Weidmüller PV DC COMBINER BOX User manual

PV DC COMBINER BOX
Operating instructions

34000001903/00/04.2020
Contents
1 About this documentation 4
1.1 Target group and contents 4
1.2 Symbols and notes 4
2 Safety 5
2.1 General safety notice 5
2.2 Intended use 5
2.3 Personnel 5
2.4 Legal notice 5
3 Device description 6
3.1 Product overview 6
3.2 Enclosure 8
3.3 DC Switch 8
3.4 Surge protection device (SPD) 8
3.5 Fuse holders 8
3.6 Fuses 9
3.7 Terminals 9
3.8 Conductors 9
3.9 Input terminals 9
3.10 String monitoring device (optional) 10
3.11 Power supply for string monitoring 10
3.12 General technical data 11
4 Transport and storage 12
4.1 Transporting 12
4.2 Unpacking the delivery 12
4.3 Storage 12
4.4 Establishing connections 12
5 Installation 13
5.1 Installation site 13
5.2 Positioning of the combiner box 13
5.3 Fixation 14
5.4 Installing the combiner box 14
5.5 Inserting the fuses 18
5.6 Connection of the inputs 18
5.7 Connection of the outputs 19
5.8 Connection of the grounding cable 20
6 Connection of the communications (optional) 21
6.1 Wiring the communications 22
6.2 Connecting the RS485 to the Transclinic 22
6.3 CongurationoftheModbusaddressandtheRS485serial
settings 25
6.4 Recommendations when using serial converters 25
6.5 RecommendationswhenconguringtheSCADA 26
7 Commissioning 27
7.1 Mainindicationsandchecks 27
7.2 Start up 28
8 Accessories and replacing parts 29
8.1 Replacing fuses 29
8.2 Replacing a switch disconnector 29
8.3 Replacing string monitoring devices 29
8.4 Replacing surge protection arresters 29
9 Cleaning 31
10 Maintenance and Service 32
10.1 Maintenace 32
10.2 Service 33
Manufacturer
Weidmüller Interface GmbH & Co. KG
Klingenbergstraße 26
32758 Detmold, Germany
T [phone]
F [phone]
www.weidmueller.com
Document no. 4000001903
Revision 00/April 2020

4000001903/00/04.20204
1.1 Target group and contents
This user manual is intended to personnel that is involved
in mechanical and electrical installation of a Weidmüller
PV DC COMBINER BOX and moreover to service and
maintenance personnel.
This user manual gives the general overview about the
complete range of PV DC COMBINER BOX, the individual
components, their function as well as their correct handling.
An individual datasheet providing the specic information
is attached to each combiner box. These information speci-
es the original features of each combiner box.
1.2 Symbols and notes
The warnings in this documentation are structured di󰀨er-
ently depending on the severity of danger.
DANGER
Imminent risk of life!
Notices with the signal word "DANGER" warn
you of situations which will result in serious
injury or death if you do not follow the instruc-
tions given in this manual.
WARNING
Possible risk of fatality!
Notices with the signal word "WARNING"
warn you of situations which may result in
serious injury or death if you do not follow the
instructions given in this manual.
CAUTION
Risk of injury!
Notices with the signal word "CAUTION"
warn you of situations which may result in in-
jury if you do not follow the instructions given
in this manual.
ATTENTION
Material damage!
Notes with the signal word "ATTENTION" warn you about
hazards which may result in material damage.
The situation-dependant safety notices may contain the
following warning symbols:
Symbol Meaning
Warning against hazardous electrical voltage
Warning against explosive atmospheres
Warning against electrostatically charged
components
Instruction: observe the documentation
Additional formatting is used in the rest of the text which
has the following meaning:
Text items next to this arrow constitute informa-
tion which is not related to safety, but which pro-
vides important information regarding correct and
e󰀨ective work.
► You can recognise handling instructions from the black
triangle in front of the text.
– Lists are indicated with dashes.
Before start working with the product, read the
documentation completely!
Keep the manual as well as the attached data
sheet stored so that it can be inspected by op-
erating personnel at any time.
The document is available to download from
the Weidmüller website.
1 About this documentation

