3phase

[peteludman]

I have to wire up an autoclave its 3 ph 415 v 9kw and doing ohms law I get 21.6 amps the question is do I devide this by 3 or would it be 21.6 a per phase

 

[solo2771]

divide by 3

 

[earlelectric]

9000/(1.732 x 400) = 13A. THIS IS WHAT EACH LINE WILL CARRY.assuming no problem with power factor.

 

[baldsparkies]

9000/1.732 x 400 = 13A. THIS IS WHAT EACH LINE WILL CARRY.assuming no problem with power factor.

This is the one you need. Your measuring an rms value divided by route 3, hence 1.73 also supply voltages are recognised as 400v 3 phase 230 single. Not 415/240

 

[Darkwood]

9000/1.732 x 400 = 13A. THIS IS WHAT EACH LINE WILL CARRY.assuming no problem with power factor.

Although you got the right answer, the equation you passed on is somewhat flawed
Try 9000/1.732 then DIVIDE by 400= 12.99amps (13amps) id like to see the cable size for your 2million+ amps

Where were you baldsparkie, you missed that one lol

 

[Tester Steve]

Although you got the right answer, the equation you passed on is somewhat flawed
Try 9000/1.732 then DIVIDE by 400= 12.99amps (13amps) id like to see the cable size for your 2million+ amps

Where were you baldsparkie, you missed that one lol

Now for the CORRECT way! 9000/(1.732x400) = 13A

Sorted!!

Steve.

----------------------------

Learn from your mistakes, but don't make too many or you will know too much

 

[baldsparkies]

Although you got the right answer, the equation you passed on is somewhat flawed
Try 9000/1.732 then DIVIDE by 400= 12.99amps (13amps) id like to see the cable size for your 2million+ amps

Where were you baldsparkie, you missed that one lol

Indeed I did, must be getting old Darkwood. Glad you have your wits about you mate.

Divide it is multiply its not.

Now for the CORRECT way! 9000/(1.732x400) = 13A

Sorted!!

Steve.

----------------------------

Learn from your mistakes, but don't make too many or you will know too much

Show Off !

 

[Notsosmart]

I would only add that you need to check on the auto-clave what its power factor is i.e p.f. 0.8
KVA=KW divided by p.f

so your current rating may well be a little higher (I assume you are looking at circuit protection &/or cable sizing)

 

[Guest123]

Well if we're going down that road then the PROPER CORRECT way is


KW________
(VxRoot3xPF)

 

[Darkwood]

Now for the CORRECT way! 9000/(1.732x400) = 13A

Sorted!!

Steve.

----------------------------

Learn from your mistakes, but don't make too many or you will know too much

Different transposition but no less or more the correct way than my solution it all gives the same result and thats all you need.

 

[earlelectric]

oops! sorry tester, missed the brackets out on my equation didnt i

 

[Notsosmart]

Well if we're going down that road then the PROPER CORRECT way is


KW________
(VxRoot3xPF)

& That's why you're the Administrator

 

[earlelectric]

Or 9000/692.8=12.99a

 

[ian.settle1]

& That's why you're the Administrator

Incorrect he is a MODERATOR not the ADMINSTRATOR there is a difference

 

[Notsosmart]

Incorrect he is a MODERATOR not the ADMINSTRATOR there is a difference

Thanks Ian, As usual i'm close but no cigar

 

[Tester Steve]

Good thing is guys, everyone got the right answer!!

Steve.

PS Why does my footer not work anymore?

 

[baldsparkies]

Well if we're going down that road then the PROPER CORRECT way is


KW________
(VxRoot3xPF)

PROPER CORRECT way is

KW________
(VxRoot3xPF= PUB FIRST)

 

[pevvers]

How about (9000/3)/230. Gives the same result within a few milliamps. And easier way to remember.

If it's a 9kW balanced load, 3kW will be from each phase, therefore divide that by 230V and Bob's your Mothers brother.

 

[peteludman]

well i think i know now, thanks to all of you for the help and i like the answer pub first