BILL CONRAD
Midwest Regional Manager
Avtron Loadbanks
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What is a Loadbank
Wet Stacking
Typical Applications
Types of Loadbanks
Loadbank Markets
Renting vs. Buying
WHAT IS A
LOAD BANK?
What is a Load Bank?
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A load bank provides an electrical
load on a power source
Load banks use resistive load
elements to convert absorbed
power into heat
Integral blower motor provides
cooling for resistors
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Continuous duty cycle
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No cool down period requirement
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What is a Load Bank?
A load bank is a controllable, stable load designed
to exercise and test a power system.
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A load bank provides an
electrical load on a
power source
Load banks typically use
resistive load elements
Common examples of
“load banks” are
toasters, hair dryers, and
light bulbs.
Typical One-Line Drawing
• A Load Bank is a device
which simulates an
electrical load.
• A Load Bank is intended to
accurately mimic the
operational or “real” load
which a power source will
see in actual application.
• However, unlike the “real”
load, which is
unpredictable, a Load Bank
provides a fully
controllable load.
Why Load Banks?
• The only way to verify that a backup power
system will perform during an outage is to
periodically test it under load. Both
generators and UPS may appear to run fine
when lightly loaded, but may fail to deliver full
load power if they are not regularly tested to
ensure they are up to the task.
What does a Load Bank do?
A RESISTIVE LOAD BANK PROVIDES EQUIVALENT
LOADING TO BOTH GENERATOR AND PRIME MOVER
For each KW (or HP) applied to the generator,
an equal amount of load is applied to the
prime mover by the generator.
By-Product of Load Banks
There are two main by-products from load banks:
Heat
• 1 kW = 3412 BTU/Hour
• 1000kW load bank will produce 3,412,000 BTU/Hour
Items to be aware of:
• Make sure there no air sensitive equipment located near
the hot exhaust air discharge.
• Make sure the hot air will not recirculate back into the
cool air intakes. (high walls, prevailing winds..etc.)
By-Product of Load Banks
There are two main by-products from load banks:
Noise
• Load banks can produce anywhere from 80 to 105 dBA at
5 feet.
Items to be aware of:
• Check local city and municipality codes on noise levels
• Check nearby facilities (local residence, school, retirement
homes...etc.)
• Avtron manufactures sound attenuated load banks to meet
the most restrictive requirements.
What does a Load Bank do?
All major engine manufacturers specify a minimum load when the
engine is running.
What does a Load Bank do?
* National Emissions Standards for Hazardous Air Pollutants
WET
STACKING
Wet Stacking
It helps to burn off Diesel Engine “Wet Stacking”
Wet Stacking is unburned fuel deposits
built up within the engine from
operation under lightly loaded
conditions
• Unburned Fuel Causes Carbon
Build Up
• Excessive Oil Consumption
• Reduced Horsepower & Power
Output (KW) causes Reduced
Efficiency
• Premature Engine Failure
• Increased engine emissions
Typical Load Bank Applications
(Wet Stacking)
TYPICAL
APPLICATIONS
Typical Load Bank Applications
• Design
Research and Development
• Manufacturing
Quality Control
• Installation
Acceptance Testing
• Maintenance Testing
• Solving Lightly Loaded Problems
Wet Stacking
TYPES
OF
LOADBANKS
Types of Load Banks
Portable Normally designed for dual (multiple) voltage
capability (240/480V), digital metering, casters
and proper dimensions required to fit thru
man doors and freight elevators.
Permanent Defined by single voltage capability (480V),
remote control panel, NEMA 3R construction
and load dump circuitry.
Radiator Defined by single voltage capability (480V),
Mounted remote control panel, NEMA 3R construction,
load dump circuitry. Load bank dimensions are
based on genset radiator core opening.
Real Time Data Logging
Permanent Outdoor Load Banks
Automatic Load Controller – Maintains minimum load on genset
Load Bank Load
Engine Generator
Desired Loading
50 to 70%
Permanent Outdoor Load Banks
Automatic Load Controller
Engine
Generator
Desired
Loading
50% to
70%
Load Bank Load
Facility Load
LOADBANK
MARKETS
Loadbank Markets
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Power Generation-Engine Generator Dealers/Distributors/OEM’s
Service/Rental-Pump and Power Depots, Load Bank Rentals
Data Centers-Server simulation, DC Battery racks, UPS systems
Telecommunications-Cell Towers, Battery Backup
Utilities-Medium Voltage and Neutral Grounding
Healthcare-Emergency power testing
Military-Deployable gen set’s, 400Hz, GPU’s & Shipyards
Government-FAA, SSA, FEMA, State and Local
Wind Farms-Odd harmonic testing & battery string testing
Aircraft Industries-400 Hz Test Stand interface & GPU’s
Transportation & Locomotive-DC Loadbanks & braking resistors
Load Bank Markets-Power Generation
Diesel Generator sets for
backup (emergency) power
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Load banks used for testing at:
Generator OEMs
Resale/Bid Specification projects at
Distributer/Dealers.
In house Generator testing at Service dept.
In the field for Generator service contracts
Rental Department for Start UP/
Commissioning
Neutral Grounding Resistors for Resale/Bid
Specification projects
Load Bank Markets-Data Centers
Uninterruptable Power Supply (UPS)
Systems, Generator(s) for backup
(emergency) power, battery strings
and rack servers for 24/7 critical data
storage.
System down time could cost
upwards of millions of dollars every
10 minutes.
