HRVS-DN

Medium Voltage Soft Starter for Mission-Critical Motors

Low-voltage (LV) soft starters operate up to 690 V and serve motors up to approximately 1,000 kW. The HRVS-DN is Solcon-IGEL’s medium-voltage (MV) soft starter, designed for systems from 2.3 kV to 13.8 kV and motors from 200 kW up to 50 MW. MV soft starters handle the high-power applications, large compressors, pipeline pumps, mine fans, ship thrusters  where LV equipment is not rated for the system voltage. The HRVS-DN is engineered specifically for these demanding MV environments and carries marine and hazardous area certifications for offshore and process industry installations.

Choose the HRVS-DN when your motor runs at a fixed speed and you need controlled starting and stopping, without the cost or complexity of continuous variable-speed control. Compared to an equivalent MV VFD, the HRVS-DN costs significantly less, generates less heat during operation (the SCRs are bypassed once the motor reaches full speed), and has fewer power conversion stages, which translates directly to lower long-term failure rates.

For fixed-speed applications, the majority of large pump, fan, and compressor installations in Oil & Gas, Mining, and Power Generation  the HRVS-DN is the correct specification. Choose an MV VFD only when the process genuinely requires variable speed, such as flow control or tension control, or where significant part-load energy savings justify the added cost and maintenance burden.

For fixed-speed applications, yes. The key reason is how each device operates at full speed. Once the HRVS-DN brings a motor up to speed, the bypass contactor closes and the motor runs directly across the MV supply — the SCR stage carries no current and is under no stress. An MV VFD, by contrast, continuously runs its full inverter, DC link capacitors, and rectifier stage at full load, 24/7.

For high-availability installations , offshore platforms, mining critical loads, power station auxiliaries  this distinction matters. Fewer components under continuous stress means fewer failure points and simpler maintenance planning. It’s one of the main reasons engineers in these sectors specify the HRVS-DN over an MV drive for fixed-duty applications.

HRVS-DN sizing is based on the motor’s full-load current (FLC) at the system voltage, not the kW rating alone. The key inputs are: motor FLC (from the nameplate), system voltage (e.g. 6.6 kV, 11 kV), starting duty class (normal or heavy), and required acceleration time. For MV applications, a full system study is recommended — Solcon-IGEL’s MV application team will review transformer impedance, cable parameters, protection coordination, and harmonic impact on the MV bus before confirming the HRVS-DN model and configuration. Contact us to initiate a free sizing review.

Yes. Selected HRVS-DN models include an integrated Ethernet interface that gives you real-time visibility of motor current, voltage, power, start count, fault log, and thermal status that is accessible directly from a browser, SCADA system, or DCS without additional hardware.

For integration with plant-wide control systems, the HRVS-DN supports Modbus RTU, Modbus TCP/IP, Profibus DP, and Profinet via optional plug-in communications cards. This makes it straightforward to connect into existing control architectures across Oil & Gas, Mining, and Power Generation facilities , whether you’re monitoring a single motor or managing a fleet of MV starters across a site.

Remote diagnostic capability is also available under Solcon-IGEL’s extended service agreements. Protocol availability and Ethernet interface options vary by model — contact us to confirm the right configuration for your system.

Yes — all Solcon-IGEL MV soft starters, including the HRVS-DN, are always installed with a dedicated bypass contactor circuit as standard. Once the motor reaches full speed, the bypass contactor closes and the motor runs directly across the MV supply; the SCR stage is de-energised and carries no steady-state current. This is a fundamental design feature of MV soft starters: it protects the SCRs from continuous thermal stress and provides a fail-safe running path in the event of a soft starter fault. The bypass is supplied either as part of the HRVS-DN assembly or as a co-ordinated external MV switchgear package — Solcon-IGEL can provide both.

The HRVS-DN is used across the major MV motor sectors: Oil & Gas (pipeline pumps, gas compressors, water injection pumps, FPSO systems); Mining (conveyor drives, ball mills, SAG mills, mine dewatering pumps, ventilation fans); Power Generation (boiler feed pumps, cooling water pumps, induced/forced draught fans, condensate extraction pumps); Marine & Offshore (main propulsion thrusters, bow thrusters, ballast pumps, fire pumps, winches); and Process Industry (large centrifugal compressors, blowers, extruder drives). The HRVS-DN is available in configurations for both indoor switchroom and outdoor/weatherproof installations.

Yes. The HRVS-DN is available in configurations certified for Zone 2 hazardous areas to ATEX and IECEx standards. The control electronics can be mounted in a safe area with only the power stage in the hazardous zone. For Zone 1 applications, the HRVS-DN is installed in a pressurised or purged enclosure to the relevant ATEX category. For marine projects, the HRVS-DN carries type approval from DNV GL, ABS, Lloyd’s Register (LRS), and Bureau Veritas — the four major classification societies. Contact Solcon-IGEL for the current certifications applicable to your project and to request class-specific documentation.

The HRVS-DN supports medium-voltage systems from 2.3 kV to 13.8 kV, including 3.3 kV, 6.6 kV, 10 kV, and 11 kV — the most common MV distribution voltages in UK, European, and international markets. At 11 kV, the HRVS-DN uses a series SCR stack rated for the full line voltage. Custom voltage ratings beyond 13.8 kV are available on enquiry. Contact the Solcon-IGEL MV application team to confirm the correct model variant and system study requirements for your 11 kV project.

The HRVS-DN range covers motors from 200 kW up to 50 MW. The upper range — used in large mill drives, pipeline compressors, and offshore thrusters — uses paralleled SCR strings and a dedicated bypass circuit to handle the full-load current. For motors above 20 MW, Solcon-IGEL conducts a detailed application study to confirm thermal rating, protection co-ordination, and harmonic impact on the MV bus. Contact us with your motor nameplate data and system single-line diagram to begin.