How does motor current increase with constant torque but …
2009年12月22日 · As you rightly say, the rated output torque of the 1200rpm motor is greater than that of the 1800 rpm motor. But, for a constant torque load, the required load torque remains the same, regardless of speed. So, even though the 1200 rpm motor can produce about 50% more torque than the 1800 rpm machine it has to produce only the same. So it will ...
Constant vs Variable Torque | Information by Electrical …
2008年11月11日 · AC Motors - Constant torque: These ac motors can develop the same torque at each speed, thus power output varies directly with speed. For example, an ac motor rated at 10 hp at 1,800 rpm produces 5 hp at 900 rpm. These ac motors are used in applications with constant torque requirements such as mixers, conveyors, and compressors. JJ
A.C. versus D.C. motor torque and horsepower | Information by ...
2014年3月25日 · The AC motor will produce a constant torque at any given speed of 590 lb ft. torque. My examples are: At 60hz 200 hp at 1780 rpm =590 lb ft. At 30hz 100 hp at 890 rpm= 590 lb ft. At 15 hz 50hp at 445 rpm = 590 lb ft. As the frequency changes, hp changes proportionally, torque remains constant throughout.
current output on a VFD | Information by Electrical Professionals …
2008年1月4日 · The output torque of the motor is thus limited by the output current capability of the inverter. The speed range where the VFD is current limited is called the 'constant torque' range. At increased frequency, the inverter is not capable of maintaining proper V/Hz ratio, and the output torque capability goes down.
torque speed and HP relation of three phase motor
2021年1月16日 · Actually, during induction motor start process there are 3 different torque: at start when rpm=0 Tstart=1-3 times rated torque [Tn]; at approximate 6-8% less than rated rpm it is the breakdown torque [maximum torque] and at 1-2% less then synchronous speed [close to no-load rpm] it will be the rated torque]. At a D.C. motor- it depends if the ...
Two Speed Motor Amp Draw | Information by Electrical …
2015年6月22日 · OK, so from that, and seeing the placement of the CT, it does make sense. It's Constant Torque and 2S2W CT is kind of unusual, but it exists. So inside of that motor, the High Speed windings are 4 pole and rated for 10HP, the Low Speed windings are 8 pole, but rated for 5HP so the torque is the same at either speed.
VFD - Minimum Speed | Information by Electrical Professionals for ...
2019年10月11日 · So an extender is a constant torque load. Current doesn’t go down much as you slow. But the motor integral fan does. So below about 15-30 Hz you run a real risk of burning up the motor. If you use a 1.15 service factor motor and expect name plate torque out then 30 Hz is it. If the load is not 100% of name plate there is more wiggle room.
Help In Understanding Voltage Drop and Motors
2015年10月8日 · With less cooling at lower speeds this really means from a practical perspective you can not run at constant maximum current at low speeds. A motor does not produce torque of some value, rather a motor supplies the torque required by the load at some speed if the motor can. AC induction and synchronous motors are a different story..
400V 50HZ operate on 480V 60 HZ | Page 4 | Information by …
2023年2月24日 · The VFD has sufficient voltage capability to maintain proper V/Hz ratio, so that the design magnetic flux density is maintained, and the motor operates at design torque per amp. Since the current is limited by motor heating and VFD current rating, if you maintain design V/Hz ratio the torque is limited to a roughly constant value.
Induction motor Across the line - reduced torque
2023年5月18日 · If a custom motor was an option, a 9-lead connection to a 2-speed motor would allow the addition of the low speed configuration used in 2-speed "variable torque" motors. This consists of a wye connection of the three pairs of series connected windings which are configured in a delta in the low speed mode of a "constant torque" motor.