Siemens has launched a new generation of line monitoring relays. Particularly, the SIRIUS 3UG5 line monitoring relays combine proven technology with new functions and applications.

The relays provide the easiest way to monitor standards-compliant grid stability and quality, ensuring proper system operation and a long service life of components such as motors or compressors. Grid monitoring relays are essential in industries that require high-quality and fail-safe supply of power.

Operates Over Wider Frequency Range

The new SIRIUS 3UG5 line monitoring relays from Siemens provide maximum protection for mobile machinery and equipment or in the event of unstable grids. Most importantly, they ensure detection of grid and voltage faults at an early stage before major subsequent damage occurs.

Furthermore, they can record creeping changes that indicate a need for maintenance, for example. In order to react flexibly to short-term disturbances such as voltage dips or load changes, the monitoring relays have adjustable delay times.

This avoids unnecessary alarms and shutdowns while increasing system availability. Depending on the variant, the relays monitor phase sequence, phase failure with or without monitoring of the neutral wire. Moreover, it also monitors frequency, phase asymmetry as well as undervoltage or overvoltage. The 3UG5618 relay also offers automatic correction of the direction of rotation.

Compared to the industry standard, the new SIRIUS 3UG5 series can operate over a significantly wider frequency range – from 15 to 70 Hertz (Hz). Thus, covering worldwide applications (e.g., 50 Hz in Europe and 60 Hz in the US).

For unstable grids, it is also possible to specify the frequency to be monitored. This extends the range of possible applications.

In addition, the devices can work behind frequency converters. Thus, it is possible to monitor railroad grids with frequencies of 16 2/3 Hz.

Suits Various Industry Standards

The IO-Link open communication standard enables the transmission and evaluation of measured values and trends in the controller or in higher-level systems. IO-Link devices can be parameterized from a PC via the TIA portal. By saving the parameters, it automatically parameterize replaced devices.

The SIRIUS 3UG5 line monitoring relays have functional safety certification in accordance with the SIL 1 (IEC 62061) and PL c (EN ISO 13849-1) standards. Thus, they are suitable for use in a wide range of applications. Demand continues to rise for safety-certified components and systems that meet high quality and reliability requirements. For example, for rail applications and power generation.

Thanks to an extended measurable voltage range up to a nominal line voltage of 690 V and a reduced variance, the relays can monitor the operation of generators, for example in wind turbines. This simplifies order selection for global use and reduces inventory costs.

A new housing with four operating buttons, a multicolor display and a teaching function allow for easy operation and parameterization without special prior training. The display, which can be powered off, provides energy savings of up to 20 percent.