Q:Say i have a 400hp ac 3-phase motor.speed is given as 3575 rpm.Does this mean that if left to run on it's own (with 60hz and the related voltage etc) or unloaded it would produce 3575rpm? and the torque would just be power/speed?if this is the case, does this mean that if i loaded the motor with double this torque its speed would half?Basically i'm trying to figure out how to work out the performance characteristic of a motor for different loads given the basic manufacturers data.thanks...

The okorder

Q:How to make the AC motor stop rotating rapidly?

Electromagnetic brake, load and DC braking or braking circuit of DC power consumption

Q:Why is an A/C motor not used as common as an Induction motor? Whereas, A/C generator is a household name.

AC Motor is Synchronous motor. Induction motor is asynmchronous motor. Unlike in DC, in AC there are two types of motors.

Q:I need to know for an economic calculation how much would it cost to uninstall a 15hp ac motor (old) and to install a new one that is attached to a industrial air compressor...please...just an estimate...

Should okorder /

Q:How many kinds of braking modes are there in AC motors? What are the characteristics of each?

Energy consumption brakingWhen the motor cuts off the AC power supply, a DC power supply is added to any two of the stator winding to generate a stationary magnetic field, and the stationary magnetic field is generated by the inertia rotation of the rotor to produce a braking torque

Q:I'm interested in learning what happens to a three phase motor if one phase loses power 1) while running, 2) prior to start?I've I've got a three phase motor with only two phases still good, can I manually rotate it to give it a quot;kick startquot; so it will continue to run in two phases?

While you probably *can*, it's not a good idea. When one phase is lost, a loaded three phase motor cannot start or may stall under load...the current flowing in the remaining winding(s), will increase to 600% of the nameplate rating...Winding insulation subjected to locked rotor current may fail in as little as 15 to 90 seconds. This winding insulation damage is permanent and cumulative. Motors should not be started during phase loss and if they stall, they must be disconnected immediately. the life of a motor operating with a 3% continuous voltage unbalance (at full load) will be cut in half.

Q:Hey guys. Not to long ago did I replace my AC resistor for my car. Its no hassle to replace but what dawns me is the fact that my old AC resistor that I replaced was burned, it literally looked like it caught on fire. The plastic melted and had some burned holes. This really puzzles me and scares me because I do NOT want my truck to catch fire because of the AC. Would you guys know any reasons why it would just burn like that? anyway to prevent it? I barley use the heater. Living in California you don't have that many cold days here accept the morning and I just use the heater to defrost my windshield and that's it.

Try following the wires to the ground lead and once you find where it is grounded clean any corrosion and dirt off of if and under the connection.

Q:what is adjustable-speed ac motor?

Sandy is right, you can use also this term: Variable Frequency Drive (VFD) There is also other means to have multiple speed for ac motor: Permanent Split Capacitor (PSC) motor and Electronically Commutated (ECM) motor I use these on Heating/Cooling equipment fans have fun!

Q:How does IGBT works in frequency inverter for ac motor control?

The IGBTs act as switches to provide a series of DC pulses to the motor. Since most AC motor frequency controls are for 3-phase motors, there are six IGBTs, two for each phase. One IGBT connects each motor terminal to the positive side of the DC supply and one connects each motor terminal to the negative side of the DC supply. In that way, each terminal to terminal or line to line voltage can be either positive or negative. By controlling the switching sequence of the IGBTs, the control provides a simulated 3-phase sine voltage with frequency and voltage control. The waveform is composed of DC pulses and doesn't look too much like a sine wave, but the effective value is a reasonably good simulation of a sine wave. Each IGBT has a diode in parallel but positioned to conduct current in the opposite direction. The anti-parallel diodes conduct the portion of the motor current waveform that lags the voltage. Look at the Wikipedia article for more details and diagrams.

Q:There is no magnets in an induction motor so is this even possible.

A vehicle's charging system is a three phase alternator - and they work just fine AC or when the output is rectified to DC.