Load power supply •• For 24 V DC load circuits, you require a load power supply unit Âwith safety separation. If an AC plug is used as the isolatingdevice, the socket must be in the vicinity of the CC and easilyaccessible (VDE 0805, 1.7.2).•• Unregulated load power supply units require a reservoir capacitorà (rated at 200 μF per 1 A load current). Connect the capacitor inparallel with the output terminals of the load power supply.•• According to DIN VDE 0113, Part 1, control systems with morethan five items of electromagnetic apparatus require isolation by atransformer; according to DIN VDE 0100, Part 725, it isrecommended Ä.Grounding •• Load power supplies should be grounded if possible Å. Provide adetachable connection to the protective conductor at the loadpower supply unit (terminal L- or M) or on the secondary side ofthe isolating transformer.CautionFor ungrounded power supplies, you must provide insulationmonitoring if•• hazardous system states can be caused by double faults;•• there is no safety separation;•• circuits are operated with voltages of more than 120 V DC;•• circuits are operated with voltages of more than 50 V AC.Power Supplies for Programmable Controllers and I/OsSystem Manual3 - 24 C79000-B8576-C199-03
