spd application guide...january 2019 spd application guide according to iec 61643-12(2018) and hd...

January 2019

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SPD APPLICATION GUIDE According to IEC 61643-12(2018) and HD 60364-5-53(2016) Igor Juricev;Application Engineer

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1.Applicable standards 2.Origin of transient overvoltages 3.Lightning protection zones (LPZ) 4.Partial lightning current calculation 5.SPD classification 6.SPD selection 7.Proper installation of SPD 8.OCPD (over-current protective devices) for

SPD protection)

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STANDARDS

EN/IEC 62305-1 Protection against lightning-Part 1:General principles EN/IEC 62305-2 Protection against lightning-Part 2: Risk managment EN /IEC62305-3 Protection against lightning-Part 3:Physical damage to structure and life hazard EN/IEC 62305-4Protection against lightnung-Part 4:Electrical and electronic systems within structures

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STANDARDS

EN/IEC 61643-11:Ed 1.0Low-voltage surge protective devices- Part 11;Devices connected to low voltage power systems-Requirments and test methods EN/IEC 61643-12 Low –voltage surge protective devices-Part 12 Surge protective devices connected to low voltage power systems-Selection and application principles

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STANDARDS

EN/IEC 61643-21Low voltage surge protective devices-Part 21: Surge protective devices connected to telecommunications and signalling networks-Performance requirments and testing methods EN/IEC 61643-22,Low voltage surge protective devices-Part 22: Surge protective devices connected to telecommunications and signalling networks-Selection and application principles

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STANDARDS

EN/IEC 61643-31 Ed1:Low voltage surge protective devices-Part 31:Requirments and test methods for SPDs for photovoltaic installations EN/IEC 61643-32/Ed1:Low voltage surge protective devices-Part 32:Surge protective devices for specific use including d.c.-Selection and application principles for SPDs connected to photovoltaic installations

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STANDARDS

EN/IEC 60364-4-44 Electrical installations of buildings-Part 4-44 Protection for safety-Protection against voltage disturbances and electromagnetic disturbances-Clause 443:Protection against overvoltages of atmospheric origin or due to switching EN-HD/IEC 60364-5-53 Low voltage electrical installations-Part 5-53:Selection and erection of electrical equipment-Isolation,switching and control-Clause 534:Devices for protection against overvoltages

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ORIGIN OF TRANSIENT OVERVOLTAGES

1. direct strikes (S1) to the external lightning protection system (LPS) of the building or lightning flashes near (S2) to the buildings

2. direct strikes (S3) and lightning induced currents (S4) distributed into the electrical network

3. overvoltages created by the distribution network, e.g., those due to switching operations

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TYPE OF STRIKES

S3 Strike to incoming service(s) S4 Strike near the incoming service(s)

S1 Strike to the structure S2 Strike near the structure

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Higher values Lower values 99 % < 125 kA 99 % > 5 kA 98 % < 102 kA 97 % > 7 kA 95 % < 73 kA 85 % > 11.9 kA

ORIGIN OF TRANSIENT OVERVOLTAGES

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LPZ 0A Direct strikes, full lightning current, full magnetic field LPZ 0B No direct strikes, partial lightning or induced current, full magnetic field LPZ 1 No direct strikes, partial lightning or induced current, damped magnetic field LPZ 2 No direct strikes, induced current, further damped magnetic field

LIGHTNING PROTECTION ZONES (LPZ)

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SPD CLASSIFICATION

LPZ 1 Surge protective devices designed to protect against partial lightning currents.Intended to protect at the boundry LPZ OB/ LPZ1.Tested with current wave 10/350. LPZ 2 Surge protective devices designed to protect against induced currents.Tested wit current wave 8/20 and intended to protect at the boundry LPZ 1/LPZ2. LPZ 3 Surge protective devices designed to protect against induced currents and switchings overvoltages.Tested with hybrid voltage wave 1.2/50 and current wave 8/20

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LIGHTNING PROTECTION ZONES (LPZ)

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SURGE CURRENT VALUES (EXTRACT FROM IEC 62305-1)

LPL FLASH TO STRUCTURE FLASH TO STRUCTURE

DIRECT AND INDIRECT FLASHES TO THE SERVICE

S1 (10/350) S1 (8/20)

S2 (8/20) S3 (10/350) S4 (8/20)

1phase 3phase Inductive coupling

Induced current


I 50 kA 25 kA 10 kA 0,2 kA 20 kA 10 kA 5 kA

II 35 kA 17,5 kA 7,5 kA 0,15 kA 15 kA 7,5 kA 3,75 kA

III / IV 25 kA 12,5 kA 5 kA 0,1 kA 10 kA 5 kA 2,5 kA

Values per conductor

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PARTIAL LIGHTNING CURRENT CALCULATION

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16 This information was prepared by Raycap and is confidential; it may not be copied, reproduced, disclosed or distributed without prior written consent from Raycap.

