OBOV20-CType 2 / Class C Surge Arrester, In 20 kA, Imax 40 kA per Pole, Up 1.3 kV, Plug-In Cover on Multibase, DIN Rail

Product Description

What this part is

An OBO Bettermann V 20-C surge arrester — a DIN-rail Type 2 (Class C) surge protective device for equipment protection and equipotential bonding in main and sub-distribution boards. The design is two-part: a Multibase base with multiple connection terminals stays wired in, and the arrester cover plugs into it and can be separated by hand with no tool, so a spent module is replaced without disturbing the wiring.

Decoding the designation

V – OBO surge arrester (Varistor / Überspannungsableiter) for power supply systems20 – 20 kA nominal discharge current classC – Class C, equivalent to Type 2 under EN 61643-11Full order codes add pole configuration and continuous voltage after the family designation — for example V20-C/1-280 for a single-pole 280 V unit, V20-C/3+NPE-280 for a three-pole plus N-PE set, and V20-C/…-150 for the 150 V range. That suffix, printed on the device label, is what fixes the pole count and Uc for a given unit

What these specs mean in practice

The two current figures are a pair, not alternatives. In, the nominal discharge current, is 20 kA on an 8/20 µs wave — the level the arrester is rated to take repeatedly. Imax, the maximum surge current, is 40 kA per pin on the same waveform and is a single-shot survival figure. Size the installation to In. The protection level Up of 1.3 kV is the residual voltage the downstream equipment actually sees, which is the number to compare against the impulse withstand of what you are protecting. Being a Type 2 device, it belongs downstream of a Type 1 lightning current arrester where a structural lightning protection system is present, not in place of one. The varistor is encapsulated and non-extinguishing, with a dynamic thermal cut-off that disconnects a failing varistor, and a window on the front shows at a glance whether the arrester is still live or has operated.

Published specifications

Class: Type 2 / Class C surge arrester per EN 61643-11 (VDE 0675 parts 6-11)Nominal discharge current In (8/20 µs): 20 kAMaximum surge current Imax (8/20 µs): 40 kA per pinProtection level Up: 1.3 kVRated voltage: 230 V AC; highest continuous operating voltage 280 V AC on the -280 versionsArrester element: encapsulated, non-extinguishing zinc-oxide varistorProtection features: dynamic cut-off unit (thermal disconnector), visual function displayConstruction: plug-in cover on a Multibase base with multiple connection terminals; cover separates from the base without tools; supplied pre-assembled and ready for connection as a complete unitApplication: distributor housings, main and sub-distribution boards; equipment protection and equipotential bonding

Quantity and configuration

Sold as 1 piece. The V 20-C is catalogued as a complete unit of cover plus base, pre-mounted and ready to wire — confirm from the photographs whether both parts are present in this item, since the plug-in cover and the Multibase base are also sold and stocked separately as spares.

Installation and setup notes

Match the pole configuration to the system earthing arrangement: a TN-S installation and a TT installation need different arrangements, and V20-C variants exist for 1, 2, 3 and 3+NPE configurations for exactly that reason. Fit the arrester downstream of appropriate overcurrent protection and keep the connecting leads as short and straight as practical — lead inductance adds to the let-through voltage, so long loops undo the 1.3 kV protection level. Check the status window as part of routine maintenance; a tripped indication means the varistor has operated and the cover needs replacing, and it will not show up as a supply fault. Where remote signalling is needed, the +IR variants add a remote-signalling contact; a plain V20-C does not have one.

Interchange guidance

The suffix is the part. V20-C/1, /2, /3 and /3+NPE differ in pole count, and the -150, -280 and -1000 designations differ in continuous operating voltage — none of those are interchangeable, and fitting the wrong Uc either shortens varistor life or raises the let-through voltage. V20-C+NPE400+IR adds remote signalling and a different N-PE arrangement. OBO’s V25-B/C combined arresters and V50 range are different classes with different discharge capacities. DEHNguard modules, though similar in concept and format, use a different base and do not plug into an OBO Multibase.