I have 20 HP,3 phase motor how much units it will consume per hour?how i may calculate?

Answer 1

There are a few assumptions that go into an answer.

The easy ones are whether you're interested in kW or kVA "units". If you electric utility bills in kW, then you're not really concerned about the power factor.

The efficiency of the motor has a very small impact, and for the purposes of this question will be ignored.

1 HP = 746 watts = .746 kW

The biggest assumption come down to "how much work is the motor doing?" You can plug in the 20 HP motor, but if there is nothing connected to the shaft the kW load is very low. It is rare for a piece of equipment to be designed for the maximum rated output of a motor. As you get close to fully loaded, the person designing the system will often specify the next larger size motor.

If you assume the motor is actually doing 20 HP worth of work, the resulting consumption will be 20 HP x 0.746 = 15 kW. Operating the motor for an hour will result in 15 kWh.

In the real world I suspect the actual load will be closer to 10 to 12 kW on your 20 HP motor.

If you've got an ammeter and volt meter, here are some instructions on how to calculate a reasonable estimate.

- Measure phase-to-phase voltage with motor running.
- Tong each phase to determine the current.
- Volts x amps x 1.73 ÷ 1000 = kVA
- Assume power factor is 0.80. kVA x 0.80 = kW


************* Final note *******************
Beside the "work" being done by the motor's shaft, the remaining factor is how the motor is operated. Is it running continuously, starting and stopping, or does it have variable load. Here are examples of all three.

Continuous: Fans, and some AC units that never shut off on the hottest days.

Cycling: Many motor applications start and stop. A sump pump or electric garage door opener are two examples. Even the motor that powers a hydraulic elevator is only doing work on the up trips. The duty cycle of the equipment will drastically affect the energy consumption over the hour interval.

Variable: Variable loads include escalators and some modern HVAC equipment. The load on the motor's shaft varies throughout the time interval.

Answer 2

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RE:
I have 20 HP,3 phase motor how much units it will consume per hour?how i may calculate?

Answer 3

A 20 HP motor, at 746 watts per 1 HP, uses about 14920 watts. Call that 15KW. Putting aside questions of efficiency and duty cycle (and the irrelevant issue of voltage) the 15000 watts is a close approximation of what it will use per hour.

Answer 4

30 Kw To Hp

Answer 5

I understand that you want to power consumption in units. If 60 Watt bulb is used for 6 hrs daily. Than daily consumption is 360 Watt (60*6). 1000 Watt = 1 unit of consumption. therefore you may be adding 1 unit in your power bill in approx. 3 days. (1000/360)

Answer 6

assuming you are wanting how many watts per hour you use the power formula, but you have to know at least two things. they are 1 the output if it is 3 phase is it 220 3 phase or 440 3 phase that is 440 volts compared to 220 volts. you need to know more information than just 20 horse power 3 phase..

Answer 7

Consumption of units depends on power factor.For caculation if we asuming 1 the formula is 1.732 multiplied by applied voltage and current. The answer will be 14.92 units per hour.

Answer 8

The 20HP rating is its maximum output. Also, motors rarely run at full load in my experience. Efficiencies and power factors fall as load is reduced from full load.

You need to measure it to know for sure. You could measure the current and estimate, but ideally you need to know power factor too so you may as well use a power meter anyway.

Answer 9

what will be the current consumption unit to be charged per day for an use of 2 persons using 150 litres per day.

Answer 10

Units of what?