Steca Xtender
Installation and Operating Instructions 723.932 Xtender V0.511 Seite 11
4.2 Earthing system
The Xtender is a protection class I unit, which is intended for cabling in a grid type TT, TN-S or
TNC-S. The earthing of the neutral conductor (E) is carried out at a sole installation point,
upstream of the RCD circuit breaker (D).
The Xtender can be operated with any earthing system. In all cases it is imperative that the
protective earth be connected in compliance with the applicable standards and regulations. The
information, notes, recommendations and diagram mentioned in this manual are subject to local
installation regulations in every case. The installer is responsible for the conformity of the
installation with the applicable local standards.
4.2.1 MOBILE INSTALLATION OR INSTALLATION CONNECTED TO THE GRID VIA PLUG CONNECTOR
When the input of the device is connected directly to the grid via a plug, the length of the cable
must not exceed 2 m and the plug must remain accessible.
In the absence of voltage at the input, the neutral and live are interrupted, thereby guaranteeing
complete isolation and protection of the cabling upstream of the Xtender.
The earthing system downstream of the Xtender is determined by the upstream earthing system
when the grid is present. In the absence of the grid, the earthing system downstream of the
inverter is in isolated mode. The safety of the installation is guaranteed by the equipotential
bonding.
The connection (link) between the neutrals (C) upstream and downstream of the
Xtender is not permitted in this configuration.
This connection type guarantees the optimal continuity for supplying the Xtender loads. The first
isolation fault will not lead to an interruption in the supply.
If the installation requires the use of a permanent isolation controller this would have to be de-
activated when the TT network is present at the Xtender input.
A
ll sockets and protection class I devices connected downstream of the Xtender must
be properly connected to the earth (earthed socket). The cabling rules above remain
valid, including fixed installations, in all cases where the Xtender input is connected to
the grid via a plug connector.
4.2.2 FIXED INSTALLATION
The installation may be equivalent to a mobile installation (with interrupted neutral).
In a fixed installation where the neutral is connected to the earth at a single installation point
upstream of the Xtender, it is permissible to carry out a connection of the neutrals in order to
preserve an unchanged earthing system downstream, independent of the operating mode of the
Xtender. This choice has the advantage of keeping the protection devices downstream of the
Xtender. This connection can be executed according to the examples in appendix 1, or carried
out by modifying the configuration {1486}
In this case the appearance of the first fault will lead to the installation stopping or the
disconnection of the protection devices upstream and/or downstream of the Xtender.
Safety is guaranteed by the equipotential bonding and by any RCD circuit-breakers placed
downstream.
This connection (C) is not permitted if a socket is installed upstream of the Xtender.
4.2.3 INSTALLATION WITH AUTOMATIC PE-NEUTRAL SWITCHING
In certain applications, it is desirable to keep the neutral upstream and downstream of the
Xtender separated (C) while reestablishing the earthing system (TN-S, TT or TNC-S) in the
absence of voltage at the input. This can be programmed by the configuration {1485} via the
RCC-02/03 remote control. This modification must be carried out possessing technical knowledge,
at the responsibility of the installer and in conformity with the applicable regulations and
standards.
This allows adherence to the requirements for an earth-neutral connection at the source.