What are the necessary requirements of cable?
Underground Cable Construction | Necessary Requirements of Cable
- Cores or conductors:
- Paper Insulation:
- Metallic sheath:
- Bedding of U. G. cable:
- Armouring of underground cable:
- Serving of underground cable:
Why is cable sizing important?
Cable Sizing and Selection Introduction: One of the important aspects of designing any electrical system is to select an appropriate type and size of a cable. Cable sizing helps us to select an accurate size (i.e. cross sectional area) and type of cable required for a particular system.
What is the meaning of 3 core cable?

3 core cable is comprised of live, neutral and earth conductors, suitable for ‘Appliance Class I’ (connectivity to earth). 2 core cable is comprised of live and neutral conductors only, suitable for ‘Appliance Class II’ (no connectivity to earth).
What is the maximum length of under ground cable recommended?
Therefore, it imposes a serious limitation in the length of AC underground cables. For example, practical transmission length for a 138 kV, XLPE cable is limited to 66 miles [1]. This paper proposes using AC underground cables for a distance slightly longer than the electrical half-wavelength.
Is it OK to oversize cable?
Using larger gauge AWG wire offers you more flexibility in how your electrical system is laid out. Your electrician can add more outlets when your wiring has increased current potential. Larger wiring can sometimes be installed in risky areas where small wiring is not recommended.
Why the size of cable must be related to the circuit over current device?

The Importance Of Cable Sizing And Selection The higher the impedance the lower will be the fault current and the longer it will take for the circuit protection to operate. For fast protection this fault loop impedance must be low.
Should I use 1.5 mm or 2.5 mm cable?
1.5 mm is most commonly used for lighting circuitry and switches. 2.5 mm is most commonly used for ring mains, plug and socket wiring. 4 mm is most commonly used for high power ring mains, plug and socket wiring. 6, 10 and 16 mm are most commonly used for high powered small appliances such as cookers.
Can you use 2.5 mm cable instead of 1.5 mm?
2.5mm should be fine so long as the breaker is <= 10a. In fact it’s actually quite a good idea as it will help with volt drop. Personally I would say that he must have some other reason for insisting on this as no spark in his right mind would get busted up over the cable size being too big.