Q:My husband accidentally used a whole can of motor engine degreaser to clean our window ac unit.

Well pull it out of the window and take it outside, because the only way to really clean it it to remove the outer cover and hose off the coils.

Q:I own a condo unit- a/c stopped working. a/c company came out and said i need to replace the blower motor to my a/c unit- told me it would cost $1,280. Blower motor is 1/6 hp 120 volt. Does this price sound right?

sounds high is it a fur down that unit above your tub or hallway if it is you might consider changing the whole unit out if its in a closet way to high a price either way make sure your evap coil is clean or cleaned

Q:Hi there everyone and merry xmas to all...In certain treadmills, the speed by which the user is running is measured and calculated using a mounted sensor near the rotor of the motor. However I found that some treadmills lack this sensor, and I am seriously wondering how this could be achieved? I know that the more the motor is rotating, the more current it consumes, but I hope to know the formula relating electrical quantity(ies) to the rotation per minute (rpm).Thanks in advance...

There are circuits that can do that but not easy to explain in detail here. The idea is to remove power from the motor momentarily and measure back emf voltage which is proprotional to motor speed. This is generally done periodically to determine motor speed. In this way a controller can adjust the motor speed. This method is not suitable for AC motors.

Q:are the electric motors used by the toyota prius dc or ac?

The motors work on three-phase alternating current, with powerful permanent magnets. The job of the inverters and the control electronics is to convert the DC supply from the battery to a suitable voltage (up to 500V on 2004-2007 Prius), current and phase for the desired torque on the motor generator. This gives the control electronics very precise control over the positioning, as every single change in the current in the coils is under the computer's control - when the engine stops, it will actually 'position' the engine shaft in the optimum position for smoothly starting it again, and the 'hill start' feature has such precise position control I often have to double-check if I took the parking brake off... It probably could have been designed using either, but I would expect DC motors to be more dangerous, as a short circuit or broken component somewhere could apply a constant voltage and make it fly off without warning (whereas applying a constant voltage on one of the coils on an AC motor locks it in place...)

Q:Can i convert it to batterry if i can't find a motor and what size battery operated motor should i buy

You should be able to find a replacement AC motor (110V, 60 Hz for use in the US) at an electrical supply store, a clock shop, a hobby supply shop, or on-line. You could even go to a major retailer like Walmart and just get a regular (cheap) AC-operated mantle clock or something similar, and then use the guts of that to replace the defective one in your grandfather clock. Make sure the old grandfather clock hands fit on the new movement, or just replace the hands when you replace the movement. As far as using a DC (battery operated) movement goes, certainly you can do that. Again, go to a hobby supply store or a major retailer and buy a battery-operated clock. Remove the DC motorized movement and put it in your grandfather clock. The required battery size is specified by the movement itself. Typically a medium to large DC clock movement requires one AA or C battery, although some movements may require 2 each AA batteries or even a special battery, such as a Type N. Either way (replacing the AC motor with another similar type AC motor, or replacing the whole AC movement with a DC one), you should be fine.

Q:i have the following specifications for an ac motor with a built in constant torque drive.10:1 constant torque3600rpm250HPWhat Does the ratio mean?

A) definite, you decide on a comments administration gadget while you're required to change velocity. you in addition to would would desire to change (or a minimum of shrink) the motor modern or you may burn it out. B) A stepper motor creates torque pulses which will jerk the burden. if the burden inertial is great sufficient, this would possibly not be a subject. for sure the torque isn't consistent, however the pulses will all be an identical till the fee turns into too great; then they're going to overlap and grow to be distorted.

Q:We rewound an ac motor but when we tested it,in a jog, one of the coil got burnt. We checked if there was a wrong connection but there was none. We checked also the number of turns,the size of wìre. We rewound the burnt coil,and test again,the same thing happened.We're wondering why it was happened?.Please help. . .

The basic reason is too much current, so need to find the cause of that. I have had experience with a motor that drew far too much current on no load, and continually burned out, and it turned out the field lamination were skewed so that the field was not properly aligned magnetically. This did not cause poling, but the problem was visible when the field was inspected. This was a manufacturing defect. Other reasons may be shorted turns, or the laminations are not well insulated, as each is supposed to be insulated from the next. I expect you have already checked for poling and that the shaft does not have excess play. I don't know what the effects of a bad rotor are. I guess the winding causing the problem can be tested and compared with others on the bench, without the rotor. Apply a low voltage from a transformer to the winding and measure the current, comparing with other identical windings. When you say tested in a jog: To me jogging is pulsing the motor to step it along a bit. Could this be grossly exceeding the current rating? I guess a particular coil would tend to burn out first, but the others would be hot too. In the end the rated current should not be exceeded for more than a few seconds, then wait for it to cool down. Some larger motors have starters that prevent the restart until it has cooled down. It is also possible that a supply phase is bad, possibly due to a faulty contactor or connection that has high resistance..

Q:I noticed that most elevators are powered not by an electric motor, but by an electric motor-generator set. Does the generator really put out enough current to make up for the friction losses?Or is the generator used for powering lights and stuff? If so, why not use inverters or some smaller, cheaper means of creating a smaller current for the lights?

That was the old way of powering the elevator. They needed to smoothly start and stop the elevator, and at the time, there was no way to control an ac motor with a variable speed. Only dc motors could start and stop smoothly based on the amount of current available. So the solution was to couple the ac motor, running all the time, to a dc generator whose field could be varied thus controlling the output current. This current was sent to the dc hoist motor, lifting the elevator smoothly, the operator controlling the field current of the generator to control elevator speed. Lights were never controlled by the generator, they just ran off the available ac supply directly. The generator does put out enough to overcome any friction losses in the system, but notice that there are counterweights on wire ropes to counterbalance the elevator car. Therefore, not as much power is used to raise and lower the elevator.

Q:I have a 13 year old Bryant Heat Pump with the compressor outside on the ground and the air handler in the garage. Its been a reliable unit so far and was wondering if I should replace the compressor fan motor since it gets well over 100 degrees here in the summer months. The old one is working fine buts its 13 years old and I was wondering if some preventative maintenance would be a good idea here.

If you wanted to do something, I would order the OEM motor and have it handy should you need it. OEM motors always last longer and if it goes bad a tech will in most cases use a generic motor. But still no reason to do this, if you have a fan motor and the compressor goes then you are stuck with the fan motor, So I would just stick to make sure it is serviced once or twice a year if you want to spend some money.

Q:Hello, I'm planning a project and I am going to need to control the rotational speed of an electric motor very accurately. Is there an easy way to do this? I was thinking about some sort of comparative op-amp but don't really understand.Also, I need the motor to be able to change speed very quickly, ie accelerate and decelerate to the required angular velocity. Is this quality the torque? Thanks

If it is an AC motor I would purchase a variable frequency drive from Grainger.