54000001903/00/04.2020
2 Safety
This section includes general safety instructions for
handling the PV DC COMBINER BOX. Specic warning
notices for specic tasks and situations are given at the ap-
propriate places in the documentation. Failure to observe
the safety and warning notices can result in damage to per-
sons and material.
2.1 General safety notice
Proper transport, storage, installation, commissioning, op-
eration and maintenance are required to ensure that the
products operate safely and without any problems.
The permissible ambient conditions must be observed.
Ensure protection against unauthorised opening. Unauthor-
ised persons must neither open nor operate the combiner
box.
Photovoltaic systems can generate hazardous voltages.
Two di󰀨erent ways of service activities are allowed on
these products:
– "Working under voltage": Only electricians who have a
qualication for working under voltage are allowed to
carry out service activities under voltage. Observe the
local regulations and make use of appropriate personal
protective equipment.
– "Working without voltage": Electricians and trained per-
sons are allowed to carry out work without voltage, when
input and output connections are safely disconnected
and secured against re-connection. Observe the local
regulations and make use of appropriate personal pro-
tective equipment.
Before connecting the cables to the input connectors,
make sure that the fuses are not inserted and that the open
circuit voltage of the corresponding string is equal to the
other strings.
Do not extract or insert fuses under load. Before manipu-
lating a fuse make sure there is no reverse current owing
into the corresponding string.
If the installation regulations are violated, all warranty and
liability claims are void.
If a malfunction on a combiner box cannot be xed after
following the recommended measures, the product in ques-
tion must be sent back to Weidmüller. Weidmüller does not
assume any liability if the product has been tampered with.
2.2 Intended use
The PV DC COMBINER BOX series are intended for use
in photovoltaic (PV) systems. The product joins di󰀨erent
strings of a PV system and contains DC over-current and
over-voltage protections for string level. String monitoring
devices are provided optionally.
Weidmüller products may only be used for the applications
described in the catalogue and in the relevant technical
documentation. If products and components from other
manufacturers are used, these must be recommended or
approved by Weidmüller.
The observance of the documentation is part of the intend-
ed use.
2.3 Personnel
All activities described in this document may
only be carried out by specialists and instruct-
ed persons with the following qualications:
– Knowledge of the functionality and principle
of PV systems
– Training in handling dangers and risks dur-
ing installation and handling electrical devic-
es and systems
– Knowledge of applicable standards and
guidelines
– Knowledge and observance of these oper-
ating instructions and the safety instructions
contained therein
It is a common practise in the sector to apply the ve safety
rules described in the standard EN 50110. Anyway, quali-
ed electricians must analyse case by case on each instal-
lation the best way to proceed with safety.
The ve safety rules are the following:
1. Disconnect completely
2. Secure against re-connection
3. Verify that the installation is dead
4. Carry our earthing and measures against short-cir-
cuiting
5. Provide protection against adjacent live parts
2.4 Legal notice
The PV DC COMBINER BOX is CE-compliant in accord-
ance with Directive 2014/35/EU (Low Voltage Directive)
and with Directive 2014/30/EU (EMC Directive).

