Electrical acceptance testing collaboration leads to improved project delivery

Acceptance testing insights

• Acceptance testing in data centers can help reduce electrical equipment failures.
• The majority of early equipment failures can be traced to design, installation or startup deficiencies. That’s why it is so important to protect a data center’s investment in new electrical equipment or systems with acceptance testing.

A thorough check of electrical power systems and components before energization can uncover and help correct problems that otherwise would lead to project schedule delays or larger, more costly issues in the future with impacts to data center downtime and consumer dissatisfaction.

What is acceptance testing and is it necessary?

Acceptance testing is the physical inspection and testing of newly installed electrical equipment. This involves thorough visual and mechanical inspections using calibrated test instruments to ensure electrical components and completed systems operate as designed. It occurs before electrical system commissioning and startup as well as before the new equipment is put into operation.

Taking this initial step verifies that manufactured devices are free from defects, operating as designed and intended and installed correctly as specified. It is important that acceptance testing be performed by a third-party testing firm that is unbiased and independent in its evaluation and findings.

Common issues when acceptance testing

Several issues that can be costly to correct after startup can be found with acceptance testing:

• Failure of cabling damaged during installation.

• Incorrect wiring.

• Mechanical operating problems.

• Nuisance tripping or breakers tripping outside of manufacturer’s curves.

• Improper relay settings and programming.

• Compromised insulation dielectric systems.

• Improper grounding.

• Wrong transformer taps and/or improper ratios for proper voltage.

• Instrument transformer and metering circuit ratio and wiring issues.

• Surge protection device defects.

• Switchgear bus and cable connections not properly assembled.

• Bus connections improperly torqued.

Acceptance testing also avoids unnecessary expenses for data centers. Finding system and component anomalies during acceptance testing — while equipment is still under warranty and in a controlled environment — is critical. Determining and correcting deficiencies before startup can save an owner capital and maintenance expenses by preventing costly outages, equipment repairs and potential safety issues.

Hyperscale data center requirements

The hyperscale data center market continues to grow and with the amount of digital information being generated, there’s no end in sight. With this growth comes a need for new data centers and/or expansion of existing facilities at a much greater rate to keep up with digital demand. The increased demand for data storage drives larger and more complex power system requirements to handle the loading, not only for the servers storing the data, but also for the thermal systems required to cool the data center equipment.

Traditionally, acceptance testing of the critical power distribution infrastructure for these types of facilities would have been performed fully at the data center. The testing agency would work alongside the electrical contractor during or in many cases after installation to complete all acceptance testing activities.

With the increased demand and the need to bring these data centers online faster that model has evolved. It is important to note, however that the quality assurance, testing and commissioning aspects of the project must always remain the goal without compromises being made.

Off-site acceptance testing opportunities

A shift in the use of system integrators creates an opportunity for testing to begin off-site. Acceptance testing at an integrator’s facility or an equipment provider is becoming more common and offers notable efficiencies. Collaboration with a system integrator at its location while the equipment is being built allows the integrator and electrical contractor to follow parallel paths for all data center assets.

The electrical contractor can be installing system components while the integrator is assembling the remaining portions of the power system distribution equipment. These components can be tested as they are connected off-site, significantly reducing time on-site. This time savings provides an improvement to the overall construction schedule that benefits all parties involved.

It is important to note that acceptance testing will still need to be conducted at the final on-site location to ensure no damage occurred during shipping or final installation. This multistep approach will help save time overall as the testing firm can uncover any issues and make corrections off-site, leading to fewer issues being found on-site.

Acceptance testing is best performed by the same independent firm working with the integrator at its location as well as with the electrical contractor during installation on-site. Keeping a consistent partner makes for smoother transitions, increased efficiencies, standard processes and procedures, communication improvements, etc.

While integrators are providing a customized solution involving numerous components from various original equipment manufacturers, the testing agency conducting the acceptance testing must be familiar with a wide range of manufacturers’ equipment. Using qualified technicians who can implement industry-recognized testing methods and procedures will help ensure the quality and consistency of testing at the data center and off-site.

Equipment tested at the system integrator’s site can include skid-mounted systems in outdoor enclosures. Each skid includes medium- and low-voltage equipment such as circuit breakers, trip units, protective relays, wiring, metering, instrument transformers, panelboards, batteries, etc. The integrator also includes their own system for power, lighting and heating, ventilation and air conditioning controls.

The electrical contractor can be wiring the loads at the data center and be ready and waiting for the skids of low- and medium-voltage switchboard and/or switchgear assemblies to arrive. Testing at the data center includes electrical contractor-installed equipment fed from the skids, such as busways, circuit breakers, bus plugs, disconnects, grounding, etc.

Tests are often conducted concurrently at the site while integrator testing is underway. Testing on equipment from the skids that cannot be performed at the integrator includes items such as interconnect wiring, grounding and complete system functional testing. These are completed at the data center to close out the on-site testing.

Choose the right partner

Due to the importance of conducting proper acceptance testing, selecting a good acceptance testing firm for which the experience and knowledge can be trusted is crucial. Consider the following criteria when selecting a suitable acceptance testing firm:

• Independence from the manufacturer to ensure an unbiased, thorough assessment of equipment.

• Ability to accurately interpret test results to determine best course of action for each unique customer environment.

• Previous work experience on similar projects to determine the value added.

• Technician certification and experience to ensure thorough testing by a trained professional.

• Size of the firm and ability to staff with qualified professionals to deliver the project on time and within budget.

• Awareness of all safety standards to ensure safe work practices and require less supervision.

• Test equipment calibration program to ensure that equipment is in proper working order to deliver accurate test results.

• Affiliations with reputable organizations such as InterNational Electrical Testing Association, National Institute for Certification in Engineering Technologies or NFPA to confirm knowledge of testing standards.

• Ability to perform new and innovative testing services to ensure a complete evaluation and comprehensive recommendations.

• Ability for the same company to be used at the system integrator as well as the physical test site.

• Strong financial standing and ability to be a long-term provider.

The above criteria are important when identifying an independent testing company that can become a trusted adviser to help to extend system life, reduce downtime and improve the safety surrounding equipment.

Electrical systems are among a data center’s most critical assets and they can have a big impact on the bottom line. In data centers that power the online economy 24/7, even a brief disruption can cost millions of dollars. Their production and management costs are high and failures almost always lead to catastrophic losses.

Hyperscale data centers are experiencing substantial growth, requiring collaboration and an integrated project delivery to improve consistency and shorten the overall construction schedule. Investing in thorough acceptance testing by using a trusted, independent testing firm can save a project money during construction and throughout the equipment life cycle.

This article was provided by the InterNational Electrical Testing Association (NETA), and originally appeared in its publication. Vertiv is a NETA member.

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