Page 6 - Industrial Technology EXTRA 28th September 2020

automation system. It is also possible to access A diagnostics function unique to Mitsubishi
drives wirelessly that might be installed in hard-to- Electric VSDs is H2S contamination monitoring of
reach locations, enabling simple remote monitoring internal components, giving an output to warn of
of the drive and the ability to fine-tune the VSD potential drive failure. This is particularly relevant in
without the need to physically be next to it. any application where there is decaying organic
Increasingly sophisticated diagnostics capability matter such as found in water treatment works or
is extending the capability of VSDs even further, effluent plants.
providing a platform for predictive maintenance. A The VSD can also derive health information
modern VSD such as the Mitsubishi Electric A800 about the load it is driving, comparing the current
series drive has the ability to monitor some of its drawn with the figures recorded during
own internal components, including the cooling fan, commissioning – a representation of the
control circuit capacitor, main circuit capacitor, relationship between speed and torque under
power module and fault contact relay. The VSD normal operating conditions. In a fan application for
monitors operational time and duty cycles and example, an increase in the current drawn might be
warns when these key components are nearing the indicative of a blocked filter or debris build-up on
end of their expected lifespan, giving maintenance the fan blades. Conversely, in a conveyor
engineers the opportunity to replace parts during application, a sudden drop in the current drawn
scheduled downtime and eliminating unexpected could highlight a broken drive belt or trunnion. The
failure. VSD can output different warning signals at preset

September 2020 • INDUSTRIAL TECHNOLOGY EXTRA • p6