Isolation monitoring relay for ungrounded (IT) networks up to 400 V AC, 50-60 Hz. Measurement range: 1-100 kOhm. Supply voltage: AC/DC 24-240 V. Dimensions: 22.5 mm, with 1 changeover switch and screw connection. This analog adjustable isolation monitoring relay SIRIUS 3UG4 is designed for monitoring ungrounded (IT) networks for insulation faults, particularly in systems with high availability requirements such as the chemical industry, automotive industry, printing presses, maritime and railway applications, or emergency power supplies. It is suitable for worldwide use due to its extensive power supply range and international certifications. The new predictive measurement principle enables extremely fast response times. The relay features permanent self-monitoring and manual testing options, as well as reliable system diagnostics provided through clear fault messages and switchable fault memory. In addition to devices for monitoring ungrounded AC voltage systems, devices for monitoring ungrounded DC and AC voltage systems with screw and spring terminals are also available. SIRIUS relays offer a comprehensive program for all applications.