Solcon HRVS-DN Medium Voltage Soft Starter 2.3-15kV 60-2700A

The Solcon HRVS-DN is a heavy duty medium voltage soft starter for standard medium voltage three-phase squirrel cage induction motors. Output current spans 60 to 2,700 A — from 200 kW up to 50 MW — across all internationally recognised medium voltage ratings: 2.3 kV, 3.3 kV, 4.16 kV, 6 kV, 6.6 kV, 10 kV, 11 kV, 13.8 kV and 15 kV. It replaces fixed-speed direct-on-line starting with step-free, continuously controlled acceleration.

The technology is phase-angle control of SCR (thyristor) devices. By gradually raising motor terminal voltage from a set initial point up to full supply voltage, the HRVS-DN lets you tune starting current and starting torque precisely to the motor and load. The alternative — direct-on-line starting — exposes the motor to surge current up to six times rated current, stressing both the supply and the switchgear, and produces a very high peak torque that loads the motor, the driven machine, V-belts and gearing. Conventional step-reduction methods such as reactors and autotransformers only reduce voltage in discrete steps; the HRVS-DN ramps it continuously. Soft stopping is a standard feature, which is decisive in pumping applications to prevent water hammer and on conveyors where an abrupt stop can damage the load.

The unit is built as a complete engineered assembly, not a bare controller. The standard package is supplied ready-to-connect in a NEMA 12 enclosure (NEMA 3R, 4 and 4X/IP67 available) and includes the digital soft starter with segregated high-voltage and low-voltage compartments, a disconnect switch (load break / fault make, with fuses), line and bypass vacuum contactors, low voltage controls and Modbus RS485 communication as standard, with Profibus and DeviceNet optional. The advanced digital firing system links the low voltage control to the high voltage section through fibre optics, the HV compartment is fully segregated from the LV compartment for safe operation, and individual phase modules can be replaced individually to minimise downtime. Chassis-type OEM kits are available to qualified integrators for building the unit into custom enclosures or switchgear.