Are the variable frequency drives phase sensitive?
The input wiring is not sensitive to phase. If one would change one set of input leads, the rotation would not change. The output of the drive is sensitive to phase. Changing one set of leads to the |
Can a mechanical motor coupling affect the operation of the drive?
Yes, but more as a problem to the entire system including
the drive. Here is a list of Do’s and Don’ts:
DO:
Determine power requirements using both HP and torque to
choose the proper |
Can I run my application at extremely low speeds?
Three major problems exist with both conventional methods of
motor control and VFD control. (1) When a motor is directly coupled and run at low speed it
becomes very inefficient. One could go with |
Does the motor need a chassis ground connection?
Yes, for several reasons. This is for protection in the event of a short in the motor that puts a live voltage on its housing. Motors and other components exhibit leakage currents that increase with |
My pump is losing speed; does the drive have a problem?
Pumps are divided into three basic categories: centrifugal,
rotary, and reciprocating. Take any of the three types and break it down
further into four parts, the rotating element, the casing, the m |
What does "inverter" mean as opposed to a drive/amplifier which are also used to describe the electronic unit that controls a motor.
The terms inverter, drive, and amplifier are used somewhat
interchangeably in industry. But there are subtle differences. A drive can
refer to the motor, the control electronics, or both. This term |
What is the difference between dual voltage and dual wound motor?
Dual voltage is a reference to a motor that can use either of two different voltage levels, usually 230V or 460V. The motor windings have multiple taps, and the connections vary depending on which vo |
What is the duty cycle?
The duty cycle is the percent of time a device is on vs. off. It can be the ratio of operating time of a motor to its resting time. This parameter usually is specified in association with the allowab |