Surge arresters

Dehn’s modular Type 2 Dehnguard M YPV SCI … (FM) surge arresters are designed for protecting low voltage equipment in photovoltaic systems. The three-stage DC switching device makes the arresters especially safe so that they fulfil IEC 60364- 7-712:2002-05 requirements for modern photovoltaic systems. The combined disconnection and short-circuiting device with electrical isolation in the protection module prevents fire damage due to DC arcs. The module locking system firmly fixes the protection modules in the base part of the arrester. Shock, vibration or enormous mechanical impulse loads, resulting from discharges, do not affect the safe connection to the protection module.

In order to avoid incorrect insertion by the installer or user, every protective circuit of the Dehnguard M YPV SCI … (FM) is mechanically coded. The protection modules are also easily replaced without tools. Three types are available for protecting photovoltaic systems up to 600 V, 1,000 V and 1,200 V. The type DG M YPV SCI 1200 is suitable for all photovoltaic systems.

To fulfil the specific requirements of photovoltaic systems, the fault-resistant Y-connection, consisting of three varistor protective circuits and the combined disconnection and short-circuiting device, are integrated in a single unit. This feature reduces the probability of an arrester failure in case of operating and fault states. This ensures that the arrester is protected against overloads without presenting a fire risk to the system. Even in the case of voltages up to 1,000 V DC, an arc, which is likely to occur when a conventional disconnection device is activated, is quenched immediately and without risk.

Fire protection is the top priority for Dehnguard M YPV SCI … (FM). A fuse which was particularly developed for photovoltaic systems was integrated into the short-circuit path to ensure safe electrical isolation. This allows deenergised replacement of the protection module without arc formation, in the case of a faulty surge protection module. This design combines surge and fire protection, as well as protection for personnel.

Dehnguard M YPV SCI … (FM) can be used in all low, medium and high performance photovoltaic systems with no need for a backup fuse due to the high breaking capacity of the integrated fuse.

Green and red indication show the readiness for operation of every protective circuit. Apart from this standard visual indication, Dehnguard M YPV SCI … (FM) also features a three-pole terminal for remote signalling. With the remote floating changeover contact, the remote signal can be used as a make or break contact depending on the circuit concept.

The Dehnguard M YPV SCI … (FM) surge arresters of the modular Dehnguard M family incorporate multifunctional terminals on a standardised spacing of one module for connection of conductors and busbars for easy wiring with other DIN mounted devices. Dehn is represented in South Africa by Surgetek.