Manual · DE/EN/ES — Trilingual (German/English/Spanish) operating instructions for the Siemens Energy 3EC3 gapless metal-oxide surge arrester for DC traction systems (Order No. 928 00019 171 e, rev. 10/2014, © Siemens Energy 2021). The 3EC3 protects DC installations with maximum operating voltages of 1 kV, 2 kV or 4 kV and is designed to EN 50123-5/A1, making it particularly suited to railway installations and electrical equipment on traction vehicles. The manual covers description and technical data for the three variants (3EC3 010/020/040), dimensions and terminal layout, rating-plate legend, transport and storage conditions, installation with mandatory electrical safety rules, screwed-joint torques, maintenance (essentially maintenance-free), and disposal guidance. Trilingual German-English-Spanish original; the English text was used for this digitization.
The 3EC3 is a gapless surge arrester built around a non-linear metal-oxide (MO) varistor housed in a porcelain insulator. The housing is closed off by a base flange that integrates a pressure relief device with a gas diverter nozzle, so that internal overpressure is vented in a controlled direction.
It is intended for protecting DC systems with a maximum prospective voltage at the installation site of 1 kV, 2 kV or 4 kV. Its primary applications are traction (railway) power installations and electrical equipment mounted on traction vehicles.
Note: checking the sparkover (response) performance can damage the arrester. It requires special equipment and must therefore only be carried out at the manufacturer's works.
The arrester can be used both outdoors and indoors. Three variants cover the DC voltage classes; all share the same discharge and pressure-relief ratings and the same insulator geometry. The design corresponds to EN 50123-5/A1.
| Parameter | Symbol | 3EC3 010 | 3EC3 020 | 3EC3 040 |
|---|---|---|---|---|
| Rated voltage | Ur | 1 kV DC | 2 kV DC | 4 kV DC |
| Continuous operating voltage | Uc | 1 kV DC | 2 kV DC | 4 kV DC |
| Residual voltage at In | Up | 2,4 kV | 4,8 kV | 9,6 kV |
| Nominal discharge current | In | 10 kA | 10 kA | 10 kA |
| Pressure relief current | PR-CL | 40 kA | 40 kA | 40 kA |
| Weight | G | 6,0 kg | 6,2 kg | 6,4 kg |
| Creepage distance | k | 165 mm | 165 mm | 165 mm |
| Flashover distance | s | 135 mm | 135 mm | 135 mm |
The dimension drawing identifies: (1) supply terminal M10, (2) earth terminal M10x30, (3) three fixing holes ø 11 mm, (4) diverter nozzle, (5) conductor, and (6) rain drain hole.
Principal dimensions from the drawing: overall height 196 mm, insulator/flange diameter 190 mm, supply stud ø 28 mm projecting 27 mm, flange height 95 mm, earth terminal at 40 mm / 24 mm levels, base footprint 135 mm + 81 mm, nozzle aperture width 100 mm. The three fixing holes are spaced at 120° (hole circle 161 mm, per the installation section).
Each arrester carries a rating plate headed "Gapless MO-Surge Arrester". It states: (1) type (e.g. 3EC3 040), (2) manufacturer, (3) nominal discharge current In, (4) rated voltage Ur, (5) continuous operating voltage Uc, (6) residual voltage Up, (7) pressure relief current PR-CL, (8) governing standard EN 50123-5, and (9) running number in the year of manufacture (e.g. Dat. 2003 / xxxx, MADE IN GERMANY).
Arresters are packed at the factory according to the transport stresses, climatic conditions and customer specifications, with handling and storage markings on the packaging. Inspect the shipment for damage immediately on arrival; notify the forwarding agent at once if damage is found, and check separately packed parts against the dispatch notes, opening all boxes for this purpose.
For longer storage periods it is recommended to leave the units and accessories in the transport packing. The arresters must be protected against mechanical, chemical and thermal influences (e.g. direct solar radiation) and stored in a normally cool, dry and dust-free environment.
Storage temperature range: -50 °C to +60 °C. Relative air humidity: below 80% at 15 °C as annual mean value, 100% at 25 °C as maximum value. Surge arresters removed from a vehicle must be thoroughly cleaned before storage.
Warning — before any work starts: switch off and isolate, secure against reclosing, verify that the equipment is dead, earth and short-circuit the equipment, and cover or fence off nearby live parts. Death, severe injury and considerable damage to property and the environment may result if these safety instructions are not followed; confirm that the measures have been carried out.
The arrester is mounted via three ø 11 mm holes in the base flange on a 161 mm hole circle. Outdoors it must always be mounted vertically; indoors any mounting position is permissible. On electric traction vehicles it is best mounted directly on the roof so it can be connected between the conductor coming from the current collector and the vehicle frame.
For connection, use multi-stranded copper conductors of at least 16 mm² or aluminium conductors of at least 25 mm²; conductors up to 50 mm² can be connected.
To fully utilise the permitted short-circuit loading, the bare conductor should be run over the gas diverter nozzle (Fig. 1). The earth wire must have a minimum cross-section of 16 mm² copper, 25 mm² aluminium or 35 mm² hot-dip galvanised iron, and should be kept as short as possible.
Grease the bolt threads with Molykote Longterm 2 plus. Caution: uncontrolled tightening can damage or loosen the bolt joints — use a torque wrench for assembly.
Required tightening torque for screwed joints: M10 = 20 ± 2 Nm.
The same electrical safety warning applies as for installation (isolate, secure, verify dead, earth and short-circuit, cover nearby live parts) before any work starts.
Regular maintenance of the arresters is not necessary. Monitoring is limited to: checking the arrester for overloads (blackening or traces of burning at the blow-out aperture of the flange — in that case the arrester must be replaced), and checking the contamination level of the porcelain. If contamination is marked or concentrated on one side, cleaning followed by siliconizing is recommended.
The arrester and its accessories are environmentally compatible products; priority should be given to material reuse, with disposal following current legislation. Constituent materials include steel, copper, aluminium, PTFE, cast resin and cast-resin-impregnated fabric, glass-fibre-reinforced plastics, polyurethane, sealing rubbers, ceramics, electronic components and silicone rubber (VMQ), and ceramic (porcelain, metal oxide).
The device can be recycled as mixed scrap or, dismantled as far as possible, as sorted scrap with a mixed-scrap residual portion. The metal-oxide (MO) arrester resistors must be disposed of as industrial waste similar to domestic garbage (not as building rubble). As supplied by Siemens Energy the device contains no hazardous substances under the German regulations; outside Germany, locally applicable laws must be followed.
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