Avtron K711 User manual

AVTRON MODEL K711
LOAD BANK
Part Number K711D36027
600 kW @ 480 VAC, 3-Phase, 60 Hz
50, 50, 100, 100, 100, 100, and 100 kW
CFM REQUIRED: 61152
© 2004 Avtron Manufacturing, Inc.
Cleveland, Ohio

AVTRON MANUFACTURING, INC.
Cleveland, Ohio
AVTRON MODEL K711A
LOAD BANK
TABLE OF CONTENTS
Page
Section I SAFETY CONSIDERATIONS...............................................................1-1
Section II DESCRIPTION........................................................................................2-1
Section III INSTALLATION ....................................................................................3-1
Section IV OPERATION...........................................................................................4-1
Section V MAINTENANCE....................................................................................5-1
Section VI REPLACEMENT PARTS LIST .............................................................6-1
APPENDIX - Avtron Load Bank Troubleshooting Guide
SUPPLEMENTAL INFORMATION
Avtron Bulletin 202 Installation Notes - Engine Generator Duct Type Load Banks
Avtron Bulletin 203 Sample Calculations Engine Generator Duct Type Load Banks
DRAWINGS
SB2196 Outline Drawing Enclosure, Wall Mount
SB2287 Outline Drawing, Load Bank
D36028 Load Bank Schematic/Interconnection Diagram
-i-
KAK/kv

1-1
AVTRON MODEL K711
LOAD BANK
Part Number K711D36027
SECTION I
SAFETY CONSIDERATIONS
Throughout this manual, you will find WARNING and CAUTIONstatements. 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 Avtron 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 reliability and
safety built into your Avtron equipment.
The Model K711 Load Bank is an industrial test unit designed to be used indoors safely. The unit
will be installed in an enclosure. However, because the function of the Load Bank is the dissipation
of electrical energy, there are inherent dangers to operators and equipment. These dangers are
outlined in this section.
Electrical energy is transformed into heat by the resistors. This heat must be removed from the Load
Bank by the customer-supplied cooling fans/blowers. If there is any restriction or stoppage of
airflow, the Load Bank will overheat and may start a fire. It is recommended that:
1. The operator should read the manual before using the Load Bank.
2. Run an approved ground wire from the Load Bank ground lug(s) to the generator frame.
Run an approved ground wire from the generator frame to a good earth ground. Size ground
wire in accordance with National Electrical Code and any local codes.
3. Do not bypass the exhaust over-temperature switch to prevent nuisance tripping.
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 Load Bank and safety of the
operator.
5. Maintenance personnel must always exercise caution when the access panels or intake
screens are removed. Personal injury from electrical shock may result if all sources of power

Safety Considerations Avtron Load Bank • Part Number K711D36027
1-2
are not disconnected before servicing. Maintenance work must be done only by qualified
personnel.
6. The Load Bank must be used in a cool, well ventilated area as described in the
INSTALLATION section of this manual. Do not allow exhaust airto recirculate through the
Load Bank. This causes a constant rise in cooling air temperature and may cause the Load
Bank to overheat.
7. 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 definite hazard. The Load Banks
should be used in a cool, well ventilated area. This Load Bank is specifically designed for
use within an enclosure.
8. After running a load test, residual heat may be removed from the Load Bank and
downstream duct work by allowing the fans 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 can 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/or fire
hazards.
11. Operators must not operate the Load Bank with the access panels or screens removed. To do
so exposes the operator and other persons to possible personal injury from electrical shock.
12. Emergency Shutdown Procedure
A. In an emergency, turn off the MASTER LOAD switch, then the generator. The
MASTER LOAD switch will allow disconnection of all load steps.
B. The power ON/OFF switch will disconnect all load steps. The Generator Emergency
"OFF" switch should be located near the load system.
13. An approved electrical fire extinguisher should be on hand at all times.
14. 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.
15. Read and heed all WARNING and CAUTION statements in the manual.

