Quick Answer: Which formula is used to calculate the total electrical degree in starter of an AC motor?

D) Total electrical degree = 180 Degree x No.

How is electrical degree calculated?

That means that 360 electrical degrees will occur when the shaft has rotated only 120 (3603) mechanical degrees. You can see that each time we divide the mechanical degrees by the number of pole pairs (or, the number of poles divided by 2). So in general we can say that θe=P2θm.

What is the electrical degree of 6pole stator of motor?

Electrical Degrees and Mechanical Degrees

Two stator poles produce one cycle of power. Each pole contains 180 electrical degrees. A two-pole stator has the same number of electrical degrees as mechanical degrees. In a four-pole stator, there are 720 electrical degrees in the 360 mechanical degrees of the stator (Fig.

How do you calculate the starting current of a motor?

An induction motor, starting “across the line”, will typically have an instantaneous draw 6x the kw it is rated to run at. e.g. a 10 hp motor is rated at 7.46 kw, so on starting it may draw 75 kw. On 480 volts 3 phase, the amperage will be I = W / (E x 1.73) = 75,000 / (480 x 1.73) = 90.4 amps.

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What is 120 in motor speed formula?

The equation for calculating synchronous speed is: S = 120 f/P speed = constant (120) times frequency of power source (60 Hz) divided by number of poles used in the motor (P).

What are electrical degrees?

1 : one 360th of a cycle of an alternating current. 2 : one 360th of the angle subtended at the axis of an alternating current by two consecutive field poles of like polarity.

What is electric angle?

[ə′lek·trə·kəl ′aŋ·gəl] (electricity) An angle that specifies a particular instant in an alternating-current cycle or expresses the phase difference between two alternating quantities; usually expressed in electrical degrees.

What is synchronous speed and it’s formula?

The synchronous speed of an AC motor is determined by the frequency of the source and the number of poles. The RPM is calculated by multiplying the frequency times 60 and dividing by the number of pairs of poles. … Actual speed of the induction motor will be less than the synchronous speed.

Why is the phase shift 120?

There are many reasons to keep the three phase lines 120 angle apart. One may be that when there is 120 phase angle among the three phases the sum of voltage at any time instant is zero which have an advantage that when there is a balance load no current will flow in neutral wire.

What is an electric rotary converter?

A rotary converter is a type of electrical machine which acts as a mechanical rectifier, inverter or frequency converter. Rotary converters were used to convert alternating current (AC) to direct current (DC), or DC to AC power, before the advent of chemical or solid state power rectification and inverting.

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How do you calculate the no load current of an AC motor?

No load current for DC motor = 0.25 x Motor Full load current.

What is the formula for motor speed?

To calculate RPM for an AC induction motor, you multiply the frequency in Hertz (Hz) by 60 — for the number of seconds in a minute — by two for the negative and positive pulses in a cycle. You then divide by the number of poles the motor has: (Hz x 60 x 2) / number of poles = no-load RPM.

How many RPM is a 6 pole motor?

Six-pole motors run at 1,200 rpm unloaded (7,200 ÷ 6) and between 1,050 and 1,175 rpm loaded.

How do you calculate motor?

In our example input electrical power of the motor is 0.22 A x 6 V = 1.32 W, output mechanical power is 1000 rpm x 2 x 3.14 x 0.00126 N•m /60 = 0.132 W. Motor torque changes with the speed. At no load you have maximum speed and zero torque. Load adds mechanical resistance.