Updated HVAC plant boosts carbon initiative to reduce energy usage

Paul Boughton
With responsibility for the service, maintenance and repair of the boiler plant in 88 BUPA care homes throughout London and the South East, heating and building services contractors Kestrel Mechanical has started an energy-saving programme to update their boiler rooms. 

In designing the HVAC control system, Kestrel has chosen Schneider Electric’s TeSys U motor starter controllers for all the pumps and motors.
The scheme to update the HVAC plant is in line with Bupa’s carbon initiative designed to reduce energy usage under the carbon levy scheme, which encourages businesses to reduce emissions by adding an energy tax on energy bills.  The key requirement for the system is remote management, which will enable all of the HVAC installations to be monitored and controlled at Bupa’s central support office in Leeds.
Engineer Oliver Ringrose of Kestrel, who had not previously used the TeSys model U range, explains:  “We are using Honeywell Hawk controllers on a Modbus network to integrate the HVAC systems and were looking for a quick-fit solution capable of being connected onto a Modbus network for the motor controllers.  It was our Honeywell contact, who had experience of the TeSys U starters in an industrial automation application, who recommended them and they have delivered everything we were looking for.”
Use of the TeSys U connected to the HVAC system enables the state of the motor starters to be constantly monitored by indicating motor load and whether they are on, off or tripped.  It means that Bupa can ensure that the plant in each of its homes is operating to pre-determined parameters, identifying unnecessary usage or unauthorised changes to manual operation.  By being able to remotely monitor individual usage in this way, Bupa can more effectively manage its energy consumption on a site-by-site basis.
Oliver Ringrose has overall responsibility for designing and building the panels and for him TeSys U offers a number of advantages. He explains: “As the whole project is driven by Bupa’s requirement for energy conservation, it was important to ensure proper control and these are the only starters on the market that cannot be linked out, i.e. the thermal overload protection function cannot be disabled.  From the design point of view, they are very compact and their construction enables us to reduce the number of input/output devices.  Basically, we have less kit to fit into the panel and so can do a lot more in the same space.”
Speed of assembly and wiring is a key feature of the TeSys U starters.  They are fully integrated devices which combine switching, isolation and protection functions in a single compact unit.  Suitable for rapid mounting on DIN rail, they require power connections only to the supply and the motor, greatly reducing the amount of wiring needed compared with conventional starters.  The flexibility of the TeSys U range means that late design changes (such as a motor size change) can be accommodated by simply plugging-in a replacement module such as an overload.  With open connectivity TeSys U supports leading industry protocols including Modbus, Profibus, DeviceNet and CANopen.
The remote monitoring capabilities of the installed systems also offer advantages to Kestrel Mechanical in their day-to-day operations maintaining the boiler rooms. 

Oliver Ringrose says:  “Because we can monitor the state of the motor controls, if a problem does arrive we can carry out a lot of diagnostics before we go to site. That means we are sending the right people and can quickly rectify any fault.”
For more information, visit www.schneider-electric.co.uk