Answer / vishvendra singh

we know that current capacity of Alluminium conductor is 2
AMP/sqmm. thats by In normal condition 300sqmm cable current
capacity -600 A & 150 sqmm capcity is -300 A.

Answer / k.k dash

now a days company manufacture lower gauge of aluminium cable for there own profit,previously 300 sqmm alu cable can take 600 amp,bt now a days 300 sqmm will take 300*1.2=360 amp at 80% load which is healthy for user,same way 150 sqmm will take 150*1.2=180 amp

Answer / 7anoter4

It depends on lot of factors. The duration of the load:
short-time[as in short-circuit case],continuous load,
intermittent load. It depends on also on ambient type [air,
underground-direct laid or in concreted duct],on thermal
resistivity of the ambient [if it is in underground],on
ambient temperature, on insulation type[bare, pvc, xlpe,
epr etc.] and other factors.

Let's say in short-circuit case for 1 sec 300 square mm
aluminum conductor pvc insulated. Permissible temperature
[for PVC short-time]= 150oC.Ambient air 30oC.
Ipermissible=27 kA[27000 A].

For the same cable in open air 30oC[NEC Table 310.15(B)
(17)] continuous load [75 oC]600 MCM=300 sqr.mm permissible
545 A

WHY TRANSFORMER IS MEASURED IN KVA?

10 Answers  

---

why earth wire is needed in a wiring system

1 Answers  

---

EXPLAIN THE APPLICATION OF RECIPROCITY THEOREM

1 Answers  

---

when i am going to take trail on a 3ph sq.i/m motor 5.5kw, i observed that RPM of the motor is very low as compared to the rated RPM and also it rotates in clockwise in first ON command,and anticlock wise in second ON command. finally i observed that on phase is no available . but iam not clear about, why the motor is rotates in both directions without any phase interchanging.pls answer to my question.

1 Answers  

---

one split ac how can told of this ac which Tr tell me us

0 Answers   Wipro,

---

what will happen if the frequency supplied is more than the frequency of the instrument...?

3 Answers  

---

pls tell me about ups internal connection & we have given only 3 phase supply to ups system how get 4 wire (R Y B N )

0 Answers   Bhel, IBM,

---

What are the conditions for sustained oscillator or what is backhouse criterion?

0 Answers  

---

How to calculate earth wire load by formula

0 Answers   Caparo,

---

Why Earthin is not required in Xformer primary side when it is in Star / star?

2 Answers  

---

How to prepare electrical preventive maintenance plan & shedule of machine tools.

2 Answers  

---

What is the diffrence between an ELCB(earth leakage circuit breaker) and RCCB(residual current circuit breaker)?which has higher degree of safety and why?

2 Answers  

---