Help please.

[EdwardCurrent]

Hello All,

400V 16KW Load PFC.8 = 50A
2.5 T+E Through insulation (+500MM) CCC = 18.5A


Correct ?
Thank you for any comments.
I just need to check.

Ed.

 

[Steve]

WHAT???

If its 400 volts, you wont be using twin and earth!

 

[EdwardCurrent]

Sorry,
they are 2 seperate questions.

Ed

 

[Steve]

I know I'm only a DIYer, but any chance you could clarify what you're asking in words and sentences? And separate the 2 questions.

 

[EdwardCurrent]

Cheers Steve,

1)Motor with a fower factor of .8, 16KW load fed by 400Volts would have a rating of 50A ?

2) The current carrying capacity of 2.5 twin and earth installed within insulation in a loft for a distance of +500mm is 18.5A ?

Ed.

 

[Steve]

Thats better! I could have done a Softus and said "please state the nature of the problem you wish to solve"

(As it happens I dont know the answers sorry!)

 

[scott6471]

The motor calc seems right, but my calcs for the T/E put its effective current rating at approx 10.5 Amps due to the thermal insulation


Scott

 

[ricicle]

Hello All,

400V 16KW Load PFC.8 = 50A
Ed.

If that is a 3 phase load then [16000/0.8]/[1.73*400] = 28A per phase

 

[EdwardCurrent]

Thanks for your input.

Now the reason for my post.

http://electricalforum.co.uk/viewtopic.php?f=7&t=37&sid=64a5f917a423575c2823e1908577d17b



Ed.

I used Table6E1, page 123 OSG for the cable calc. Reference method 4.

 

[ricicle]

Yes, the answer is 28.8A (I didn't show the decimal place this morning as I was in a rush!)

 

[Spark123]

The 2.5mm² twin and earth one, the cable is method 15 which is 21A. Table 4D5A.

 

[ricicle]

The motor calc seems right, but my calcs for the T/E put its effective current rating at approx 10.5 Amps due to the thermal insulation


Scott

Back to school, my friend.............

 

[scott6471]

Thank you ricicle

Very basic and foolhardy error on the motor calc, but as for the cable in the thermal insulation Ed neglected to mention it was exposed on one side, in his words "through thermal insulation for 500mm" which following the link it obviously is not.

Scott