Interested to Buy Any Domain ? << Click Here >> for more details...
how to calculate cable size, olr rating, contactor rating
and mccb rating,to below given details three phase motor
75 kw,415 v,.85 pf,50 hz?
- 5 Answers
- 73985 Views
- Cabin Crew, Essar, I also Faced
- E-Mail Answers
Answer Posted / rsbangra
motor rating 75kw,so it taken full load p=1.732*v*I*cosfy
i= p/1.732*v*cosfy
=123 amp. so we requared a cable to carry 123 amp
contonious rating. so require to run motor in star delta
starter . in star delta connection load current is 58% of
line current. we require 58% of 123 amp carring capasity
cable.it is around 71 amp.generly copper cable taking 4
times current of cable rating and alluminium cable taken
1.5 times of cable ratting .so for 71 amp carring alu.
cable 50mm2 suffisent but due to high starting curent its
take 70 mm2 cable ib best.
its overload relay ratting is in range to 71 amp. it to be
60-80 amp,and mccb rating is 2.5 times of full load =300amp
is best.
| Is This Answer Correct ? | 47 Yes | 57 No |
Post New Answer View All Answers
what is the difference b/w pvc cu conductor and cu breaded wire..?
How do apply electrical 'c'license......pls advice
how flow current in 220 kv line to line
how we decide the require size is this for a known current at fuu load?
describe the Operation of induction generators from bus bars
Which Class insulation is prefered for the sandwich Busducts ? Why?
how can we determine size of a cable by knowing the kw or current rating of a load?how can we calculate the resistance box of a slip ring motor?
what is the mechanism of operation of brushless dc motor why is it more wexpensive then ordinary permanent magnet motors
Is it possible to measure correct value of earth resistance & cable insulation ristance with out disconncting earth lead & both sides of cable ends? If not, any other method to measure ER & CIR with out disconneting from the system.
What is miller crystal oscillator? Explain its operation?
what is quality factor in series resonance circuit and calculate the factor of voltage magnification? how it happens?
can any one tell in easy method for circulating current ??
If 24 KVA AVR having Input voltage 200-400v, Output voltage 415+-1%, what will be the voltage if Load is 13A.
A ray hit a smooth regular surface at an angle of 20 from the normal. Calculate : 1. The angle btw the incident and reflection ray. 2. The angle of deviation.
What is the tipical Online UPS input voltage for 20 KVA load ( 3 Phase or 1 Phase )? Why ? Explain it...?
