Using Load Bank Solutions
to Optimize Building Commissioning
Introduction
The overall goal of commissioning is to confirm a facility meets the design intent
and the owner’s requirements. For critical facilities, such as data centers and
hospitals, proper commissioning ensures a reliable and resilient operation.
Load bank solutions are used during the commissioning process to verify the
electrical and thermal systems operate per specifications.
For more formal definitions, the Building Commissioning Association
(BCA) says the basic purpose of commissioning is “to provide documented
confirmation that building systems function in compliance with criteria set
forth in the Project Documents to satisfy the owner’s operational needs.” BCA
members represent a cross section of interests, including owners, engineers,
architects, contractors, commissioning providers and users of commissioning
services.
According to the American Society of Heating, Refrigerating and Air
Conditioning Engineers (ASHRAE), commissioning is defined as “a
quality-oriented process for achieving, verifying and documenting that the
performance of facilities, systems and assemblies are planned, designed,
installed, tested, operated and maintained to meet the owner’s project
requirements.” By following a detailed commissioning plan, the commissioning
process enhances the delivery of a project.
This eBook will discuss the commissioning process and how it is used to
validate that the installation, performance and operation of new equipment is
performing as required before it supports a critical load. Specific topics include:
●● Why Test with Load Banks?
●● Overview of Data Center Commissioning Practices
●● Developing a Structured Commissioning Plan
●● When Should You Develop a Plan for Load Testing?
●● Who Should Participate on the Commissioning Team?
●● What Are the Objectives of Facility Commissioning Plan?
●● Which Systems Should You Load Test during Building
Commissioning?
●● Which Load Bank Solution Is Best for Your Commissioning Project?
●● What Happens If You Don’t Develop a Proactive Commissioning Plan?
●● Should You Buy or Rent Load Banks for Commissioning?
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Why Test with Load Banks?
Load banks are used in the integrated system test typically performed immediately before handoff
to a customer operation. Some of the tests performed during the integration phase will support the
characterization and validation of an electric power systems’ operational performance. Additional issues to
consider relate to the integration with the utility system. You must be confident the system has been installed
and integrated safely and reliably prior to transferring responsibility over to the operations personnel.
Using load bank solutions may uncover quality problems with critical primary or backup systems. Once
placed under a load, these systems can fail because the equipment settings were incorrect, damaged in
transit or not installed properly. You may be unaware there’s an issue until the equipment is tested under a
load that represents the anticipated maximum load profile expected. Commissioning provides a systematic
way to confirm proper performance levels and identify any problems before the facility is brought on-line.
Key reasons to use load bank solutions during building commissioning include:
Saving Money
- Load bank testing reduces the financial risk building owners face. During
testing, engineers, facility managers and vendors work together to minimize the likelihood of costly
post-deployment repairs or configuration changes.
Although owners will incur a cost for load bank equipment, this investment is far surpassed by the
money saved from not having to fix problems after the facility launches. Identifying issues during
commissioning gives you an opportunity to avoid expensive problems that could surface after
deployment.
In addition, load testing ensures proper configuration of equipment and systems. When everything
is working as it should, you can keep your operating costs low. You also won’t require additional IT
labor to re-engineer system configurations or repair equipment
Maintaining the Project Schedule
- Using load bank testing allows testing to be done to reflect
all anticipated load conditions. Any failures can extend your project schedule and push-out your
facility launch date. A delayed launch can lead to increased project costs.
Improving Performance
- Using load bank solutions during commissioning validates the
performance of electrical and mechanical components. It isolates problems and allows you to take
corrective action before your facility is placed into production.
In facilities such as data centers, the demand for higher server density increases complexity and
makes it difficult to simulate operations. These situations require load bank testing to precisely mimic
the actual electrical load, heat generation, airflow and physical dimensions of the server racks.
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Plus, load bank testing is the only way to verify a backup power system will operate during an
outage. Generators and UPS equipment may perform adequately under light loads. But, without
proper testing during commissioning, they may fail to deliver when tasked with a full power load.
The integrated system test allows the system to perform with the actual utility connection and other
facility loads. Failures caused by inrush currents, impact on the utility network, and impact of internal
switching equipment can only be determined with this method.
- When you load test during building commissioning, you can verify
proper room design and equipment placement. Load banks can vary the electrical load, heat and
airflow to predict hotspots created by the computer equipment. Simulating maximum operating
conditions with load bank testing is essential to a successful facility launch. It also provides the data
necessary to effectively manage future expansions and upgrades.