4000001903/00/04.20206
3 Device description
Figure 3.1 Product range
3.1 Product overview
PV DC COMBINER BOX is a complete range of tai-
lor-made Level 1 combiner boxes for utility-scale photovol-
taic systems. The combiner boxes are installed to join and
protect the DC strings that go from the PV panels to the
solar inverter.
The PV DC COMBINER BOX product range o󰀨ers solu-
tions from 8 to 32 inputs and 1 or 2 outputs. These can
be designed for systems with string voltage of 1000 or
1500 V DC.
The necessary string cables (+ and -) are to be connected
at the inputs whereas one or two DC+ and DC- main ca-
bles will be at the output side. The output cables must be
connected to a Level 2 combiner box, which will join DC+
and DC- from other Level 1 combiner boxes, or directly to
the solar inverter.
Parameters inuencing the selection of the optimal
PV DC COMBINER BOX
– Ambient temperature
– Degree of protection needed
– DC voltage range
– ISC of the PV string
– DC earthing system
– Number of inputs
– Number of outputs
– Fuses in one or both poles (by default in both poles)
– Type of surge protection (by default Type II SPD)
– Type of input terminals (by default multivia cable glands)
– String monitoring (if yes: single or pair monitoring)

74000001903/00/04.2020
Device description
5
1
3
4
2
6
Figure 3.2 Main components of the PV DC COMBINER BOX (exam-
ple)
1 DC Switch
2 String monitoring device Transclinic 16i+ (optional)
3 Output DC+/-
4 Ground terminal
5 Fuse holders
6 InputDC+/-(cableglands,alternativelyWM4Cconnectors)

Device description
4000001903/00/04.20208
3.2 Enclosure
The enclosure of the PV DC COMBINER BOX is made
of Glass Fibre Reinforced Polyester (GFRP). The en-
closure provides IP65 and IK07 or higher in accordance
with IEC 62208. Each enclosure is equipped with hinged
door(s).
Figure 3.3 Enclosure
3.3 DC Switch
Figure 3.4 DC switch
The PV DC COMBINER BOX has a DC disconnection
switch by default. The DC voltage of the switch depends on
the voltage of the PV string. The switch disconnector mak-
ing and breaking capacity (according to the IEC 60947-3)
has been selected to assure that it can switch the circuit at
full load at the maximum operating temperature.
3.4 Surge protection device (SPD)
Figure 3.5 Surge protection device
The surge protection device has been selected corre-
sponding to the customers requirements and in accord-
ance with the standard for low-voltage surge protective
devices IEC 61643-32.
Special units for 1 kV or 1.5 kV are used to provide the
best performance in each specic system conguration.
3.5 Fuse holders
Figure 3.6 Fuse holders
The fuse holders provide the interconnection between the
string input cables and other elements inside the combiner
box. The fuse holders ensure that the fuses are placed in
the optimum position to perform their protection function.
Additionally, the type of fuse holders (IP 2X) enable the au-
thorised personnel to operate the fuses in a safe manner.
These products allow multiple setups which helps to build
up specic tailor-made solutions of PV combiner boxes.

94000001903/00/04.2020
Device description
3.6 Fuses
Figure 3.7 Fuse
The fuses protect the PV strings against over-current situ-
ations. The PV DC COMBINER BOX is provided with gPV
fuses in accordance with IEC 60269-6:2010.
Each design of combiner box contains the most suitable
fuse rating specially selected for each project, depending
on Isc of PV strings, on voltage rating and on ambient tem-
peratures.
To assure the best performance of the complete solution,
PV DC COMBINER BOX is delivered with fuses, optional
without.
ATTENTION
Material damage!
Only use fuses with silver plated end-caps. If you have to
replace a fuse inside a PV DC COMBINER BOX, use the
same type of fuses delivered with the original combiner
box. Pay special attention to the voltage and current rate
as well as the size and material.
3.7 Terminals
Figure 3.8 Terminals
The fuse holder terminals allow to connect the string ca-
bles safely.
3.8 Conductors
To realise the connections regard the following conductor
specications:
Stripping length (regard the tolerances below) 18 mm
Clamping range, min. / max. 0.5 mm2... 16 mm2
WireconnectioncrosssectionAWG,min./max. AWG20...AWG4
Solid H05(07) V-U, min. / max. 0.5 mm2... 16 mm2
Stranded H07V-R, min. / max. 6 mm2... 16 mm2
Flexible H05(07) V-K, min. / max. 0.5 mm2... 16 mm2
Wire end ferrule with plastic collar, DIN 46228-4, min. / max. 0.5 mm2... 16 mm2
Wire end ferrule, DIN 46228-1, min. / max. 0.5 mm2... 16 mm2
Plug gauge acc. to EN 60999 a x b; Ø 5.3 mm (B6)
Conductor cross section Tolerance of stripping length
< 4 mm2± 1 mm
6 – 10 mm2± 1.5 mm
> 16 mm2± 2 mm
In order to assure a reliable connection we re-
commend to use appropriate crimping tools, as
an example PZ 10 HEX (Order No.1445070000).
Please check the Weidmüller product catalogue
to select the appropriate tool.
3.9 Input terminals
A B
Figure 3.9 Cable glands (A) and WMC 4 connectors (B)
The PV DC COMBINER BOX is equipped either with cable
glands or with special photovoltaic connectors WMC 4.
The WMC 4 connectors reduce the installation time as well
as the maintenance time. They fullll the DIN EN 50521
and are TÜV certied.
The cost-e󰀩cient cable glands on the other hand allow the
installer to adjust the necessary number of cables even in
the eld.

