Innovative power monitoring technology is being employed by K E Brown (KEB) electrical switchboards. This is to radically expand energy efficiency and systems security for industries with dynamic load capacities, including data processing, green buildings and process and control systems.
The KEB group is using Schneider Electric PowerLogic family H704 series branch circuit monitors to measure the individual current draw of each breaker in a distribution board. The individual current draw of each breaker is better than the collective draw created by boards that may include many dozens of such breakers.
The benefit of this monitoring technology is that switchboard controllers can see exactly how much power individual circuits are drawing. This enables them to achieve
- load-based cost allocation,
- overload protection,
- load management and
- load balancing, for example.
PowerLogic SMS software helps
- minimize energy costs,
- reduce peak demand charges,
- reduce power factor penalties and
- ultimately downtime.
The H704 solid-core Modbus RTU branch circuit monitor updates power usage data about once a second. This helps to safeguard security of data processing and industrial processing operations. This is by determining precisely the level at which current draws in individual circuits should provide alerts to operators and when they should close down an operation to prevent damage. Such fine control also greatly facilitates trouble-shooting in commercial, retail and industrial data control and intelligent building processes.
“One immediate benefit is that the technology enables users to accurately bill clients according to exact usage of power in their sub-circuit, which is a radical improvement” says KEB Operations Manager Peter Silsby. Individual sub-circuits can represent individual clients in data processing applications, for example, or individual building or factory functions in an intelligent building. This helps operations managers target problems and prevent energy waste.
The new KEB technology has already been adopted by telecommunications, computer and retail organisations in Australia. “It is wonderful technology because it is so precise and easy to use. You could even sit at home and monitor outputs on the internet,” said Silsby.
“You can drill down into the system for so much power usage information. Previously one major data processor had 84 circuits on the one board, which is not unusual. Now they can access a wealth of information about exactly what is going on in each individual circuit on that board, which provides both billing accuracy and overload protection. The protection gives great peace of mind to both the system operator and the system user, because integrity of supply is critical in data processing, building and industrial situations,” says Silsby, whose company is involved in design, manufacturing, servicing and ongoing maintenance operations.
Schneider Electric customer service engineer Robert Christensen says the impetus for the switchboard innovation came when a major international computer group drew on KEB’s engineering expertise to find a way to monitor critical final sub-circuits in their datacenters without the need, complexity and expense of using one meter per circuit.
“KEB build a wide range of switchboards for contractors and end-users throughout Australia and sought a product to complement the PM850MG range of PowerLogic meters already selected as the computer group’s preferred meter for critical databases. Because of the engineering expertise at KEB – and their ongoing relationship with Schneider Electric – it was an easier process to integrate another member of the PowerLogic range into the solution provided. Instead of using a power meter per circuit, the PowerLogic Branch Current Monitor was selected to monitor 42 critical circuits in real time and to communicate selected load and alarm setpoints via MODBUS RTU.”
As the rows of H704s monitor the current draw of each breaker, the accumulated information can be transmitted to a modbus host and/or viewed on an RS485 network. As a circuit approaches capacity, warning and alarm bells can be triggered. Additional capacity can then be added, or loads balanced, to prevent costly downtime from overloaded circuitry and unexpected breaker trips.
KEB has engineered the technology to provide benefits across a broad spectrum of users, including the retrofit market. They are also an early adopter of the H704-42E multiple (42 breaker) mounting, which eliminates wiring of multiple current sensors.
Up to 42 breakers can be collectively installed in two neat rows on the one H704-42E branch current monitor. The H704-42, as employed by KEB, consists of a data acquisition board and two 21-unit current sensor strips mounted each side of the distribution board along the termination points of each breaker.
The conductor passes through the appropriate current sensor before terminating at the breaker. Each strip transmits the current data to the data acquisition board through snap-on ribbon cable. Schneider Electric provides split core, snap-fit H704s for easy retrofit installations.