Description Avtron Load Bank • Part Number K711D36027
2-1
SECTION II
DESCRIPTION
The Avtron Model K711D36027 Load Bank is a duct mount style unit designed to provide a
balanced resistive load of unity power factor, at a specified 3-phase voltage. The total load
capability of the K711 Load Bank is 600 kW at 480 VAC, 3-phase, 60 Hz. Load steps are 50, 50,
100, 100, 100, 100, and 100 kW. Using the toggle switches on the control panel, any combination of
the available load steps may be selected to achieve a desired load.
An integral 480:120 volt control transformer is installed to provide 120 VAC, single phase, 60 Hz
control power.
A generator exerciser/controller is built into the Load Bank. This controller consists of a
programmable weekly timer, which will initiate a generator start signal. After an adjustable time
delay period, the Load Bank will apply load blocks of 100, 150, 150, and 200 kW sequentially.
After an adjustable exercise period, the load steps will be removed, based upon adjustable timed
settings.
The control panel contains a POWER ON-OFF switch with a POWER ON light, an OVER TEMP
light, a MASTER LOAD ON-OFF switch, a MODE SELECT MANUAL/AUTOMATIC switch, an
AUTO ON light, a clock, and individual KW LOAD STEP switches. All load step switches are the
toggle type with metal levers. The control panel also contains a FUSE for protection of the control
circuit. A Digital Metering Package is also included which monitors Volts, Amps, Frequency, and
kilowatts.
The control panel is supplied mounted in a remote wall mount enclosure. Refer to SB2196 for
dimensional information.
The Load Bank is sized for a core size of 104” high by 98” wide. Refer to SB2203 for dimensional
information.
*************************************************************
C A U T I O N
Never exceed the rated voltage as this will cause the Load Bank to
overheat.
Do not apply DC voltages as the contactors do not have arc blowout
magnets.
*************************************************************

Installation Avtron Load Bank • Part Number K711D36027
3-1
SECTION III
INSTALLATION
INSTALLATION CHECKOUT PROCEDURE -
TO BE DONE PRIOR TO OPERATION
This Installation Checkout Procedure is intended to be used upon initial receipt of equipment and
following any relocation of a permanent mounted Load Bank. These procedures apply to Load
Banks in general and may include steps not relevant to the specific unit being installed. Disregard
those procedures which do not apply.
*************************************************************
W A R N I N G
THE FOLLOWING TESTS ARE TO BE ACCOMPLISHED BY A
QUALIFIED ELECTRICIAN OR TECHNICIAN USING
EXTREME CAUTIONASPOTENTIALLY LETHALVOLTAGES
AND DANGEROUS ROTATING COMPONENTS ARE
PRESENT. IF ASSISTANCE IS REQUIRED, AVTRON CAN
PROVIDE START UP SERVICE AT A NOMINAL CHARGE.
AVTRON ALSOWILLPROVIDETELEPHONE ASSISTANCEIF
REQUIRED BY CALLING [phone].
*************************************************************
1. Verify the Load Bank placement meets the installation requirements found in the
INSTALLATION section of the instruction manual:
A. Check the clearance from both intake and exhaust to any obstruction.
B. If the location has a prevailing wind, make the wind aid in the cooling of the resistor
elements.
C. Duct exhaust air outdoors via a customer-supplied exhaust hood which, along with
intake losses, createsno more than 0.25" total system static pressure(pressure drop).
2. Check the mechanical integrity of all customer-supplied interconnection wiring:
A. Check lugs that they are properly crimped.
B. Check terminations that they are properly torqued.
3. Utilize system schematics to ohm out customer-supplied interconnectioncontrolwiringand
safety circuits:

Installation Avtron Load Bank • Part Number K711D36027
3-2
A. If control wiring is all the same color, ohm out each individual wire to confirm
proper labeling and placement.
C A U T I O N
Control wiring must be a minimum of 14 AWG for wire runs
under 50 feet. Consult Avtron factory for wire sizing when
wire run exceeds 50 feet.
B. Confirm the correct wire gauge has been used for interconnection wiring. Control
wiring should be a minimum of 14 AWG for control panel to Load Bank lengths of
50 feet or less. For lengths of greater than 50 feet, consult the factory.
4. Energize the source of control power only:
Check the control voltage and confirm it is within 10% of the required voltage.
*************************************************************
W A R N I N G
Control power is present on terminal block in steps 4 through 6.
*************************************************************
5. Verify the proper relays energize with each individual load switch.
A. Turn on each load step individually and observe that each relay or relays pulls in
without chatter or hesitation.
B. Turn off the master load switch. Turn on all the load steps. Turn the master load on
and observe the pull in of all the contactors. If chatter or hesitation is observed,
locate the cause of the voltage drop causing the problem.
This checkout procedure is intended to be a guide to Load Bank installations in general. Special
installation considerations not addressed herein may be necessary due to installation site or
environment. Any questions or concerns regarding Load Bank installation should be directed to
Avtron Field Service at [phone].
LOCATION

