Lamarche A31 User manual

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This manual is subject to change without notice. You may obtain the newest version of the manual at www.lamarchemfg.com
106 Bradrock Dr. Des Plaines, IL 60018-1967
CPN 40966
Instruction Drawing Number: P25-LA31STD-1
Tel: [phone]
Fax: [phone]
Revision A08
Rev. Date: 01/21
ECN: 22782
Installation and Operation Manual
La Marche Manufacturing Company
www.lamarchemfg.com
A31
DC –AC Sine Wave Inverter

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Important Safety Instructions
Before using this equipment, read all manuals and other documents related to this inverter and other equipment
connected to this inverter. Always have a copy of an inverter’s manual on file nearby, in a safe place; if a
replacement or latest copy of a manual is needed, it can be found at www.lamarchemfg.com.
Electrical Safety
WARNING: Hazardous Voltages are present at the input of power systems. The output from inverters
and from batteries may be low in voltage, but can have a very high current capacity that may cause
severe or even fatal injury.
When working with any live battery or power system, follow these precautions:
•Never work alone on any live power system; someone should always be close enough to come to your aid.
•Remove personal metal items such as rings, bracelets, necklaces, and watches.
•Wear complete eye protection (with side shields) and clothing protection.
•Always wear gloves and use insulated hand tools.
WARNING: Lethal voltages are present within the inverter. Parts inside the inverter may still be
energized even when the inverter has been disconnected from the AC input power. Check with a meter
before proceeding. Do not touch any uninsulated parts.
•A licensed electrician should be used in the installation of any inverter.
•Always disconnect the inverter from the supply, batteries, and loads before performing maintenance,
replacing parts, or cleaning.
•Always assume that an electrical connection is live and check the connection relative to ground.
•Be sure that neither liquids nor any wet material come in contact with any internal components.
•Do not operate this inverter outside the input and output ratings listed on the inverter nameplate.
•Do not use this inverter for any purpose not described in the operation manual.
Mechanical Safety
•This inverter or parts of the inverter may get very hot during normal operation, use care when working
nearby and do not place any items on top of the inverter.
•Do not expose equipment to rain or snow. Always install in a clean, dry location.
•Do not operate equipment if it has received a sharp blow, been dropped, or otherwise damaged in any way.
•Do not disassemble this inverter. Incorrect re-assembly may result in a risk of electric shock or fire.
•If modifications to the enclosure are necessary, such as drilling for conduit fitting, ensure the interior is
protected from metal shavings and debris. Additional precautions should be taken to remove any remaining
debris from interior of inverter prior to energizing.
Battery Safety
WARNING: Follow all of the battery manufacturer’s safety recommendations when working with or
around battery systems. DO NOT smoke or introduce a spark or open flame in the vicinity of a battery.
Some batteries generate explosive gases during normal battery operation.
•If it is necessary to remove battery connections, always remove the grounded terminal from the battery first.
•Remove personal metal items such as rings, bracelets, necklaces, and watches.
•Always wear rubber gloves, safety glasses, and a rubber lined vest/apron when working near a battery.
•Have plenty of fresh water and soap nearby in case battery electrolyte contacts skin, clothing, or eyes.
•If the battery electrolyte contacts skin or clothing, wash immediately with soap and water.
•If the electrolyte enters the eye, immediately flood the eye with running cold water for at least ten (10)
minutes and seek medical attention immediately.
•Do not drop or place any materials on a battery. A spark or short-circuit could cause an explosion.

