oSIST prEN IEC 61439-8:2024

SLOVENSKI STANDARD
01-julij-2024
Sestavi nizkonapetostnih stikalnih in krmilnih naprav - 8. del: Sestavi za uporabo v
fotonapetostnih inštalacijah
Low-voltage switchgear and controlgear assemblies - Part 8: Assemblies for use in
photovoltaic installations
Ta slovenski standard je istoveten z: prEN IEC 61439-8:2024
ICS:
29.130.20 Nizkonapetostne stikalne in Low voltage switchgear and
krmilne naprave controlgear
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

121B/199/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 61439-8 ED1
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2024-05-24 2024-08-16
SUPERSEDES DOCUMENTS:
121B/185/CD, 121B/198/CC
IEC SC 121B : LOW-VOLTAGE SWITCHGEAR AND CONTROLGEAR ASSEMBLIES
SECRETARIAT: SECRETARY:
Germany Mr Jörg Hußmann
OF INTEREST TO THE FOLLOWING COMMITTEES: PROPOSED HORIZONTAL STANDARD:

TC 23,SC 23E,TC 64,TC 82,SC 121A
Other TC/SCs are requested to indicate their interest, if
any, in this CDV to the secretary.
FUNCTIONS CONCERNED:
EMC ENVIRONMENT QUALITY ASSURANCE SAFETY
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the final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Low-voltage switchgear and controlgear assemblies - Part 8: Assemblies for use in
photovoltaic installations
PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:
download this electronic file, to make a copy and to print out the content for the sole purpose of preparing National
Committee positions. You may not copy or "mirror" the file or printed version of the document, or any part of it,
for any other purpose without permission in writing from IEC.

IEC CDV 61439-8 © IEC 2024 2 121B/199/CDV

1 CONTENTS
2 CONTENTS . 2
3 FOREWORD . 5
4 INTRODUCTION . 7
5 1 Scope . 8
6 2 Normative references . 8
7 3 Terms and definitions . 9
8 3.1 General terms . 10
9 3.1.101 photovoltaic assembly . 10
10 3.1.102 PV string . 10
11 3.1.103 photovoltaic string combiner box. 10
12 3.1.104 photovoltaic array combiner box . 10
13 3.1.105 test situation . 10
14 3.1.106 form of internal separation . 10
15 3.1.107 Solar irradiance . 10
16 3.2 Constructional units of assemblies . 10
17 3.2 Constructional units of PVAs . 10
18 3.2.101 withdrawable part . 10
19 3.2.102 test position . 10
20 3.2.103 isolated position . 10
21 3.2.104 isolating distance . 11
22 3.4 Structural parts of assemblies . 11
23 3.4.101 active cooling . 11
24 3.4.102 pressure relief flap . 11
25 3.5 Conditions of installation of assemblies . 11
26 3.5.101 assembly location with restricted access . 11
27 3.5.102 assembly location with non-restricted access . 11
28 3.103 Electrical connections of functional units . 11
29 4 Symbols and abbreviations . 11
30 5 Interface characteristics . 11
31 5.1 General . 12
32 5.2 Voltage ratings . 12
33 5.2.2 Rated operational voltage (U ) (of a circuit of a PVA) . 12
e
34 5.3 Current ratings . 12
35 5.3.1 Rated current of the assembly (I ) . 12
nA
36 5.3.2 Rated current of a main outgoing circuit (I ) . 12
nc
37 5.3.3 Group rated current of a main circuit (I ) . 12
ng
38 5.4 Rated diversity factor (RDF) . 12
39 5.6 Other characteristics . 13
40 6 Information . 13
41 6.1 Assembly designation marking . 13
42 6.1 PVA designation marking . 13
43 6.2 Documentation . 13
44 6.2.2 Instructions for handling, installation, operation and maintenance . 13
45 7 Service conditions . 14
46 7.1 Normal service conditions . 14
47 7.1.2 Pollution degree . 14

IEC CDV 61439-8 © IEC 2024 3 121B/199/CDV

48 7.101 PVA under solar radiation conditions . 14
49 7.2 Special service conditions . 14
50 8 Constructional requirements . 14
51 8.2 Degree of protection provided by an assembly enclosure . 14
52 8.2 Degree of protection provided by a PVA enclosure . 15
53 8.2.1 Protection against mechanical impact (IK code) . 15
54 8.2.2 Protection against contact with live parts, ingress of solid foreign bodies
55 and water (IP code) . 15
56 8.2.101 PVA with withdrawable parts. 15
57 8.3 Clearances and creepage distances. 15
58 8.3.2 Clearances . 15
59 8.4 Protection against electric shock . 15
60 8.4.1 General . 15
61 8.4.3 Fault protection . 16
62 8.4.5 Limitation of steady-state touch currents and charge . 16
63 8.4.6 Operating and servicing condition . 16
64 8.5 Incorporation of switching devices and components . 16
65 8.5.2 Removable parts . 16
66 8.5.2 Removable and withdrawable parts . 16
67 8.5.3 Selection of switching devices and components . 17
68 8.5.4 Installation of switching devices and components . 18
69 8.5.101 Description of the types of electrical connections of functional units . 18
70 8.101 Internal separation of PVA . 18
71 8.102 Thermal cycling durability . 19
72 8.103 Climatic durability . 19
73 9 Performance requirements . 19
74 9.1 Dielectric properties . 19
75 9.1.3 Impulse withstand voltage . 19
76 9.2 Temperature-rise limits . 19
77 9.2.1 General . 19
78 9.3 Short-circuit protection and short-circuit withstand strength . 19
79 9.3.1 General . 19
80 10 Design verification . 20
81 10.1 General . 20
82 10.2 Strength of materials and parts . 20
83 10.2.2 Resistance to ultraviolet (UV) radiation . 20
84 10.2.6 Verification of protection against mechanical impact (IK code) . 20
85 10.2.8 Mechanical operation . 21
86 10.3 Degree of protection of assemblies (IP Code) . 21
87 10.3 Degree of protection of PVA (IP Code) . 21
88 10.9 Dielectric properties . 21
89 10.9.3 Impulse withstand voltage . 21
90 10.10 Temperature-rise . 21
91 10.10.1 General . 22
92 10.10.2 Verification by testing . 22
93 10.10.4 Verification assessment . 23
94 10.11 Short-circuit withstand strength . 26
95 10.11.5 Verification by test . 26
96 10.101 Thermal cycling test . 26
97 10.102 Climatic test . 26

IEC CDV 61439-8 © IEC 2024 4 121B/199/CDV

98 11 Routine verification .
...