ICS adds value to Bow Bells control systems
ICS control strategy contributes to energy-efficiency targets of Bow Bells development.
There are no centralised motor-control panels in Stanhope’s recently completed £55 million Bow Bells development in London’s Cheapside. Instead, the structure and specification for the highly intelligent control in this 20 000 m2 development called for extensive localised control of variable-speed drives. The installation of the systems to control the plant and achieve the objective of exceeding the requirements of Part L by more than 20% was carried out by Integrated Control Systems in a £650 000 contract awarded by Bovis Lend Lease. ICS interfaced with plant power centres, the large LV switchboards provided by electrical contractors who undertook power wiring to the variable-speed drives or other packaged pieces of equipment. ICS carried out all secondary wiring from the VSDs to the various devices they served and interfaced them with the building-management system. In the absence of traditional panels, ICS built 25 distributed BMS plant controls enclosures dedicated to specific equipment or plant, normally determined by their location in the building. These enclosures control equipment such as boilers, pumps, chilled-water plant and air-handling units. They also monitor passenger lifts, smoke-extract systems, public health amenities, landlord and tenant switches etc. To cater for a possible dual tenancy of the building, two enclosures on each of the seven floors have a cat 5 interface offering the facilities to connect Tridium Java Application Control Engine (JACE) communications controllers/routers to constant-volume boxes and the 64 fan coils on each floor. The JACE provides the management-level platform and uses a LON interface to connect to the constant-volume boxes and fan-coil units, a separate ModBus connection to a series of electricity and all other metering operations and BACnet communications with the variable-speed dries. John Reid, managing director of ICS, says, ‘The initial specification was for an infrastructure to meet all HVAC requirement. We have provided added value by enabling landlords and tenants to connect their own metering systems into our infrastructure rather than using additional dedicated systems.’ Further value was added by using the ICS installation to support the automatic blind system, siting the Somfy controls package on the same PC as the BMS and wiring in the motor controllers connected to the blinds and associated control sensors Lighting systems could be similarly treated using the Dali lighting-control protocol. The distributed BMS system minimises wiring by placing controllers next to the equipment they serve and dispenses with some of the traditional features of a standard motor-control panel by using a BACnet link to monitor operating parameters, status etc. The variable-speed drives are an extension of the BMS and are effectively a controller node.
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