Design Guide: Coordination of Surge Protection Devices

 

Coordination of Surge protection devices  Design guide Surge arresters for commercial and industrial buildings

 

Protection Load protection

Surge protective device coordination

Coordination between the surge protective device and its disconnect circuit breaker

MCCB / MCB

I

Disconnector coordinated with surge protective device

 An external disconnecting device must be coordinated with a surge protective device in order to achieve: b  continuity of service: v  do not trip due to surge current, v  do not increase (Up) voltage protection level. b  effective protection against all types of overcurrents: v  overload due to SPD aging, v  short circuit of low intensity (impedant) due to temporary overvoltages, v  short circuit of high intensity due to SPD degradation.

MCB

L

SPD

L

MCCB = Molded-case circuit breaker. MCB = Modular circuit breaker. SPD = Surge protective device.

Circuit breaker open

Circuit breaker closed 

Circuit breaker closed  Nonconducting SPD

L

Loads

Surge protective device in normal operation

Conducting SPD

Loads

Surge protective device in operation during the lightning stroke

Conducting SPD

Loads

Surge protective device at end of life on short circuit

The disconnecting device must be coordinated with the surge protective device. It is designed to meet the following two constraints:

Resistance to lightning current The resistance to lightning current is an essential characteristic of the surge protective device's external disconnecting device. The device must be capable of passing the following standardized tests: not trip upon 15 successive impulse currents at In.

Resistance to short-circuit current The breaking capacity is determined by the installation rules (IEC 60364 standard): b  the external disconnecting device must have a breaking capacity equal to or greater than the presumed short-circuit current Isc at the point of installation. b when this device is integrated into the surge protective device, conformity with product standard IEC 61643-11 naturally ensures protection.

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Protection Load protection

Surge protective device coordination coordinat ion (cont.)

External disconnecting Fuse protection combined device with the SPD

Circuit breaker protection combined with the SPD

Circuit breaker protection integrated into the SPD

Lightning protection of equipment

= = =  All types of disconnecting disconnecting devices protect the equipment equipment satisfactorily Protection of installation = + ++ (at end of the surge protective  Achieved if compliance compliance with the MCB/SPD coordination table Achieved during product design device's life) Protection from (impedant) short circuits Protection against (impedant) short circuits of low intensity of low intensity not well ensured Continuity of service + + + (at end of the surge protective Only the surge protective device circuit is shut down device's life) = + + Maintenance (at end of the surge protective device's life) Change of fuses Immediate resetting

Main reasons why the disconnecting device recommended by the manufacturer should be used: b if the disconnecting device's rating is lower than the recommended rating: risk of the disconnecting device opening in normal operation. b  if the disconnecting device's rating is higher than the recommended rating: risk of non-disconnection during a temporary voltage surge.

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Protection Load protection

Surge protective device coordination coordinati on (cont.)

Coordination between the surge protective device and its disconnect circuit breaker in the event of a short circuit This table shows: the rating, curve and short circuit current level of the disconnector coordinated with the surge protective device. Isc (kA) 50 NG125L   NG125L C63 A

