What causes power to flow through an AC motor?
As the coils are energized, the magnetic field they produce between them induces an electric current in the rotor. The interaction between the two fields causes the rotor to turn. As the magnetic field alternates between the red and blue coils, it effectively rotates around the motor.
How AC motor speed can be controlled?
When a voltage is applied to an AC induction motor, it runs at a certain speed. At 60 Hz, the motor will run at 1800 RPM. A variable frequency drive controls the motor speed by using PWM (Pulse Width Modulation) to alter the power supply frequency that’s fed to the motor.
Can any AC motor be variable speed?
– Variable speed drives (VSDs): These drives change the speed of a motor by changing the input voltage and can be used with both AC and DC motors. Variable speed drives supply specific amperage and voltage to a motor.
What determines the speed of an AC induction motor?
AC Induction Motor Speeds The speed of an AC motor is dependent on the number of poles it has and the line frequency of the power supply, not on it’s voltage. Common AC motor units are constructed with either two or four poles.
Why starting current is high in motor?
This high current in the rotor will create its own magnetic field which opposes the main stator magnetic field, this weakens the stator magnetic field so the back EMF in the stator will drop and the supply voltage will be much higher than the stator back EMF and so the supply current increases to a high value.
How can we avoid inrush current in motor?
One is to use a soft starter — a device that gradually increases supply voltage to the motor terminals during startup, thus lowering inrush current and controlling startup torque. Similarly, a variable frequency drive reduces inrush current by controlling the voltage supplied to the motor.
Can I put a VFD on any motor?
Output voltages are available for VFDs to match almost any existing motor voltage. However, very few, if any, VFDs have a direct 13,800-volt output for very high-voltage motors. For these cases, using a step-up transformer on the output of the VFD is often necessary to match the motor voltage.
What’s the problem with my Chevy Tahoe AC?
By the way, if you want to visit a FANTASTIC Tahoe forum site where I found the solution to my Tahoe’s problem, visit: http://www.automotiveforums.com. They have many more topics and ANSWERS!!! The problem was a flapper valve actuator. AC Delco part number 15-72506.
Is the AC / heater blower motor working on Level 4?
AC/Heater blower motor only works on level 4 (highest speed). haven’t fixed it yet. Blower motor only worked on settings 0 and 4. If set in between, freon continues to circulate through the system without any cool air being blown into the cabin.
Why does my air conditioning run at only one speed?
But what happens when you get in and discover you’ve left the air conditioning on the lowest possible speed setting, rendering it practically useless? Or when you set foot inside your car on a moderately hot day only to discover that the A/C blasts you with the max amount of cold air — air so frigid you don’t need it but can’t turn it down?