How do I select soft starters for use with IE3 Motors?

There are many misconceptions about motor starting. It is often believed that the start current of a motor under full voltage conditions depends on the driven load, but this is totally incorrect. The start current of the motor depends on the motor design, rotor speed and stator voltage from zero speed until full speed is […]

I have a 90kW motor with soft starter 90kW installed. How much kVA Generator do I require for the motor?

Limited information means you need to make a few assumptions on power factor and efficiency. Assume PF of 0.75 and efficiency of 90% kVA = (kW / Power factor) / efficiency so kVA = (90 / 0.75) / 0.9 = 133.33 kVA So 133.33 kVA minimum but better to add a little extra to be […]

Why use a bypass contractor with a soft starter?

The Bypass contactor opens when the motor reaches full speed to reduce power (heat) losses in the solid-state power section. This translates to much smaller enclosures without need for special cooling. Also, the bypass contactor is internal to the soft starter, eliminating the need for additional devices, further reducing enclosure sizes and minimizing installation time. […]

What is the difference between a VSD and a Soft Start Starter?

We are frequently asked, what the difference is between a variable speed drive and a soft starter? The difference is the speed that the motor can run when at full speed. With a soft start starter, the motor is reduced when voltage is started; and then when the motor is at full speed, or a […]

Can a variable frequency drive replace a Soft start?

Yes, a variable frequency drive can replace a soft start 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 […]

Can a variable frequency drive replace a Soft Start?

Yes, a variable frequency drive can replace a soft start 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 may still be the correct product for the application. This […]

What is the difference between a VSD and a Soft Start Starter?

The difference is the speed that the motor can run, when at full speed. With a soft start starter, the motor is reduced voltage started, and then when the motor is at full speed, or a timing circuit has timed out, a “running by-pass contactor” pulls in and the motor continues to run at full […]

What is the difference between a Softstarter and a Variable Speed Drive?

In this post, we answer your frequently asked question: What is the difference between a softstarter and a Variable Speed Drive? The main difference between a Softstarter and a Variable Speed Drive, is that a Soft Start does not have the capacity to actually vary the speed or frequency of the motor. A Variable Speed Drive can perform […]

Do you know the difference between a Variable Speed Drive and Soft Start?

The difference is the speed that the motor can run when at full speed. With a soft starter, the motor is reduced voltage started, and then when the motor is at full speed, or a timing circuit has timed out, a ‘running by-pass contactor’ pulls in and the motor continues to run at full base […]