Distributed frequency inverter for conveyor system applications

The Sinamics G120 series of inverters from Siemens Automation and Drives (A&D) is being expanded with a distributed version with degree of protection IP65. The Sinamics G120D is characterized by its very flat type of construction, a uniform footprint and high degree of uniformity for power outputs from 0,75 to 7.5 kW. The distributed frequency inverter also features integrated safety functions which are outstanding in this power class. The inverter is primarily suitable for conveyor system applications such as those encountered in the automotive industry.

The Sinamics G120D has an especially compact design and, thanks to its flat shape, is easy to mount even in very narrow places. The uniform footprint for all power outputs allows simple replacement and expansion. The large power output range of 0,75 to 7.5 kW covers nearly all requirements in the area of conveying systems. The safety functions which are integrated in the Sinamics G120D and provide encoderless protec-tion for people and machines are unique. They include STO (safety torque off), SS1 (safe stop 1) and SLS (safely limited speed). The functions are activated and deacti-vated by means of the Profisafe protocol.

Thanks to an innovative power-infeed concept, the Sinamics G120D needs only around 80 per cent of the power of comparable frequency inverters. Due to this reduction of the input current by a fifth, less reactive power is needed as well. This helps to reduce the costs of electricity and, at the same time, enables installations to be designed for lower power levels. A line commutating reactor, brake chopper and brake resistor are no longer necessary. The inverter also returns energy to the power supply system during braking with considerable less line harmonic distortion than in the case of standard frequency inverters. There are no additional heat losses.

The new Sinamics G120D inverter is very user-friendly. Commissioning, diagnostics and maintenance are considerably simplified by plug-in connectors and large illuminated displays. Due to the modular design, modules can be replaced easily whenever necessary. This ensures a high level of availability because the power section can be replaced without disconnecting the wiring or fieldbus connection.

Due to the metal housing and degree of protection IP65, the frequency inverter is suitable for rough environments. On the inside, painted electronic modules and convection cooling ensure reliable operation and a long useful life irrespective of the influences of the surroundings. The well protected Micro Memory Card for simple data storage enables rapid cloning and replacement.