Answer / itsme

1. find load.... 8kw shower
2. find current Power/voltage ie. 8000/230 =34 amps
3. Use next fuse size up from current...40amp fuse/breaker
4. select a size cable suitable to carry 40amps
5. Find length of run. ie 20 meters.
6. carry out volt drop calculation

design current (34amps) x Length of run (20 meters) x
millivolt drop per meter (7.83 mvolts/meter for 4 square
cable) >>> 34 x 20 x 0.00783 = 5.44 volt drop!

if volt drop exceeds 9.2 volts use bigger cable

Answer / peer

If we know power calculate I(current) then select Breaker
and choose cable according to that.
Ex: Power is 50KW 3Ph supply.

I=100A (Apprx)

Breaker size for the above is 4c.35 sqmm+1c 16sqmm
E.C.C.

Answer / vzvodator

See this program -
http://miroshko.kiev.ua/cablesel/wiresel_mini_en

Answer / iftekhar mahmud

Caterpillar generator produce (Two generators) 127*2=254 amp
at 11 kv .
What would be the cable size (XLPE) to supply 256 amp at 11
kv? Air or surrounding Temperature is 32 degree C. Cable
will go under ground at 2.5 feet depth. Group Rating Factors
is 3 cables. Clearance between cables is 7 cm. Soil
Temperature (Ambient) 28o C Soil Thermal Resistivity is 1.2
K.m/W


I would like to use 3 separate single core instead of using
3 core cable.

Some says I should use three separate single core 120RM cables.
Some says 70RM .some says 95.
I m totally confused.
Is there ant specific rule to determine cable size?
Ifte
My e mail address is ifte13@yahoo.com
Anyone please send me the answer to my e mail address,
i will be very glad.

Answer / vijay shinde

it simple it should be select on how much current will
cable carry

Answer / ahmed bilal

for calculating cable load, you have to email me
aoabilal@gmail.com

Answer / ashutosh tiwari

according to kelvins economic choice of conductor size
formula is
total cost = (P1+p2*a)+p3*a
a>>>conductor size

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