Electrical Connection; Connection Instructions; Preliminary Checks - SMA STRING-COMBINER DC-CMB-U15-16 Manuel D'installation

6

Electrical Connection

6 Electrical Connection

6.1 Connection Instructions

6.1.1 Preliminary Checks

Before connecting the Combiner Box to the photovoltaic plant, make sure that:
•
The fuses are not inserted in the fuse holder.
•
The disconnecting switch is open (lever set to OFF).
•
The Combiner Box is in good condition and there was no damage during transport.
•
The Combiner Box is firmly anchored to walls and stable supports.
•
There are no remaining metallic parts, chips and derivatives from the installation activities.
After performing the checks listed in the points above, proceed to wire the cables according to what is shown in the
wiring diagram, making sure to use suitable sizes and colors. Before connecting the cables coming from the strings at
the top of the fuse holder inside the enclosure, it is recommended to join them end-to-end with suitable tips in order to
prevent possible short circuits between adjacent cables.
Note that the panel does not contain blocking diodes
If the photovoltaic array has zones that are not irradiated evenly (for example, due to partial shading), use blocking
diodes to prevent the circulation of inverse currents in the strings which may lower the system's performance.
Make sure the yellow-green grounding conductor is connected to the arrester and to the terminal.
Make sure that the DC connections are properly secured inside the terminals in order to prevent possible overheating
that may lead to dangerous situations.
Use tools with control torque with the following data:
Fuse holders:
Output DC cable: Screw M12 type 70 Nm
Before closing the fuse box bases, check the entire side of the photovoltaic array for any wiring errors such as polarity
inversion of the strings or excessive voltages above the maximum permissible values. These types of wiring errors can
cause serious damage to the system or cause dangerous situations for people.
These types of wiring errors may cause fires.
18 DC-CMB-IA-U15-xx-en
2 Nm
SMA Solar Technology AG
Installation Manual