Fundamentals of Load Banks
© 2020 Schneider Electric. All Rights Reserved.
Schneider Learning Series – ASCO Offer
6thOctober 2020
:
Course Code: CEU 301
CEU Value: 0.1 CEU
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Learning Objectives
What is a Load Bank?
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Why do you need a Load Bank?
Basic types of Load Banks
How to Recognize a Load Bank
Load Bank Applications
Load Bank Control Platforms
Load Bank Markets
Load Bank Safety
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This webinar will be recorded and made available through our website.
Please use the “Questions” feature to ask
technical questions.
© 2020 Schneider Electric. All Rights Reserved. | Page 3
Speaker
David Jesberger
Senior Field Sales Engineer of Load Banks
David started his career as a design engineering for a defense contractor in the Naval
Nuclear program. He worked in a laboratory environment testing power equipment. He
transitioned into a sales engineering role for a load bank manufacturer where he helped
design and engineer solutions for customers.
In his current role he serves as product manager for ASCO load banks. He works with
customers to understand market needs and leads product innovation. He leads new
product development projects and serves as the product champion for the controls
platform for load banks. David also has broad experience providing detailed load bank
technology training to customers across various industries and end markets.
David holds a BS in Computer Hardware Engineering from Penn State University.
What is a Load Bank?
A load bank provides an electrical
load on a power source.
Load banks typically use resistive
load elements.
Common examples of simple
“load banks” are:
1. Toasters
2. Light Bulbs
3. Hair Dryers
1
2
3
What is a Load Bank?
Modern industrial load banks utilize a fan,
and use the corresponding airflow to cool
the resistive elements.
Modern units also have individual load
steps which allow for precise and
repeatable loading.
Properly rated load contactors with branch
fuse protection are used to apply and
remove load steps.
What is a Load Bank?
Typical one line of a load
bank in a emergency
backup power application
Why do you need a Load Bank?
Resistive Load Bank testing affects all main components of genset.
Radiator & Cooling System Exhaust System Control Panel
Circuit Breaker
Diesel Engine
Alternator
Why do you need a Load Bank?
A load bank test will affect the following systems on a genset:
• Wet stacking is an industry term for the
accumulation of unburned fuel in the
exhaust system of a diesel engine.
• Wet stacking commonly occurs when
engines are under loaded.
• Wet stacking commonly occurs when
engines do not reach their operating
temperature.
• If uncorrected, wet stacking can reduce
engine output and efficiency and result in
premature failure.
• In general, operating a diesel generator
between 30-50% of the nameplate rating
allows the engine to reach its
recommended operating temperature and
burn off any fuel deposits.
Why do you need a Load Bank? Wet Stacking
Using a Load Bank on a diesel generator set helps the engine
run at proper temperatures. This prevents fuel build up and
promotes cleaner emissions.
Load Banks test power sources so they run efficiently. This
efficiency helps with lower emissions and to reduce energy
waste.
Load Banks can also test other power sources to help
determine if their carbon footprint is as small as it can be.
Load Banks help ensure the proper running of emergency
backup power equipment in the event of power outages.
Why do you need a Load Bank? Emissions
The National Fire Protection Association (NFPA) is a United States trade association, albeit with some international
members, that creates and maintains private, copyrighted standards and codes for usage and adoption by local
governments.
NFPA 99 - Healthcare Facilities Code - Healthcare facilities must exercise Emergency and Standby Power Systems
under load and operating temperature conditions for at least 30 minutes at intervals of not more than 30 days
NFPA 110 - Standard for Emergency Generator Systems - Monthly testing is performed on generators whose failure
could result in injury or death. If a generator fails a monthly test, it should be tested annually for two continuous hours
using a load bank. Under the continuous test, the generator should be operated at 25 percent of the nameplate kilowatt
rating for 30 minutes, at 50 percent of the kilowatt rating for 30 minutes and at 75 percent of the kilowatt rating for 60
minutes.
Why do you need a Load Bank? NFPA Code Compliance
The National Electrical Code (NEC) is a regionally adoptable standard for the safe installation of electrical wiring and
equipment in the United States.
NEC Article 700 - Emergency Systems – Emergency systems are required to receive an operating permit as determined
by the local code enforcement authority. This requirement is a lifeline for occupants, ensuring that lighting and life safety
loads take priority over other building loads. Should the main electrical power supply fail, backup emergency power for life
safety systems must be available within 10 seconds.
NEC Article 701 - Legally Required Standby Systems – It requires standby power to be available to legally required
systems within 60 seconds of power loss. While NEC 700 is designed to ensure that people can exit a building, NEC 701
responds to the needs of firefighters and other personnel responding to an emergency.
NEC Article 702 - Optional Standby Systems – This applies to situations where standby generators are optional. In
these cases, the systems may be put in place to protect against economic loss or business interruptions. For instance,
data centers may elect to install backup power because an outage could result in large revenue losses.
