Answer / kh

3 core is used for 3-ph loads/systems which do not require
neutral e.g. motors. 3.5/4 core is used wherever 1-ph
supply is also required (tapped between 1ph-N) in addition
to 3 phase supply. 4 core used for smaller cables usually
upto 16 sqmm where neutral core is of same size as phase
cores while 3.5 core is used for higher sizes where neutral
core is half the size of phase cores.

Answer / at

3 core cables are used where ever the system is ungrounded.

3.5 core cables are used where the major load in an
industry / plant etc. is three phase but also has single
phase loads or loads that can cause a little unbalancing
and thus the nutral might carry some current but not always
and not as much as the line current. Therefore a smaller
cross section of nutral can solve the purpose as current
through nutral will be very small as compared to the rated
current of the cable.

4 core cables are used in systems where all loads are
single phase or majority loads are single phase. so there
are chances of high degree of unbalancing. and nutral has
to carry a larger amount of current.Therefore half cross
section of nutral may not solve the purpose and we opt for
4 core cables. This arrangement is used for small cross
section cables used in homes and industries. for lighting
and other small applications.

Answer / pawan mishra

3.5 core cables contain 4 cores i.e. 3 for phase and 1 for
neutral.
it is known as 3.5 coz it s netral thickness is half the
diameter of phase core.
netral is requried only in l.t. network

Answer / p.k.chadhar

3 core cable can be used for three phase power supply
without earthing
3&1/2 cable can be used for three phase power supply with
earthing because 1/2 core is mostly used for earthing or
gounding
4 core cable can also be used for three phase power supply
with earthing this cable can also be used for control supply
it depends on size of the cable if it is 1.5 mmsq.then
control ,if size is more can be used for power connection.

Answer / ashok

4 core cables are used for the rating more than 5KW,and the
3 core ,31/2 are used for below 5kw and 5kw supply.

Can anybody tell the formula to calculate temparature rise in the cable with respect to current?

1 Answers  

---

why r we using shell transformer for low voltage

0 Answers  

---

why autotransformers are not safe for supplying low voltage from a high voltage source?

5 Answers  

---

Technical specification of a wind farm

1 Answers  

---

I want to know which cable would be best to carry 125A current to a distance of 50m. Voltage is 3phase. Kindly share the formula with answer.

1 Answers   Medway Educational Consultant,

---

---

what is the principle to generate energy from water or coal, plz define the step by step how & when electricity energy start from resource area to ours home meter & separate & how meter read the voltage or current?

1 Answers  

---

what happen if the parallel generator phase angle shift by 1 degree in manual mode

0 Answers   EEEC, MEC,

---

n1 =1000 n2 =?;v1 =200:v2 =400

1 Answers   APGenco,

---

What is LSIG ?

6 Answers   Apollo Power,

---

What the difference between ac and dc inductor an capacitor

0 Answers  

---

we use 3 phase supply for induction motor why not use two phase supply .

4 Answers   TLC,

---

For what purpose an AVR in generator sensing generator output voltage?and how the sensing is done by AVR?

3 Answers  

---