Validating Facility Design
Minimizing Future Outages - The main goal of load bank testing is to uncover problems in
a controlled situation rather than during an actual power failure. Commissioning can reduce the
risk of future unplanned outages and downtime. You can also validate your equipment meets all
manufacturer specifications.
Simplifying Regulatory Compliance and LEED Certification - Load bank testing during
commissioning helps ensure compliance with local, state and federal environmental regulations. It
also helps facility owners attain Leadership in Energy and Environmental Design (LEED) certification.
LEED is a green building certification program that recognizes best-in-class building strategies
and practices. To receive LEED certification, building projects must satisfy certain operational
prerequisites. Load bank testing can help verify a facility is operating efficiently and meeting LEED
certification requirements.
In some situations, standards compliance may dictate load bank testing. For example, the National
Fire Protection Association (NFPA) “Standard for Emergency and Standby Power Systems”
provides requirements for initial commissioning of an emergency power supply, as well as ongoing
testing. Other standards organizations imposing requirements for load testing include the IEEE
1547 Interconnection standard, ANSI/NETA Standard for Maintenance Testing Specifications for
Electrical Power Equipment and Systems, and the Joint Commission on Accreditation of Healthcare
Organizations.
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Overview of Data Center
Commissioning Practices
A new trend in precision commissioning uses highly adjustable modular rack-mounted load banks. This
solution that reduces labor hours to perform integrated system testing.
Many data centers are tested and commissioned using bulk-room power and thermal load simulation. In
this application, you typically use 75-100 kW load banks, sometimes referred to as suitcase load banks.
To provide straightforward setup and execution, these load banks are dispersed throughout the room to
simulate the power and heat generated by computer equipment.
Another method of data center commissioning is discrete zone testing, which uses rack-mounted load
banks installed in the racks of the computer room. Although setting up rack-mounted loads banks is more
time-consuming, this method provides more precise simulation of rack-level architecture.
Some noteworthy considerations of current practices include:
●● Suitcase load banks produce disproportionate temperature readings compared to the rack-level
equipment. As a result, inaccurate data may lead to inappropriately sized HVAC equipment and
miscalculated total cost of ownership.
●● Actual rack-level equipment can be reconfigured if rack-mounted load bank testing reveals extreme
temperature gradients on the intake and/or exhaust sides of the racks
●●Rack-mounted load banks can more precisely simulate the power and heat load distribution of the actual
rack-level equipment as specified in the data center design.
●● Precise simulation of airflow throughout the rack yields areas where hot or dead zones must be
addressed by containment or other HVAC strategies.
●● Actual rack-level equipment can be reconfigured if testing reveals extreme temperature gradients on the
intake and/or exhaust sides of the racks.
●●Precise emulation of the actual rack architecture allows HVAC equipment to be optimized versus
under- or over-sized.
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In precision commissioning for data centers, a test is conducted when the equipment is installed, connected
and live to verify correct operation. Before handing off the facility to the operations team, commissioning
evaluates a complex system to ensure it performs according to its expected configuration and load. To
accurately test all of the components for the integrated systems tests (IST), commissioning tests may take
two weeks or longer.
Given recent product innovations, precision commissioning offers a more labor-efficient method.
Commissioning agents can show that redundancy in the system design works – the system will operate if
source one or two fails.
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Developing a Structured Commissioning
A facility running at optimal capacity requires a comprehensive commissioning plan that incorporates
the load bank testing during the acceptance testing phase immediately before handoff to operation. At a
minimum, the commissioning plan should answer these questions:
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When Should You Develop a Plan for Load Testing?
The overall building commissioning process should be defined in the facility’s pre-design phase.
During this design phase, the commissioning team is assembled and the owner’s project
requirements identified.
At this juncture, it is also important to begin creating the load bank testing plan as a part of the
overall acceptance testing plan. This plan outlines all parameters of the load test, including the
testing timeline, vendor selection, load bank equipment needed, load bank configuration, etc.
The sooner you start preparing for load testing, the greater opportunity you have for on-time and
on-budget commissioning. A proactive approach to load testing helps you identify problems before
the facility becomes operational.
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Who Should Participate on the Commissioning Team?
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What Are the Objectives of Facility Commissioning Plan?