Device description
4000001903/00/04.202010
3.10 String monitoring device (optional)
Figure 3.10 String monitoring device Transclinic 16i+
In case the PV DC COMBINER BOX is equipped with a
string monitoring device, this device is a Transclinic 16i+
1k5 HP with PUSH-IN terminals.
This device simplies the connection work inside the
combiner box and reduces maintenance tasks due to the
PUSH IN terminals. The Transclinic 16i+ can operate at full
load (25 Amps) at maximum temperature range (+70 ºC).
3.11 Power supply for string monitoring
Figure 3.11 Power supply for string monitoring device
The string monitoring device is supplied by a Transclin-
ic BKE DC/DC power supply device. Depending on the
maximum voltage the device is a Transclinic BKE 1k0.4
(≤ 1000 V DC) or a Transclinic BKE 1k5.4 (≤ 1500 V DC).

114000001903/00/04.2020
Device description
3.12 General technical data
Main application features
Inputs 8 to 32
Outputs 1 or 2
Operating ambient temperature range -20 ºC ... +50 ºC
Rated DC voltage ≤1.000VDCor≤1.500VDC
Input connectors WM4Cconnectorsorcableglands
Input connector technology Screw tied inputs (up to 16 mm2cable)
DC earthing system Floating, negative grounded or positive grounded system
Main electrical current protections
Rated DC current per input ≤40 A(single, double or triple string connection)
Maximumfuserating 30Afor10x38/32Afor10x85/63Afor22x58
Protection against overcurrent gPV fuse-links according IEC 60269-6
Fuses 10x38 mm for 1 kV, 22x58 mm for 1.5 kV
Switch-disconnector Yes (optional)
Switch-disconnector making and breaking capacity (acc. to IEC 60947-3) ≤500A(otheroptionsondemand)
Enclosure
Enclosure material GFRP (Glass Fiber Reinforced Polyester)
Enclosurexingsystem Wall mounted or pedestal
Degree of protection (acc. to IEC 60529) IP65
Form factor Cabinet with hinged door or removable cover
Surge protection
Surge protection device Type I, Type II and Type I+II
Auxiliarycontacts optional
SurgeprotectiononEIA-RS485ports optional
String monitoring (optional)
String monitoring device Transclinic 16i+ 1k5 H
Mainmonitoredparameters Voltage, current, temperature, DI status and auxiliary alarms
Communication RS485 (3-wires)
Protocol Modbus/RTU
Self-powered Yes (DC/DC power supply)
Standards
Standards IEC 61439-2 ed 2.0 / EN 61439-2:2011
Please regard the data sheet attached to each
combiner box.

