Last : How does a VSD ...
Next : AC MOTOR CON...

Are the variable frequency drives phase sensitive? 

Are the variable frequency drives phase sensitive?

No, variable frequency drives are not phase sensitive. You can adjust the direction of rotation of the motor, through the software of the drive.

Can a variable frequency drive replace a soft starter?

Yes, a variable frequency drive can replace a soft starter, since most drives give you a current limiting ramp to start and stop your motor. BUT, if you do not need to vary the production speed of your motor, then the soft start starter is still the correct product for the application. This is because the cost of the soft start starter is less than the cost of a variable frequency drive. 

Can one Inverter be used to drive multiple motors?
Yes. Make the settings under the following condition:
Inverter Rated Current ≥ Motor Rated Current × 1.1 (at continuous operation) 
Check whether the current is within the Inverter's overload capacity at maximum load. Electronic Theermal relays cannot be used, so install a protective Thermal relay for each motor. 
We are using an Inverter for speed control. How can we calculate the rotational speed of an induction motor?
Generally, the speed (N) of an induction moror is expressed by the following formula: 
N = (120f/P) × (1 - S) (rpm)
f: Primary frequency 
P: Number of Motor poles 
S: Slip 
Where f = 60 Hz, P = 4 poles, and S = 3%,
N = ( (120 × 60) ? 4) × (1 ? 0.03) = 1,746 (rpm

There are two kinds of noise filters available as Inverter accessories: the input noise filter and output noise filter. How are these filters used?
The "Input" and "Output" means that these Inverter Noise Filters are connected to the Inverter's input side and output side.
Input Noise Filter:
Reduces noise escaping to the power supply line.
This filter influences the devices connected to the same AC power supply system.
Output Noise Filter:
This filter can suppress noise emitted from the power cable between the motor and Inverter as well as ground noise due to the leakage current from the motor.
This filter influences devices with wiring near the Inverter as well as devices that use the same ground.
The difference between these filters is their different applications.
For example, the Input Noise Filter influences the operation of Sensors such as 2-wire AC Proximity Sensors.
Is it necessary to select an Inverter with a capacity that is one class higher than the capacity of the motor being used?
Our Inverters use an oversized power module that can output 200% of the motor's rated output, so it is not necessary to select an Inverter that is one class higher.
On the other hand, there are some cases in which it is better to select an Inverter that is one class higher, even if an POWTRAN Inverter is being selected.
Applications with a large amount of regeneration
Applications operating continuously with high torque at low speed (such as a load moving slowly on a vertical axis)
Is it possible to control multiple motors from a single AC drive?

Yes, if the desired effect is to control all motors at the same relative speed and a few application requirements are met. Generally, the AC drive is sized so that it's amp rating exceeds the sum total of all the connected motors by a factor determined by the type of connected load. Individual motor overload and short circuit protection should be provided. In some cases, special attention should be given to the motor lead lengths.

I am moving an Inverter from a location with a 50 Hz power supply frequency to another location with a 60 Hz power supply frequency. Are there any settings that need to be changed?
One of the features of the Inverter is that it will control operation at the same speed regardless of the power supply frequency.
The Inverter initially converts the input power supply to DC and then converts from the DC power supply back to AC, so differences in the power supply frequency have no effect on operation.
When I want to electrically disconnect I/O, is it acceptable to insert a relay in the Inverter input power supply line?
From a safety standpoint in case of an internal inverter failure, install a circuit breaker or magnetic contactor in the Inverter's input power supply line, and install a circuit to disconnect the inputs and outputs.