Motors generally have to withstand 10 % overspeed. But it in no way means many motors cannot withstand much higher over speeds.
Can a VFD overspeed a motor?
VFDs can be used not only to slow down a motor, but also to drive it beyond its rated speed (overspeed) by increasing the VFD output frequency above 60 Hz. Some HVAC equipment manufacturers overspeed a motor to allow for fan and motor combinations that really shouldn’t have been allowed in the first place.
How fast can you run a motor on a VFD?
With the use of Variable Frequency Drives (VFD), motors can be run at higher than 60 Hz, known as an overspeed condition, typically as direct drive fan wall/plenum fans (per NIH DRM 6.2. 4.2, the maximum operating speed is 90 Hz).
How much can you overspeed a 3 phase motor?
Normal motor can run at +20% of max speed (IEC) without problems but generally be prudent of course. Special AC motors, example for spindle, can run up to 30000rpm. The master limit is generally on bearing system.
How does VFD increase motor speed?
Input Frequency and Motor Speed
VFDs can be used to control AC motor speeds by changing the motor’s frequency without sacrificing the output power of the motor. This is done by turning the speed pot (explained in section three) of an AC motor drive.
Can I run the motor higher than 50hz by using a VFD?
As long as you operate your VFD within maximum tolerable frequency for motor, there won’t be any substantial damages but might result into the losses depending on motor parameters.
Can you run a motor over 60Hz?
Rules of thumb- a 3600 rpm motor can be run safely up to about 75 Hz (or 25% above its rated speed). … Standard AC motors rated for 60Hz operation may be run at higher frequencies when powered by an AC drive. The top speed depends upon the voltage limits of the motor and its mechanical balancing.
What will happen if an electric motor is run at a higher rpm than the rated rpm?
When motor operates at higher V/Hz than rated, the overfluxing occurs, which may cause saturation of the stator and rotor magnetic core. Saturation causes overheating and can lead to motor failure. When motor operates at lower V/Hz than rated, the magnetic flux is reduced.
Can I run a 50Hz motor at 100 Hz?
If this is a standard, inverter rated, three phase induction motor it is probably safe to run it at 100 Hz. The danger to the motor is more from the unfiltered inverter wave form than from the higher frequency.
Can you run a 50 Hz motor on 60 Hz?
It will run with following problems for a 50Hz motor running on 60Hz: … As the core loss will increase, the Power Factor of motor will reduce. The motor speed will be higher, so shaft load will increase. Motor will be overloaded at rated load.
How does a VFD slow down a motor?
They control motor speed using pulse width modulation, whereby waveform alteration rather than voltage adjustment is used to slow down or even speed up off-the-shelf induction motors relative to nameplate values, provided shaft bearings and cooling are up to the task.
What is current VFD limit?
The maximum current you set on a VFD is the current “limit“. When you hit that limit the voltage will droop (foldback) to prevent more current being drawn and the motor rapidly overheating.