North Building Technologies

Mechanical Maintenance Inc have completed their first integration project using North equipment. MMI, based in a Phoenix, AZ, is a well-established national h&v controls and integration engineering organisation, providing solutions all over the US. MMI have committed to providing integration solutions based on the North range, augmenting their existing experience with Trend and Novar h&v controls.

Background

The construction of Toltec school in Arizona City was completed early in 2002. With nearly 600 students, a floor area of around 70,000 ft² and positioned in the Arizona desert, accurate, reliable and co-ordinated use of heating and ventilation was a vital pre-requisite. A Trend IQ h&v control system takes care of air conditioning and central plant, such as pumps, but two York Millennium YCAS Air Cooled Screw chillers had been specified which were to be commissioned complete with their own in-built, Modbus-compatible control system.

Modbus everywhere

MMI selected the North Compass product to make the serial link between the Trend h&v controls and the chiller control system. Vital data such as start/stop signals, fault alarms, compressor current and control setpoints are passed between one system and the other, with MMI having the freedom to engineer which values are transferred where, and at what rates. Since the Compass product was being used for the chiller controls, it became a logical progression to use the same interface to link into the on-site ABB model ACH 400 Variable Speed Drives, which were again factory-fitted with Modbus-compatible support. Values such as current, RPM and frequency enhanced the information that would normally be read from the drives. Quite apart from this flexibility, MMI were delighted with the ease of set-up of the Compass system. Dave Snowdon, Technical Support Manager for Novar at MMI, said :

"It took just an hour from installation to the full commissioning of this interface. We were also extremely pleased with the support from North - they provided us with Modbus register files for ObSys which enabled the job to go incredibly smoothly. We have big plans for the whole North range, and we can see huge potential for integration nationwide."

PRODUCTS

CP/TRENDIQ/RS232 Compass Point for Trend h&v control system
CP/JBUS/RS232 Compass Point for Modbus/JBus-compatible system

Search the North e-Library for more information and technical documentation on the Modbus & JBus interface.

INSTALLATION & ENGINEERING

MECHANICAL MAINTENANCE INC
304 North Delaware Street
Chandler
AZ 85225-1131
USA

Tel: +1 480 497 1100
Fax: +1 480 497 8333
Web: www.mmi-az.com

Contact: Richard French
Email: rfrench@mmi-az.com

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