Indirect Lightning Protection

1 SPD for Low Voltage Power Supply System
Lightning protection zones concept Surge Protectors parameters
2 SPD Application Recommendation
Class I Class II Class III
3 Co-ordinated SPD
4 SPD for Telecom(Data network Series)
5 SPD Installation(Click here to view)
6 Standards(Click here to view)  
7 Certificates(Click here to view)  
8 Go to Products
   
The purpose of the SPD is to protect modern electronic equipment connected to telecommunications and signalling networks with nominal system voltages up to 1 000 V (r.m.s.) a.c. and 1 500 V d.c.

These systems may be exposed to the effects of lightning and power line faults, either through direct contact or induction. These effects may subject the system to overvoltages or overcurrents or both, whose levels are sufficiently high to harm the system.

SPDs are intended to provide protection against overvoltages and overcurrents caused by lightning and power line faults.

Classification of SPD based on different Standards
IEC61643 (EN61643) VDE UL1449 IEEE
    Type 1  
Class I Class B Type 2 Type 3
Class II Class C Type 3 Type 2
Class III Class D Type 4 Type 1

Lightning protection zones concept

External zones:

  • LPZ 0A –Area exposed to direct lightning strike and unattenuated electromagnetic fields.
  • LPZ 0B –Area shielded from direct lightning strikes but still exposed to unattenuated electromagnetic fields.

Internal zones:

  • LPZ 1 –Area shielded from direct lightning. Fields and currents on conductors are significantly attenuated compared with LPZ0A and LPZ0B.
  • LPZ 2-Area shielded from direct lightning. Fields and currents on conductors are significantly attenuated compared with LPZ1 etc.

Surge Protectors parameters

  • Operating voltage ( Uc): The maximum continuous operating voltage (MCOV) Uc is the r.m.s voltage which may be applied continuously to the SPD.
  • Discharge current - In and Imax: The maximum discharge current (Imax), applicable to Class C/II SPD, is the maximum impulse current 8/20 μs a surge protector can withstand without destruction .The nominal discharge current (In) is the level of impulse current a surge protector Class B or Class C can withstand repeatedly (15 surges) without destruction.
  • Impulse current – Iimp: The impulse current (Iimp), used in Class I test applicable to Class B SPDs, is the maximum impulse 10/350 μs current a surge protector can withstand without destruction. This test simulates the effect, on AC power surge protectors, of a direct lightning strike on an installation.
  • Open circuit voltage – Uoc: This parameter is used only for Class III test, applicable to Class C SPD and consists of the injection of a combination wave (1.2/50 μs in open circuit - 8/20 μs in short circuit).
  • Protection level – Up:This is the maximum voltage on the surge protector output when subjected to an impulse current equivalent to its nominal discharge current (In). Therefore, this parameter characterizes the performance of the SPD in limiting the transient overvoltage across its terminal in order to protect the equipment.
    • Class I (B) SPD classification
    Designed to be installed where a direct lightning strike risk is high, especially when the building is equipped with external lightning protection system (LPS or lightning rod).

Surge protection(IEC61643-1) II
Test waveform 10/350 10/350
Protection Type I
SGI Model: Spark Gap Technology SGI-G50 and SGI-G100
Voltage Protection Level Up 1.5 KV
Impulse current (Iimp) 50 kA (10/350) & 100 kA (10/350)

 

Uc 320 V~ 255 V~
Iimp 50kA (10/350) & 100kA (10/350)
Up 50kA (10/350) & 100kA (10/350)  
Special spark gap technology allow window fault indication and remote alarm terminal


Designed to be installed at the beginning of the installation in the main switchboard, or close to sensitive terminals, on installations without LPS (lightning rods). These protectors are tested following the Class II test from IEC61643-1 or EN61643-11standards and based on 8/20 μs impulse current injection.
 

Surge protection(IEC61643-1) II
Test waveform 8/20
Protection Type 2
SGI Model:
MOV Type
GDT Type (N-PE)
 
SGI –V40
SGI - T40
Voltage Protection Level Up `1.5 KV
Max discharge current (Imax) 50 KA (8/20)

 

Technical Data :
Uc
75 V~ 150 V~ 275 V~ 320 V~ 440 V~ 600 V~
In 20kA (8/20)
imax 50kA (8/20)
Up
500 V 800 V 1.3 kV 1.5 kV 2.2 kV 3 kV


Surge protection(IEC61643-1) III
Test waveform 1.2/50 - 8/20
Protection Type 3
SGI Model:
MOV Type
MOV/GDT Hybrid Type
(L-N+N-PE in one mode)
 
SGI –V5 series
SGI – VT5 series
SGI-DS10 series
Voltage Protection Level Up `1 KV
Nominal discharge current In 5 KA~20KA (8/20)

 

Technical Data :
Uc
75 V~ 150 V~ 275 V~ 320 V~ 440 V~ 600 V~
In 2.5kA (8/20)
imax 5kA (8/20)
Up
400 V 800 V 1.3 kV 1.5 kV 2.0 kV 2.6 kV


In order to provide maximum protection efficiency, it is necessary to create a ‘coordination diagram’: that means installation of a ‘primary’ SPD at the network entrance and a ‘secondary’ close to sensitive equipment.Efficient SPD coordination is performed by including between primary and secondary SPDs a minimum length of wire (> 15 m) Or coordination inductors.

SGI coordinated class I & II SPD:
  • No need inductance between Class I & Class II
  • Spark Gap technology for Class I
  • MOV technology for Class II
  • Iimp 25KA~100KA 10/350
  • Imax up to 200KA 8/20
  • Low Up

 

Data Network ProtectorDM series :
  • N35 mm DIN-rail mounting design
  • Pluggable type design, surge protection modules to be exchanged easily
  • Signal transmission is not interrupted when exchanging modules
  • Comply with RDSO spec
Lightning Equipotential Bonding :
  • Iimp=100KA (10/350)
  • In=100kA(8/20)



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