SPD CLASSIFICATION

LPZ zones

Test class of SPD in acc. to IEC 61643-11

Category of SPD in acc. to IEC 61643-21

0/1 Test class 1 D1 1/2 Test class 2 C2 2/3 Test class 3 C1

SPD T 2 Zone 1/2

SPD T 3 Zone

2/3 PD

SPD T 1 Zone 0/1

UIn 1 4 kV

UIn 2 2.5 kV

UIn 3 1.5 kV

UP1 UP2 UP3


SPD SELECTION

NO LPS (Lightning Protective System)

LPL FLASH TO STRUCTURE FLASH TO STRUCTURE DIRECT AND INDIRECT FLASHES TO THE SERVICE

S1 (10/350) S1 (8/20) S2 (8/20) S3 (10/350) S4 (8/20)


Induced current



Values are per conductor


SPD SELECTION

NO LPS (Lightning Protective System)



S1 (10/350) S1 (8/20) S2 (8/20) S3 (10/350) S4 (8/20)


Induced current




SPD SELECTION


S1 (10/350) S1 (8/20) S2 (8/20) S3 (10/350) S4 (8/20)


Induced current



With LPS (Lightning Protective System)



SPD SELECTION (based on Uw)


SPD SELECTION(protective distances)

• The lead lenght connecting the SPD does not exceed 50 cm, the distance between SPD and equipment is shorter than 10 meters and Up is bellow 0.8xUw

• The lead length connecting the SPD does not exceed 50 cm, the distance between SPD and equipment is greater than 10 m but 2 x Up remains below 0.8xUw

• The lead length connecting the SPD exceeds 50 cm, the distance between SPD and equipment is shorter than 10 m and Up/f is bellow Uw

• The lead length connecting the SPD exceed 50 cm, the distance between SPD and equipment is more than 10 m but 2 x Up/f remains below Uw

Note: Up/f= voltage at the connection point of the SPD assembly resulting from The voltage protection level of the SPD with possible SPD disconnector and the Wiring voltage drop in the leads/connection


SPD INSTALLATION

Example: strike of 10 kA (8/20 μs), conductor length 2 m Voltage drop: UR ~ 20 V UL ~ 2500 V Typically:1kV/meter

V(t) = iR + Ldi/dt


SPD INSTALLATION

Rule: earthing conductor min.cross sectional area: - Class I/1 SPD = 16 mm2

-ClassII,III/T2,T3 SPD = 6 mm2

Rule: live conductor min. cross sectional area: -ClassI/T1 SPD = 6 mm2

-ClassII,III/T2,T3 SPD = 2.5 mm2


SPD INSTALLATION (CT1)


SPD INSTALLATION (CT2)

L1

L2

L3

N

F1

SPD

F2

PE

SPD SPD SPD

IEC 1916/08


SPD INSTALLATION

CT1(connection type) is used:

-TN-C systems

-TN-C-S systems

-TN-S systems

-TT systems (only after the RCD)

-IT systems

CT2(connection type) is used -TT systems

-IT systems

-TN-C-S systems

-TN-S systems

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OCPD1 > OCPD SPD ⇨ OCPD 2

OCPD SELECTION WITH OVERCURRENT PROTECTION

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OCPD 1 > OCPD 2= OCPD1/1.6 FOR gG /1.45 FOR MCB

SELECTION ON OCPD SELECTIVITY

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ISCCR > ISCCR SPD ⇨ OCPD 2

0CPD SELECTION ON ISCCR

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Typical rated

current of the fuse

Typical Pre-arcing value, crest current from simplified formula and real testing

Cyl gG NH gG

Pre-arcing Calculated After test Ratio Pre-arcing Calculated After test Ratio

I²t 8/20 8/20 I²t 10/350 10/350

25 800 7,6 5 0,66

32 1 300 9,6 7 0,73

40 2 500 13,4 10 0,75

50 4 200 17,3 15 0,87

63 7 500 23,1 17 0,73

80 14 500 32,2 25 0,78

100 24 000 41,4 30 0,72 20 000 8,8 5 0,57

125 40 000 53,4 40 0,75 33 000 11,3 7 0,62

160 60 000 15,3 10 0,65

200 100 000 19,75 15 0,76

250 200 000 27,93 20 0,72

315 300 000 34,21 25 0,73

FUSE SELECTION (from 61643-12)

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THE METHOD OF SPD SELECTION

PV installation without LPS

all SPDs are class 2 / type 2

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THE METHOD OF SPD SELECTION

2 & 3: class 1 / type 1 SPD

1 & 4 class 2 / type 2 SPD

PV installation with LPS

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THE METHOD OF SPD SELECTION PV installation with LPS (safety distance is not kept)

2 & 3 always class 1 / type 1 SPD

if only SPD at location 1: class 2 / type 2 SPD

1 & 4 class 1 / type1 SPD

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Scenarios to select Class 1/Type 1 SPD: 1. According IEC/EN 62305 series: if no risk assesment is calculated, the minimum partial lightning current for class 1/Type 1 SPD is 12,5kA (10/350); 2. According IEC /EN 61643-32 a. green field PV installations b. roof PV installations

CLASS I /TYPE 1 SPD SELECTION

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According IEC /EN 61643-32 a. green field PV installation

LPL Lightning protection level

10/350

Voltage limiting SPD

IIMP ITOTAL

III or IV 100 kA 5 kA 10 kA


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According IEC /EN 61643-32 b. roof PV installations

LPL Lightning protection

level 10/350

Number of external down-conductors < 4 ≥ 4

IIMP ITOTAL IIMP ITOTAL

I 200 kA 10 kA 20 kA 5 kA 10 kA II 150 kA 7,5 kA 15 kA 3,75 kA 7,5 kA III 100 kA 5 kA 10 kA 2,5 kA 5 kA


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SPD CONNECTIONS ON PV SIDE

Of all of the above, Y connection is the most universal, since it offers many advantages over the others. Let me highlight the essential ones:

regardless of the configuration of the photovoltaic generator, there is no possibility of connection with earth (which there is with all other connections). The error of earth connection results in the inverter switching off, which means the loss of exploitation of the photovoltaic plant and the additional cost of defect remedy and intervention of the system maintenance.

protective level Up is equal in all directions (+ against -, - against PE and + against PE) and lowest when compared to other connections.

spd application guide...january 2019 spd application guide according to iec 61643-12(2018) and hd...

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