Effective Detection of Residual Currents from Siemens Automation
- Published: Friday, 01 March 2013 18:48
The Siemens Industry Automation Division presents a new solution for residual current monitoring in the range from 30 milliamperes (mA) to 40 amperes (A).
The two Sirius 3UG4625 and Sirius 3UG4825 relays for IO-Link have two separate outputs that can be assigned different limit values for a two-phase alarm system involving a warning and subsequent shutdown. The residual currents are measured using the Sirius 3UL23 differential current transformer (also new) in six different sizes that monitors line systems with phase currents up to 630 amperes. The measuring accuracy of the system, including the 3UL23 differential current transformer, is subject to an extremely low deviation of just plus/minus 7.5 percent.
Sirius 3UG4625 and Sirius 3UG4825 for IO-Link detect residual currents that can occur in industrial plants and machines as a result of, for example, inadequate insulation at terminals or on cables, humidity, contamination, or material aging. With the residual current monitoring relays users can define two different limit values within the measuring range. A separate output is available for each of the two values. When the first value is reached, initially a warning is triggered, but when the second value is exceeded, an alarm is triggered via the second output and the monitored line system is interrupted or tripping takes place. While simple monitoring relays immediately issue an alarm or trigger a shutdown when residual currents increase, users here can react early to the warning and avoid unplanned plant standstills thanks to the two-phase limit values.
Sirius 3UG4825 with IO-Link interface can also be connected to a higher-level controller. Via IO-Link, the monitoring relay can be parameterized via the controller, or measured values and diagnostics data can be transferred to higher-level monitoring applications. Both Sirius 3UG4625 and Sirius 3UG4825 for IO-Link are equipped with an LCD that enables simple parameterization, measured value display, and fault diagnostics directly at the device.