4000001903/00/04.202012
4 Transport and storage
4.1 Transporting
► Always wear work shoes with foot protection
when transporting and unpackage the combi-
ner box.
►Regard the total weight and use appropriate transporta-
tion equipment.
4.2 Unpacking the delivery
► Before unpacking, check that the product contained is
the one you have ordered (see the label laterally on the
package).
If the product that you have received is not what
you have requested or is incomplete, please do
not open the shipping boxes. Please contact
your Weidmüller representative o󰀩ce, your dis-
tributor or the relevant contact person immedi-
ately.
► Check the delivery for completeness. For the scope of
delivery, see the enclosed data sheet and dispatch doc-
uments.
If you detect any issue or damage, do not install
the unit. Please contact your Weidmüller repre-
sentative o󰀩ce, your distributor or the relevant
contact person immediately.
► Store away the transport packaging.
►Ensure that the operating instructions are accessible to
the user at all times.
4.3 Storage
Make sure that in case of long-term storage the following
conditions are met:
– Ambient temperature: -25 °C to +40 °C
– Relative humidity: 0 % to 50 %
ATTENTION
Material damage!
The combiner box must be stored lying at on the rear
side. Otherwise the cable glands and connectors at the
bottom of the enclosure can be damaged.
In the event that after the storage there is any ingress of
dirt, pollutants or liquid into the equipment, or the formation
of condensation, damage or any other failures the equip-
ment must not be commissioned until the correct remedial
procedure has been discussed with and approved by
Weidmüller.
4.4 Establishing connections
ATTENTION
Material damage!
The tension of the cables can cause mechanical stress to
the enclosure. For this reason, depending on the instal-
lation height, a strain relief underneath the combiner box
may be needed. Regard the national regulations.
– Use only electrical solar cables rated for the voltages,
currents and environmental conditions (temperature, UV,
etc.) expected at the installation site.
– Ensure that you lay all cables with short-circuit protec-
tion and ground fault protection.
– As feeders use only single-core cables with double or
reinforced insulation in accordance with IEC 60364-5-
52.
– To ensure short-circuit-proof and ground-fault-proof in-
stallation in accordance with IEC 60364-5-52, the follow-
ing requirements must be fullled:
– Cables must not be installed in the proximity of com-
bustible materials.
– Cables must be accessible.
– Cables must be protected against mechanical dam-
age.
– Do not lay the wires over sharp edges.

134000001903/00/04.2020
5 Installation
5.1 Installation site
The PV DC COMBINER BOX is suitable for protected
outdoor installation. Regard the following aspects when se-
lecting the installation site:
– The location must be protected from the weather and
direct sunlight.
– The location must be easily accessible for installation
work and later maintenance work.
– The installation site must not be in close proximity to
easily ammable materials, gases or vapours.
– The combiner box must be positioned as described in
the following section.
– It must be ensured that unauthorised personnel cannot
access the combiner box.
– The installation area must be stable enough to enable
installation and maintenance work safely.
– The combiner box and especially the feeder conductors
must be installed in such a way that damage cannot be
caused by rodents.
– Regard the permissible ambient conditions:
– The temperature range is indicated on the label inside
the box.
– The relative humidity may temporarily be as high as
100 % at a maximum temperature of +25 °C.
– Ensure that no object is blocking the pressure compen-
sation elements.
– Ensure that neither the string input cables nor the PV
output cables will be damaged by a lawnmower or simi-
lar agricultural implement.
– When installing, ensure rain cannot penetrate the com-
biner box.
Exposure to direct sunlight and direct rain for
extended periods and excessively high or low
temperatures can result in a shorter lifetime or
damage to the internal components of the com-
biner box.
To protect the combiner box against direct
sunlight and rain, it shall be installed under the
photovoltaic modules or a protective canopy or
sunshade. Take air circulation around the box
into account.
Figure 5.1 Installation under the PV modules
5.2 Positioning of the combiner box
The PV DC COMBINER BOX is designed to be installed
vertically with the cable glands or connectors leading down.
Merely a positive inclination from 15º to 90º is allowed.
90°
Figure 5.2 Installation in upright vertical position