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Inverter Location
•Allow at least 6 inches of free air on all vented surfaces for proper cooling.
•Allow sufficient clearance to open the front panel for servicing.
•Do not operate this inverter in a closed-in area or restrict ventilation in any way.
•Do not place inverter below battery.
•Never allow battery electrolyte to drip on this inverter when reading the specific gravity or filling the battery.
•Never place this inverter directly above a standard flooded battery. Gases from the battery will corrode and
damage equipment.
•A sealed maintenance free or valve regulated lead acid (VRLA) battery may be placed below this equipment.
Check for Damages
Prior to unpacking the product, note any damage to the shipping container and take pictures. Unpack the product
and inspect the exterior and interior of product for damage. If any damage is observed, take pictures and contact
the carrier immediately to file a damage claim. Contact La Marche for a Return Material Authorization number to
have the inverter sent back for evaluation and repair.
CAUTION: Failure to properly file a claim for shipping damages, or provide a copy of the claim to La
Marche, may void warranty service for any physical damages reported for repair.
Returns for Service
Save the original shipping container. If the product needs to be returned for service, it should be packaged in its
original shipping container. If the original container is damaged/unavailable, make sure the product is packed
with at least three inches of shock-absorbing material to prevent shipping damage. La Marche is not responsible
for damage caused by improper packaging of returned products.
Inspection Checklist
Enclosure exterior and interior is not marred or dented.
There are no visibly damaged components.
All internal components are secure.
Printed circuit boards are firmly seated.
All hardware and connections are tight.
All wire terminations are secure.
All items on packing list have been included.
Handling
Equipment can be very heavy with uneven distribution of weight. Use adequate manpower or equipment for
handling. Until the equipment is securely mounted, care must be used to prevent equipment from being accidently
tipped over or dropped.

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Table of Contents
Important Safety Instructions ........................................................................................................................ i
Electrical Safety......................................................................................................................................... i
Mechanical Safety...................................................................................................................................... i
Battery Safety ........................................................................................................................................... i
Inverter Location .......................................................................................................................................ii
Check for Damages ...................................................................................................................................ii
Returns for Service ....................................................................................................................................ii
Inspection Checklist...................................................................................................................................ii
Handling ...................................................................................................................................................ii
Table of Contents ........................................................................................................................................iii
Model Scope/General Description.................................................................................................................. 1
Understanding the Model Number................................................................................................................. 1
1.0 Equipment Handling.......................................................................................................................... 2
1.1 Storing the A31............................................................................................................................. 2
1.2 Moving the A31............................................................................................................................. 2
2.0 Installation ....................................................................................................................................... 2
2.1 Mounting the A31.......................................................................................................................... 2
2.1.1 Rack-Mounting the A31.............................................................................................................. 3
2.1.2 Floor-Mounting the A31 ............................................................................................................. 4
2.2 Making the DC Input Connections .................................................................................................. 5
2.3 Making the AC Output/AC Bypass Line Connections......................................................................... 6
3.0 Operation......................................................................................................................................... 6
3.1 A31 Start-Up................................................................................................................................. 6
3.2 Checking the Installation ............................................................................................................... 6
3.3 Start-Up Sequence ........................................................................................................................ 6
3.4 LED Indicators .............................................................................................................................. 8
3.5 Factory Settings ............................................................................................................................ 8
4Service ................................................................................................................................................. 9
4.1 Performing Routine Maintenance.................................................................................................... 9
4.2 Troubleshooting Procedure ...........................................................................................................10
4.3 Troubleshooting Chart ..................................................................................................................11
Appendix A: A31 Specifications ....................................................................................................................13
Appendix B: Power Wiring Guide..................................................................................................................14
Appendix C: Manufacturer’s Standard Warranty ............................................................................................15
Appendix D: Manufacturer’s Extended Parts Warranty...................................................................................16
Appendix E: Document Control and Revision History .....................................................................................17

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Model Scope/General Description
The La Marche Model A31 is a transistorized DC to AC inverter designed to power an AC load.
The Model A31 will provide a sine wave output with approximately 5% total harmonic distortion into AC loads
with power factors up to 0.8 over a wide DC input range.
The ferroresonant output transformer provides input to output isolation, output regulation, current limiting, and
filtering. The DC input from the battery source is switched by transistors in all solid-state electronic circuitry to
produce a sine wave output.
The DC input sources are sensed for low and high voltage conditions, the unit is turned off automatically if the
DC input is not within the proper range.
Understanding the Model Number
The A31 model number is coded to describe the features that are included. Find the model number on the
nomenclature nameplate of the inverter. Follow the chart below to determine the configuration of the inverter.
Optional Accessories Included in the Inverter
This inverter may have been outfitted with a number of optional accessories or option packages. To determine
the options included (if any) refer to the cover page of the manual package. If the manual package that is included
with the inverter is no longer available, contact La Marche and provide the model or serial number of the inverter
to receive a list of the included accessories.

