What is the TT System?

What is the TT System?

TT system Definition

It has both the source and the consumer’s installation connected to the earth through separate electrodes. These electrodes do not have any direct connection between them. This type of earthing system is applicable for both three-phase and single-phase installations.

TT System Advantages

• Eliminates any risk of electric shock due to a break in the neutral conductor or contact between live conductors and earthed metal parts.

• Avoids any unwanted currents in metal pipes or structures that are connected to the earth at different points.

• Allows for more flexibility in choosing the location and type of earth electrodes.

TT System Disadvantages

• Each installation needs an effective local earth electrode, which can be challenging or costly depending on soil conditions and space availability.

• Requires additional protection devices such as RCDs or voltage-operated ELCBs to ensure a reliable disconnection in case of a fault.

• May result in higher touch voltages on exposed metal parts due to higher earth loop impedance.