Avtron 2000 Series User manual

2000 Series Load Bank
User’s Guide
Part Number: Manual Toggle Switch
Revision Date: November 2022 V3

AVTRON 2000 SERIES USER MANUAL
MANUAL TOGGLE SWITCH
© 2022 Avtron Power Solutions, LLC October 8, 2018
Cleveland, Ohio Rev. November 2022

Form 831B-LB Rev 10-2022
PROPRIETARY NOTE
This document contains information PROPRIETARY TO
Load Bank products and systems by Avtron Power
Solutions, LLC. It is furnished solely to provide
information sufficient for instruction, operation,
maintenance, evaluation, and testing of the equipment
herein disclosed; is not to be used for manufacturing or
procurement; and is not to be disclosed to anyone other
than persons in the Division, or the Company, or the
Government, as the case may be, responsible for action
relating to this document without the express written
permission of Avtron Power Solutions, LLC.
WARRANTY
The last page of this document contains an express
limited warranty. The provisions of this warranty cover
any and all rights extended to holders of Load Bank
products and systems by Avtron Power Solutions, LLC.
6255 Halle Drive, Cleveland, Ohio 44125
Tel: [phone]

AVTRON POWER SOLUTIONS, LLC
Cleveland, Ohio
AVTRON 2000 SERIES
LOAD BANK
TABLE OF CONTENTS
Section Page
I SAFETY CONSIDERATIONS............................................................. 1-1
II DESCRIPTION ................................................................................... 2-1
III INSTALLATION .................................................................................. 3-1
IV OPERATION....................................................................................... 4-1
V MAINTENANCE.................................................................................. 5-1
-i-

1-1
AVTRON 2000 SERIES
LOAD BANK
SECTION I
SAFETY CONSIDERATIONS
Throughout this manual, you will find WARNING and CAUTION statements. Personal
injury or death may occur to an operator using or repairing the equipment if a WARNING
statement is ignored. Damage to the equipment and potentially hazardous conditions for
personnel may occur if a CAUTION statement is ignored.
Each unit is safety checked for opens and shorts, and the insulation is high potential tested
to ensure safe operation. All fuses, safety interlocks, and related safety equipment have
been proven reliable as part of the testing procedure of each unit.
As part of your safety program, an initial inspection after receiving the unit(s) and periodic
preventive maintenance and safety inspections should be conducted to ensure the reli-
ability and safety built into your equipment.
The Load Bank is an industrial test unit designed to be used indoors. However, because
the function of the Load Bank is to dissipate electrical energy, there are inherent dangers to
the operator and to the equipment. These dangers shall be outlined in this section.
Electrical energy is transformed into heat by the resistor elements. The heat may be
removed from the Load Bank by airflow through the resistor elements. If there are any
restrictions or stoppage of airflow, the Load Bank may overheat and may even start a fire.
The following recommendations are made:
1. Read the manual before operating the Load Bank.
2. Run an approved ground wire from the Load Bank ground lug located on the
customer connection panel to the frame of the power source. Run an approved
ground wire from the power source frame to a good earth ground. Size ground wire
in accordance with National Electrical Code and any local codes.
3. Do not bypass the temperature sensing switches to prevent nuisance tripping. The
switches will drop out the load if insufficient cooling air is reaching the elements.
4. Replace any burned out bulbs on the control panel. Each lamp is an indication that
a system is active or has failed and is important to the operation of the unit and
safety of the operator.