Installation
4000001903/00/04.202014
15°... 90°
Figure 5.3 Tolerable inclination for the installation
The combiner box must not be installed horizon-
tally laying at on the rear neither in any other
orientation.
The combiner box must not be installed indoors.
5.3 Fixation
The xation of the combiner box directly a󰀨ects
the proper performance and the lifetime of the
product.
Ensure that the requirements described in chap-
ters 5.1 and 5.2 will also be observed.
Mounting material
Most of the Weidmüller combiner boxes are supplied with
metal or plastic mounting lugs, depending on the model.
Fixation screws are not delivered as standard with each
model. Please check your delivery before starting the in-
stallation.
Requirements
The PV DC COMBINER BOX shall be xed to a suitable
and stable metallic structure or a wall that will support the
weight of the combiner box during the entire lifetime.
Always use all xations that are supplied with the product.
In case the installation is done on a pedestal, this should
be xed on the top of it with the specic accessories sup-
plied with the unit.
Figure 5.4 Fixing the enclosure to a structure or on a pedestal
5.4 Installing the combiner box
CAUTION
Risk of injury due to the size and the
weight!
►Always install the combiner box with two
persons to avoid any injury or accident.
Installers should be qualied for the specic
works according IEC standards and/or local
regulations and should bring the necessary
safety equipment.
ATTENTION
The product can be destroyed!
– Never drill the enclosure to add any extra hole or to
modify any of the existing holes. Otherwise the IP pro-
tection will get lost as well as the product warranty.
– If necessary lay down the combiner box only on the
rear side after unpacking. Otherwise the cable glands
and connectors at the bottom of the enclosure can be
damaged.
► Remove the combiner box from the original packaging.
►Measure the exact distances between the drilling holes
and mark the positions in the mechanical structure (or
wall).
►Drill the holes in the mechanical structure (or wall).
► Mount the combiner box using the xing lugs.

154000001903/00/04.2020
Installation
► Check the installation:
– Verify that the combiner box is correctly secured and
xed.
– The surface of the enclosure should be totally at. If
the combiner box is bended over the edges, the tight-
ness is not guaranteed.
Figure 5.5 Fixing lugs enclosure type A
Figure 5.6 Fixing lugs enclosure type B
Each model has been designed according individual
specications and this has been approved by customer.

Installation
4000001903/00/04.202016
Enclosures mounting lugs and xing points1)
Size
Dimensions H x W x D (mm)
A
B
C D
A
B
A
B
C
mm mm mm
54
530 x 430 x 200
A325 A325
B 465 B 455
C 455
D 590
64
647 x 436 x 250
A330 A330
B 465 B 544
C 555
D 690
75
747 x 535 x 300
A430 A430
B 565 B 655
C 655
D 790
86
847 x 636 x 300
A530 A560
B 665 B 755
C 755
D 890
108
1056 x 853 x 362
A750 A750
B 885 B 955
C 955
D 1090
573
538 x 750
A786
B 125
C –
5103
538 x 1000
A1036
B 125
C –
7103
788 x 1038
A1052
B 375
C –
1010
788 x 1038
A1050
B 312.5
C 312.5
1012
1038 x 1200
A1302
B 312.5
C 312.5
1)Thistableisareference.Forspecicmeasureofyourproductpleaserefertothedocumentationdeliveredwiththeproduct.

174000001903/00/04.2020
Installation
Enclosures mounting lugs and xing points1)
Size
Dimensions H x W x D (mm)
A
B
C D
A
B
mm mm
75
735 x 535 x 270
A483
B 580
C 682
D 780
86
835 x 635 x 300
A583
B 680
C 782
D 880
108
1035 x 835 x 300
A783
B 880
C 982
D 1080
PS 440
1000 x 1000 x 320
A783
B 1060
PS 452
1000 x 1200 x 320
A783
B 1260
1)Thistableisareference.Forspecicmeasureofyourproductpleaserefertothedocumentationdeliveredwiththeproduct.

