Technical Seminar for Cathodic Protection

to GOGC Design Unit Specialists

Dr. Nick Kioupis, Cathodic & Lightning Protection

Section Head, DESFA

Downward Flash (cloud-to-earth lightning flash)

Upward Flash (earth-to-cloud lightning flash)

Part 1 - General principles:

This part presents general information on lightning and its characteristics and general data, and introduces the

other documents.

Part 2 - Risk management:

This part presents the analysis making it possible to calculate the risk for a structure and to determine the

various protection scenarios in order to permit technical and economic optimization.

Part 3 - Physical damage to structures and life hazard:

This part describes protection from direct lightning strokes, including the lightning protection system, down-

conductor, earth lead, equipotentiality and hence SPD with equipotential bonding (Type 1 SPD).

Part 4 - Electrical and electronic systems within structures:

This part describes protection from the induced effects of lightning, including the protection system by SPD

(Types 2 and 3), cable shielding, rules for installation of SPD, etc.

This series of standards is supplemented by:

the IEC 61643 series of standards for the definition of surge protection products

the IEC 60364-4 and -5 series of standards for application of the products in LV electrical installations

Main LPS application and design

standard IEC EN 62305

Standards of requirements for lightning protection components

other than SPDs

• EN 50164-1

Connection components

• EN 50164-2

Conductors and earth electrodes

• EN 50164-3

Isolating Spark Gaps

• EN 50164-4

Conductor fasteners

• EN 50164-5

Earth electrodes inspection housings and earth electrode seals

• EN 50164-6

Lightning strike counters

• EN 50164-7

Earthing enhancing compounds

Standards for testing SPDs

• SPDs for power lines

– EN IEC 61643-1 (2005)

– EN IEC 61643-11 (2002)

• SPDs for telecommunications/ signaling networks

– EN IEC 61643-21 (2001)

SPDs

SPDs

Standards for selection and installation of SPDs

• SPDs for power lines

– EN IEC 61643-12 (2006)

• SPDs for telecommunications/ signaling networks

– EN IEC 61643-22 (2006)

Inductance

V=l*L*di/dt

L (mH)=.2*l*(.5+loge(2*l/w+h))+.11*(w+h/l) for a flat conductor. l,w&h are measured in metres

L (mH) = .2*l*(loge(2*l/r –1) for a round conductor

.1mH/m

Unnecessary creation of inductance loops

Correct installation of spark gap

Device Speed Sensitivity Energy Stability

Air Gap Fast Poor High Poor

GDT Fast Good High Good

Zener diodes V Fast V Good V Low Excellent

Transorb V Fast Good Low Excellent

Varistors V Fast Poor High Poor

Relays V Slow Good Medium Good

Fuses Slow Fair Medium Good

Comparison of Protection Components

Susceptibility of components to damage

Motors & Transformers

Relays

Valves

Passive components

Diodes

Transistors (power)

ICs

Microwave diodes

10 10 10 10 10 10 10 10 10 -8 -6 -4 -2 0 2 4 6 8

J

No damage Possible damage Destruction

TV

Telephone Lines

400/230 V

Power Plant

110 kV

ABC Company

GSM phones lines

Τelecommunication line

Distance of damage by a lightning strike

Bldg. “A” Bldg. “B”

Data Line

200kV

Distance

15kV

100m

V = 12kV

3kV

500m

Voltage

Communication port damage

Direct strike to building

Bldg. “A” Bldg. “B”

Data Line

50%

50%

100kA

IEC61024

IEC61312

11kV

415v

Equipotential bonding of service lines entries

into a building

Cathodically Protected Liquid Fuel Pipeline

Equipotential Bonding Bar

Water

Natural Gas

Power

Exte

rn

al

LP

S

Foundation Earthing

Z

Air Termination System

01.04.03 / 1041_a

External and Internal LPS according to IEC 62305-3

Foundation earth electrode

EBB

Service Entrance Box

Direct equipotential bonding for heating, water, sanitation etc.

Lightning equipotential

bonding

Separation Distance

Down conductor system

Earth termination

system

Lightning Current Arrester 230/400 V, 50 Hz (SPD class I)

Lightning Current Arrester for telephone line

Concrete support

Concrete

facade

Fixed earthing

point

Soil surface

Eathing ring conductor

Steel support

Tape conductor holder

Shielding and Equipotential bonding

Earthing bus

Reinforcement

Reinforcement

Connection to earthing

Common earthing system

Incoming Surge SPD DC Power

To

distribution

earth

Preferred earthing system

Incoming Surge SPD DC Power

To

distribution

earth

Disastrous earthing system

Incoming Surge SPD DC Power

To

distribution

earth

SPDs’ with IS Barriers

Hazardous Area

SPD IS Barrier

Safe Area

TX

SPD

SPDs’ with Galvanic Isolation

Galvanic Isolator

Hazardous Area Safe Area

TX

SPD SPD