Installation Avtron Load Bank • Part Number K711D36027
3-3
The Load Bank must be used in a cool, well ventilated area. It must be installed where cool air is
continually available and where hot exhaust air will not be recirculated through the Load Bank. The
Load Bank must not be operated in a closed space.
The exhaust air may exceed 300F above ambient under full load conditions. The unit must not be
installed near any equipment, wiring, or plumbing which may be damaged by high air temperatures
or which may constitute a fire hazard.
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
elements. A Load Bank should not be installed so close to any surface as to reflect the
exhausted air back to the air intake.
2. Restriction of Cooling Air - Any obstruction located within five (5) feet of the inlet and
twelve (12) feet of the exhaust hood (duct) will restrict the Load Bank's airflow. Airflow is
also restricted when two or more Load Banks have air inlets positioned close to each other.
This competition for cooling air causes a low pressure area, restricting adequate airflow.
3. The Load Banks are designed to tolerate up to 0.25" water gage additional system airflow
resistance. This includes air intake resistance (building make up air pressure) and resistance
due to exhaust duct/louvers/screen.
4. If exhaust duct exits through motorized louvers, the design must be interlocked to assure full
open prior to operation. Consideration must also be given for louver design and actuator to
prevent heat problems.
Consult the factory if strong prevailing winds exist.
CONTROL CONNECTIONS
The control panel is supplied mounted in a 19-inch rack-type enclosure. Connect terminals of the
control panel to terminals of the Load Bank as shown on the schematic/interconnection diagram
D36028.
Control power is derived from an externally supplied 480V, 3-phase, 60 Hz power source connected
to the Load Bank terminal block TB1 terminals 19 and 20 as shown on schematic D36028.

Installation Avtron Load Bank • Part Number K711D36027
3-4
LOAD CONNECTIONS
Load connections are made to the main line power distribution bus bars. (Refer to Outline Drawing
SB2203.) The connections are marked A, B, and C. Cables to the Load Bank should be of adaquate
size to handle maximum rated load according to the National Electrical Code and any local codes.
The ampacities of these load connections are shown on the Load Bank schematic diagram, D36028.
GROUNDING
A permanent ground conductor must be connected to the Load Bank enclosure by an individual
ground wire to prevent a potential above ground on the enclosure. This ground conductor should be
run with the load power conductors to provide the lowest impedance fault path. The ground stud
must be connected to both the power source frame and to a good earth ground. The ground
conductor should be sized per the National Electrical Code Section 250-95, if not superseded by
local codes.

Operation Avtron Load Bank
4-1
SECTION IV
OPERATION
*************************************************************
C A U T I O N
Never exceed the rated voltage as this will cause the Load Bank to
overheat, resulting in damage to equipment.
Do not apply DC voltages as the contactors do not have arc blowout
magnets.
DO NOT allow objects to enter or block screens.
*************************************************************
MANUAL OPERATION
1. Place all switches on the control panel to the OFF position. Place MODE SELECT
MANUAL/AUTOMATIC operation toggle switch to MANUAL position.
2. Verify that all electrical connections (Control, Load, and Grounding) to the Load Bank have
been completed as described in the INSTALLATION section.
*************************************************************
C A U T I O N
DO NOT operate the Load Bank over the rated voltage as this will
cause catastrophic failure in the Load Bank.
*************************************************************
3. Place the control power ON/OFF switch to the ON position. The POWER ON light will
be energized, indicating control power is present.
4. Start the generator under test.