NG125L C63 A

NG125L C63 A

C80 A /

Compact NSX 100N 

Compact NSX 160N 

100 A

160 A

Compact NSX 100F 

Compact NSX 160F 

100 A

160 A

Compact NSX 100B 

Compact NSX 100B 

Compact NSX 160B 

100 A

100 A

160 A

Compact NSX  100N 

*

100 A

36 NG125H   NG125H C63 A

NG125H C63 A

NG125H C63 A

C80 A /

Compact NSX  100F 

*

100 A

25

NG125N  

   r    o     t    c    e15    n    n    o    c    s      i     D

iC60L C20 A

iC60L C10 A

NG125N C40 A

NG125N C50 A

C80 A /

Compact NSX  100B 

*

100 A

C120H  iC60H C10 A

iC60H C50 A

iC60H C20 A

iC60H C50 A

C80 A /

Compact NSX  100B 

*

100 A

10 iQuick PRD 40r

iQuick PRD 20r

iQuick PRD 8r

C120N 

6

iC60N C10 A

iC60N C40 A

iC60N C20 A

iC60N C50 A

C80 A /

Compact NSX  100B 

*

100 A

iQuick PF 10

iPRD 8r 

iK60N C20 A

iPF K 20

iK60N C40 A

iPRD 20r

iPF K 40

iK60N C50 A

iPRD 40r

iPF K 65

iPRD 65r   iPRF1 12.5r  PRD1 25r 

PRD1 PRD 1 Master Master PRF PRF1 1 Master  Master 

Surge protective device 8 kA

10 kA

20 kA 

40 kA 

65 kA 

12.5 kA

25 kA

35 kA

Imax / Iimp

2.5 kA

5 kA

5 kA

15 kA

20 kA

25 kA

25 kA

50 kA

In

Type 3(1) (1) Uoc: 10 kV.

Type 1

Type 2 Low risk

Medium risk

High risk

Maximum risk

( ) For lightning impulse current withstand 

*

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Protection Load protection

Surge protective device coordination coordinat ion (cont.)

Coordination between the surge protective device and its disconnect fuse in the event of a short circuit

Isc (kA) 50

Fupact 125 A gG  gG  max.

36 Fupact 125 A gG  gG  max.

Fupact 125 A gG  gG  max.

25

   r     t    o    c    e    n15    n    o    c    s      i     D

Fupact 63 A gG Fupact 80 A gG

SBI + 25 A gG (14x51 mm)

10 STI + 25 A gG (10x38 mm)

SBI + 63 A gG (22x58 mm) STI + 32 A gG (14x51 mm)

Fupact 160 A gG

SBI + 80 A gG (22x58 mm)

Fupact 315 A gG

Fupact 250 A gG

Fupact 315 A gG

SBI + 50 A aM (14x51 mm)

6

iPRD 8r 

iPF K 20

iPRD 20r

iPF K 40

iPRD 40r

iPF K 65

iPRD 65r

 

iPRF1 12 12.5 r

PRD1 25 25r

PRD1 Ma Master

PRF1 Ma Master  

Surge protective device 8 kA

20 kA 

40 kA 

65 kA 

12.5 kA

25 kA

35 kA

Imax / Iimp

2.5 kA

5 kA

15 kA

20 kA

25 kA

25 kA

50 kA

In

Type 3(1) (1) Uoc: 10 kV.

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Type 2 Low risk

Medium risk

Version : 1.0

Type 1 High risk

Maximum risk

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Protection Load protection

Surge protective device coordination coordinati on (cont.)

Coordination between two surge protective devices, upstream/downstream When two surge protective devices are installed in an electrical installation, coordination is needed according to IEC 61643-12 61643 -12 to obtain an acceptable stress distribution between the two surge protective devices according to their permissible energy "E".

L Zd I2

I1

IF

MCB

MCB

Up1

Up2 SPD

L and Zd Up2: Uw: Imax: I F :     E: MCB: SPD:

1

SPD

2

represent the the cable length length and impedance impedance resp respectively ectively betwe between en the 2 surge  protective devices. level of protection of surge protective device SPD2. impulse withstand voltage of the equipment to be protected. maximum discharge current. lightning current: y  Imax  Imax of SPD1

= I1 + I2  permissible energy. energy. modular circuit breaker. surge protective device.

For coordination between two surge protective devices, a minimum cable length between these 2 surge protective devices is needed to ensure that:

 I2 < Imax SPD2.

@

 Up2 < Uw.

@

 E2 < E max SPD2.

@

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Protection Load protection

Surge protective device coordination coordinati on (cont.)

Minimum distance between two surge protective devices, upstream/downstream For a cable section of 16 mm 2 and an impulse current equal to the maximum discharge current (Imax) of the upstream surge protective device.

Example If iPRD65r is installed inst alled in the incoming panelboard, the second SPD iPRD8r iPR D8r must be installed at a cable length of 8 meters from the first one.

