Interested to Buy Any Domain ? << Click Here >> for more details...
what is difference between 3.5 core and 4 core cable
- 5 Answers
- 78440 Views
- Havells, I also Faced
- E-Mail Answers
Answer Posted / kapil tayade
3-Core Cables
These cables are used generally for a perfect balanced 3-phase system. When the currents on the 3-live wires of a 3-phase system are equal and at an exact 120° phase angle, then the system is said to be balanced. The 3-phase loads are identical in all respects with no need of a neutral conductor.
An important example of 3-phase load is electric motor and that is why, they are fed through 3-Core cables in most cases.
3.5-Core Cables
A 3-phase system may have a neutral wire. This wire allows the 3-phase system to be used at higher voltages while it will still support lower voltage single phase loads.
It is not likely in such cases that the loads will be identical, so the neutral will carry the out-of-balance current of the system. The greater the degree of imbalance, the larger the neutral current.
When there is some degree of unbalance and the amount of fault current is very small, then 3.5 core cables are used. In these types of cables, a neutral of reduced cross section as compared to the 3-main conductors is used, which is used to carry the small amount of unbalanced currents.
4-Core Cables
When there is severe out-of-balance conditions, the amount of fault current will raise to a very high level. Generally in the case of linear loads, the neutral only carries the current due to imbalance between the phases.
The non-linear loads such as switch-mode power supplies, computers, office equipment, lamp ballasts and transformers on low loads produce third order harmonic currents which are in the phase of all the supply phases.
These currents do not cancel at the star point of a three-phase system as do normal frequency currents, but add up, so that the neutral carries very heavy third harmonic currents.
| Is This Answer Correct ? | 20 Yes | 1 No |
Post New Answer View All Answers
What does quality factor depend on in resonance?
what is the ckt diagram of a tubelight and is it the simplest ckt of electrical engineering and also the component?
In siemens PLC, why do we want to move the data ?
Sir, My doubt on cable sizing calculation, Load:74 KW calculated cable 1 run 50mm2. Now client asking us to reduce cable size by increasing runs. Sir, My question now when my mind strikes with 2 options 1) Divide load 74/2 = 36 and calculate cable for 36+36 making it 2 runs or 2) Simply i can divide 50mm2 /2 ie. 2 runs of 25mm2 Please suggest me sir
Inductor and capacitor........power in one phase and ...... in it another phase.
If 100 KAV USP dedicated earth got disconnect / Cut. What will happen at load.
What are the no-load losses for the 11000/415V transformer with the following rated capacity? 1.1500 kVA 2. 2000 kVA 3. 2500 kVA 4. 3000 kVA
why induction motors are rated at 0.8 power factor.
What are the specifications for conducting earth leakage test as per IEC standard?
What is the difference between a Root Locus plot and a Bode plot?
What is transient Phenomenon?
A cylindrical wire is compressed in length by 10%. The percentage decrease in the resistance will be?????
What is the need of earthing transformer for delta side of a transformer. (Think of a line section between a star/delta transformer at a grid substation and delta/star transformer at a village. An earthing transformer is there at the delta side of the star/delta transformer at grid substation). As there are no ground reference there will not be fault current if a one phase is grounded. Further L-L phase will be sensed by the primary side of star/delta transformer as a L-G fault. So why an earthing transformer is required at delta side
What is meant by bus bar protection?
Why earthing is necessary for any equipment?
