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.

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In an era of rising energy costs and increased environmental regulation, businesses across all sectors are placing greater emphasis on reducing energy waste and improving operational efficiency. One of the most effective and actionable starting points for organisations is to undertake an energy monitoring survey.

Energy monitoring surveys provide a structured method for assessing real-time energy usage across a site. By identifying inefficiencies, abnormal consumption patterns and areas of unnecessary load, these surveys enable informed decision-making that leads to measurable cost savings and improved energy performance.

What Is an Energy Monitoring Survey?

An energy monitoring survey involves the temporary or permanent installation of metering equipment to capture detailed data on electrical usage within a facility. The purpose is to understand where, when and how energy is consumed so that corrective actions can be taken.

Depending on the objectives, monitoring can take place at the main incomer, at individual distribution boards or on specific loads or processes. These surveys typically run over several days or weeks, providing a representative sample of usage across operating cycles, including peak and off-peak periods.

At Powerpoint Engineering, energy surveys are conducted by experienced engineers using compliant energy metering equipment, ensuring accurate, standards-compliant results.

Why Conduct an Energy Monitoring Survey?

There are multiple reasons organisations choose to invest in energy monitoring:

• Energy Cost Reduction – Identifying and addressing inefficiencies allows businesses to lower consumption and reduce utility bills.
• Operational Efficiency – Monitoring can uncover overloading, underutilised systems or equipment that consumes power unnecessarily.
• Regulatory Compliance – Many energy efficiency initiatives and frameworks (e.g., ISO 50001, SEAI programmes) require documented evidence of monitoring and energy performance.
• Sustainability and Carbon Goals – Understanding energy profiles supports carbon reporting, net-zero initiatives and improved environmental performance.
• Supporting Investment Decisions – Real usage data strengthens the business case for energy-efficient technologies, such as lighting upgrades, HVAC improvements or automation systems.

Components of an Effective Energy Monitoring Survey

A professional survey typically includes the following stages:

1. Initial Consultation and Planning

An engineer or energy consultant assesses the facility, identifies key areas for measurement and selects the appropriate metering points and equipment.

2. Equipment Installation

Temporary or permanent metering devices—such as power loggers or multi-channel energy analysers—are installed. These measure parameters such as voltage, current, active power (kW), reactive power (kVAr), apparent power (kVA) and power factor.

3. Monitoring Period

The site is monitored continuously over a defined period. This allows the survey to capture variations during typical operating hours, weekends, shift changes or seasonal fluctuations.

4. Analysis and Interpretation

Collected data is processed using specialised software, producing detailed graphs and performance summaries. Engineers then evaluate:

• Load profiles and daily usage trends
• Peak demand periods
• Base load conditions
• Equipment-specific consumption
• Power quality issues, such as harmonics or voltage fluctuations

Many surveys combine energy monitoring with power quality analysis—measuring harmonic distortion, voltage sags and flicker—in line with EN50160 standards. This dual approach provides a more comprehensive view of both energy usage and electrical quality, helping facilities prevent performance issues, equipment degradation or compliance breaches.

5. Final Report and Recommendations

A professional report is delivered outlining key findings, visualising trends and identifying opportunities for improvement. These may include behavioural changes, load shifting or investment in more efficient technologies.

Typical Applications Across Sectors

Energy monitoring surveys are relevant in a wide variety of environments:

• Data Centres and IT Infrastructure – Monitor energy-intensive cooling systems and high-density electrical loads.
• Manufacturing and Industrial Facilities – Uncover high-consumption processes and identify machinery running inefficiently or unnecessarily.
• Healthcare Settings – Verify the performance and consumption of critical systems such as HVAC, lighting and standby power.
• Commercial Buildings and Offices – Optimise energy usage across lighting, air conditioning and IT systems.
• Public Sector and Educational Institutions – Support energy audits, carbon reporting and sustainable building certifications.

Best Practices for Energy Monitoring

To ensure effective results from an energy monitoring survey:

• Work with Qualified Professionals – Accurate installation and interpretation are essential for useful results.
• Select Key Monitoring Points – Focus on high-load areas or zones with suspected inefficiencies.
• Use Accurate, Standards-Compliant Equipment – IEC61000-4-30, Class A or Class S rated meters provide reliable, audit-ready data.
• Allow Adequate Monitoring Duration – Longer surveys provide more representative data across operating conditions.
• Act on the Findings – The greatest value comes from implementing the energy-saving measures identified through analysis.

Long-Term Value

Energy monitoring surveys are not just one-off diagnostic exercises. They form the basis for long-term energy strategies. Repeating surveys annually or installing permanent energy monitoring systems allows organisations to benchmark performance, track improvements and respond quickly to new inefficiencies.

Integrating power quality monitoring also ensures equipment protection and regulatory compliance, particularly in facilities with sensitive electronics or heavy electrical loads.

Conclusion

An energy monitoring survey is a powerful tool for any organisation seeking to reduce operational costs, improve energy efficiency and meet sustainability targets. By providing precise, data-driven insights into how energy is used across a facility, these surveys support smarter energy decisions and long-term performance improvements.

Powerpoint Engineering offers comprehensive energy monitoring surveys carried out by experienced professionals using high-specification equipment. Learn more about our services and how they can support your energy goals here.

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:

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.

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.