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W A R N I N G
Personal injury from electrical shock may result if all sources
of power are not disconnected before servicing. Maintenance
work must be done only by qualified personnel.
5. Maintenance should be performed with no power on the unit. The majority of
troubleshooting can be performed with an ohmmeter. There are multiple sources of
power input to the Load Bank. Ensure each is disconnected.
6. Venting the heated air from the exhaust toward overhead cables, sprinkler systems,
or into a room with insufficient volume or "Make-Up" air, is a potential hazard.
The Load Bank should be used in a cool, well- ventilated area.
7. Allow cool room air to pass into the unit to cool the elements. Do not allow the unit
to be placed where hot exhaust air can recirculate back through the unit causing a
constant rise in cooling air temperature.
8. After running a load test, residual heat may be removed from the Load Bank by
allowing the blower to operate for a few minutes after load is removed. This
procedure is not required for maintaining Load Bank integrity, but it may guard
operating personnel from possible burn injuries.
9. The operator should avoid coming in contact with the resistor elements or
surrounding covers during and for some time after operation. These portions of the
Load Bank become quite hot and may result in a serious burn should contact be
made with them.
10. Do not allow objects to enter or block the air intake or exhaust of the Load Bank. A
blockage would cause Load Bank overheating. If an object enters the screens, it will
cause damage to the resistor elements, possibly shorting them and causing shock
and fire hazards.
11. Emergency Shutdown Procedure
A. In an emergency, shut down the MASTER LOAD switch, then the power
source. The MASTER LOAD switch will allow disconnection of all load steps
and still allow for motor to run, cooling any heated elements.
B. The POWER ON/OFF switch will disconnect both load steps and fan motor.
The power source EMERGENCY OFF switch should be located near the
load system.
12. An approved electrical fire extinguisher should be on hand at all times.

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13. It is the responsibility of the customer to take diligent care in installing the Load
Bank. The National Electrical Code (NEC), sound local electrical and safety codes,
and the Occupational Safety and Health Act (OSHA) should be followed when
installing the equipment to reduce hazards to persons and property.
14. Read and heed all WARNING and CAUTION statements in the manual.

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SECTION II
DESCRIPTION
The Series 2000 Load Banks are designed for electrically loading and testing power
sources. The Load Bank is designed for production line and job site use.
Refer to the schematic for the load bank KW (Current), voltage, phase and frequency
rating. Using the toggle switches on the control panel, any combination of the available
load steps may be selected to achieve a desired load.
The control panel is integrally mounted on the Load Bank. The controls/metering on the
control panel will vary depending on the model and available accessories. Refer to the
schematic for specific controls associated with the load bank provided. The general
arrangement for the control is:
MODELS 2100/2200
1. MASTER LOAD ON/OFF switch – Applies power to the Load Bank fans and allows
the instantaneous connection and disconnection of all switched ON load steps.
2. OVER TEMP/VOLT indicator – Indicates an air failure/insufficient cooling airflow or
an over voltage condition.
3. VOLTAGE SELECT switch – Configures load resistor circuit for dual voltage
applications if applicable.
4. LOAD STEP switches – Connect and disconnect load steps. Load values are shown
above each switch.
5. ANALOG/DIGITAL METERS – Displays Volts and Amps of Load Bank.
MODEL 2400
1. POWER ON/OFF switch – Applies power to the Load Bank and fan. The POWER
indicator lights when power is applied.
2. BLOWER FAILURE indicator – Indicates an air failure or insufficient cooling airflow.
3. MASTER LOAD ON/OFF switch - Allows instantaneous connection and
disconnection of all switched ON load steps.
4. LOAD STEP switches – Connect and disconnect load steps. Load values are shown
above each switch.

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MODEL 2500
1. POWER ON/OFF switch – Applies power to the Load Bank and fans.
2. VOLTAGE SELECT switch – Configures load resistor circuit for dual voltage
applications if applicable.
3. MASTER LOAD ON/OFF switch - Allows instantaneous connection and
disconnection of all switched ON load steps.
4. LOAD STEP switches – Connect and disconnect load steps. Load values are shown
above each switch.
MODELS 2600/2700
1. POWER ON/OFF switch – Applies power to the Load Bank and fans. The POWER
indicator lights when power is applied.
2. OVER TEMP indicator – Indicates an air failure/insufficient cooling airflow.
3. VOLTAGE SELECT switch – Configures load resistor circuit for dual voltage
applications if applicable.
4. MASTER LOAD ON/OFF switch - Allows instantaneous connection and
disconnection of all switched ON load steps.
5. LOAD STEP switches – Connect and disconnect load steps. Load values are shown
above each switch.
MODELS 2800/2900
1. CONTROL POWER INTEGRAL TRANSFORMER SELECT switch – Configures the
internal control transformer to the voltage selected and that matches the UUT
voltage.
2. CONTROL POWER INTEGRAL TRANSFORMER ON/OFF pushbuttons –
Energizes the configuration relays for the control transformer to the voltage selected
above.
3. BLOWER VOLTAGE SELECT INT/EXT switch – Used to select the correct voltage
and either from the internal bus or from an external voltage source. If internal, this
switch must match the voltage selected with load voltage select switch.
4. LOAD VOLTAGE SELECT switch – Selects the voltage of the UUT.
5. BLOWER START/STOP pushbuttons – Energizes the fan start/stop circuit.
6. FAN ROTATION ABC/CBA – Used to reverse the rotation of the cooling air fan.
Turn fan off by depressing the BLOWER STOP pushbutton and allow the fan to
come to a complete stop before reversing the fan rotation.