Installation
4000001903/00/04.202018
5.5 Inserting the fuses
For each string voltage (1000 V DC and 1500 V DC) there
are two types of fuse holders that can be used in the
PV DC COMBINER BOX:
– for 1000 V
– for 1500 V
WARNING
Do not operate under load.
A serious damage on persons and equipment
can occur by high voltage.
► Ensure that there is no current owing
through the strings.
►Open the fuses carrier by pulling the fuse holder handle.
► Insert the fuse link laterally into the fuse holder carrier
and push gently.
►Proceed in this way with all fuses that are to be inserted.
5.6 Connection of the inputs
The enclosure is equipped either with cable glands or with
PV connectors (WM4 C or PV stick).
In order to realise proper connections we recommend to
use wire end ferrules as well as appropriate stripping and
crimping tools.
Input connections via cable glands
Each multivia cable gland has entries for 8 dif-
ferent cables. Pay attention to the string number
as well as the polarity in order to avoid mistakes
during connection.
Make sure that you have the electrical drawing
provided with the combiner box to hand.
►Insert the DC string input cables through the multivia ca-
ble glands into the interior of the enclosure.
►Strip the conductor for 18 mm with an appropriate tool.
►Crimp the conductor with a tubular wire end ferrule with
18 mm length of the sleeve (the conductive part).
► Check the terminal in the electrical drawing and insert
the conductor in the fuse holder connection insert.
►Use an appropriate screw-driver and thighten the screw
with the torque indicated in the product drawing.
►Pull down the cables to assure that all of them are well
connected.
► Make sure there is su󰀩cient strain relief for the DC main
lines and DC string input cables.
► Make sure that the cables are not mounted under me-
chanical load which could create an undesirable force.
►Proceed in this way with all input cables needed.

194000001903/00/04.2020
Installation
Input connections via PV connectors
Both connectors (box connector and eld con-
nector) must be from the same brand and same
model to ensure the correct performance and
reliability of the solution. Please assure that there
is 100% compatibility between both connectors.
Weidmüller supplies the range of combiner box-
es with WM4 C terminals, so it is mandatory the
usage of same connector.
If another connector should be used, this needs
a specic authorisation by Weidmüller.
With PV connectors there is no need to get access inside
the PV combiner box because all the cabling is already
done. The installer has only to connect the DC string ca-
bles to the PV connectors at the bottom side of the enclo-
sure by using a WM4 C connector or PV-Stick.
To read more about these connectors, please check oper-
ating instructions on the Weidmüller website.
►Follow the instructions in the user manual coming with
the PV connectors.
Figure 5.7 Connection of the PV connectors
►Pull down the cables to assure that all of them are well
connected.
5.7 Connection of the outputs
The output connections depend on the design of each
tailor-made PV DC COMBINER BOX. The output cables
must be connected to the poles of the switch disconnector
or to the terminals prepared for this purpose. Regard the
delivered datasheet for the cable glands and a description
of the clamping area.
Please ensure that the cable that you are going to use ts
with the specications.
– The cross section of the conductor must be selected ac-
cording to the rated current of the system and to the size
of the cable gland of the combiner box.
– Use copper or aluminium cables only. When using alu-
minium cables regard the section "Preparing aluminium
conductors" before starting the installation.
– Weidmüller is not responsible for the performance of the
terminal lugs, terminal ring or terminal cage neither the
output cable selected.
WARNING
Do not operate under load.
A serious damage on persons and equipment
can occur by high voltage.
► If string cables form the eld are connect-
ed into the terminals, ensure that the pow-
er supply is disconneted.
►Ensure that the DC switch disconnector is
in OFF position.
►Ensure that there is no voltage in the out-
put cables and that all safety measures
have been considered.
► Before starting the installation check that the
terminal lugs will t through the cable glands.
►Insert the DC main cables through the cable glands into
the enclosure.
►Regard the polarity when connecting the DC conductor
to the appropriate terminal lug, ring terminal or cage ter-
minals and follow the instructions of that component to
crimp it in the right way.
►Connect the DC conductors to the stud terminals or di-
rect to the switch-disconnector.
► Check the terminal in the electrical drawing provided
with the combiner box.
► Check and apply the right tightening torques to the ter-
minal lugs of the switch disconnector (the correct tight-
ening torques can be found in the specic documenta-
tion inside each PV DC COMBINER BOX).
►Tighten the cable glands.
► Make sure there is su󰀩cient strain relief for the DC main
lines/DC feeder cables.
► Close all unused cable glands with blanking plugs to
prevent moisture penetrating the combiner box.