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1.0 Equipment Handling
1.1 Storing the A31
If the A31 is to be stored for more than a few days after delivery, it should be stored within its shipping container.
The location chosen for storage should be within an ambient temperature of -40 to 140°F (-40 to 60°C) with a
non-condensing relative humidity of 0 to 95%. Storage should not exceed 2 years due to the limited shelf life of
the DC filtering capacitors when they are not in service.
1.2 Moving the A31
After careful inspection and upon verification that the A31 is undamaged, identify the enclosure style and weight
of the A31 inverter. Refer to the table below:
Output
Voltage
AC Output
1KVA
1.5KVA
2KVA
3KVA
4KVA
5KVA
7.5KVA
10KVA
15KVA
20KVA
24 VDC
9D Case
9D Case
9E Case
170.1 lbs
85 lbs
230 lbs
77.1 kg
38.6 kg
104.3 kg
48 VDC
9D Case
9D Case
9E Case
9E Case
9E Case
9E Case
44 Case
176 lbs
195 lbs
225 lbs
267 lbs
205 lbs
240 lbs
910 lbs
79.8 kg
88.4 kg
102 kg
121.1 kg
156.9 kg
170.1 kg
412.7 kg
120 VDC
9D Case
9E Case
9E Case
9E Case
9E Case
9E Case
72 Case
72 Case
44 Case
47B Case
182 lbs
220 lbs
230 lbs
288 lbs
330 lbs
372 lbs
715 lbs
758 lbs
1170 lbs
1900 lbs
82.5 kg
99.8 kg
104.3 kg
130.6 kg
149.7 kg
168.7 kg
324.3 kg
343.8 kg
530.6 kg
861 kg
Table 1 –Case Type and Weight Table
2.0 Installation
2.1 Mounting the A31
When mounting the A31 in any configuration, consider the size and weight of the inverter. The rack and/or floor
must be able to support the weight of the inverter, as well as an additional safety factor. Refer to data sheet to
verify the weight of the inverter and the method of mounting using the table below. The location chosen for the
inverter should be within an ambient temperature range of 32˚F to 122˚F (0˚C to 50˚C) with a non-condensing
relative humidity no higher than 95%. The inverter should be mounted in an area free of explosive materials and
away from any liquids. The A31 utilizes convection cooling so a clearance of at least 6 in (152 mm) of free air
must be maintained on the top, bottom, left and right side for cooling air. Maintain 36 in (914 mm) or more of
clearance at the front of the inverter in order to allow for operation and maintenance. The bolts or screws used
to secure the inverter should be sufficient length to assure a vibration-free mounting. The preferred fastener is a
machine bolt backed with a flat washer, lock washer, and nut. All hardware should be corrosion resistant.
Enclosure
Number
Cable Entry
Standard
Mounting
AC Input
DC Output
39
Right
Left
19”/23” Rack
33
Right/Top/Bottom
Left/Top/Bottom
23” Rack
9D
Right
Left
23” Rack
9E
Right
Left
23” Rack
70
Bottom
Bottom
Floor
72
Top/Bottom
Top/Bottom
Floor
44
Top/Bottom
Top/Bottom
Floor
47B
Top/Bottom
Top/Bottom
Floor
Table 2 –Mounting Methods

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NOTE: All dimensions are in inches. For further A31 enclosure information, see the outline drawings online at
http://www.lamarchemfg.com/info/enclosure-drawings.html
2.1.1 Rack-Mounting the A31
The A31 can be installed in most relay racks with standard EIA hole spacing. If a relay rack is needed, they are
available for purchase from La Marche. The 9D, 9E, 33, and 39 enclosures are shipped from the factory with
the necessary brackets installed for rear mounting on a relay rack . The rack mounting bracket for the 39 enclosure
allows for mounting on a 19” or 23” rack, and the 9D, 9E, and 33 enclosures allow for mounting on a 23” rack.
Rack Mounting Procedure
Before installing the inverter on the rack, locate the conduit entrances and assure the knockouts on the top,
sides, or bottom of the inverter are accessible after the inverter is rack mounted. Provide at minimum 6in (152mm)
of air space above and below to allow for cooling.
Figure 1 - 39 Enclosure Bolt Pattern
Figure 3 –9D/9E Enclosure Bolt Pattern
Figure 2 - 33 Enclosure Bolt Pattern
10.438

