Application Story

The Easy Answer to Marquee Maintenance

[montage: easy unit and marquee cleaning] When Havencrown, the UK's leading developer and supplier of marquee washing systems, decided to expand its range by producing a new fully automatic twin-tank machine, it found that an Easy intelligent relay from Moeller Electric provided a flexible and cost-effective basis for the new machine's control system.

Havencrown has been making marquee washing machines since 1995, and the company has always used Moeller Electric components in its products. The new HN5000TT is, however, the company's first fully automatic machine and, as such, it required a more sophisticated control system than the earlier machines. A solution based on conventional relays and timers would have been possible, but when Colin Bonney, Moeller Electric's sales engineer, was told about the application, he suggested the use of an Easy700 series intelligent relay.

Easy relays are low-cost compact units that can be readily programmed to perform a range of simple control functions. With most models, programming facilities are built-in making the units completely self contained. The programming language uses straightforward ladder logic, making Easy relays attractive for users who are more familiar with control systems based on conventional relays.

"The Easy relay was just what we needed," said Richard Bonham-Christie, a director of Havencrown. "It eliminated the need for a substantial number of relays and timers along with their associated wiring, which saved us a considerable amount of money, and its compact size also meant that we could use a smaller control panel. This saved us more money, and the smaller panel was easier to accommodate on the machine."

Another important benefit which resulted from the use of the Easy relay was the simplicity of making changes to the control sequence and process timings. This was particularly useful with the first machine, as it allowed its operation to be fine tuned and optimised quickly, without the costly and inconvenient rewiring which would have been needed with ordinary relays.

"We are washing machine experts, rather than control system specialists," said Richard Bonham-Christie, "and this was the first time that we had used any kind of programmable control device. Nevertheless, thanks to the excellent support provided by Moeller Electric and, in particular, by Colin Bonney, we had no problems whatsoever."

Three of the new HN5000TT machines are now in service, with a fourth under construction. In addition to Easy relays, all of the machines make extensive use of other Moeller Electric products, including star-delta and direct-on-line starters, pushbuttons, rotary switches and power supplies.

"Moeller Electric products are readily available, competitively priced and dependable. In addition, by buying equipment from a single manufacturer, we're always sure of compatibility," said Richard Bonham-Christie. "Add to that the excellent support we get from the company, and you can see that we have every reason to be a very happy customer!"

It's versatile control system means that Havencrown's new HN5000TT machine offers greatly enhanced levels of convenience and performance for its users. Unlike most other machines of its type, the HN5000TT does not simply give the marquee covers a quick spray with detergent followed by a scrub. Instead, it immerses the dirty covers in a tank of detergent solution for up to a minute, giving the solution the time it needs to work effectively. To further enhance the cleaning process, the solution is heated to an accurately controlled temperature. When the washing period is complete, the cover is transferred to a second tank for rinsing. This arrangement means that the detergent solution is retained, and can be re-used several times before it needs to be replaced. This helps to minimise operating costs.

After rinsing in the second tank, the covers receive a final spray rinse, and then pass through brushes which remove most of the excess water. The last step of the process is drying with air knives to remove any remaining moisture.

The washing, rinsing and drying sequence is fully automatic, with all steps controlled by the Moeller Electric Easy700 series relay. The HN5000TT machine can process a 50 metre cover, dry-to-dry, in less than 30 minutes.

This page last updated: 5 May 2006