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Connect and go01 November 2007Wiring takes up a large proportion of any panel build project time, so any innovation that helps to reduce the wiring effort must be welcome. Such was the situation facing panel builder, L.Con, when it decided to take advantage of a novel plug-in link system that virtually quartered the wiring burden on a fast-track projectPresented with exceptionally tight deadlines for the build and commissioning of a control panel for a cooling water process plant, electrical engineering and contracting specialist, L.Con turned to one of its preferred suppliers of panel equipment, Moeller Electric, for help. A regular user of Moeller products, the Hyde, Cheshire based company decided that the xStart motor controlgear range, with its reduced wiring requirements, would help them to complete this fast-track project on time.
A key benefit of xStart motor starters is their tool-less plug connection. Starter components are interconnected via plug-in links, greatly reducing the need for time-consuming wiring. This plug-in arrangement applies not only to ordinary direct-on-line starters, but also to reversing starters, as well as the star-delta units used in this particular project. L.Con managing director, Les Carrington takes up the story:
“The plug-in arrangement used in xStart starters greatly reduced the amount of time we took to wire the panel, which is not surprising when you consider that with a star-delta starter, four plug-in links replace 21 wired connections. That wasn’t the only benefit, however. The starters are fast and easy to mount, as they just clip to the DIN rail, and they’re compact, which allowed us to keep the size and cost of the enclosure to a minimum. The star-delta starters also have an internal mechanical interlock which takes up no extra space and, of course, the plug-in links eliminate wiring errors, which makes for fast, easy testing.” For L.Con, the benefits of xStart’s plug-in system were also apparent onsite, during the commissioning phase of the project.
By unplugging the links between the contactors and the motor protection circuit breakers in the starters, it was possible to check the control sequence by observing the operation of the contactors without applying power to the motors. Removal of the links also provided a quick, easy and safe method of isolating individual motors during commissioning, irrespective of whether or not the motor was fitted with a local isolator.
Other products from Moeller’s automation range were used in this project, including an ‘Easy’ intelligent control relay, which L.Con chose for its versatility and ease of use, and an MFD-Titan HMI unit, which is capable of displaying text messages and graphics, and which interfaces directly to the Easy relay.
For the panel’s main isolating switch, L.Con selected a Moeller Electric NZM circuit breaker, not only for its electrical characteristics, but also because it is available with a door interlock. Easy to install, yet sturdy and dependable, this unit comes with a door-mounted operating handle that is IP65 rated - an essential requirement for this application.
“Using equipment from Moeller Electric, and particularly the xStart starters, played a big part in making it possible for us to build and commission this control panel on time,” recalls Les Carrington. “The end-customer is absolutely delighted, and has even complimented us on the very neat appearance of the interior of the panel - something else which xStart made it easy for us to achieve. We already use Moeller Electric equipment wherever we can, and, after our very positive experience with xStart, this will certainly be our preferred starter for all future projects.”
Pole position
For applications in which a switched neutral is needed, Moeller Electric can now supply its xStart contactor range with four poles. The new DILMP models cover current ratings from 22 to 200A in four frame sizes, and have identical dimensions for ac- and dc-operated versions, thus simplifying panel design and construction.
Suitable for mains/standby changeover, heating control, and distribution systems for IT installations, xStart four-pole contactors, like their three-pole counterparts, have low consumption coil assemblies. This enables units up to 45A to be controlled directly from low current PLC outputs, avoiding the need for interposing relays or the additional cost of high-power output modules.
A range of accessories for use with the new four-pole contactors include mechanical interlocks; auxiliary contacts in standard and early-make/late-break versions; suppressors for ac-operated types; and insulating shrouds. Moeller claims a mechanical life for these contactors of at least 10 million operations. Contact Details and Archive...Most Viewed Articles... |
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