Operation Avtron Load Bank
4-2
5. The resistive loading is selected by toggle switches, using any one or combination of the
toggle switches to make up a given load.
6. By placing the MASTER LOAD switch to the ON position, the preselected load will be
applied to the power source.
7. Any available load step can be added or removed as required while the MASTER LOAD
switch is closed (ON).
8. To remove the load, open the MASTER LOAD switch by placing it in the OFF position.
MANUAL SHUTDOWN PROCEDURES
1. Place the MASTER LOAD switch to the OFF position.
2. Place the control power ON/OFF switch to the OFF position, and other switches on the
control panel should be turned OFF.
3. Shut down the power source/sources.
4. Disconnect the Load Bank from the power source(s).
AUTOMATIC OPERATION
1. Place all switches on the control panel to the OFF position. Place MODE SELECT
MANUAL/AUTOMATIC operation toggle switch to the AUTOMATIC position.
2. Verify that all electrical connections (Control, Load, and Grounding) to the Load Bank have
been completed as described in the INSTALLATION section.
3. Place the control power ON/OFF switch to the ON position. The control power light will be
energized, indicating control power is present. The AUTO ON light will also be energized.
4. When the programmed test cycle begins, a generator start signal will bring the engine
generator on-line. The Load Bank will add load steps in increments of 100, 150, 150, and
200 kW. After the programmed exercise period has expired, the load steps will be removed.
An adjustable generator cooldown period will allow the generator to operate in a no-load
condition. Refer to schematic D36028 for field adjustable functions and settings.
EXERCISER/CONTROLLER THEORY OF OPERATION

Operation Avtron Load Bank
4-3
The automatic exerciser/controller circuitry within the Load Bank allows for the generator to be
exercised on a programmable, weekly basis.
A programmable weekly timer (K216) is installed on control panel D36083. During a programmed
test cycle, a contact closure from K214 at TB1(17-18) will start the engine generator. K214 is a
“delay-off” relay which, at the end of the programmed exercise cycle, (controlled by K215), will
allow the engine generator to cool down, under a no load condition. When the propertemperature is
sensed, K51 will energize. K51 will initiate the adjustable “delay-on” relays K202, K204, K206,
and K208. These relays control adjustable “delay-off” relays K203, K205, K207, and K209, which
in turn control pilot relays K210, K211, K212, and K213. Each pilot relay controls a portion of the
Load Bank load. Based on the time delay settings of the adjustable relays, a wide range of exercise
control is available. Reference schematic D36028 for sample control scheme.

Maintenance Avtron Load Bank • Part Number K711D36027
5-1
SECTION V
MAINTENANCE
To provide long equipment life and to reduce the chance of electric shock, fires,and personal injury,
good maintenance procedures must be used. Before servicing, review the SAFETY
CONSIDERATIONS section of this manual.
The following examples of scheduled maintenance procedures are not intended to be all-inclusive,
but must be accomplished to maintain the equipment in a good, safe condition. All maintenance
work must be performed only by qualified personnel.
*************************************************************
W A R N I N G
Personal injury from electrical shock or from the moving fan blade
may result if ALL sources of power are not disconnected. Refer to
the SAFETY CONSIDERATIONS section of this manual.
Eye protection should be worn when cleaning the unit with
compressed air.
*************************************************************
DAILY
1. Remove any restrictions to the airflow through the Load Bank.
2. Check the screens to make sure that no objects have blocked or entered the openings. If
freezing conditions exist (below 32F or 0C) and freezing rain, sleet, or snow block the
exhaust hood/duct/louver, the following special precautions must be taken. Clear area
around exhaust opening.
3. Verify that the airflow is in the proper direction.
4. Assure that there is no recirculation of the exhaust air through the Load Bank.
THREE MONTHS

Maintenance Avtron Load Bank • Part Number K711D36027
5-2
1. Remove the access panels and screens, and inspect the load resistors for mechanical
breakdown which is demonstrated by excessive sagging of the elements. Replace worn
resistor elements with new resistor elements as required.
2. Inspect for broken ceramic insulators. Replace any broken or cracked insulator with a new
ceramic insulator.
3. Inspect for loose hardware or loose connections. Tighten where required.
4. Inspect all connections for oxidation or corrosion. Clean the connection or replace the
hardware where required.
5. Inspect all magnetic contactors to make sure that the contacts are not severely pitted or
corroded. The contacts must move freely and be properly seated.
6. Clean all dirt and debris out of the Load Bank. This can be accomplished by blowing the
inside of the units with clean, dry compressed air (not to exceed 40 PSI). Eye protection
should be worn when cleaning the Load Bank with compressed air.
7. Inspect all the wiring for any sign of insulation failure.
8. Replace all access panels and screens. Tighten all the fastening hardware securely.
9. Check the indicator lamps on the control panel.
ANNUALLY
The fan blower motors should be lubricated per the motor manufacturer's requirements and
specifications on the motor nameplate.

