Production equipment is often built from different basic building blocks, each kind employed at several places in the installation. Examples include various
types of conveyor sections and machinery like mixers, scales, fillers, labellers, palletisers, packaging machines etc.
Illustration 1.5: Centralised cabinet
In a truly modular machine, all basic elements are self-confined and need nothing but electricity, water, compressed air or similar to function.
Modularisation therefore requires the distribution of intelligence to the individual sections and modules.
Sure, centralised installations can be modualarised, but then motor controls will be physically separated from the rest of the module.
Fewer cabinets, cooling and cable trays
Further savings will result from smaller cabinets, less cabinet cooling and fewer cable trays. Motor controls generate heat and are often mounted side by
side due to limited space, as illustrated in illustration 1.5. Forced cooling is therefore required to remove the heat.
Less Commissioning
Time spend commissioning at the end-user is significantly reduced using
decentralised solutions - especially when fieldbus communication is com-
bined with decentralised motor controls.
An Australian brewery has installed a line of 96 decentralised drives from
Danfoss connected by DeviceNet. An excessive amount of time was saved
as the commissioning of the variable speed drives was done in a few days.
The brewery estimates a saving exceeding AUD 100,000 compared to
traditional centralised installation.
Illustration 1.6: Decentralised brewery installation
Minimal Need for Additional Fieldbus Cables
Power cable savings are not offset by the additional cost for expensive fieldbus cables. Fieldbus cables will be extended in a decentralised installation,
but since fieldbus cables will be distributed in the plant anyway to connect sensors or remote I/O-stations, the extension will be limited. Decentralised
products from Danfoss can even be used as remote I/O stations to connect sensors to the fieldbus and reduce direct costs even more.
VLT
®
Decentral FCD 300 Design Guide
1 The Decentral Concept
MG.90.S1.02 - VLT
®
is a registered Danfoss trademark
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