Load banks used for testing:
• Generator
• UPS Systems
• Back up battery string
• Rack Server for HVAC for Server
Room
• Commissioning
Load Bank Markets-Telecommunications
Backup or Prime power on cellular
towers. Typically smaller (25-65 KW
generators) are used.
Load banks used for testing:
• Generator
• Batteries
• Commissioning
Load Bank Markets-Utilities
Substations and transformers for
utility (prime) power generation.
Load banks used for:
• Medium Voltage Load banks for
off grid testing
• Harmonic Filters (tuned grid
resistors)
• Neutral Grounding Resistors
• Utility substations
Load Bank Markets-Oil and Gas
Offshore platforms utilize generators for
prime power applications.
Onshore pipeline pumps utilize backup
generators.
Load banks used for testing:
• Generators-600V up to 15kV
• UPS Systems
• Back up battery string
• Braking Resistors
Load Bank Markets-Healthcare
Backup power generators for
emergency power. Power is needed
for all life saving equipment, but also
HVAC systems.
Load banks used for testing:
• Generator
• UPS Systems
• ASHE* compliance
• Back up battery string
* American Society of Hospital Engineers
Load Bank Markets-Military
Deployable generator sets for in
theatre operations, flight lines,
Naval shore power and routine
maintenance.
Load banks used for testing:
• Diesel Generators
• Turbine Generators
• GPU’s (400 HZ)
• Utility substations on military
bases
• NiCad and Lead Acid batteries
Load Bank Markets-Government
Backup power for emergencies,
testing and data retention (SSA)
Load banks used for testing:
• Generator
• UPS Systems
• Back up battery string
• HVAC for Server Room
• Neutral Grounding
Load Bank Markets-Wind Farms
• Produces unsteady power output
due to the uncontrollable nature of
wind.
• A steady output is always the goal.
• A wind turbine must always have a
load applied for proper operation.
Load banks used for testing:
• Turbines
• Steady and unsteady load inputs
• Battery capacity testing
Load Bank Markets-Maritime
Generators for shipboard power
and HVAC.
Load banks used for testing:
• Generator nameplate testing
(.8 PF)
• UPS Systems
• Back up battery string
• Dry Dock testing
Load Bank Markets-Nuclear Power
Redundant backup power required by
NRC. Electrical Distribution System
(EDS) must operate at peak efficiency
Load banks used for testing:
• Under voltage/over voltage setpoints.
• Grid condition
• Fault protections
• Back up battery string
• Emergency Power capacity
Load Bank Markets-Aircraft Industries
400 Hz generator testing. Ground
Equipment usage and
maintenance.
Load banks used for testing:
• 400 Hz Generators
• AGE usage and maintenance
• OEM custom testing
• Test Stand interface
Load Bank Markets-Transportation & Locomotive
High speed transportation utilize high
capacity digital drives for power.
Resistors are used to help “brake”
these trains as disc brakes can’t stop
the train completely.
Load banks used for testing:
• Braking resistors
• Motor starting and speed control
• Snubber resistors (High Frequency
switching)
RENTING
VS.
BUYING
Load Bank Renting
Who Rents Load Banks?
Generator & UPS Service Companies: Large & small service companies often rent load banks due to an overflow of work
or because they do not have enough business to justify the purchase of a unit.
Hospitals & Healthcare Facilities: National Fire Protection Agency (NFPA) regulations require that all critical healthcare
facilities load test emergency and stand-by generator systems several times per year. As a result, many facilities employ
trained staff to perform the testing, but rent the load banks as needed.
Computer/Data Centers: Financial institutions and government offices are examples of facilities that often operate
24 hours/day and depend on stand-by generator systems in case of a power outage. As a result, the systems are tested
frequently using rented load bank systems.
Military Bases & Government Installations: Although many bases own their own load banks, the frequency of rental is
increasing as budget cutting effects equipment inventories.
Municipalities: Critical systems (like 911) exist that cannot afford to be shut down due to power outages.
As a result, they utilize a wide range of generator sizes and often rent load banks to perform testing.
Larger Industrial Manufacturers: Many companies have critical systems that cannot afford to be shut down due to a
power outage. As a result, they often employ trained staff to maintain and test the generator systems, often with rented
load bank systems.
Original Equipment Manufacturers (OEM’s): UPS manufacturers and other OEM’s often elect to rent products like
load banks (vs. making a capital expenditure) due to certain budgetary and tax advantages that may be available.
Load Bank Renting-Pro’s
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Renting vs. Buying
• Renting is a cost saving approach since it
requires no capital expenditures, balance
sheet liability or property taxes
• No storage worries-equipment leaves
when test is finished
• Maintenance support included in rental
rate. If equipment fails it will be replaced.
• Rental companies typically have expert
logistic support
Load Bank Renting-Con’s
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Renting vs. Buying
• Renting is Expensive
• Must rent for a week or month
• Technicians may be needed to (hire or
rent)
• Load cables are usually extra
• Comparing cost need to include:
 Rental fees
 Cable fees
 Technician fees
 Delivery to & from/set up charges
SUMMARY:
• Loadbanks
•
•
•
•
•
•
What is a Loadbank
Wet Stacking
Typical Applications
Types of Loadbanks
Loadbank Markets
Renting vs. Buying
QUESTIONS?
Contact Information:
Bill Conrad
Avtron Loadbanks
Midwest Regional Manager
Ph. 216.573.7600, ext. 1558
william.conrad@emerson.com