Load Control

Predictive Load Control – Financial Sector

Medium Application Complexity

The requirement was for a control system that would, during times of power failure, disconnect non-essential loads to a level at which the generators could be safely started. Once generator supplies had been established a load take up routine would operate which would continuously monitor the load on the generator. Excessive generator load would result in shedding of low priority loads. If the generator was running below capacity suitable loads would be connected in stages. An algorithm was created to prevent load hunting and excessive operation of breakers.

The facility used a PLC system and a distributed i/o system networked across the building. A central SCADA system was supplied to provide status and configuration information. The user interface provided a means where the load shedding and take-up behaviour of the system could be customised to changes that naturally occur during the life of a building.

The system is backed up using a UPS system and is immune to normal power outages.

To ensure quick commissioning and minimised disruption a simulation of the entire system was demonstrated to representatives of the building owners, tenants and major contractors.

Supported PLCs

Dynamic Load Control – Emergency Care

Medium High Application Complexity

During times when the hospital is being supplied from five emergency standby generators the PLC controlled LV Transfer System controls the connection and disconnection of non-critical loads to ensure the critical loads of the hospital are protected.

The order of None Critical load Connection / Disconnection is determined by a load priority lookup table and available Generator Load

Supported PLCs