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).
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