Installation guide

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4.3 Types of surge protection devices
Although the power line is the most obvious source of high-voltage surges, any wire connection between
your system and its environment can carry surges and stray voltages. Surges on data cables, for example,
can bring down the entire network, this means loss of valuable power production while repairs are made to
inverters and supporting equipment. The type of surge protection device used is determined by the nature of
the voltages and currents that the wires normally carry.
Weidmuller SPD devices are available with digital status outputs, which can be wired to the Transclinic digital
inputs, to indicate that the SPD has protected the system and will need replacement.
4.3.1 DC arresters for PV Array side protection
Since the array and associated ground grid represents a large target for lightning strikes, surge protection for
the inverters and other high capital cost items is critical. Weidmuller supply purpose built plug-in style surge
protection modules for string arrays that include indicators that show a device has protected the system and
needs replacement. Surge protection for Solar Panels and strings of solar panels require special considera-
tion because they operate at high DC voltages and currents and can be subject to grounding faults.
4.3.2 AC arresters for supply side protection
Weidmuller have a wide range of standard AC devices that will protect your system from any surges caused
by lightning strikes and voltage variations on the power grid side. A core element of Weidmuller AC side
SPDs is a high-performance varistor, designed as a pluggable component and thermally triggered on over-
load in the event of a fault. Following the fault, which is indicated by the red/green function indicator, the
pluggable arrester module can be easily replaced.
4.3.3 Surge protection for data communications equipment
In the data sector it is, of course, important that data is sent from the transmitter to the receiver without
transmission losses and corruption and without picking up any damaging surges. This is best achieved by
having a series protection component included in the design. For data circuit protection, an SPD with low at-
tenuation values are the best choice, particularly at high data rates.