Siemens 6RA7085-6GV62-0 SIMOREG DC Drive Unit

Module Feature

6RA7085-6GV62-0 belongs to Siemens SIMOREG DC Master series digital DC drive. It uses thyristor bridge structure and supports 4-quadrant reversible operation, enabling motor forward/reverse rotation and regenerative braking. It integrates armature and field rectifier, built-in current, speed and voltage closed-loop control. The freely programmable function blocks allow custom logic, limit protection and signal interlock. Communication interfaces include USS, Profibus (with optional CBP2 board). This model is widely used for rolling mills, extruders, wire drawing machines, cranes and paper machine DC drives. This series is obsolete.

Working principle

The digital control board samples line voltage, armature current and field current continuously. The firing angle of thyristors is adjusted according to speed setpoint and feedback signal. It maintains stable motor speed under varying load. When regenerative condition occurs, power is fed back to AC grid. It triggers fault shutdown when overcurrent, overvoltage, overtemperature or field loss is detected.

Onboard components

Thyristor power stack, cooling fan, current/voltage sensing transformer, digital control mainboard, field rectifier unit, pulse trigger circuit, terminal block for power and signal, optional communication card slot.

LED indicators

Front panel LEDs indicate power, run status, fault and alarm.

Hardware self‑diagnosis

Power-on and continuous self-check detects fan failure, over-temperature, phase loss, armature overcurrent, field loss, thyristor fault and communication failure, and displays fault codes.

Programming software

Siemens DriveMonitor, used for parameter setting, optimization, fault trace and backup.

Electrical & Process Parameters

Model:6RA7085-6GV62-0 Brand:Siemens Device type:Digital 4-quadrant DC Converter Function:Closed-loop speed and torque control for DC motors

Mechanical & Structure

Mounting:Cabinet rack installation Protection class:IP20 Housing:Metal enclosed drive frame

Environmental

Operating temperature:0℃ ~ +45℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing Certification:CE compliant Status:Siemens original DC drive spare, obsolete type

Installation

Mount in well-ventilated cabinet, separate power wiring and control wiring. Set motor nameplate parameters, perform current loop and speed loop optimization. Check fan and heatsink regularly.

Interface

AC power terminals, DC armature terminals, field winding terminals, analog/digital I/O terminals, serial communication port, panel operator interface.

Diagnostic

F001 overcurrent: Motor short circuit, cable fault, wrong current limit setting. F004 field loss: Field circuit open, field fuse blown. F030 overtemperature: Fan blocked, heatsink dirty, overload continuous running. No communication: Wrong station address, damaged communication card.

Product BriefSiemens 6RA7085-6GV62-0 SIMOREG DC Master four-quadrant thyristor DC drive, for rolling mill, crane and extruder DC motor speed regulation.