cable sizing 1

[Mefi01]

Hello everyone, I am very new to cable design in building services. I would like to know the effects that volt drop has on cable sizing?

 

[ScottyUK]

Fat cables = less volt-drop, thin cables = more volt-drop.

 

[magoo2]

To add to what Scotty said
- A cable that is adequate to handle the amps for short distances will generally have voltage problems for long distances. By voltage problems I mean the resulting voltage will be too low at full load if the length is too long.

 

[ScottyUK]

You should also consider earth loop impedance so that the protection will operate within the required time in the event of a fault at the remote end of the cable. Often this becomes the dominant factor in cable sizing.

 

[Mefi01]

Thank you so much everyone. Could you please let me know the equations that normally govern the voltage drop and cable sizing?

 

[waross]

Ohm's law?? Voltage drop tables which consider inductive reactance as well as resistance.

Bill
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"Why not the best?"
Jimmy Carter