How to survey an electrical installation for metering and targeting?

Sites’ layout and electrical installations are unique, most customers do not exactly know what they want to monitor, and many customers have pre-existing metering installations that must be integrated. Any monitoring and targeting project therefore starts with a site survey to learn the status quo.
 

 

Site surveys must be carried out to define the exact monitoring requirements to support the project’s execution and validation. In particular, site surveys are necessary to:

  • Gather information about electrical installation
  • Devise clear energy management/breakdown strategy
  • Quote exactly what is going to be installed
  • Avoid surprises
  • Serve as reference to go back to when managing conflicts with end-customer

 

Step 1: Get a quick understanding of what the customer wants

Although project specifications are mostly driven by what the project is trying to achieve, precious insights can be gathered by discussing with the end-customer. Very often these will add additional monitoring requirements and drive the project towards a successful outcome. A number of questions can be asked to the end-customer:

  • Have they got any metering system in place already
  • Do they have archived data sets they want to integrate
  • Do they want specific equipment to be monitored
  • Do they know how energy is used throughout the site
  • Do they know the main energy offending machines and areas
  • Are they interested in electricity, water and gas metering, or more
  • Have they already conducted an energy audit to base your work on

This information helps focus the site survey and match the customer’s expectations.

 

 

Step 2: Get an overview of the electrical installation setup

Electrical installations are generally the result of original installations combined with a number of changes and upgrades made over the years to accommodate site expansion or new business requirements. Subsequently, electrical wiring is very often not optimised or logical, and more importantly poorly documented. A number of checks should be made to provide you with the most up-to-date information.

  • Get your hands on the electrical wiring diagram and ask the site electrician to explain it to you and to point what recent changes have been made
  •  

  • Take a tour to the main switch room where all the site distribution boards are fed from to get a better understanding of what you are working with
  •  

  • Walk-through the building to locate the main distribution boards and their type as a way to assess the monitoring complexity
  •  

  • Pictures, pictures, pictures… notes, notes notes… sub-board cabinets, labels, wiring sheets, cable size, MCB size, etc, anything that will help you later on to remember the setup

 

Bus bars and double/multiple-fed circuits will require more expensive CTs and Rogowski coils. Generally, any circuit rated over 600A will require more expensive current measurement devices.

Labeling is the key to a successful installation, and non-existent or incomplete labeling of circuits can jeopardise profits. No labeling means that the link between electrical loads and circuits monitored is unknown. When labels do not exist or exist but are incorrect or meaningless then the measurements provided on your dashboard are misleading. Inconsistent labeling should be identified during the project proposal stage, because customers will otherwise expect you to label circuits (which is lengthy and difficult) at no extra charge, leading installation to be lengthened, postponed or canceled.

 

Step 3: Find out how you can deploy your system

Deploying a monitoring system comes with a number of requirements in terms of power supply, access to cables and access to the Internet.

  • Where can the meter be located (DIN rail/panel mount), will you need a separate enclosure
  • Where will the CT leads pass through to reach the cable chamber from the meter(s)
  • Is there a spare MCB and neutral that can be reused for the installation or must they be deployed. Can they be deployed on installation date considering board shutdown is necessary for that
  • Are wall sockets available to power up laptop for installation or GPRS/3G router
  • Can the customer network infrastructure be used to connect the Wattics system to the Internet
  • Is there a wired Internet point in the vicinity of the board that can be used
  • Is the GSM signal strong enough should a GPRS/3G router be needed (you can check with your phone)

 

 
 

Step 4: Discover future problems early

  • Machines that are fed from multiple power sources in different locations, e.g. production lines
  • Circuits feeding more than one machine
  • Machines that can only be powered down during scheduled shutdown periods
  • Labels are non-existent or not clear

 

Step 5: Size effort for dealing with 3rd parties

  • Switching off loads (is management pre-approval required, should person with authority be present during installation, can machines or board be switched off, etc)
  • Integrating 3rd party systems (getting authorisation from utilities, city councils can be tedious and lengthy, datasheet and technical information may not be available)
  • Obtaining tariff information (what are the tariff and charges applied)
  • Access to IT network (connection to IT infrastructure requires cat5 cabling and network settings, IT team to be aware and available)
  • Access to on-site electrician (electrical work to be conducted by site electrician prior to installation date)

 

 

Please contact us at support@wattics.com if you need any clarification on the steps outlined.

Anthony Schoofs

Anthony Schoofs

Chief Technical Officer at Wattics
Anthony drives Wattics' innovation on energy efficiency for industrial and grid environments. Anthony is also behind WSNbuzz.com, a blog covering technology advances within the smart grid and IoT markets, and was listed in 2011 amongst the top 100 IoT thinkers. Anthony was recently awarded the Globe Sustainability Research Award for his contribution to advancing knowledge on sustainability.
Anthony Schoofs

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