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2.1.2 Floor-Mounting the A31
Floor-Mounting Procedure
Floor-mounting the 70, 72, 44, and 47B enclosures is standard. To floor-mount the A31, install four anchor
bolts into the floor. Place the inverter on the anchor bolts, add appropriate mounting hardware, and tighten
securely. Refer to the figure below for hardware specifications and floor-mounting dimensions. All dimensions are
given in inches.
Case Size
A
B
Bolt Size
70
25.75"
13"
1/4"
72
25.75"
17.5"
1/4"
44
22"
17.06"
3/8"
47B
36.5"
37.5"
9/16"
Figure 4 –A31 Enclosure Footprint

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2.2 Making the DC Input Connections
Before beginning any work inside the inverter, ensure that all incoming AC/DC power is de-energized and/or
isolated. Verify that no voltage is present inside the case by using a voltmeter at all input and output terminals.
Assure the inverter that is being used is the same number and type of cell as the inverter front nameplate
specifications. Select wire size using the table below. This is based on an overload current of 110-115% of the
input current listed on the inverter nameplate.
NOTE: Feeder breaker should be sized to match the size of the DC protection used in inverter.
Breaker Size/
Fuse Size (Amps)
Minimum Wire Size Requirement
for Customer Connection
Equipment Grounding
Conductor Minimum
3
#14
#14
5
#14
#14
10
#14
#14
15
#14
#14
20
#12
#12
25
#10
#12
30
#10
#10
40
#8
#10
50
#8
#10
60
#6
#10
70
#6
#8
80
#4
#8
90
#4
#8
100
#4
#8
125
#2
#6
150
#1
#6
175
#1/0
#6
200
#2/0
#6
250
#4/0
#4
300
250 MCM
#4
Table 4 –AC/DC & Ground Wire Size Minimum Requirements
(All wires specified in the table are rated at 90 °C or 194 °F)
NOTE: These are recommended sizes per La Marche Standards. The National Electrical Code (NEC) and Local
Wiring Codes must be followed.
DC Connection Procedure
Select proper size for the DC wires using the table above. If the distance between the inverter’s DC input and the
battery/load exceeds 10 feet, use the Power Wiring Guide in Appendix B to minimize the voltage drop across the
wire distance.
Make sure that the AC/DC breakers and the Inverter ON/OFF switch are OFF. Check polarity of DC input cables
and verify with multimeter. The positive battery wire should be connected to the POS terminal and the negative
battery wire should be connected to the NEG terminal.
NOTE: It is recommended to use a battery disconnect breaker between inverter and battery bank; helpful during
battery or inverter maintenance.

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2.3 Making the AC Output/AC Bypass Line Connections
A terminal strip is provided for the AC load, as well as for the AC bypass line if applicable. Before beginning any
work inside the inverter, ensure that all incoming AC/DC power is de-energized and/or isolated. Verify that no
voltage is present inside the inverter by using a voltmeter at all input and output terminals.
First, select wire size using the Table 4. Connect an adequate earth ground lead (use table on previous page for
sizing) to the terminal marked ground and to the LINE SYNC INPUT (GND) terminal.
For the AC load, connect the AC load phase (hot) to the LOAD (Ø) terminal and the AC load neutral to the LOAD
(N) terminal.
For the AC bypass line, connect the AC bypass line phase (hot) to the LINE SYNC INPUT (Ø) terminal and the AC
bypass line neutral to the LINE SYNC INPUT (N) terminal.
NOTE: For inverters with the static switch option (22P, 22S, 164, or 165), also connect the AC bypass line phase
(hot) to the LINE (Ø) terminal and the AC bypass line neutral to the LINE (N) terminal.
Figure 5 –One-Line Diagram for Typical A31 Inverter Application
3.0 Operation
3.1 A31 Start-Up
All equipment is shipped from the factory fully inspected and adjusted to manufacturer defined default values
based on the model number. Do not make any adjustments unless the equipment has been energized and the
settings have been determined to be incorrect.
3.2 Checking the Installation
Before attempting to start up the A31, check and verify that all connections are correct. Check that all terminations
and contacts are tightened securely. Check for any loose connections or unsecured components in the inverter.
Verify that the AC bypass line and battery/load voltage match the voltages on the nameplate of the inverter.
3.3 Start-Up Sequence
Before starting the A31 inverter, determine whether the inverter does or does not have the static switch option
(22P, 22S, 164, or 165) by referring to the front page of the manual, then follow the appropriate instructions
below:

