Metering is an essential part of building management systems and allows energy managers to understand how much energy a building is using. However, making sense of the data is often difficult with an increasing need to provide greater detail to where the energy is actually being used. Mike Lawrence of Havells outlines how to maximise your sub-metering installations, keeping them compliant and now with the addition of renewable energy, how to future-proof them too.
There has been an enthusiastic uptake of sub-metering in the UK since legislation was introduced to encourage it (Part L2 of the UK Building Regulations). This is to be applauded and it is satisfying how many are now recognising the benefits that a well-executed sub-metering installation offers. While this is good news and there are many examples of successful sub metering installations, there is now a large enough body of experience and data to ask whether these perceived benefits are actually being achieved and if not, why not, and what kind of equipment can help us do things better?
There are various approaches to installing sub-metering. In some cases all metering is provided at the in-coming main switchboard. This has the advantage of installation simplicity and makes data collection easy. It also gives a good overall picture of energy consumption which is useful on one level but does have its drawbacks if more detail is required. Because this type of approach will typically be monitoring a mixed bag of lighting, power, motors etc indiscriminately, you will have your overall energy consumption figures, but rarely will this type of approach generate the level of detail that allows meaningful conclusions to be drawn from the collected data. An effective sub-metering installation will deliver information that the building owner / operator can act on.
There are many boards on the market that allow separate measurement of just two types of load (lighting and power, for example), however there is clearly a need for a board that can monitor three types of load simultaneously, so consumption figures for other categories, such as building services equipment, can be separated out. In this way, the data collected for your client is more accurate and relevant to their actual application.
The power of three 
Havells has developed Tri-Load, a UK specific distribution board which squarely addresses the new sub metering requirements to the mutual benefit of installers and end users.
Tri-Load is a unique distribution board design offering integral metering with the facility to monitor three independents load types from one digital multi-function meter. The boards can be configured to operate as tri-load, or dual-load, using a simple menu interface. This allows users to identify various different load combinations depending on the project metering requirements. This separate energy monitoring for power, lighting and mechanical services, is the ideal solution for compliance with Part L2 of the Building Regulations.
In addition to this there are also features designed with the installer in mind which contribute to improved electrical safety. Current Transformers (CTs) are integrated within a single-piece busbar design to reduce the number electrical connections which are commonly required by other manufacturer’s solutions. This reduces potential hot spot failures. Furthermore, all meters and CTs are fully pre-wired and a trunking interface kit is supplied as standard.
The Tri-Load board has been designed to minimise the amount of on-site work for the contractor (often meaning a reduced number of metered boards are installed), whilst at the same time, providing the end-user with improved data collection and reporting functionality. The future for electrical contractors working in the commercial environment has to be to consider this type of client-focused solution.
Going green
Energy managers are increasingly looking to renewables such as PV or wind to reduce their buildings energy footprint. The energy created from a renewable source is often fed in through a feed-in tariff meter where accessing the data is complicated as its main beneficiary is the energy company.
The Tri-Load product family has now been developed further to address the complicated integration of micro generation. The new Tri-load Renewable range provides a convenient connection point for these generated sources. The board monitors power and lighting loads, but also provides measurement of the export energy from renewables by adapting the mechanical services to capture export energy data.
Tri-Load Renewable will future-proof your sub-metering installation by offering clear visibility of how much energy your building is producing and then offsetting it against how much you are using, all of this within a standard MCB distribution board. Each Tri-Load board has Modbus serial communications as standard allowing simple integration into building management systems.
We all know the future will be green with a greater push towards micro-generation in buildings to reduce energy costs so it’s essential that building mangers are ready and understand exactly how much energy a building is not only using but also producing.
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