How Effective Is The SELV Design In Providing Safety Solutions?

With the shortage of energy resources in the world experts are finding new ways to cope the descending energy sources. One of them is the extra low voltage system which uses low voltages in commercial and residential buildings including offices, warehouses, homes, gardens which eliminates the risk of electric shock and also saves valuable voltages.

Usage of low voltage systems in developed countries:-

In extra low voltage systems alternate current is meant to be below 50 volts and direct current voltages need to be below 120 volts. Many developed countries are using this latest system to gain advantages of low voltage usage and saving money. Qatar is one of these countries that are implementing this futuristic system in the buildings which will save them millions of dollars in the future.

Let’s discuss the separated extra low voltage system here

What is SELV?

SELV refers to an electrical circuit which is separated electrically from high voltage carrying circuits. According to ELV design consultant Qatar, under normal conditions or under single fault conditions the voltage should not exceed the limit of extra low voltage. The separated extra low voltage system is separated from the earth in such a way that even if a fault happens there is no risk of electric shock to anyone who may be in contact with the system.

Designing:-

The designing of it is based on guaranteed minimum distances between the insulating barriers and conductors, and usage of an insulation transformer. The separated extra low voltage cables should be double insulated when the chances of them coming into contact with other circuits is high.

Separation of wires:-

The wiring should also be separated completely from high voltage cables and also from circuits of SELV, PELV and from the earth ground. For lower voltages of up to 25 volts, un-insulated terminal screws are permitted to be used. But it is strongly recommended to use insulation to avoid battery short circuits.

Why SELV system is safe:-

This system is safe due to following reasons

1. One safety aspect of it is that the voltages of this system never exceed DC of 120 volts and AC of 50 volts. These current levels are too low to give serious electric shocks.
2. Current doesn’t have a return path from the ground
3. Almost no contact with high voltage cables

Normal usage places of this system:-

The system is used where the usage of some electrical appliances to risky to pose serious threats to life and safety of humans. Amusement parks, swimming pools and some domestic appliances like radio and oven also use this system.

Other places of usage:-

Some known examples of it are as follows

• CCTV and security systems
• Computer cabling and data systems
• Light control panels
• PABX
• Access control systems

ELV Design Consultant Qatar separates the higher voltage systems from the extra low voltage system by creating a partition to enhance the safety measures and less usage of volts. The combination of low voltage, basic insulation and usage of protective separation makes it the safest electrical system.