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For Standard Inverters (No Static Switch):
1. Push and hold the Pre-Charge button until the green READY LED illuminates. *
2. Release the Pre-Charge button and immediately turn on the DC breaker, then turn the inverter ON/OFF switch
(SW-1) to the ON position. The inverter should begin to emit a humming sound.
3. Turn on the AC breaker.
4. Measure the output voltage of the inverter across the AC LOAD terminals to assure that it agrees with
nameplate.
For Inverters with 1ms Static Switch (Option 22P/22S):
1. Push and hold the Pre-Charge button until the green READY LED illuminates. *
2. Release the Pre-Charge button and immediately turn on the DC breaker, then turn the inverter ON/OFF switch
(SW-1) to the ON position. The inverter should begin to emit a humming sound.
3. Turn on the AC breaker. The front panel LEDs will perform a lamp test. After the lamp test, the Inverter
Available LED should be lit. For option 22P, the Preferred Source LED should also be lit. For option 22S, the
Alternate Source LED should also be lit.
4. Turn on the AC bypass source (utility). After a couple of seconds, and the Phase Lock and Utility Available
LEDs should additionally be on. Assure the inverter is set to Auto Retransfer by setting the Retransfer toggle
switch to Auto. For inverters with Option 22D, please read the appropriate instruction manual. For option 22S,
the Preferred Source LED should also turn on and the Alternate Source LED turn off.
5. Measure the output voltage of the inverter across the AC LOAD terminals to assure that it agrees with
nameplate.
For Inverters with 10-15ms Static Switch (Option 164/165):
1. Push and hold the Pre-Charge button until the green READY LED illuminates. *
2. Release the Pre-Charge button and immediately turn on the DC breaker, then turn the inverter ON/OFF switch
(SW-1) to the ON position. The inverter should begin to emit a humming sound.
Inverter Prime (Option 164):
A. Turn on the AC breaker. The LOAD ON PRIME and PRIME AVAIL. LEDs should be lit on the 139A static
switch board. On the front panel, the green INVERTER AVAILABLE LED should be lit.
B. Turn on the AC bypass source (utility). The yellow BYPASS AVAILABLE LED should additionally be lit.
C. Measure the output voltage of the inverter across the AC LOAD terminals to assure that it agrees with
nameplate.
Inverter Standby (Option 165):
A. Turn on the AC breaker. The LOAD ON PRIME and PRIME AVAIL. LEDs should be lit on the 139A static
switch board. On the front panel, the green INVERTER AVAILABLE and the red LOAD ON ALTERNATE
LED should be lit.
B. Turn on the AC bypass source (utility). The yellow BYPASS AVAILABLE LED should additionally be lit. The
LOAD ON ALTERNATE LED should be off after a couple of seconds.
C. Measure the output voltage of the inverter across the AC LOAD terminals to assure that it agrees with
nameplate.
CAUTION: Before resetting the DC breaker, the pre-charge instructions must be followed before restarting the
inverter or damage to the inverter may occur.
*NOTE: If the green READY LED does not light, check the type and number of cells of the battery to verify that
it is correct. If the red REVERSE POLARITY LED illuminates, the battery has not been installed correctly.
Disconnect the battery wires immediately or damage to the inverter may occur.

