With the discussion before on the static phase converter, there isn't much to explain about the rotary phase converter. The rotary converter is nothing more than a second motor in the circuit which is acting as a generator. With the static converter, the tool's motor performed this function, but at the cost of some loss of power. With the rotary converter, the idler motor is under no physical load, but it cleans up the signal a little. If you examine the drawing below compared to the first drawing, the only difference is that we added the idler motor.
The output of the rotary phase converter is closer to being a true 3-phase source than the static converter. This provides more power to the tool motor, and also brings it up to speed faster. The rotary converter is best served when you have a motor which is started and stopped frequently, and you need the full power of the motor. Furthermore, a single rotary converter can drive several different 3-phase tools.
Setting up the rotary phase converter is the same as the static converter described above. The only decision to be made is the size of the idler motor. The idler motor needs to be larger than the largest tool which will be operated.
Since the static converter will provide a motor with 80% of it's normal operating power, and the rotary phase converter uses a static phase converter as a starter, your idler motor should be 125% of your tool(s) motor size. That is, if your tool is a 5 horsepower motor, your idler should be between 6 and 7 horsepower. It is always better to err on the high side, so I would use a 7 horsepower idler motor. If the converter will operate more than one tool, make sure the current rating of the idler motor is 125% of the sum of the tool motors
No comments:
Post a Comment