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7. BLOWER FAIL indicator - Indicates an air failure or insufficient cooling airflow.
8. MASTER LOAD ON/OFF switch - Allows instantaneous connection and
disconnection of all switched ON load steps.
9. LOAD STEP switches - Connect and disconnect load steps. Load values are shown
above each switch.
A single phase, 60 Hz power source is required for the control circuit. This power is derived
either from an external source or from an internal control power transformer connected to
the load bus.
There are some Models that will require a DC source which is provided from the load bus.
Refer to schematic diagram.
Fan power is obtained from either the power source under test (connected to Load Bank
main load bus) or from a remote source (external power source).
ENCLOSURE
The outside dimensions of the Load Bank are shown on the Outline Drawing. The Load
Bank is fabricated of aluminized steel, assembled with SST hardware, and mounted either
with feet or casters. Handles may be provided for lifting and transporting the Load Bank.
C A U T I O N
Do not allow the Load Bank to be placed where hot exhaust
air can recirculate back through the unit causing a constant
rise in cooling air temperature.
The Load Bank contains fans which provide the necessary cooling air for the load
elements. Sensors are provided to monitor the flow of cooling air. These sensors are
electrically interlocked with the load application controls and if the fans are not working
properly the load steps are disabled.
Air to cool the load elements enters the screened intakes located on one end of the Load
Bank. The air passes over the resistive elements and is then discharged through the
screened opening at the opposite end of the Load Bank.
The Load Bank contains a control fuse and depending on the model the load circuit will be
protected with either branch circuit or main line fusing for short circuit protection.

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W A R N I N G
Do not operate the Load Bank with any screen or cover
removed. This may expose the operator to high voltage and
rotating fan blades.

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SECTION III
INSTALLATION
BEFORE INSTALLATION
Inspect the Load Bank for obvious damage such as broken wires, broken or dented panels,
cracked ceramic insulators, or any other component breakage that may have occurred in
shipment.
LOCATION
The unit is a portable Load Bank, designed for indoor use, and should be used in a cool,
well-ventilated area. Cool air must be continually available and the hot exhaust air must be
dissipated, not recirculated through the unit. Install the Load Bank so that the inlet and
exhaust panels have unrestricted airflow clearance.
C A U T I O N
Installation must prevent hot exhaust air from recirculating into
the air intake. Inlet air temperatures exceeding 120oF may
cause damage to the Load Bank. After installation, test the
unit at full load and verify that the inlet air temperature does
not exceed 120oF.
AIRFLOW CONSIDERATIONS
Even with an ample supply of cooling air, the Load Bank may overheat if it is not properly
installed. There are two types of airflow problems that should be avoided:
1. Recirculating Airflow - If the hot, exhausted air is permitted to recirculate through the
Load Bank, it will reach such a high temperature and low density that it will no longer
cool the resistance elements. A Load Bank should not be installed so close to any
surface as to reflect the exhausted air back to the air intake. When two or more
Load Banks are being used, care must be taken in positioning the Load Banks so
that the exhausted air of one unit does not feed the air intake of another.