NEC Article 708 - Critical Operations Power Systems – This article was developed following the 9/11 World Trade
Center, Hurricane Katrina, and Hurricane Rita disasters in the United States. It requires a commissioning plan for on-site
backup generation, baseline testing, and periodic witness testing, as well as a documented preventive maintenance
program, written test records, and a method for testing all critical power systems for maximum anticipated load conditions.
Why do you need a Load Bank? NEC Code Compliance
The Joint Commission is a United States based nonprofit organization that accredits more than 21,000 US healthcare
organizations and programs. Their standards for emergency power testing are summarized in the table below.
Why do you need a Load Bank? Joint Commission Accreditation
Types of Load Banks
Resistive: Most common type of load bank. It uses resistors to load the power source.
Resistors have a unity (1.0 Power Factor).
Reactive:
These load banks are u
sed anytime an AC power source requires testing at
a lagging power factor. (OEM Factory Testing, Military)
DC:
This type of load bank is used to test DC power sources such as batteries,
inverters and Ground Power Units (GPU’s).
Capacitive:
It is u
sed anytime an AC power source requires testing at a leading power
factor. (UPS OEMS, Crest Factor Loads)
Portable:
Defined by dual voltage
capability, digital metering, casters
and proper dimensions required to fit
thru man doors and freight elevators.
Permanent: Defined by single voltage
capability
and stationary (pad
mounted) installation.
Trailer Mounted:
Defined by outdoor
rated,
high capacity, factory mounted
on a properly balanced DOT trailer
.
Types of Load Banks
How to Recognize a Load Bank
1. Mounted on the radiator
of a genset
2. Mounted on a concrete pad
3. Portable on casters
4. Mounted on a trailer
5. Container
1
2
3
4
Types of Load Banks- Common Formulas
Power Information
kW- kilowatts
kVA- kilo volts-amperes
kVAR-kilo volt-amperes reactive
Pf-power factor
Formulas
kW= kVA x pf
kVA= kW/pf
pf= kW/kVA
Voltage Derating
Applied Voltage
2
Rated Voltage
2
= D
D x Rated Capacity= Derated kW capacity
Types of Load Banks | Typical Voltages
VOLTAGE PHASE FREQUENCY
120 Single 60
208 Single or Three 60
240 Single or Three 60
400 Three 50
415 Three 60
480 Three 60
600 Three 60
690+ (Medium Voltage) Three 60
Schematics
What is a Load Bank? Schematic
What is a Load Bank? Control Circuit
What is a Load Bank? Blower Circuit
What is a Load Bank? Load Circuit
Control Platforms
Load Bank Controls | Simple to Sophisticated
Standard Toggles
Digital Control
Digital/Software/Modbus
Comprehensive Control Options from
Simple Toggle Switches to Sophisticated PLC
Remote I/O
PLC
• Standard Toggle
• Digital Controls
• Software Control
• Auto Load Control
• Site Load Control
• Modbus
• Remote I/O
• PLC
Cost
- Digital Toggles
- Hand-Held
- Networking
- Software Control
- Remote Hand
Held Control
- Modbus Interface
- Site Load Control
- Networking
Multiple
Load Banks
Features
- Manual Load
Application
- Critical Power
Management
Systems
- Load Banks
have Remote
I/O option for
Interface
- Programmable
Logic Control
- Typically used
for Large
System
Integration
Load Bank Controls | Manual Toggle
• Simple easy to use, straight forward operation
• Toggle switch design ensures reliability
• Basic, resistive load testing
• Ideal for remote and extreme locations
• Offers automatic load control: allows permanently installed or
radiator mounted load banks to provide load levelling
• Digital metering is often included for indication of applied load in
amps and kW
Key Features
• Takes conventional manual control to next level with
SYNCHRONOUS load steps
• Automatic blower operation with fail safe directional sensing
• True single phase load control and instrumentation
• Digital Toggles have a 10x longer life span than standard toggle
switches
• 100,000 vs 10,000 actuations
• Standard In-Out port allows for networking and use in remote control
• LED instrumentation for high visibility
Load Bank Controls | Digital Toggle Switches
Key Features
• Robust light weight aluminium construction with a long life touch screen
• Color display – with intuitive and simple user interface
• Instrumentation and control screens
• Data logging and easy firmware updates via USB port
• Single or Three phase load control and instrumentation
• No Manual Calculations needed
• Individual load bank control optimized for data center testing
Load Bank Control | Hand-Held
Key Features
PC Software Control
• Load Bank Control Software
• Designed for sophisticated control of multiple load banks
• Scripting load control
• Data acquisition
• Comprehensive reporting and connectivity to customer MRP
• Data analysis to ISO 8528
• Dedicated pass/fail to International Testing Standard
• Allows for user-defined test configuration
• Personalized names for load banks
• Customized grouping based on user test layout
• Allows for system, user defined group, and individual load bank
monitor and control
• Monitoring and data logging of full 3 phase instrumentation for
each load bank
• Time stamped status, alarm, and error logs
Key Features
Site Load Correction
• Automatically maintains set load level
• Prevents Wet Stacking
• Local Set-Point switch to set load level
• Remote control via Modbus
Markets
Diesel Generator Sets for
Backup (Emergency) Power.
