How do you choose a drive for an application in the food industry?
There's no one drive that covers all eventualities, but go for well
engineered products with proven track records in the industry and
suppliers that are going to stand by you after the sale has been finalised
The UK's food and beverage industry is one sector that has seen continued
growth in the last few years and has seen restructuring and realigning to
improve volume, lower costs and enhance profits. This has meant continued
capital investment in improved processes to reduce costs and improve
quality and consistency and, with the Climate Change Levy starting to
bite, many companies have looked to variable speed drives to reduce their
energy consumption
Within these industries the individual applications are many - mixers,
bottling plants, conveyors, mincing and chopping machines, extruders,
compressors, palletisers and refrigeration plants as well as fans and
pumps. All of these applications require motor control, preferably a
variable frequency drive, ac or dc, open or closed loop control and
stand-alone or as part of a factory-wide integrated control system. So,
how to choose the drive?
The selection may be made for you if there is a company-specified drives
supplier but, if not, how do you select the right one for the job? The
answer is, of course, that there is no one drive that will perform the
required function. But looking at the overall picture, taking into
consideration lifetime costs, continuity of support and spares supply and
future production changes that are not even on the horizon, then other
factors come into play.
It is rare that an industrial drive stands alone in an application. In
the majority of cases, drives are part of a system. As such, it is
necessary for the parts of the system to communicate with one another,
transmitting commands and/or data. This communication can be in many
forms, from traditional analogue signals, through to wireless
communication systems. The drives industry has been working hard to
produce lower cost, higher performance drives, with good flexible and
dynamic interfaces to other industrial products such as PLCs, HMIs etc.
Other suppliers have taken a more holistic view of the needs of their
customers, moving from a component supply situation to a solution
provider.
Drives are but a part of the electrical system within a typical machine,
yet the way machines have been controlled has been heavily influenced in
recent years by the growing capabilities of drives. Traditionally,
systems have been controlled by powerful centralised controllers at the
process level. But as the cost of PLCs has come down, control has been
distributed to the machine level. However, the real threat to PLCs in
this role is coming from drives, which have processing power to spare,
and, importantly, direct contact with most of the critical variables of
the system, thereby offering new opportunities in terms of optimised
control.
Electrical variable speed drives are used for many and varied
applications in the food and beverage industry. Flexibility in
connectivity and on-board 'intelligence' has been shown to offer systems
designers and end customers significant advantages in performance, cost
and reliability. There is no single answer to any application solution.
The applications engineer, who understands the application better than
anyone, is in the best position to decide on the structure of the
solution.
Wherever there is a requirement for hygienic wash-down or where there is
a high level of dust such as in dry foods processing or packaging, a
protective cabinet for a drive adds enormously to the total cost of the
installation. This is the market for drives that have IP66 ingress
protection, which can be mounted direct to wall or 'next to motor',
giving significant savings in cabling, cabinet and installation labour
costs.
Drives from