Products

• GPS Rider
• ISPU
• LDT Filter
• Reply Telegram Generator
• SSI Link Analyser
• TCOD & Pinbrazer
• TFM Input Tester
• TRCU
• Under development

Isolating Surge Protection Unit

Park Signalling's Isolating Surge Protection Unit (ISPU) for SSI Data Links is an improved surge protection unit that incorporates a transformer to greatly enhance immunity to common mode surges and voltages and is plug compatible with units designed to GS/ES 1937.

The SSI system requires that the data link and Data Link Modules (DLMs) be protected from lightning, traction and other electrical surges. This is conventionally achieved by the use of Surge Protection Units (SPU) placed at DLMs, along with Data Link Isolating Transformers (DLITs). The ISPU combines the functions of these two units.

There have been several successive generations of surge protection for SSI, each giving enhanced protection compared with the earlier generation. The most recent standard, Engineering Specification: SSI Trackside Data Link Surge Protection Module GS/ES 1937, defines a plug-in unit to a prescribed 11-pin base design.

Park Signalling's ISPU is the only ISPU with Network Rail approval.

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© Park Signalling Limited 2008