A facility’s commissioning team should include the owner, the owner’s representative, commissioning
authority, design team, operating and maintenance personnel, construction personnel, end users
and appropriate vendors. Basically, the commissioning team consists of the individuals who assume
responsibility for implementing the commissioning Process. The Commissioning Authority is the
entity on the team the owner assigns to lead, plan, schedule and coordinate the commissioning
Team.
A written plan outlines the commissioning of each project and is updated as the project progresses.
A structured commissioning plan should accomplish a wide range of functions, including:
●● Identifying the commissioning team and each member’s role
●●Defining and communicating the owner’s project requirements
●●Identifying the systems to be commissioned
●●Defining the scope and activities of the commissioning process
●●Defining the commissioning budget
●●Creating a commissioning schedule
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Which Sub-Systems Should Be Load Test during Building Commissioning?
When commissioning a building, the following devices should be load tested:
Back-Up Generators - When utility power becomes unavailable, generators are the long-term
source of back-up power. So, load testing them at their nameplate power factor is critical. The testing
also confirms the operation of the paralleling controls for multiple generators.
UPS Systems - A crucial component in many operations, an uninterruptible power supply (UPS)
allows a computer to keep running for a short time during a primary power source outage using
stored energy in batteries (or a flywheel). It also provides protection from power surges. Even if full
load testing was conducted by the manufacturer, you still want to load test the UPS systems during
commissioning to ensure controls operate properly and can distinguish between long-term power
outages and other transients.
Automatic Transfer Switches (ATS) - ATS components are commonly used in facilities to
distribute power to priority loads after the loss of the primary source. Given their role in providing
seamless power during a utility outage, ATS components must be load tested prior to facility
deployment.
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Power Distribution Units (PDUs) - These devices control electrical power in critical facilities such
as data centers. They distribute electrical power to computer racks and networking equipment. More
sophisticated models include floor-mounted PDUs that bridge primary power to equipment racks;
and rack-mounted PDUs that control power to specific servers, switches and other devices.
Computer Room Air Conditioning (CRAC) Unit - These systems monitor and maintain the
temperature, air distribution and humidity in a network room or data center. Given the heat generated
by computer equipment, climate control plays a vital role in a data center operation. Therefore,
CRAC units must be load tested before the facility goes live.
Generator Paralleling Switchgear - These components connect and synchronize two or more
generator sets, so they can act as emergency backup for large facilities. Multiple generators are
used due to the demand in facilities being larger than individual generators available and also for
redundancy to increase the probability the generator will be available. Because of the number of
generators that can be connected, paralleling switchgear systems are rated for very heavy loads.
Main Electrical Switchgear - Distribution Switchgear distributes power to all of the downstream
electrical equipment. Circuit breaker settings must be correct coordinated, tested and verified
throughout all main electrical distribution equipment. A fault in the system requires selective
coordination so the fault is isolated as far downstream as possible.
Static Transfer Switch (STS) - Like an ATS, STS components seamlessly transfer loads between
two sources during failure and maintenance events. However, they are designed to transfer these
loads within a few milliseconds.
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Electrical Power Monitoring System (EPMS) - The EPMS monitors all electrical systems within
the facility from a single location and ensures all systems are operating properly. Load testing helps
confirm the EPMS is monitoring systems correctly.
Simulated Computer Equipment - This testing can be accomplished through estimating the load
of the computer equipment to be installed, then approximating this load using 100kW load banks
dispersed throughout the computer room.
Precision Simulation of Computer Equipment - This testing is accomplished by placing small
specialty load banks in the racks to precisely test the entire system and precisely simulate the
thermal profile expected.
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Which Load Bank Solution Is Best for Your Commissioning Project?
To determine the right testing configuration, you must create a load profile. A broad overview of
the main categories of load bank solutions include:
Resistive - The most common load bank, resistive solutions mimic the operational load that a
power source will see in actual use. They convert electrical energy (current) into heat using power
resistors and dissipate the heat using air or water.
Types of resistive load banks include small DC portable units, small AC portable units, large AC
portable units, trailer-mounted AC units, permanent AC units, radiator-mounted units and AC
water-cooled units.
Reactive - These solutions simulate systems affected by electric motors or other electromagnetic
devices on a power network. Reactive load banks can simulate either an inductive or capacitive load
depending on the type of load expected on the power system.
Examples of devices producing reactive/inductive loads include motors, transformers and chokes.
Reactive/capacitive load testing is used in applications requiring heavy inductive loads and/or power
factor correction, such as in the manufacturing and mining industries.
