SIMOREG 6RA70 Siemens DC Master – Variable Speed DC Drive

SIMOREG 6RA70 DC Drive Controller complete: (Digital Type)
  • Designed to meet the requirements of NEMA, IEEE, NEC, UL Listed and CSA
  • 6 Pulse SCR (Silicon Controlled Rectifier) Bridge, 1 quad or 4 quad
  • Microprocessor Control Board with 16 bit 38 Mhz high performance multi-tasking microprocessor
  • User interface keypad and digital display
  • Power and interface control board
  • Individual pulse transformers per SCR (comb fire VA rating)
  • R/C snubbers across each SCR
  • Current transformers for current regulator feedback
  • Run/Ready light
  • Plug-in wiring harness between boards
  • Shunt field excitation circuitry with field current loss protection and field economizing (if required for motor heating, programmable)
  • Terminal blocks for incoming/outgoing wiring connections
  • High speed AC Silicon SCR rated power fuses
  • 115VAC phase non-critical control power transformer
  • Power supply transformer
  • Digitally fired burst type SCR gate pulses
  • 1600PIV rated thyristors are standard
  • Built-in A/D converter accepts external reference sources
  • Digital and analog tachometer generator feedback or Voltage feedback speed loop selection
  • Serial communication via RS232 or RS485 serial ports
  • General purpose P-I-D loop for additional regulation modes
  • Freely programmable blocks for mathematical functions
  • Software programming package to aid in start up
  • Peer to Peer Link
  • Tachometer to Voltage Feedback switching
  • Four layer parameter
  • 5 Binary and analog outputs
  • Priority access code protection
  • Minimum speed
  • Maximum speed
  • Linear acceleration
  • Linear deceleration
  • S-Curve rounding
  • Jog and thread speed presets
  • Current Limit
  • Tapered current limit
  • IR compensation for voltage feedback drive application
  • Motor armature current rating
  • Motor field current rating
  • Self turning routine automatically adjust each SIMOREG drive controller to optimum performance matching to motor malfunctions
  • Motor Over speed
  • CEMF crossover voltage (for field weakened speed ranges)
  • Overspeed
  • Field current loss
  • 12t motor overload
  • Instantaneous overcurrent
  • Line tolerance monitoring
  • Phase sequence monitoring
  • Phase loss
  • dv/dt Protection on the SCR’s
  • SCR type high speed AC line fuses
  • DC output fuse on regenerative units
  • Heat sink thermostat
  • Isolated electronics


There are more than 120 diagnostic messages for troubleshooting, including fault and warning indication and memory retention of the last four faults. Some of the diagnostics include:

  • Line voltage out of tolerance
  • Line frequency unstable/out of tolerance
  • Phase loss
  • Motor stalled
  • SCR failure detection and identification
  • Loss of speed of voltage feedback
  • Current overload
  • EEPROM/Microprocessor
  • Quick Stop
  • 8 Channel data storage
Standard LCD Display includes:
  • Speed reference
  • Operating speed
  • Current reference
  • Actual speed
  • Gating angle
  • CEMF
  • Armature voltage
  • CEMF/Speed
  • RMS AC phase to phase voltage
  • All parameter set points (1-941 as apply)
  • Torque direction
  • Operating time
  • Field current reference/field current actual
6RA70 dc speed regulator

SIMOREG 6RA70 Converters

SIMOREG 6RA70 converters
are fully digital, compact units for connection to a three-phase AC supply. They in turn supply. the armature and field of variable-speed DC motors. The range of rated DC currents extends from 15 A to 1680 A in the modular design. Higher HP designs are also available from 2700 A to 14500 A.SIMOREG 6RA70, 15A Base Drive Panel.

Converters for single-quadrant or four-quadrant operation are available to suit individual applications. As the converters feature an integrated parameterization panel, they are autonomous and do not require any additional parameterization equipment. All open-loop and closed-loop control tasks as well as monitoring and auxiliary functions are performed by a microprocessor system.

SIMOREG 6RA70 converters are characterized by their compact, space-saving design. An electronics box containing the closed-loop control board is mounted in the converter door. This box also has space to hold additional boards for processrelated expansion functions and serial interfaces. This design makes them especially easy to service since individual components are easily accessible.

External signals (binary inputs/ outputs, analog inputs/outputs, pulse encoders, etc.) are connected by way of plug-in terminals. The converter software is stored in a flash EPROM. Software upgrades can easily be loaded via the serial interface of the basic unit.SIMOREG 6RA70, 1660 A Power Module.

Customer Preference

For the purpose of versatility and selection the SIMOREG 6RA70 is available in the base drive and power module offering. The base drive panel designs consist of the power module mounted on a base panel with the addition of line fuses, control transformer, and contactor. The base drive panel designs allows for easy customer connection of the power cables to the supplied connection points mounted on top of the assembly.