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2. Restriction of Cooling Air - Any obstruction located within two (2) feet of the inlet and
four (4) feet of the exhausts (Models 2100/2200), three (3) feet of the inlet and six
(6) feet of the exhaust (Models 2400-2700) and four (4) feet of the inlet and eight (8)
feet of the exhaust (Model 2800/2900) will restrict the Load Bank's airflow. Airflow is
also restricted when two or more Load Banks have air inlets positioned too close to
each other. This competition for cooling air causes a low pressure area, restricting
adequate airflow.
W A R N I N G
It is vitally important to install the Load Bank properly.
Installation errors may result in a catastrophic failure. The
overtemperature switches in the Load Bank will guard against
some of these problems. If protective circuitry prevents
application of the load, determine the source of the problem.
DO NOT DISABLE THE OVERTEMPERATURE SWITCHES.
This causes a safety hazard and voids our warranty. The
following installation instructions are critical to the safe
operation of the Load Bank. Refer to the SAFETY
CONSIDERATIONS section of this manual.
3. The heated exhaust air stream can damage any temperature sensitive items if they
are positioned near the exhaust air.
4. Load Banks mounted into a channel, trough, hollow, well, or pit, or exhausting into a
full wall or corner, require special considerations even if above conditions are met.
In these cases, provide a detailed sketch of site layout for manufacturer to inspect
and comment.
POWER REQUIREMENTS
The Load Bank requires a 120 volt, single phase, 60 Hz source of power for operation of
the control circuit. Control power may be derived internally from the unit under test with a
control power transformer, or from an external source. A power cord for control power may
be provided with the Load Bank. Reference the schematic for specific control power
requirements and control connections.

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C A U T I O N
If the Load Bank includes a control transformer, never connect
a control power line cord to the secondary of the control
transforme
r
. This would permanently damage the control
transformer.
LOAD CONNECTION
Load power is connected to the Load Bank either through receptacles located on the
exterior of the Load Bank or bus bars located within the Load Bank.
For units with receptacles on the exterior, loose connectors may be provided for the load
cable to be connected to the load bank.
For internal connection to bus bars, run cables through opening in the Load Bank frame up
to bus bars. Reference the outline drawing for the location of the opening. Verify proper
phase to phase clearance on cable lugs, mounting hardware, and wiring.
For either load connection, cables to the Load Bank should be of adequate size to handle
the maximum rated current according to the National Electric Code and any local codes.
The current can be determined by the following formula:
Line Current
=
kW × 577
VOLTAGE (Line to
Line
)
Lower voltages and different frequencies may be applied to the load circuit of the Load
Bank. Frequency change causes no derating of the load; however, the applied kW with a
lower voltage is computed by using the following formula:
)
RatedVoltage(
)
AppliedVoltage(
kW
=
kW 2
2
RatedApplied 
W A R N I N G
Do not energize the Load Bank with any covers removed.

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GROUNDING
A permanent ground should be connected to the Load Bank enclosure either by a
grounded conduit or with a separate ground wire to prevent a potential above ground on
the enclosure. No internal ground connections are made to any terminal on the Load Bank.
The ground conductor should be run with the load power conductors to provide the lowest
impedance fault path. The ground stud on/within the Load Bank must be connected to both
the generator frame and a good earth ground. The ground conductor should be sized per
the National Electric Code Table 250.122 if not superseded by local codes.
C A U T I O N
Never exceed the Load Bank rated voltage as this will cause
the Load Bank to overheat.
BLOWER MOTOR CONNECTIONS
For units with blower motor connections separate from the control power circuit, the blower
circuit consists of fuses, motor starters, contactors, overload relays, and the fan motor. The
blower may be connected in one of two ways.
A. INTERNAL BLOWER POWER OPERATION: The blower motor is connected to
load bus through a relay and fuses. When operating the blower motor from the unit
under test, an additional load will be applied. This additional load will be reflected in
the meter readings and should be noted on load readings to prevent errors.
B. REMOTE BLOWER POWER OPERATION: When testing single phase system or
systems or a frequency other than 60 Hz, the blower motor must be run from a
separate source. First review schematic, set the control panel selector switch to
match the external voltage applied and then connect external power. Connect the
external blower power source to terminals as shown on the schematic.
C. NON-STANDARD BLOWER MOTOR FREQUENCY: blower motor will operate
between 208 and 250 V (low voltage) and between 416 and 500 V (high voltage) at
3-phase 60 Hz. Connections for 50 Hz operation are identical to 60 Hz, with a motor
voltage range of 190 to 220 V (low voltage) and 380 to 440 V (high voltage)

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W A R N I N G
When operating at 50 Hz the motor speed (RPM) is reduced
which also reduces the cooling of the load bank. Do not
exceed 400 V in the 480 V mode or 200 V in the 240 V mode
to the input bus when the fans are running at 50 Hz.

