In technical rooms and maintenance facilities DOLD covers two things: supply monitoring and the safety circuits of workstations. The MK 9300N multifunction measuring relay supervises the supply of switchboards and generator sets - phase sequence and phase failure, asymmetry, voltage, current, frequency and power factor - in one module configured from a menu, which replaces a set of single-function relays.
Rolling stock maintenance stands, platforms, gates and drives in halls require emergency stop and guard monitoring. The UF 6925 module handles buttons and guard switches on two channels with outputs on forcibly guided contacts, and the SAFEMASTER W wireless system (UH 6900 module, RE 6900 handheld transmitter) carries the emergency stop over radio between the moving and the stationary part of a stand. DOLD has references in Germany in securing entrances and guards in rolling stock maintenance halls with the SAFEMASTER STS safety switch and key transfer system, described in the material on the brand page.
The safety circuit design follows the risk assessment to EN ISO 13849-1; the datasheets give Category 4 / PL e and SIL 3 for the modules, and the complete system is validated according to EN ISO 13849-2.
The supply of switchboards is also supervised by the RN 9877 phase monitor without auxiliary voltage and the UG 9400 measuring relay, which presents measurements and alarms on Modbus RTU to the supervisory system; standby batteries are supervised by the UH 9830 symmetry monitor.
