AVC TECH LTD - Electrical installation services

29/08/2026

We are Electricians! (by Ace)

16/08/2026

⚡ **HOW BASIC PROTECTION & FAULT PROTECTION (ADS) WORK** ⚡

When we talk about protection against electric shock, there are two important principles every electrician should understand: **Basic Protection** and **Fault Protection**.

🔵 **BASIC PROTECTION – BASIC INSULATION**

Basic insulation protects us during normal operation.

The insulation around the live conductors creates a **non-conductive barrier** between the conductor and a person.

For example:
🟤 Brown insulation protects the line conductor
🔵 Blue insulation protects the neutral conductor

The purpose is simple:

**Basic insulation → prevents contact with live parts → protects against electric shock.**

But what happens if that insulation fails? 🤔

🟢 **FAULT PROTECTION – AUTOMATIC DISCONNECTION OF SUPPLY (ADS)**

With Class I equipment, exposed metal parts are connected to the installation's means of earthing through a **Circuit Protective Conductor (CPC)**.

Under normal conditions, the metal enclosure is not live and no current should flow through the CPC.

⚠️ **NOW LET'S CREATE A FAULT...**

Imagine the insulation on the line conductor fails and the conductor touches the metal enclosure.

The enclosure can become live.

However, because it is connected to earth through the CPC, a **low-impedance fault path** is provided.

A high fault current can now flow:

⚡ **Line → Fault → Metal Enclosure → CPC → Earthing System → Source**

This is the **earth fault loop**.

The fault current causes the protective device — such as a **fuse, MCB or RCBO** — to operate and automatically disconnect the faulty circuit from the supply.

The earth fault loop impedance must be sufficiently low to allow enough fault current to flow for the protective device to operate **within the required disconnection time**.

This is:

🛡️ **AUTOMATIC DISCONNECTION OF SUPPLY – ADS**

In simple terms:

**FAULT → HIGH FAULT CURRENT → PROTECTIVE DEVICE OPERATES → SUPPLY DISCONNECTED → DANGER REDUCED**

💡 This is why the CPC, earthing arrangements, earth fault loop impedance and protective device are all essential parts of electrical safety.

Knowing **what to test** is important.

Understanding **why we test it** makes you a better electrician. ⚡🧰

28/03/2026

ElexShow at AllyPally (Alexandra Palace), London. it was good to see the new innovations in the electrical industry. I tried the Multifunctional testers of the leading companies and i was quite impressed by Megger and Metrel, and more budget friendly TIS and Kewtech. For me, Megger and Kewtech are more user friendly. the others can be a bit confusing

08/03/2026

In-Service inspection and Testing of electrical equipment - The legal requirements

07/03/2026

How to work safely on an electrical installation: Safe Isolation Procedure - updated version (AI Voice Duplicate)

06/03/2026

Electricity - the beginning. Learn the fundamental principles with my latest video. Enjoy

04/03/2026

https://share.synthesia.io/c8e7fd2b-7c86-4272-aa50-937ef73c2460

Click to watch the AI video "Safe Isolation Procedure" generated with Synthesia.

25/12/2025

Merry Christmas and a Happy New Year!