# What causes a motor to draw more current?

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## What is the reason that when it starts the motor It takes a lot of current and then when the motor starts running it takes less current?

As the speed of the rotor is zero at the start, the rotor conductor will cut the maximum flux and the maximum voltage will be induced in the rotor. As the motor starts accelerating the speed of the rotor will align in the direction of synchronous speed of the motor and the slip will get reduced.

## What determines how much current a motor draws?

Calculate the amps used by dividing the wattage by the voltage. For example a 500-watt motor — running on 50 volts — will draw 10 amps. A motor with the same wattage — running on 20 volts — will use 25 amps. This is the theoretical number of amps used by the motor.

## How do you reduce amps on a motor?

According to Ohms Law (I=E/R or Amps=Volts/Ohms) if the voltage in the circuit remains constant and the resistance is increased, the current should decrease. Try adding resistance to the circuit to lower the current output.

## Why is starting current high in a DC motor?

Answer: The starting current is high as there is no back EMF or counter EMF present in the armature circuit because atstarting counter EMF is zero. … It’s armature has very less resistance due to this it need more current at starting time. Hence DC starters are used to limit the starting current ofmotor.

## What is the difference between inrush current and starting current?

Inrush current – The near instantaneous current produced by the fields building within a motor or transformers. Starting current – The extra current needed to overcome the inertial of the motor and load.

## What determines current draw?

Divide the watts of a given electrical item by the total number of volts available from the electric outlet to calculate amperage draw. The amount of current flowing through the wire is measured in amperes, or amps. The equivalent of available electricity at the power source is voltage, or volts.

## How many amps does a motor draw?

Common Horsepower to Amps Conversions

Horsepower Amps Voltage
.25 HP 1.73 A 120 V
.5 HP 3.45 A 120 V
.75 HP 5.18 A 120 V
1 HP 6.91 A 120 V

## What does high amp draw mean?

If it is drawing more than it is rated for its running rating it is working harder than it is rated for. It is moving too much air, a bearing is running tight, a capacitor is failed or it is the wrong motor in the appliance.

## How do I reduce amp draw?

Lowering amperage is done by applying Ohm’s law, given by the formula I = V/R, where I is the circuit’s total current in amperes, V is the voltage and R is the resistance. Add resistors to the circuit to increase the total resistance. A higher resistance results in a lower amperage.

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## Is a higher amp motor better?

Amps basically measure how effectively the motor cools itself, not how much power it has. With this in mind, more amps can be good because motors will run longer and won’t heat up as fast. Remember heat is what kills a motor. … Regarding cordless tools, the more amps the battery has, the longer the tool will run.