Motors

[shieldssecurity]

I don't know if this question has a simple answer but here goes.

If I had a 3 phase .75 motor what size would be the equivelent in single phase

Thanks

 

[shieldssecurity]

0.75 what? A kw is a kw just like a hp is a hp

So the answer would be the same, depending on the single phase motor however ( permanent cap, split phase, capacitor start-capacitor run etc ) they would have different starting torques compared to the 3 phase

I had a feeling there was more to it. I'll go back and have a look,

Its just this company supplied an animal feed system with three phase motors, on realising there was no 3 phase available, they swapped them for single phase motors which are the same size and shape. On switching the system on the motors are struggling to pull the feed through and eventually overload.

I'll get some more details today

 

[shieldssecurity]

I'll get all the details today and post later.

thanks for the advice

 

[Sidewinder]

shields,

Did they sort out the control systems or not by the way?

Motors as per Canoey^.

You need rating plate data off both really.

1ph motors tend to have a lower starting torque than 3ph (ish)

 

[shieldssecurity]

Well the story goes like this......................

The feed system was quoted by a middle man, he got all the bits from different copmanies and supplied it to my customer. In regards to the control panel, I got the correct 3 motor set up from a company called Collinsons. Its a fully automated system.

So I wire it all up and run the system dry and all is well. As soon as we introduced the feed the motors started struggling so I finnaly get in touch with the company that supplied the motors and the realist that the .75 watt motors are not powefull enough and the would send us a 1.1kw to try out.

When it arrived the fan casing was smashed and so was the fan.

As it stand now is that they can't get any more motors until a week on Wednesday when the promise we will get 3 new 1.1kw motors.

All I can do is wait and see

 

[Riggy]

Suppliers (or Collinsons) have probably already told you this, but just in case: these feed auger systems need some run time to polish the auger spiral, and reduce friction. Normal commissioning procedure therefore is to run the system with bin slide just cracked open allowing only a trickle of feed, monitor the motor current, and keep opening the slide as the current drops off.

 

[shieldssecurity]

That makes total sense, what I'll do is when we change the motors we'll do exactly what you have explained.

Thanks