Installation
4000001903/00/04.202020
Preparing aluminium conductors
– Aluminium conductors are only suitable for installation
sites that are free from humidity or aggressive atmos-
pheres.
– It is recommended to use bimetallic connectors.
– Use neutral grease (e.g. acidfree and alkalifree vaseline)
to protect the surface of the alumimium from oxidation.
As a well known characteristic aluminium forms a thin,
non-conductive layer of oxide as soon as it is exposed to
the air. This layer increases the contact resistance between
the aluminium conductor and the current bar of the terminal
which can lead to poor contact. As a precondition regard
the following steps to prepare the aluminium conductors:
►Scrape the stripped end of the conductor carefully, e.g.
with a knife, to remove the layer of oxide.
Do not use brushes, les or emery paper be-
cause particles of aluminium can be deposited
on other conductors.
►Coat the end of the conductor immediately with a neutral
grease, and connect it to the terminal immediately.
►Tighten the screws with the maximum permissible tight-
ening torque.
Repeat the above procedure each time after the
conductor has been disconnected and shall be
reconnected.
5.8 Connection of the grounding cable
The PV DC COMBINER BOX is designed without any me-
tallic mounting plate or similar. The enclosure is made of
GFRP (Glass Fiber Reinforced Polyester). Therefore the
unique ground connector is used for the surge protection.
Note that this cable must be connected to provide the cor-
rect operation of the surge protection device (SPD).
Protective conductors and other earthing conductors for
functional and protective purposes cannot generally be
considered as equipotential bonding dedicated for surge
and lightning protection.
According to the standard CLC-TS 50539-12, the cross
section of connecting conductors to SPDs on the DC side
of PV installations must be as it follows:
– Earthing conductors of SPDs Type I shall have a min-
imum cross section of 16 mm2copper or equivalent or
equal to the cross section of live connectors, if greater
than 16 mm2.
– Earthing conductors of SPDs Type II shall have a min-
imum cross section of 6 mm2copper or equivalent or
equal to the cross section of live connectors, if greater
than 6 mm2.
– The cross section of the connecting conductors from
the SPD to live conductors shall not be smaller than the
cross section of the live conductors of the associated
circuit.
To ensure that the live conductors of the PV installation can
withstand the surge current stress, the cumulated cross
section of these conductors should not be less than 6 mm2
for SPD Type II and 16 mm2for SPD Type I.
Otherwise, if in the combiner box there is a specic ground-
ing terminal for this purpose, check the specications on
the electrical diagram attached inside the product.
►Strip the conductor for 12.5 mm using an appropriate
tool.
►Verify with the electrical diagram attached in the combi-
ner box where to connect the cable (ground connector of
the SPD or a specic terminal for this purpose).
► In case the grunding cable is connected to a specic
terminal, connect the cable and tighten it with the screw
(2 ... 4.5 Nm).
►Verify the correct connection of the grounding cable to
the terminal.