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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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In the realm of electrical engineering, precise measurement and monitoring of current flow is essential for maintaining power quality and ensuring efficient energy management. Current transformers (CTs) play a pivotal role in this process by enabling the accurate measurement of high alternating currents (AC) in power systems. This article explores the fundamentals of current transformers, their various types, operational principles, applications, and key considerations for selection in the context of power quality and energy monitoring.

What is a Current Transformer?

A current transformer is an instrument transformer designed to reduce high AC currents to a lower, more manageable value. This scaled-down current can then be safely monitored and measured by standard instruments. CTs are indispensable in scenarios where direct measurement is impractical due to the high magnitude of the current. They provide a means to monitor electrical systems without directly exposing measurement devices to high voltages and currents, thereby ensuring safety and accuracy.

Types of Current Transformers

Current transformers (CTs) are essential components in electrical systems, enabling the measurement and monitoring of current flow. Various types of CTs are designed to cater to specific applications and installation requirements. Below are some common types:

1. Split-Core Current Transformers: These CTs feature a core that can be opened, allowing installation around a conductor without disconnecting it. This design is particularly useful for retrofitting existing systems or for temporary measurements.
2. Cable-Through Current Transformers: In this type, the primary conductor (cable) passes directly through the CT’s core without the need for a primary winding. They are typically used for measuring currents in insulated cables and are known for their straightforward installation.
3. Primary Wound Moulded Case Current Transformers: These CTs have a primary winding wound within a moulded case. They are designed for precise measurements and are commonly used in applications where the primary current is relatively low, but high accuracy is required.
4. Bar-Through Current Transformers: Featuring a solid bar as the primary conductor passing through the core, bar-through CTs are robust and suitable for high-current applications. They are often employed in industrial settings where durability and reliability are paramount.
5. Millivolt Current Sensors: These are specialized CTs designed for retrofitting wall mounted energy metering panels in electrical switch-rooms where the metered circuit is a distance away from the metering panel. These CTs are typically split-core, measuring high levels of AC current and converting it to a millivolt signal. The signal can be transferred accurately over longer distances than conventional CTs.

Selecting the appropriate type of current transformer is crucial for ensuring accurate measurements and optimal performance in energy monitoring and power quality assessment. Factors such as the installation environment, current levels, required accuracy, and physical space constraints should be carefully considered when choosing a CT for a specific application.

How Current Transformers Work

The operation of a current transformer is based on the principle of electromagnetic induction. When an AC flows through the primary winding, it generates a magnetic field around the conductor. This magnetic field induces a proportional current in the secondary winding of the CT. The ratio of primary to secondary current is determined by the turns ratio of the transformer. For instance, a CT with a turns ratio of 100:1 will produce a secondary current that is 1/100th of the primary current. This allows for safe and accurate measurement of high currents using standard metering equipment.

Applications of Current Transformers

Current transformers are integral to various applications, particularly in power quality assessment and energy monitoring:

• Energy Metering: CTs enable accurate measurement of electrical consumption in residential, commercial, and industrial settings. By scaling down high currents, they facilitate the use of standard meters to monitor energy usage effectively.
• Protection Relays: In power systems, CTs provide critical inputs to protection relays. They detect abnormal conditions such as overcurrent or faults and initiate protective actions like circuit breaker tripping to prevent equipment damage.
• Power Quality Monitoring: CTs are used to assess the quality of power by monitoring parameters such as harmonic distortion, load imbalances, and transient events. This information is vital for maintaining system reliability and efficiency.
• Control Systems: In industrial automation, CTs supply current measurements to control systems, enabling real-time monitoring and adjustment of processes to optimize performance and energy usage.

Considerations When Selecting Current Transformers

Choosing the appropriate current transformer is crucial for ensuring accurate measurements and system safety. Key factors to consider include:

1. Current Rating: Select a CT with a primary current rating that matches or exceeds the maximum current expected in the application. This ensures linearity and accuracy in measurements.
2. Accuracy or Protection Class: Depending on the application, different accuracy classes are required (eg Class0.2s metering class or 5P10 protection class). For precise energy metering, a higher accuracy class is essential. Protection relays may tolerate a lower accuracy class, but will not saturate in over-current conditions, allowing a controlled disconnection of supply under fault conditions.
3. Burden: The burden refers to the load connected to the CT’s secondary winding, including the impedance of meters and connecting wires. It’s important to ensure that the CT can handle the total burden without compromising accuracy.
4. Frequency: Ensure that the CT is rated for the operating frequency of the system, typically 50 Hz or 60 Hz, to maintain measurement accuracy.
5. Insulation Level: The CT must have adequate insulation to withstand the system’s operating voltage, ensuring safety and longevity.
6. Physical Size and Installation Constraints: Consider the available space and installation conditions. Split-core or window-type CTs may be preferable in retrofit applications where uninterrupted service is necessary.
7. Environmental Conditions: Assess factors such as ambient temperature, humidity, and exposure to corrosive elements. Select a CT with appropriate environmental ratings to ensure reliable operation under these conditions.

Conclusion

Current transformers are indispensable components in modern electrical systems, facilitating accurate measurement and monitoring of high currents essential for power quality assessment and energy management, while also facilitating Protection Relay functionality. Understanding the different types of CTs, their operational principles, and the critical factors in their selection enables engineers and technicians to implement effective solutions tailored to specific applications. By carefully considering these aspects, one can ensure the safety, reliability, and efficiency of electrical installations across various sectors.

For more information please email us here or call us on 057 866 2162.