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Resistive/Reactive - These solutions combine both resistive and reactive elements in one load
bank package. Resistive/reactive loads are able to mimic motor loads and electromagnetic devices
within a power system, as well as provide purely resistive loads by allowing to set a specific power
factor.
Using a resistive/reactive load bank enables comprehensive testing from a single unit. Resistive/
reactive load banks are great choices for testing turbines, switchgear, rotary UPS, generators and
UPS systems. They can also be used for integrated system testing of utility substation protection
systems.
Rack-Mounted Load Banks - These smaller load banks allow precise estimation of the expected
load and thermal distribution. They allow optimization of the computer room air conditioner.
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What Happens If You Don’t Develop a Proactive Commissioning Plan?
Many unexpected things can surface during the commissioning of a facility. The commissioning
team may also encounter issues with infrastructure components after the facility goes live. These
equipment problems can lead to serious schedule delays and/or unplanned downtime. Load testing
helps you avoid complications and the associated costs.
A proactive commissioning plan identifies how load bank testing will be conducted and ensures it’s
completed within the project’s scheduling parameters. If you don’t plan properly, your project is at
risk of suffering major setbacks and incurring additional cost. You must begin load test planning early
in your project, such as during the pre-design or design phase, to avoid things going wrong.
These issues may involve:
Cable Runs - Having to make location changes affects the cable runs. If load banks must be
located farther from systems than originally anticipated, you may experience schedule delays and
incur added cost.
Weather - Indoor load banks having to be moved outdoors because of access issues are subject to
bad weather delays.
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Equipment Placement - Load bank equipment may not be able to reach its destination inside the
facility because it won’t fit in freight elevators, through doors or around obstacles. Access issues will
cause you to invest in expensive retrofits or relocate load banks outside.
Design and Layout - Load testing must be conducted when all systems are configured and located
at their final destination. For example, testing of IT equipment before it’s in place will not be able to
fully validate hot-aisle/cold aisle layout and CRAC performance.
Other coordination issues may involve:
System Validation - Without a proactive approach to load testing, you would not be able to
validate design specifications and operational performance of the entire facility before it goes live.
Simulating operational thermal and electrical loads for entire systems requires extensive planning
and scheduling. By conducting full IST of critical systems during commissioning, you establish an
accurate baseline for ongoing operational performance.
Team Coordination - Everything must be designed and constructed appropriately before load
testing begins to avoid performance issues and costly configuration changes. Working together from
the project start with clear definition of responsibilities, the design firm, general contractor, electrical
contractor, mechanical contractor, commissioning agent and load bank supplier can develop an
integrated plan that delivers a project within budget and on schedule.
Developing a comprehensive plan in the pre-design and design phases helps ensure all commissioning
specifications are met. By validating system design and performance before production, load bank testing
ensures the operational success of a newly constructed facility and reduces the likelihood of costly
post-production reconfigurations.
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Should You Buy or Rent Load Banks
for Commissioning?
Some facilities elect to purchase and install
permanent load banks. With load banks onsite, you
can commission a new building, as well as perform
ongoing testing of critical components required by
building code after repairs and upgrades. Permanent
load banks can save time and labor when failed
critical equipment must be reinstated to 100%
performance. Most often these are installed to
comply with NFPA 110 fire protection code requiring
periodic “exercising” of the generator system.
Renting load banks required for the facilities
integrated system testing is common practice. By
partnering with a load bank company, critical facilities
managers and engineers can identify potential problems early in the process. You can then avoid delays
and cost overruns during commissioning, as well as operational downtime post-deployment.
A number of companies rent load banks and provide load bank service to help you commission your
mission critical systems. You should choose a load bank partner that is knowledgeable, experienced and
available to work with you to ensure the successful commissioning of your new facility.
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ComRent Load Bank Testing Solutions
ComRent is a global leader in load bank rentals and service for testing
and commissioning mission-critical power generating equipment. With
more than 30,000 load tests performed and a 99.99% on-site performance
rate, we bring a level of service, expertise and experience unmatched in
the industry.
We add value by taking a consultative approach to every commissioning
and testing project. By getting involved early in a strategic process, we’re
able to integrate load bank test planning into the design, scheduling and
budgeting phase of each project.
ComRent’s team of experts is ready to help ensure your system is
successfully interconnected. We offer a complimentary consultation to
review your project and propose the right load bank solution for your
application. Contact us today at 888-881-7118 or visit our website for
more information on load bank testing.
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COMRENT CORPORATE HEADQUARTERS
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