soft starter for asynchronous motor

[Mick1234]

I’ve got a fan with a very heavy blade and it takes about 10 second to get up to speed. The problem is, by that time the overload sometimes trips or the fuse blows on the supply transformer.

What I need is to reduce the starting current and allow the fan to accelerate more gradually.

The motor is 110V single phase, with a running current of 16A and a peak DOL start current of around 80A.

I thought the “ATS01N125FT, 110V - 480V Soft Starter for Asynchronous Motors” would be perfect for the job, but it didn’t have the expected results. Even with the start time set to maximum, there didn’t seem to be any difference in start up time or start up current and the fuses still kept blowing and overload tripping. I tried various initial voltages, but it didn’t seem to make much difference.

How do I extend the start up time beyond 10 seconds, or is that the limit for this device?

The unit is wired as shown on the drawings that came with the unit for single phase motors. I’m I doing something wrong?

[Mick1234]

After another site visit with more detail monitoring, I found with the ATS01N125FT set to maximum time, that it hit full voltage after 6 seconds and in 3 seconds when set to the minimum time.

I need much longer starting times. Do I have a faulty unit or is 6 seconds the maximum start time?

[NeiB]

Dear @Mick1234 ,

Hope you are doing well.

Yes, the maximum starting time of ATS01 ending in FT is 5 seconds as indicated on the documentation attached (the table below):

Sadly this is the only model on the Altistart family dedicated to single phase application. The models for three phase does have a longer starting time and a BOOST function to improve start torque however it does not work with single phase systems.

Best Regards,

Neide

[Mick1234]

Well, that was a waste of £££ then! 🙄

Thank you for sharing the information. The PDF I downloaded didn’t have that detail.

I assumed there would be a sufficient start up time. I mean, why would anyone make a soft starter with a shorter start time then when the motor starts up direct on line! The whole purpose of a soft start is to extend the start time.

[NeiB]

Hi @Mick1234 ,

Yes, sorry to hear that.

The point is that ATS01 has been in the market for a while and it used to be suitable for most of the standard application, however this has changed a lot lately.

I recommend that every time you have an application with our products that are new to you, come to our community and ask to see if more knowledge is available to help you to take a better decision and not waste $$$ again.

There is also the technical support of Schneider in your country that is available for whatever question you have.

See you.

Best Regards,

Neide