THBBU 400 relay – Priority, delay on pull-in


The THBBU 400 is a pull-in and drop-out relay which can be directly pull-in by “0V” on d3 pin. This command is priority on relay pull-in. It is equipped with 4 double make / double break C/O contacts (form Z). The relay is fully programmable with a dip switch for time setting. The access to dip switch is available by removing time delay cover. This feature prohibits frivolous field time delay setting. Function can be also be factory set on order.
The plug-in design offers secure locking feature for maximum ease of maintenance (no wires need to be disconnected or other hardware removed for relay inspection or replacement). The resistance to impact and vibration is conform to standards in force for Railway Transported Equipment.
Positive mechanical keying of relay to socket is built into relay and socket during manufacture and terminal identifications are clearly marked on identification plate that is permanently attached to the relay.
The THBBU 400 relay is pluggable in the following sockets: EA 102 B, EA 102 BF, EA 103 BF, EA 104 B, EA 104 BF, EA 105 BF, EA 112 BF.


The THBBU 400 timing relay is designed for heavy duty applications with timing function used for example in HVAC and lighting.


  • Delay priority delay-on pull-in relay
  • The relay can be direct pull-in by a “0V” on d3 pin. This command is priority on relay pull-in
  • Time delay programmable by dip switch from 0.25 s to 63.75 min
  • Status LED indicator
  • Plug-in design with secure locking feature for maximum ease of maintenance
  • 4 double make / double break C/O contacts (form Z), 12 A
  • Weld no transfer contacts standard
  • Contact life (mechanical) of 100 million cycles
  • -40 °C…+85 °C operating temperature


  • Proven reliable in heavy duty application
  • Weld no transfer
  • Long life cycle
  • Accurate timing selection finger safe
  • Easy to maintain and replace
  • Low life cycle cost
  • No maintenance

Railway compliancy

  • NF F 62-002 Rolling stock – Instantaneous relays contacts and sockets
  • NF F 16-101/102 Fire behaviour – Railway rolling stock
  • EN 50155 Railway application – Electronic equipment used on rolling stock
  • IEC 61373 Railway application – shock and vibration tests



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