Load banks used for testing:
• Generator OEMs
• Tier 4 Emission Compliance
• Resale/bid specification projects
at distributors/dealers.
• In house generator testing at service dept.
• In the field for generator service contracts
• Rental department for start-up/commissioning
Load Bank Markets | Power Generation
Uninterruptable Power Supply (UPS)
Systems, Generator(s) for Backup
(Emergency) Power, Battery Strings,
and Rack Servers for 24/7 Critical Data
Storage.
Load banks used for testing:
• Generator
• UPS Systems
• Back up Battery String
• Commissioning
Load Bank Markets | Data Centers
Backup Power Generators for
Emergency Power.
Reliable power is critical for all life saving equipment,
but also for HVAC systems.
Load banks used for testing:
• Generator
• UPS Systems
• Compliance
• National Fire Protection Association (NFPA)
• American Society for Hospital Engineers
(ASHE)
• Joint Commission Accreditation of Healthcare
Organizations
• Back up Battery String
Load Bank Markets | Healthcare
Custom Engineered Load Banks for
Specific Product Requirements.
Load banks used for Research & Development,
Production and Quality Control testing:
• Generators
• Turbines
• Fuel Cells
• Inverters
• Batteries
• UPS
• Automotive
• Rotary UPS
• Welding
Load Bank Markets | OEMs/Test Cells
Substations and Transformers for
Utility (Prime) Power Generation.
Load banks used for testing:
• Medium Voltage Load banks for off Grid
Testing
• Harmonic Filters (tuned grid resistors)
• Code Compliance
• Utility Substations
• Water Treatment Facilities
Also an opportunity for Neutral
Grounding Resistors
Load Bank Markets | Utilities
Generators for Prime Power
Applications for Offshore Platforms.
Backup Generators for Onshore
Pipeline Pumps.
Load banks used for testing:
• Generators 600V up to 15kV
• Supplemental Loading
• UPS Systems
• Back up Battery String
Load Bank Markets | Oil and Gas
Load Banks Help Maintain Power
to Desired Level.
These types of power generation produce
unsteady output due to the uncontrollable
nature of wind, the sun, and water.
Load banks used for testing:
• Turbines
• Commissioning
• Collection System (at full load)
• Steady and Unsteady Load Inputs
• Battery Capacity
Load Bank Markets | Wind, Solar, Hydro
Load Bank Safety
A Load Bank is an industrial test unit designed and manufactured with the latest safety
features.
However, because the function of the Load Bank is to dissipate electrical energy, there are
inherent dangers to operators and equipment.
Electrical energy is transformed into heat by the resistors. This heat must be removed from the
Load Bank by the cooling fans/blowers.
• The Load Bank should never be used without the fan motor(s) operating. Inadequate
cooling airflow will result in resistor elements causing overheating and a definite fire
hazard.
• Do not bypass the airflow safety switch or exhaust over-temperature switch to prevent
nuisance tripping.
• Never exceed the rated voltage as this will cause the Load Bank to overheat.
• DO NOT touch the top exhaust hood/duct or cover panel during operation.
• If the AIR FAILURE indicator light stays on for more than a few seconds, shut down the
Load Bank, and do not operate the unit until the problem is corrected.
• It is always recommended to use PPE when installing and operating a load bank.
• Quiz, PDH and CEU certificates
All attendees will receive an email an hour
after the webinar with instructions regarding the
link to download your PDH certificate and Quiz
Questions for you to receive your CEU
certificate.
• Speaker’s contact
Feel free to reach out to the speaker by
email should you have any questions:
David Jesberger
David.Jesberger@ascopower.com
For further information
Page 40© 2020 Schneider Electric. All Rights Reserved. |
Thank You!
For more information, contact:
customercare@ascopower.com or +1 800.800.2726
© 2020 Schneider Electric. All Rights Reserved. Schneider Electric and Life Is On Schneider Electric are trademarks and the property of
Schneider Electric, its subsidiaries, and affiliated companies. All other trademarks are the property of their respective owners.
© 2020 Schneider Electric. All Rights Reserved. Schneider Electric and Life Is On Schneider Electric are trademarks and the property of
Schneider Electric, its subsidiaries, and affiliated companies. All other trademarks are the property of their respective owners.
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