Chapter 2 Installation and wiring
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2.3.1 Inverter connection and cabling conditions
(1) Place the control signal cables and the mains and other power lines apart.
(2) Use a twisted pair or two-wire shielded conduit with a cross section of 0.5 to 2 mm
2
to
avoid interference.
(3) Ensure that the terminals used are suitable for maximum voltage and current load.
(4) Use the correct earthing terminal E, the earthing resistance must be less than 10 ohms,
according to STN EN 62305-3.
Use the prescribed cross section of the grounding wire. Protective wire cross sections must
be calculated or determined according to the table (all according to STN 33 2000-5-54). The
grounding point should be as close as possible to the inverter and the wire length should be
as short as possible. In TN networks, the following requirements must be met:
(4.1) The earthing resistance of the source node shall not be greater than 5 Ω.
Under difficult soil conditions, a maximum of 15 Ω is allowed.
(4.2) The total earthing resistance of PEN wires (including wires from the transformer and the
ground point) for 230 V AC networks must not exceed 2 Ω.
(4.3) The wire PEN in the TN-C network or the PE wire in the TN-S network must be grounded
by a separate earthing device or connected to an existing system. The individual earthing of
the PEN and PE wires should have a ground resistance of no more than 15Ω. At the end of the
line and branch lines at the neutral point, the earthing resistance should be maximum 5 Ω.
(5) Fulfil the requirements for the connection of each terminal, the right selection of
accessories such as potentiometers, voltmeters, power supplies, cables, terminals, etc.
(6) Power can be turned on after the connection is complete and checking that everything is
properly connected.
(7) The total length of the line should not exceed 100 m. Particularly in the remote connection,
the current limiting function may be reduced, or the device or equipment connected to the
inverter output side or the charging current may be malfunction due to a long electrical
installation. Therefore, note the total lead length. It is recommended to use for outputs from
inverter shielded cables, such as NYCY 3x cross section, NYCWY 3x cross section or ÖLFLEX®
4G, to minimize interference.
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