US overload rating 

The converters listed in this guide contain a US rating allowing a 150 % overload for 60 seconds. All base drive components have been selected based on this rating.

CoolingSIMOREG 6RA70, 30 A Converter, open door view.

Converters with rated DC cur rents up to 100 A are selfcooled, while converters with rated DC currents of 140 A and higher have forced-air cooling (fan assembly).

Base Drive Description

Series 6RA70 SIMOREG DC MASTER (Siemens 4th Generation DC Drive) base drive converters are complete drive assemblies ready to be installed and operated. They include a 3-phase armature converter, single-phase field converter, main contactor, protective semiconductor fuses, control power transformer, and power / control terminals.

Base drive converters are fully digital, compact units which supply the armature and field of variable speed DC drives with rated armature currents from 15A to 1660A. The motor field circuit can be supplied with DC currents of up to 40A (current levels depend on the armature rated current).

General Information

Series 6RA70 SIMOREG DC MASTER converters are characterized by their compact, space-saving construction. Their compact design makes them particularly easy to service and maintain since individual components are readily accessible. The electronics box contains the basic electronic circuitry as well as any supplementary option boards.

All SIMOREG DC MASTER units are equipped with a PMU simple operator panel mounted in the converter door. The panel consists of a five-digit, seven-segment display, three LED’s as status indicators and three parameterization keys. The PMU also features connector X300 with an USS interface in accordance with the RS232 or RS485 standard. The panel provides all the facilities for making adjustments or settings and displaying measured values required to start-up the converter.

The OP1 S optional converter operator panel can be mounted directly in the converter door or externally, e.g., in the cubicle door. When mounted remotely, the OP1 S can be connected to the converter with cables up to 5 meters (15 feet) length. Cable up to 200 meter (600 feet) in length can be used if a separate 5 VDC power supply is available. The OP1 S connects to the SIMOREG through connector X300 using the RS485 interface. The OP1 S can be installed as an economic alternative to conventional door mounted metering devices (Le., voltmeters, ammeters, and speed indicator).

The OP1 S features a liquid crystal display with 4 x 16 characters for displaying parameter names in plain text. English, German, French, Spanish and Italian can be selected as the display languages. In addition the OP1 S can store parameter sets for easy downloading to other drives.

The converter can also be parameterized on a standard PC with appropriate software connected to the serial interface on the basic unit. This PC interface is used during start-up, for maintenance during shutdown and for diagnosis in operation. Furthermore, converter software upgrades can be loaded through this interface for storage in flash memory.

On single-quadrant converters, a fully controlled three-phase bridge supplies the armature. On four-quadrant converters, two fully controlled three-phase bridges are connected in an inverse-parallel connection to allow both positive and negative armature current. For the field converter, a single-phase, half-controlled 2-pulse bridge supplies the motor shunt field.

The armature and field converters can operate with AC line frequencies from 45 to 65 Hz. If required for a specific application, the frequency of the armature and field AC supplies can be different. The armature converter 3 phase AC supply is phase insensitive however on base drives rated 1180 and 1660 amperes, the 3 phase cooling fan must be connected to get the proper direction of rotation. The power section cooling system is monitored by means of temperature sensors.

The power section for the armature and field converters is constructed of isolated thyristor modules for converters rated from 15A to 850A at 460V AG-line voltage. The heat sink in this case is electrically isolated and at ground potential. On converters rated 1180 and 1660 amperes at 460 VAC, the power section for the armature circuit is constructed using disk thyristors and the heat sinks are at line voltage potential. The housing and terminal covers on power connections provide protection against accidental contact for operators working in the vicinity. All connecting terminals are accessible from the front.

All open and closed-loop drive control and communication functions are performed by two powerful microprocessors. Drive control functions are implemented in the software as program modules that can be “wired up” and changed by parameters.

Rated DC Current:

The rating plate of the converter module has 3 rated currents listed on it. The first two are IEG ratings and have no bearing on the base drive rating. The third rating is the US (NEMA) rating which the base drive rating is derived from.

The US (NEMA) rated current allows operation at rated current followed by an overload of 150% for 60 seconds in a 45°G ambient. The overload can be applied no sooner than every 10 minutes. Base drives are designed using the US rating which means that fuses, contactors, and terminal blocks are sized for the rated US (NEMA) current.

The IEG class I rating is the maximum current the power module can supply continuously with no overload. Because an overload is not possible the class I rated current is higher than the US rating. The IEG class I rating cannot be used with base drives because the base drive fuses, contactors, and terminal blocks will be overloaded.

The microprocessor calculates the current 12t value of the power section cyclically to ensure that the thyristors are not damaged in overload operation.

Base Drive Catalog Numbers

(Amps DC)
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