In the vehicle equipment cabinet DOLD serves the control circuits at onboard battery voltage: the HL 3094N interface module multiplies a controller signal onto forcibly guided contacts and separates the control circuit from the load, the SK 7817N/200 time relay provides delays and switching sequences, and the RN 5897/010 insulation monitor supervises the insulation resistance of the unearthed onboard network and reports an earth fault before a second fault trips the circuit.
The datasheets of these three products refer to EN 50155: the interface module declares a design to the standard with temperature classes T1…TX, the time relay and the insulation monitor give a temperature classification and vibration and shock resistance to EN 61373. For the boards of the vehicle's own electronics modules DOLD offers the OA 5621 and OA 5622 safety relays with forcibly guided contacts in a wash-proof housing, and for heaters and loads with high switching frequencies the POWERSWITCH solid-state switches, including the PK 9265 contactor for DC loads.
Selection starts with the temperature class of the installation location and the battery voltage against the supply range of the product; for the insulation monitor the leakage capacitance of the onboard network, which extends the response time, is checked in addition.
Circuits that must remember their state after a loss of battery voltage - interlocks, fault memories, mode selection - are handled by the UG 8851 latching relay with forcibly guided contacts.