Replacement Parts List Avtron Load Bank • Part Number K711D36027
6-1
SECTION VI
REPLACEMENT PARTS LIST
INTRODUCTION
The parts list in this section contains the description, quantity required, and Avtron part numbers for
each listed part. The list alsoincludes, where appropriate, the manufacturer's name and part number,
as well as schematic reference designators to facilitate parts identification.
NOTE
Every effort has been made to ensure the accuracy of this
information. However, changes are sometimes necessary and
revisions to the parts list may be made at any time without notice.
REFERENCE DESIGNATORS
Service personnel may use this parts list along with the Avtron system schematics to identify and
order replaceable parts. The reference designators were carefully selected and matched to those on
the schematic diagrams and equipment to simplify the troubleshooting and repair process.
NOTE
When ordering replacement parts, be certain to state the part's
description, Avtron part number, and the schematic reference
designator number if one is available. Also include the model and
serial number of the equipment.

Replacement Parts List Avtron Load Bank • Part Number K711D36027
6-2
SCHEMATIC
REFERENCE DESCRIPTION
MANUFACTURER
and PART NO.
AVTRON
P/N
QTY/
UNIT
Form No. 277
AVTRON MODEL K711 K711-
LOAD BANK D36027
.SCHEMATIC/INTCON DIAGRAM D36028 REF
.INSULATOR 411141 1728
.INSULATOR 411145 72
.RESISTANCE ELEMENT 606337 72
K1,2,3A-7A, .RELAY B14796 12
3B-7B
F1-6,7A-21A, .FUSE, 80A, 600V1 LITTELFUSE 324420 36
7B-21B JLLS-80
XF1-6,7A-21A, .FUSEBLOCK BUSSMANN 324967 12
7B-21B T60100-3C
.CERAMIC 411181 144
.CERAMIC 411182 288
S60 .TEMPERATURE SWITCH EMERSON ELECTRIC 360379 1
60T-13 203546
CT2,3 .CURRENT TRANSFORMER, 800:5 INSTRUMENT 370908 2
TRANSFORMERS
7RBT801
.CONTROL ENCLOSURE ASSEMBLY D36083 1
..SCHEMATIC/INTCON DIAGRAM D36028 REF
S50 ..SWITCH, TOGGLE CARLINGSWITCH 360591 1
2GL54-73
S1-7,20,21 ..SWITCH, TOGGLE CARLIGSWITCH 360589 9
2GK51-73
F101 ..FUSE, 600V, 10A LITTELFUSE 324128 1
KLKR-10
XF101 ..FUSEHOLDER BUSSMANN 325022 1
HPF-WT
DS21 ..LIGHT, INDICATOR, RED DIALIGHT 329714 1
556-3105-304
DS20,50 ..LIGHT, INDICATOR, GREEN DIALIGHT 329715 2
556-3205-304
K99 ..RELAY POTTER & BRUMFIELD 350525 1
T92S7A22120
M1 ..METER MULTITEK 336992 1
M801-MD4-VE
K216 ..CLOCK, WEEKLY TIMER OMRON ELECTRONICS 369270 1
H5S-B
T1 .CONTROL TRANSFORMER HEVI-DUTY ELECTRIC 370984 1
E500
K215 .RELAY OMRON ELECTRONICS 369269 1
H3CA
K203,205,207, .TIMER, DELAY ON BREAK SYRELEC SA 369262 5
209,214 88-865-305
XK215 .SOCKET, RELAY OMRON ELECTRONICS 358656 1
P2CF-11

Replacement Parts List Avtron Load Bank • Part Number K711D36027
6-3
SCHEMATIC
REFERENCE DESCRIPTION
MANUFACTURER
and PART NO.
AVTRON
P/N
QTY/
UNIT
Form No. 277A
XF102-107 .FUSEBLOCK BUSSMANN 324615 2
BM6033SQ
XF102,103 .FUSE, 3A, 600V LITTELFUSE 324453 2
KLDR-3
F104-106 .FUSE, 1A, 600V LITTELFUSE 324449 3
KLDR-1
K202,204,206, .RELAY, TIME DELAY CROUZET 351981 4
208 88-865-215
XK51,201,210- .SOCKET, RELAY POTTER & BRUMFIELD 358280 6
213 27E893
K51,201, .RELAY POTTER & BRUMFIELD 351060 6
210-213 KUP14A15
XK51,201, .RETAINER, RELAY POTTER & BRUMFIELD 467550 6
210-213 20C318
F107 .FUSE, 10 AMPS, 600V LITTELFUSE 324128 1
KLKR-10