3 phase supply size

[netblindpaul]

There are also still some glaring errors in posts on this thread ignoring the so called "misunderstanding" of kW per phase or across 3 phases that are sufficient to kill people.

 

[Darkwood]

Allan, my course tutor, has just told me that (in his opinion) if the plate on a 3 phase motor says (eg) 10kW, that's the total consumption.

Do us a cheeky favour tell your tutor the KW rating on a motor is the energy output down the shaft and a replacement value for horsepower and not to be confused with what the motor consumes thus the relevant equation has to be done to get the current before you can say whether its across the phases or per phase - Im interested ho you are taught today and what his answer would be!

 

[Marvo]

There are also still some glaring errors in posts on this thread ignoring the so called "misunderstanding" of kW per phase or across 3 phases that are sufficient to kill people.

Yes there are but it's a discussion, not a tutorial and if anything should be taken from the thread by a person looking for advice it should be that they ought to confirm with the agents or supplier before making any assumptions.

 

[trev]

Deleted following a PM conversation

 

[happysteve]

Do us a cheeky favour tell your tutor the KW rating on a motor is the energy output down the shaft and a replacement value for horsepower and not to be confused with what the motor consumes thus the relevant equation has to be done to get the current before you can say whether its across the phases or per phase - Im interested ho you are taught today and what his answer would be!

To be fair to Allan, he did say rather a lot more than the sentence I typed quickly on my phone during the brew break! I realise now that in my rush, I probably misrepresented what he explained. Apologies.

Over 3-4 minuts he talked about how (as you say) it's related to the output power of the motor in terms of the work it can do. He mentioned horsepower, and when he put it in this perspective it started to make sense. He did mention efficiency too; he didn't actually say, "Your total electrical power consumption will be greater than the rated power due to the efficiency always being less than one (100%)," but we covered the equations in an earlier lesson so I guess he left this for us to work out.

I like Allan. He's alright.

 

[Silly Sausage]

@NickD

I'll apologise now for taking this off topic (as I know it's now frowned upon)

Nick do you find Asperger's is much of a hindrance to how you deal with your life on a day to day basis?
My great nephew has it and it's a daily struggle for him.

I reckon he had his Bell End pulled and he's replaced it with this lame attempt.

 

[trev]

Deleted following a PM conversation

 

[Silly Sausage]

I wonder what he'll think when he gets access to Arms!

 

[GLENNSPARK]

I wonder what he'll think when he gets access to Arms!

eh?...

 

[GLENNSPARK]

it`s what others will think....

 

[Silly Sausage]

eh?...

Av a shufty in the pub, you'll see!