Topic 5: Earthing and surge suppression concepts

Topic 5: Earthing and surge suppression concepts •Protect people against injury•Provide a reference point for voltage and signal measurement•Assist anti-surge devices to protect equipment from high voltages on the line•minimise some types of electrical interference•transmit control signals between equipment

Topic 5: Earthing and surge suppression concepts

Fig 1: Earth Leakage Circuit Breaker

Topic 5: Earthing and surge suppression concepts

Fig 2: Earthed star point in a three phase electrical system

Topic 5: Earthing and surge suppression concepts

Fig 3: MEN

Topic 5: Earthing and surge suppression concepts

Fig 4: Equipotential Bonding

Topic 5: Earthing and surge suppression concepts

Fig 5: Telecommunications Earthing

Topic 5: Earthing and surge suppression concepts

Fig 6: TRC and CES

TRCTelecommunications

ReferenceConductor

CESCommunications

EarthingSystem

Topic 5: Earthing and surge suppression concepts

Fig 7: Telecommunications reference conductor (TRC)

A TRC distribution system may consist of the following:

•TFEE where required•TFE conductor, estending the earth from the TFEE to the earth bar at the CD/BD•TRC conductors extending from the CD/BD earth bar direct to a CSS or CE, or to FD earth bars and subsequent

Topic 5: Earthing and surge suppression concepts

Fig 8: Bonding via a differential earth clamp

Refer to Technical StandardTS 009

Figures 1 to 4 for details on the connection of TRC

Topic 5: Earthing and surge suppression concepts

Fig 9: Communications Earth Systems-earthing wires

CES = TRC + PE

Refer to: Technical StandardTS 009

Figures 1 to 4for details on the connection of

CES

Topic 5: Earthing and surge suppression concepts

Fig 10: Surge Suppression- causes of surges

Topic 5: Earthing and surge suppression concepts

Fig 11: Surge Suppression- surge protection1. Interception of the lightning strike

Topic 5: Earthing and surge suppression concepts

Fig 13: Typical surge suppressors