45kw motor and generator problem

[westward10]

The relay would be more tolerant to current peaks whereas the mcb is not and that is the problem. The same goes for the BS88 fuses.

 

[Dozer 73]

A handy little tool for selecting gen set sizes etc
Macfarlane Generators Power Calculator - https://www.macfarlanegenerators.com.au/power-calculator.php

 

[Dozer 73]

A handy little tool for selecting gen set sizes etc
Macfarlane Generators Power Calculator - https://www.macfarlanegenerators.com.au/power-calculator.php

Know it's the the solution to your post , just a good tool to have

 

[Rocboni]

I turned the changeover time up to 10 seconds and it's been fine ever since however I have ordered a D type so will fit that for piece of mind.

 

[westward10]

That is what I suggested way back in #6, glad it seems to have resolved it.

 

[Rocboni]

I know you did westward, just didn't get the opportunity to test during operation as I had to leave the isolator in place until their busy days were over and they could afford the inconvience of it possibly tripping. Understandably it doesn't look good if it cuts out mid ride.

I think the C125 is operating right on its limit though with the regular however short current spikes so I think a D would be more suitable. The RCD is holding fine as well so all good.

 

[MikeM3]

Normal delay in a star delta setup should
be around 9 seconds.

Mike.

 

[davesparks]

Normal delay in a star delta setup should
be around 9 seconds.

Mike.

How can you have a 'normal' delay when each machine is going to be different and take a different length of time to start?

 

[Cadgey123]

How can you have a 'normal' delay when each machine is going to be different and take a different length of time to start?

I agree depends on the motor application and loading

 

[Rocboni]

Further update on this, MCB was holding fine until the colder nights set in, the MCB began to trip when transitioning to delta due to the oil viscosity, the D type was fitted and there have been no other issues.

It's such an unusual load, I was observing the display on the generator at the weekend where it was going non stop for 2-3hrs riding full, the load peaks to 132kw for a second then down to about 60kw, somtimes read minus 10Kw.

It's an interesting industry

Anyway if there was going to be an issue it wouldn't have happened that night!