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SECTION IV
OPERATION
LOAD BANK OPERATION
All tests start with control panel switches in the OFF position.
C A U T I O N
Before energizing any load, verify that load voltage does not
exceed rated voltage of load bank.
C A U T I O N
Do not attempt operation if the cooling system is not running.
Fan inlet and exhaust must be unrestricted. The operation of
the fans is vital to the safe operation of this Load Bank. If the
safety circuit indicator light comes on and stays on for more
than a few seconds without the load dropping out, shut off the
power switch at once. Remove all power to the unit and check
f
o
r
proper operation of fan safety circuit. Failure to correct
cooling air loss condition will result in destruction of the Load
Bank. Refer to the SAFETY CONSIDERATIONS section of
this manual.
OPERATING INSTRUCTIONS
1. Place all switches on the control panel to the OFF position.
2. Connect a conductor from the Load Bank ground to the unit under test frame.
3. Ensure the unit under test frame is grounded.
4. Connect the unit under test to the load bank as described in Section III,
INSTALLATION.
5. Connect the load bank to a 120 volt, single phase, 60 Hz power source if required.

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6. With POWER and MASTER LOAD switches in the OFF position, start the generator.
7. Position the LOAD VOLTAGE SELECT switch and the BLOWER VOLTAGE
SELECT switch to the correct voltages (if applicable) to the voltage being applied.
8. Place the POWER switch in the ON position. Verify that the red OVER TEMP lamp
momentarily lights. The CONTROL POWER lamp will light.
9. For load banks with a three-phase blower motor. Depress the BLOWER START
pushbutton. Verify airflow is in the correct direction. IF not, shut down the blower by
depressing the STOP pushbutton. Wait until the fan blade stop rotating then switch
fan rotation switch ABC/CBA and restart the blower motor.
10. Position the LOAD STEPS switch(es) to the desired load.
11. Turn on the MASTER LOAD switch to apply desired load. Load steps may be
added or deleted at any time.
12. Monitor load applied with analog/digital meter(s), if present.
13. After running tests, remove the load by turning off the MASTER LOAD switch.
After running a load test, residual heat may be removed from the load bank by
allowing the blower to operate for a few minutes after load is removed. This
procedure is not required for maintaining load bank integrity, but it may guard
operating personnel from possible burn injuries.
W A R N I N G
DO NOT touch the exhaust screen during operation. The
screen will become hot from the exhausted heat and may
cause a serious burn. Refer to the SAFETY
CONSIDERATIONS section of this manual.
DO NOT allow objects to enter or block screens.
14. Place the POWER switch to the OFF position.
15. Shut down all power sources connected to the Load Bank.
16. Disconnect the power source cables and the ground connection from the load bank.
17. Disconnect the 120V source that may be to the load bank (if required).

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L1
L3
L (Line)
N (Neutral)
SINGLE-PHASE OPERATION (Dual Voltage/Three-Phase Load Bank)
Single-phase operation is achieved by connection between two phase terminals, one of
which is used as neutral.
L1-L3 Connection Mode: The L1-L3 connection mode shown in Figure 4-1 will give
approximately 50% loading capacity when the nominal load bank supply voltage is
connected. Or 17% load capacity when a single-phase (√3) equivalent supply is used.
Figure 4-1: L1-L3 Connection for a Single-Phase Supply
NOTE
Place VOLTAGE SELECT switch in the low voltage mode.
W A R N I N G
The three phase C bus and any attached wiring are
electrically hot when operating Load Bank in single phase, per
Figure 4-1.
L1/L2-L3 Connection Mode: The L1/L2-L3 connection mode shown in Figure 4-2 will give
approximately 66% loading capacity when the nominal load bank supply voltage is
connected or 22% loading capacity when a single-phase (√3) equivalent supply is used.

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L1 (A)
L2 (B)
L (Line)
L3 (C) N (Neutral)
Figure 4-2: L1/L2-L3 Connection for a Single-Phase Supply
NOTE
Place VOLTAGE SELECT switch in the low voltage mode.
W A R N I N G
The three phase C bus and any attached wiring are
electrically hot when operating Load Bank in single phase, per
Figure 4-2.