Drives and Controls Magazine
VSDs are ‘first with on-board corrosive gas detection’
Published:  09 November, 2020

Mitsubishi Electric has released a new generation of variable-speed drives which, it claims, are the first to incorporate internal detection of corrosive gases which, combined with AI (artificial intelligence) functions, will extend their operating lives and reduce downtime. The compact FR-E800 drives also have built-in support for multiple networks – including CC-Link IE TSN (Time Sensitive Networking), Ethernet/IP, Profinet and Modbus TCP/IP – without needing costly option cards.

The drives, first announced in Japan last year and now available in Europe and North America, initially cover ratings from 0.1–7.5kW and will be extended within a few months up to 22kW. They have autotuning functions not only for standard induction motors, but also for surface and interior permanent magnet motors (SPMs and IPMs) and, in the future, for synchronous reluctance motors as well, reducing the need for users to stock spares.

The drives can be incorporated into SIL3 PLe, Cat 3 safety systems and have built-in STO, SS1, SBC and SSM safety functions. Also built in is a 2,000-step PLC which avoids the need for an external controller and allows several VSDs to be controlled by a single master. It also helps to shorten set-up times, with an entire system being set up via the master.

There are two Ethernet ports which support line, ring and star topologies. The bookshelf-format drives can be mounted side-by-side, without gaps.

The corrosive gas detection system can identify the presence of any corrosive gases, including hydrogen sulphide, allowing operators to improve the drives’ operating environment, thus extending their lives. The system uses tiny (1.6 x 0.8mm) PCB-mounting sensors incorporating thin metal films, which rely on the fact that corrosive gases cause metals to rust, increasing their electrical resistance. Mounting several of these sensors on a drive PCB and monitoring their resistance allows the presence and progress of any corrosion to be detected without needing external sensors, and remedial actions to be undertaken before the drive fails.

Mitsubishi’s FR-E800 compact VSDs support several different communications technologies, including TSN, as standard and have advanced condition-monitoring capabilities

AI-based predictive maintenance functions also analyse the remining lifetimes of critical components such as capacitors, relays, cooling fans and in-rush current-limiting sensors, allowing troubleshooting without needing expert knowledge, and helping to cut downtime. The fans and capacitors have ten-year design lives.

Android and iOS apps are available to set drive parameters and monitor their performance. A QR code on the front of each drive takes users to a dedicated Web site where they can find manuals, FAQs and set-up instructions.

The FR-E800 drives – which supersede the earlier FR-E700 series, with no increase in price – will build into range of about 120 models. Mitsubishi, which claims to be the world’s largest producer of VSDs by volume, expects to sell around 850,000 of them in 2021.

Miniature sensors on the drives’ PCB (shown by red lines) check continuously for the presence of corrosive gases that could damage the circuitry