I would like to share some knowledge of surge protection devices. This presentation highlights some concepts of surge and surge protectors. Presentation Index is as follows: > Types of Surge > Sources of Surge > Surge Current & Voltage waveform > Importance of Surge Protectors > Types of Surge protectors > Location of Surge Protectors

1. Power Surge Protection Device

2. Concept of Surge
 Surge is delivered along the line or circuit and is the transient wave form of the electric current,
voltage, or power with rapidly increasing and gradually decreasing characteristics.
Sources of Surge
Internal
Sources
Switching od
electrical
loads
Magnetic &
Inductive
Coupling
Static
Electricity
External
Sources
Direct
Lightning
Indirect
Lightning

3. Causes of Surge Occurrence
 Direct Strike
 Lightning directly strikes the structure, equipment, and power line, and the voltage with about 20kv or
higher and the overcurrent with several 200kA or higher occurs.
 Indirect Strike
 It strikes the power transmission and communication line, and surge is transmitted through the line. It
occurs the most frequently and has the very large energy with 6,000V or higher so that the damage caused
by it is the most frequent and the most.

4. Surge current wave form
 10/350μsec current wave from direct lightning
strikes, it takes 10μsec rise time to reach 90% of
maximum current value and 350μsec to go down to
the 50% of descending value.
 8/20㎲ Surge current wave form
 In case of the current wave form, it takes 8㎲ to reach
the 90% of the maximum current value (1pk) in the
10% of the elevation curve and 20㎲ to go down to
the 50% of the descending curve.

5. Surge Waveform
 1.2/50㎲ Surge voltage wave
form
 In case of the voltage wave
form, it takes 1.2㎲(IEC 60-1)
for the induced impulse to go
up from the start to the
10~90% of the maximum
value induced at that time and
50㎲for it to reach the 50%.

6. What is SPD (Surge Protective Device)?
• SPD is the device protecting various types of equipment from surge.
• SPD is the device attenuating the overvoltage and noise and is called SPD or TVSS
 (Transient Voltage Surge Suppressor). Specialists in the industry call it SPD. The
 terms such as SPD and TVSS are used interchangeably.
• SPD is the equipment designed to attenuate the dangerous overvoltage at the very
 Short moment appearing in the power line (Power SPD) or telephone line (Telecom SPD), data network (Data &
Network Protection SPD), the power line and control line connected to the electronic equipment.

7. Direct Lightning Strike
• A direct lightning strike can cause a significant amount of
damage to the electrical and nonelectrical items in the
system. It can also cause structural damage to the
structure.
• Lightening current directly strikes on a structure- Direct
Lightning current of (10/350) waveform enters into a system
where the structure receives a direct lightning strike.
• Lightning current flow when lightning strikes to a nearby
service line. Direct Lightning current of (10/350) waveform
strikes an overhead service line.

8. Indirect Lightning Strike-
• An indirect lightning strike is the more common type,
where a nearby lightning enters the system through wires
or pipes that extend outside. Damage from this type of
event is generally less severe as compared to a direct
lightning strike.
• Lightning current flow when lightning strikes near the
structure- Indirect lightning strikes near the structure
represented by 8/20 current wave.
• Lightning current flow when lightning strikes

9. Classification of Lightning Protection Zones
9
Lightning
Protection
Zones
Example Specific Target Facility
LPZ 0A
Facilities outside the lightning rod protection
range except for the outside lights (street lights
and security lights).
LPZ 0B
Facilities inside the lightning rod protection
range out of outside facilities such as
penthouse receiving (cubicle) facility, air
conditioning outside device, airline failure
light, and antenna.
LPZ 1
Facilities in the Inlet Part inside the Building:
Receiving and transforming facilities, MDF, and
weak electricity terminal box.
LPZ 2
Individual shielding area inside the building
such as trunk line distribution board, common
facility control panel, IS room, and
disaster prevention room.

10. Type, Class & Application of SPDs
Type of SPD Description Test Class
Test Waveform
µsec
Application
1
Equipotential Bonding or
Lightning current SPD
I 10/350 current
Main Distribution
board
2 Overvoltage SPD (TOV) II 8/20 current
Sub-distribution
board
3 Overvoltage SPD (TOV) III
Combination
1.2/50 voltage
and 8/20 current
Terminal
equipment, sub
distribution
board
Note: Test waveform as per IEC 61643

11. Thermally Protected MOV
Thermal Disconnector
Fast response to abnormal heat of MOV body
before thermal runaway
Remote Signalling Contact
Fault/ Degradation Indicator

12. Surge Protection Device Technology
 GDT: Gas Discharge Tube
 TSG: Transient Spark Gaps (100kA)
 MOV: Metal Oxide Variastor

13. Highlights of IEC 61643 Testing
• Electrical Test
 Residual voltage with 8/20µsec current impulses
 Front-of-wave sparkover voltage (1.2/50µsec)
 Limiting voltage with the combination wave (Open Circuit Voltage Measured Uoc)
• Mechanical Test
 Terminal & Connection
 Pulling test
• Environmental & Material Test
 Heat resistance test

14. Worldwide SPD Testing Standards
 IEC 61643-11: Low-voltage surge protective devices - Part 11: Surge protective
devices connected to low-voltage power systems - Requirements and test methods
 UL 1449: Surge Protective Device
 IEEE C62.62: Test Specifications for Surge-Protective Devices (SPDs) for Use on the
Load Side of the Service Equipment in Low-Voltage (1000 V and Less) AC Power
Circuits

15. Types of Surge Protection Devices
Surge Protection
Devices
Box Type SPD DIN Rail SPD
Class I+II SPD
(MOV & TSG based)
Class II AC SPD
(MOV based )
Class II DC SPD
Solar/ PV system
Telecommunication
SPD
Data Protection
SPD

16. Power SPD (Din rail type)
• TYPE I+ II (Class I +II) (10/350µsec & 8/20 µs)
• TYPE II (Class II) (8/20 µs).
• TYPE III (Class III) (8/20 µs & 1.2/50µsec)
NOTE: Above SPDs are main variants, further divided
into poles & current rating

17. Typical Usage
Main
Distribution
Panel
Class I+II SPD Class II SPD
Sub
Distribution
Panel
Class II SPD
Type of SPD Remark
Main Distribution
Board
Class I+II Main distribution
board will have class
I+II SPDs with Class II
SPD
Class II
Sub Distribution
Board Class II
Mainly Class II SPD to
protect from over
voltage
Distribution Board Class II
Install one more SPD
distance is greater
than 30meter
Low Voltage
Equipment
Class III

18. Application
Electricity Panels Railways
Industrial Control System
Building System

19. Thank you