22Kw Motor, 415v Cable Installation

[LCSE]

Hi all,

Just a quick check to make sure I've got the right size cable really.

I have been asked to wire up a conveyor system which has a 22Kw, 415v motor. With the following information I have determined that I require a 50mm 4 core SWA cable for the installation and would just like to clarify that this is correct. I have run the information through a cable sizing calc as well and have come up with 50mm csa per phase as well

22Kw Motor 415V
Cable run in Meters apx 430m
22Kw Soft Starter (41 amp)
Either installed on Cable Tray or Buried Direct in to the ground (worst case scenario) with no other cables
70C Thermoplastic Insulated Multi-Core Armoured
Ambient Temp of 30C if on Tray and if Buried 20C
Soil Thermal Resistivity 2.5 K.m/W (if required)
Short Circuit kA 25

My client has been told (by another) that he will require either a 70mm cable or a 95mm cable. Is this correct or have I missed something given the information above?

Also it would be a nightmare trying to connect either a 70mm or 95mm cable to the motor connections

Any help or enlightenment would be helpful

LCSE

 

[Martinm]

What amperage did your calculation throw you up?

Why are you using a 4-core for?? Do you require a neutral at this motor?

 

[LCSE]

it did mean to say 3 core SWA. No neutral required.

36.39amps per phase if that is what you mean by amperage?

 

[Hobsoni]

4- core would give you a nice sized CPC though.

 

[Martinm]

Run a single CPC out to it, I believe you only really require half of the CSA of the Line conductors..

See Table 54G in regs, I think it is.

It will work out cheaper.

 

[Hobsoni]

I thought you had to calculate the potential Ze to prove cpc selection is correct...............unless it is the same size as the line conductors?

Sorry, don't have my regs close by.

 

[LCSE]

Sorry. I was looking for the correct size/csa of the Line Conductors given the information above.

 

[Amp David]

Whats protecting this cable, as this will have a bearing on cable selection also

 

[Amp David]

You'll be sizing to satisfy your voltdrop here

 

[i=p/u]

50mm 25mm cpcwill give you vd of 3%

 

[Knobhead]

Well that's his work done. All with no effort on his part.

 

[i=p/u]

Would you trust me and my app

 

[Knobhead]

Would you trust me and my app

Am I missing something here?

 

[telectrix]

tony, i think he's got a cable calc. app. on his phone. i'd only trust it if you'd prepared it. LOL.