30kw boiler cable calculations

[meggerlover]

Hi guys just a quick check in my calculations for a quote I'm doing

15meters clipped direct

30,000w divided by 400v
= 75a per phase

im using sy cable and think 16mm 5 core is best

What you guys think

 

[meggerlover]

then you need to brush up on your calculations. hint 6mm clipped direct will just dso it.

Thanks tele I have obviously missed something out , could you recap how you got to 6mm

 

[Kris]

Megga im still curious is this a domestic or commercial boiler , would think domestic at that size ?? thats why i asked about the 16mm seems huge

 

[snowhead]

Thanks tele I have obviously missed something out , could you recap how you got to 6mm

IET Forums - kw to amps, 3 phase calc

 

[telectrix]

30,000/ ( 1.732 x 400 ) = 43.3A. or a quick jobby. 30,000/3 = 10,000Watss /phase. 10,000/230 = 43.5A.

 

[meggerlover]

Megga im still curious is this a domestic or commercial boiler , would think domestic at that size ?? thats why i asked about the 16mm seems huge

Its an industrial boiler not used for heating it's used for boiler vast amounts if water in order to manufacture chemicals

 

[meggerlover]

30,000/ ( 1.732 x 400 ) = 43.3A. or a quick jobby. 30,000/3 = 10,000Watss /phase. 10,000/230 = 43.5A.

Whats your 1.732 represent

 

[telectrix]

root3. come on mate. this is basic stuff.

 

[D Skelton]

Electrician qualified to the current 17th edition requirements

What qualification exactly?

 

[meggerlover]

root3. come on mate. this is basic stuff.

My god I don't know where my head is

all lol I had to do is divide my 75 by sq root 3 to get 43amps

cheers guys

 

[meggerlover]

What qualification exactly?

A full bloody apprenticeship fully qualified ELECTRICIAN svq III
17 the edition 2394&5

 

[BES]

What qualification exactly?

A full bloody apprenticeship fully qualified ELECTRICIAN svq III
17 the edition 2394&5

Ah scottish

 

[D Skelton]

A full bloody apprenticeship fully qualified ELECTRICIAN svq III
17 the edition 2394&5

Still doesn't answer the question.

What number? 2330? 2357? 2397?

 

[meggerlover]

Yes no

 

[Andy78]

Megga im still curious is this a domestic or commercial boiler , would think domestic at that size ?? thats why i asked about the 16mm seems huge

As a gas fitter you are probably thinking of the boiler's size in terms of heat output, expressed in either kW or btu. A 30kW output boiler would be common in a domestic house. The calculation being done here is for the electrical energy (input) being drawn by the heater, in this case 30kW. In comparison a household kettle would draw about 2.2kW.

Your previous question about cable size ...... cable is measured by the cross sectional area of the conductors. 16mm is actually 16mm squared. It doesn't relate to the diameter of the cable as a whole.

 

[Badged01]

..... svq III ....

That explains why there is no root 3 then! ...... and fortunately no PF's or Eff's :smiley2:

 

[BES]

Yes no

So you were one of the ones who put both down on ballot paper.

 

[Kris]

root3. come on mate. this is basic stuff.

You guys should be gettin paid to teach on here lol, i find loads of guys claiming to be sparks on here but need to ask you guys for all the info,
Next door in plumbing forum unless they prove they are gassafe reged then we simply cant help them lol

 

[Kris]

As a gas fitter you are probably thinking of the boiler's size in terms of heat output, expressed in either kW or btu. A 30kW output boiler would be common in a domestic house. The calculation being done here is for the electrical energy (input) being drawn by the heater, in this case 30kW. In comparison a household kettle would draw about 2.2kW.

Your previous question about cable size ...... cable is measured by the cross sectional area of the conductors. 16mm is actually 16mm squared. It doesn't relate to the diameter of the cable as a whole.

Cheers andy

 

[Andy78]

You guys should be gettin paid to teach on here lol, i find loads of guys claiming to be sparks on here but need to ask you guys for all the info,
Next door in plumbing forum unless they prove they are gassafe reged then we simply cant help them lol

Unfortunately we have no such similar scheme. The only schemes we have drag people off the streets, take their money, tell them they are electricians, and devalue our trade. All with the full backing of the govt.

 

[Badged01]

Daddy, when I grow up I want to get into organised crime! ........ is that with the Govt or private sector son?