Type 2

Type 1

Upstream surge protective device iQuick PRD 20r

iQuick PRD 40r

iPRD 20r

iPRD 65r

iPRF1 12.5r

PRD1 25r

PRD1 Master

0m

10 m

10 m

10 m

0m

2m

10 m

10 m

10 m

3m

2m

10 m

10 m

0m

2m

10 m

10 m

iPRD 40r

iPRD 65r

iPRD 40r

    2    e    p    y     T

   e    c      i    v    e      d    e    v      i     t    c    e     t    o    r

iPRD 20r

   p iQuick    e PRD 40r    g    r    u    s      m    a    e    r iQuick     t    s PRD 20r    n    w    o     D iPRD 8r

    3    e    p    y     T

0m

0m

2m

0m

0m

0m

1m

0m

2m

2m

10 m

10 m

3m

7m

4m

9m

8m

10 m

10 m

2m

6m

4m

7m

7m

10 m

10 m

10 m

iQuick PRD 8r

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Protection Load protection

Surge protective device coordination coordinati on (cont.)

Cascading in the event of a short circuit between the surge protective device disconnector and the upstream circuit breaker What is cascading? Cascading means using the circuit breakers' breakers ' limiting power, which allows circuit breakers of lower performance to be installed downstream. The upstream circuit breakers then act as a barrier for major short-circuit currents. They thus enable circuit breakers of breaking capacity lower than the presumed short-circuit current (at their point of installation) to be loaded in their normal breaking conditions. Since current limiting takes place all along the circuit controlled by the upstream current-limiting current-limiti ng circuit breaker, breaker, cascading concerns all the devices located downstream downs tream of that circuit breaker. It is not restricted to two consecutive devices.

Case 11   Disconnect circuit breaker not integrated into the surge protective device. For this type of study, refer to the existing coordination tables. tables . see 557F4200 catalogue module.

MCCB / MCB

MCB

SPD

MCCB = Molded-case circuit breaker. MCB = Modular circuit breaker. SPD

8

= Surge protective device.

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Protection Load protection

Surge protective device coordination coordinat ion (cont.)

Case 2  Disconnect circuit breaker integrated into the surge protective device.

Isc (kA) 50

NG125L C25 A NG125L C25

NG125L C63 NG125L C63 A

NG125L C63  C63 A NG125L

iQuick PRD 8r

iQuick PRD 20r

iQuick PRD 40r

NG125H C25 NG125H C25 A

NG125H C63 NG125H  C63 A

NG125H C63 NG125H C63 A

iQuick PRD 8r

iQuick PRD 20r

iQuick PRD 40r

36

MCCB / MCB

SPD

25 MCCB = Molded-case circuit breaker. MCB = Modular circuit breaker. breaker. SPD = Surge protective device.

15

NG125H C20  C20 A NG125H iQuick PF 10

10

iQuick PRD 8r

iQuick PRD 20r

iQuick PRD 40r

20 kA 5 kA

40 kA 15 kA

iC60N C20 iC60N C20 A iQuick PF 10

6

iQuick PF 10

Imax In

8 kA 2.5 kA

10 kA 5 kA

Type 3(1) (1) Uoc: 10 kV.

CA903014E

Version : 1.0

Type 2 Low risk

26/05/2015

Medium risk

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 .    d   e   v   r   e   s   e   r   s    t    h   g    i   r    l    l    A     c    i   r    t   c   e    l    E   r   e    d    i   e   n    h   c    S      5    1    0    2    ©

Schneider Electric Industries SAS 35, rue Joseph Monier CS 30323 F- 92506 Rueil Malmaison Cedex

As standards, specifications specifications and designs change from time to time, please ask for confirmation of the information given in this publication. Printed on ecological paper 

www.schneider-electric.com Publication: Schneider Electric Publication: Photos: Schneider Electric Printing:

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Protection Load protection

Surge protective device coordination coordinat ion (cont.)

 s  n  o  i  t  E v o l u

   g  

T      

h  i   

 

s  p 

1.0

12/05/2015

Indice

Date

CA903014E

 

   b

 p  p  u

   o  r e  b  b e f

   n     i     h    i  s    l

 must be re m o v e d

a g e e  

Creation

Sonovision

Modifcation

Name

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