Energy Metering System Validation – Case Study

Powerpoint Engineering Limited recently installed an Energy Metering System (monitoring Gas and Electricity usage on site) at a metal fabrication factory in Cork. The electrical energy meters were retrofitted on existing switchgear, using any existing infrastructure available (Measure-Voltage fused signals and current transformers). The factory is Ireland’s only independently owned manufacturer of extruded aluminium profiles. They specialise in aluminium extrusion, powder coated aluminium and sheet metal fabrication as well as providing many other services from their vast 250,000 sq. ft. facility.

The installed system consists of:

  • 30 Electrical energy meters and 10 gas meters, capturing total site consumption and significant energy users (SEU’s);
  • Modbus data communication over ethernet for all meters;
  • Energy metering software (Powerstudio Scada) with real-time meter reading, historical data trending and automated periodic reporting;

After the system installation was complete, the installed meters were accuracy tested and validated. For electrical energy meters, this is generally achieved by using a calibrated portable power analyser and comparing the installed panel mounted energy meter reading against the reading on the portable analyser. This process ensures that each sub meter reading can be deemed to be valid.

Once the meters had been validated for electrical accuracy, then the communications between the meters and the software system were configured.

In the Energy Metering software, all electrical and gas meters were set up in a hierarchical grouped fashion.

The metering system was now started recording and allowed to log for a time period. After this time period the site was re-visited for final validation.

On this system, there were 3 electrical switch-rooms and one main ESB supply. The were 10 gas meters, including the main incoming gas supply.

As part of system validation, the total energy consumption at the main electrical meters at each switch-room was summed and compared to the total main supply energy consumption (ESB meter). This validation was also performed for all gas sub-meters against the total incoming gas supply meter.

This validation proved successful, where the total of the sub-meters equalled the total main meter for both electricity and gas.

The next level of validation was performed at each individual switch-room. The main meter reading was compared to the sum of the sub-meters at that location. For two out of three of these areas this validation was successful. At one switch-room, it was found that the main meter reading was less than the total of the sub-metered total. On investigation, it was found that the main meter was measuring correctly. This pointed to an issue with one or more of the sub-meters. All sub-meters were found to be reading correctly, with the exception of one meter.

This meter of concern was found to have been configured incorrectly. This was a retrofit project, where some existing wiring was utilised and old meters were replaced with new meters. The assumption was made that the original wiring was correct. It was found that the phase sequence of the meter voltage signal wiring did not match that of the meter current signals. It was also found that the connected load being metered was unusually, highly inductive (75kW, 150kVAr lag, 170kVA, 0.43 power factor). This actual load was validated using a portable power analyser. The panel meter was incorrectly reading 163kW, 170kVA @ 0.96 power factor. This reading would appear to be ‘normal’. It was also noted that the Power Factor Correction equipment was connected to the same busbar with 4 x 50kVAr stages connected (200kVAr total). The meter wiring was corrected and the meter was re-configured. The following table shows the before and after, meter readings:

Meter readings – Before remedial works
Meter Name kW kVA kVAr power factor
Sub meter 163 170 48 0.96
Main Breaker 167 174 49 0.96
Power Factor Correction 200
Meter readings – After remedial works
Meter Name kW kVA kVAr power factor
Sub meter 73 170 153 0.43
Main Breaker 167 174 49 0.96
Power Factor Correction 200

The remedial works now showed that all sub-metered loads were now summing to approximately 98% of the total supply at this switch-room. It was also found that the sum of the switch-rooms main meters summed to the main ESB meter reading (Total site supply).

This validation process in summary should consist of a number of stages:

  • individual meter validation against a calibrated portable power analyser;
  • logging data for a period of time and then compared to utility bills;
  • with reconciliation of sub-metered loads versus main meters;

For further information, email or call us on 057 866 2162, we’d be happy to answer any queries you might have.

Electricity, Gas Meter & Water Meter Installation Case Study

This is a synopsis of power quality case study regarding the installation of electrical energy meters, gas meters and water meters at a third level education institution. An ongoing contract with a tertiary education institution has seen the installation of a large number of electrical energy meters, gas meters and water meters which are all connected over the site LAN back to a central PC.

Read more about the power quality issues faced, and learn what solutions were offered by Powerpoint Engineering Ltd.

Electricity Gas Water Meter Installation

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The TracePQM “Traceability routes for electrical power quality measurements” research project has now concluded. The overall aim of this project was to develop and validate a modular metrology grade system for the measurement of power and PQ parameters using digital sampling techniques. Arising out of the project, the NSAI, National Metrology Laboratory, Glasnevin, Dublin 11 – hope to develop a capability for the calibration of power & power quality meters and calibrators.

The Project stakeholders included: ESB Networks, UCD Energy Institute, Compliance Engineering Ireland, Fluke Calibration, various European Universities and Calibration Houses and Powerpoint Engineering Limited. Powerpoint Engineering Limited was represented on the Stakeholder’s committee by Garrett Kelly.

More information on this project can be found by contacting Garrett Kelly or at

Distributed Electrical Energy Metering Case Study – Telecoms Sector

Transmission Mast
This is a synopsis of power quality case study regarding the installation of Distributed Electrical Energy Metering in the telecoms sector. The requirement was for a high accuracy metering system that could measure energy consumption on a number of site loads over a number of sites.

Read more about the power quality issues faced, and learn what solutions were offered by Powerpoint Engineering Ltd.

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Voltage Sag Case Study – Pharmaceutical Company

This is a synopsis of power quality case study regarding the phenomenon of Voltage Sag experienced at a pharma plant. A pharmaceutical company site in Dublin had been experiencing some critical sags at their incoming supply.

Read more about the power quality issues faced, and learn what solutions were offered by Powerpoint Engineering Ltd.

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Case study – Cement Factory

Garrett KellyA Sunday evening, 8.30pm, a cement factory in Ireland suddenly came to a complete stop. Unipower representative Garrett Kelly was called in to investigate.

8 years earlier the factory had installed PQ Secure system and a UP 2210 for post-processing of data. Meter was still logging as it should and after downloading data, investigation showed an arcing earth fault causing the interruption.

Yet more important was that the data showed that the shutdown could have been avoided.

Cement Factory Case Study

PQ Secure is designed to be an early-warning system so after a system upgrade PQ Secure is now in use documenting as before and at the same time alerting for abnormal values and disturbances. More UP 2210s have also been added to strategic connections.

For full details please refer to the Unipower Newsletter

Click here to contact us or call us on 057 866 2162.

Powerpoint Engineering will exhibit at ISO50001 Ireland in Croke Park on May 24th

Register for ISO50001 Ireland 2017Register for ISO50001 Ireland 2017


Powerpoint Engineering Ltd will be exhibiting at ISO50001 Ireland 2017 in Croke Park on May 24th. You can visit us at Stand 5! Garrett Kelly and Aidan Ryan will be on hand to discuss how Powerpoint Engineering can design, supply and install Energy Metering to help your company set Benchmarks and Measure KPIs in the implementation of ISO 50001 EnMS.

ISO 50001 is an international standard that offers a comprehensive framework to setup, apply maintain and enhance the effectiveness of Energy Management Systems (EnMSs).

If you would like to attend, you can register at We look forward to seeing you there!