Single-axis controllers Wiring Devices in the range 2 ... 24 A (0.37 ... 11 kW) 4 4.6 4.6.3 IT system Stop! Overvoltage on components: On IT systems an earth fault in the installation can cause impermissible overvoltages. Possible consequences: Destruction of the device. Protective measures: If the devices are operated on IT systems, the internal connection of the filters to the protective earth in the installation backplane has to be disconnected. According to the relevant EMC product standard EN 61800-3 there are no limit values for noise emission in the high-frequency range. Therefore, the technical data for EMC do not apply.
Proceed as follows to disconnect the internal connection of the filters to the protective earth: 1. Remove the IT insulating cap from its parking position c . – To do so, place a screw driver at the right or left side and lever off the insulating cap. – Alternatively, the insulating cap can be pulled off carefully using an appropriate pair of pliers. 2. Plug the IT insulating cap onto the earthing jumper d until it snaps into place. 1 2 SSP94IT001 Fig. 4.6-2 Plugging the IT insulating cap onto the earthing jumper c Remove the IT insulating cap from its parking position. Place a screw driver at the right or left side and lever off the insulating cap or remove it using pliers.
d Plug the IT insulating cap onto the earthing jumper until it snaps into place. 4.6-9 EDS94SPP101 EN 3.1-04/2007