Siemens Automation and Drives (A&D) is enhancing its Sirius family of 3UG4 products with three new relays for level, speed and residual-current monitoring.
With the level monitoring relay, users can monitor liquids in combination with one-, two- or three-pole probes. Users can therefore react in good time before containers overflow or pumps run dry, or when leakages occur.
The new Sirius speed monitoring relay ensures that motors are used efficiently. Operating via external sensors, it measures the time a motor or a driven wheel needs for one revolution and responds accordingly if the speed exceeds or falls below the limits previously set. Speed monitoring relays are used, for example, for overload protection when bearings seize, belt slippage occurs or in the event of load shedding when a belt breaks.
The residual-current monitoring relay, used in conjunction with a 3UL22 summation current transformer, protects and monitors plant. Residual-current monitoring relays are primarily used where, for example, insulation problems occur frequently due to humidity, contamination or cable damage. Due to freely selectable warning and disconnection thresholds, the monitoring relay draws attention to impending insulation problems before switching off equipment in order to protect the plant when a critical value is exceeded.
All versions of the 3UG4 Sirius monitoring relays are available in a slim design only 22.5mm wide. They feature removable screw-type or spring-loaded terminals. A display and three function buttons enable easy parameterisation of the speed and fault-current monitoring relays. In addition, the display allows the latest measured values and the exact monitoring status to be shown continuously, and it also enables rapid diagnosis in the event of a plant fault.