowatt) is a unit of real power commonly used to measure the power output or consumption of electrical devices.

Formula:

kW = (Volts * Amps * Power Factor) / 1000

Formula Breakdown:

Volts: Volts represents the voltage supplied to the system or electrical device. It measures the electrical potential difference across the circuit, typically measured in volts (V).
Amps: Amps refers to the current flowing through the system or electrical device. It measures the rate of flow of electric charge, typically measured in amperes (A).
Power Factor: The power factor is a unitless value that represents the efficiency of electrical power utilization in a circuit. It ranges between 0 and 1, where 1 indicates ideal power factor (maximum efficiency).
Constant (1000): The constant 1000 is used to convert the result of the multiplication from VA (volt-amperes) to kW (kilowatts). It accounts for the unit conversion from watts to kilowatts.
To calculate kW, you multiply the volts, amps, and power factor, and then divide the result by 1000.

Amps (Amperes) is a unit of current.

Formula:

Amps = (kW * 1000) / (Volts * Power Factor)

Formula Breakdown:

kW: kW represents the power in kilowatts consumed or supplied by the system. It measures the rate of energy transfer or consumption, typically measured in kilowatts (kW).
Volts: Volts represents the voltage supplied to the system or electrical device. It measures the electrical potential difference across the circuit, typically measured in volts (V).
Power Factor: The power factor is a unitless value that represents the efficiency of electrical power utilization in a circuit. It ranges between 0 and 1, where 1 indicates ideal power factor (maximum efficiency).
Constant (1000): The constant 1000 is used to convert the result of the multiplication from kW (kilowatts) to VA (volt-amperes). It accounts for the unit conversion from kilowatts to watts.
To calculate Amps, you multiply the kW by 1000, and then divide the result by the product of volts and power factor.

Amps (Amperes) is a unit of current.

Formula:

Amps = (kVA * 1000) / Volts

Formula Breakdown:

kVA: kVA represents the apparent power in kilovolt-amperes. It measures the total power in an electrical circuit, taking into account both real power (kW) and reactive power (kVAR).
Volts: Volts represents the voltage supplied to the system or electrical device. It measures the electrical potential difference across the circuit, typically measured in volts (V).
Constant (1000): The constant 1000 is used to convert the result of the multiplication from kVA (kilovolt-amperes) to VA (volt-amperes). It accounts for the unit conversion from kilovolt-amperes to volt-amperes.
To calculate Amps, you multiply the kVA by 1000, and then divide the result by the volts.

Amps (Amperes) is a unit of current.

Formula:

Amps = (HP * 746) / (Volts * Efficiency * Power Factor)

Formula Breakdown:

HP: HP represents the horsepower of the motor. It measures the power output of the motor, typically measured in horsepower (HP).
746: 746 is a constant that converts horsepower to watts. It accounts for the unit conversion from horsepower to watts.
Volts: Volts represents the voltage supplied to the motor. It measures the electrical potential difference across the motor, typically measured in volts (V).
Efficiency: Efficiency represents the efficiency of the motor. It measures the ratio of useful power output to the total power input, usually expressed as a percentage (%).
Power Factor: Power Factor represents the ratio of real power (kW) to apparent power (kVA). It measures the effectiveness of the power utilization in the motor system, typically expressed as a decimal value between 0 and 1.
To calculate Amps, you multiply the HP by 746, and then divide the result by the product of volts, efficiency, and power factor.

Motor Rating (HP)	CURRENT (A)	208V	230V	460V
1/4	1.11	.96	.48	.38
1/3	1.34	1.18	.59	.47
1/2	2.4	2.2	1.1	.9
3/4	3.5	3.2	1.6	1.3
1	4.6	4.2	2.1	1.7
1 ½	6.6	6	3	2.4
2	7.5	6.8	3.4	2.7
3	10.6	9.6	4.8	3.9
5	16.7	15.2	7.6	6.1
7 ½	24.2	22	11	9
10	30.8	28	14	11
15	46.2	42	21	17
20	59.4	54	27	22
25	74.8	68	34	27
30	88	80	40	32
40	114	104	52	41
50	143	130	65	52
60	169	154	77	62
75	211	192	96	77
100	273	248	124	99
125	343	312	156	125
150	396	360	180	144
200	528	480	240	192
250	--	--	302	242
300	--	--	361	289
350	--	--	414	336
400	--	--	477	382
450	--	--	515	412
500	--	--	590	472