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LED3 (HV) –
High Voltage Shutdown
LED2 (LV) –
Low Voltage Shutdown
LED1 (PL) –
Phase Lock
3.4 LED Indicators
All A31 inverters include the S2A-167S oscillator/line sync board which has voltage sensing circuitry and oscillator
circuits, providing protection for low/high DC input voltages and assuring the inverter output syncs with the AC
bypass line. The S2A-167S board includes 3 red status LEDs, as follows:
Phase Lock (PL) – This PL LED will turn on if the inverter output is in sync with the AC bypass line.
High DC Voltage (HV) – This HV LED will turn on and output from the inverter will be inhibited if the DC input
voltage rises above the specified voltage threshold. The LED will turn off once the high DC voltage condition is
no longer present.
Low DC Voltage (LV) – The LV LED will turn on and output from the inverter will be inhibited if the DC input
voltage falls below the specified voltage threshold. The LED will turn off and the inverter output will once the low
DC voltage condition is no longer present.
3.5 Factory Settings
All A31 inverters are set at the factory based on the model number with the following settings:
Low DC Voltage Shutdown: 1.73 V/C for LA
1.10 V/C for NC
High DC Voltage Shutdown: 2.45 V/C for LA
1.60 V/C for NC
Phase Lock Frequency Range: 57.5 Hz –62.5 Hz
Current Limit: 150% of nominal output current (fixed; not adjustable)
NOTE: V/C –Volts per Cell, LA –Lead Acid, NC –Nickel Cadmium, Hz –Hertz
Figure 6 –S2A-167S Oscillator/Line Sync Board

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4 Service
All work inside the A31 inverter should be performed by qualified personnel. La Marche is not responsible for any
damages caused by an unqualified technician.
Before working inside the A31, ensure the AC power is off at the main breaker box and the battery has
been removed from the inverter’s DC input terminals, either by removing the battery cables or exercising
the battery disconnect. Verify that no voltage is present by using a voltmeter at all input and output
terminals.
4.1 Performing Routine Maintenance
Although minimal maintenance is required on the A31 inverter, routine checks and adjustments are recommended
to ensure optimum system performance.
Yearly
1. Confirm air vents are open. Remove dust and debris from interior of inverter.
2. Verify all connections are tight.
3. Perform a visual inspection on all internal components.
4. Check front panel meters for accuracy and LED operation.
5. Check capacitors for electrolyte leakage and replace if necessary.
Every 7 Years
1. If the inverter is consistently operated in extreme temperature environments, the capacitors should be
replaced.
Every 10 Years
1. Check magnetics, components and wiring for signs of excessive heat.
2. Replace capacitors if not done at the 7-year interval.

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4.2 Troubleshooting Procedure
Troubleshooting should be performed only by trained service personnel or experienced electricians. Before setting
up any complicated testing or making any conclusions, inspect the inverter using the guide below.
Check the following:
1. Check AC output cables, connections, battery type, and number of cells against the inverter’s rating.
2. Check input connections, input voltage and breaker size.
3. Check for shipping damage, loose connections, broken wires, etc.
4. Check the DC input cables to make sure they are proper polarity and secure. The DC voltage input must be
above 1.73 volts per cell (lead acid) and 1.1 volts per cell (nickel cadmium).
5. Check the AC bypass line connections to make sure they are proper and secure. Total load must not exceed
the nameplate rating.
6. Certain failures can be caused by defective batteries and user loads; make sure batteries and loads are free
from defects.
NOTE: If the problem is found to be located in the printed circuit boards, the board should be replaced. No
attempt should be made to repair circuit boards in the field.
La Marche Service Technicians are available to help with troubleshooting or with scheduling inverter service.
When calling for a service inquiry or for troubleshooting assistance, be sure to have all of the following information
on hand:
1. Equipment model number and serial number.
2. The measured DC input voltage and AC bypass voltage (if applicable).
3. The measured AC output voltage, with and without the loads.
4. Result of the check of the AC and DC breakers.
5. The AC output current and voltage, measured with load connected to inverter.
NOTE: When ordering replacement parts, drawings, or schematics, provide the model number, serial number,
and description of problem, if available.
La Marche Phone Number: [phone]
24-hour Emergency Number: [phone]

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4.3 Troubleshooting Chart
Isolate from all power sources prior to performing any interior verifications or part replacements.
Symptom
Possible Cause
1
Inverter AC Breaker Trips
Overload Condition
Shorted Equipment or Component on AC output
Defective AC Breaker
Shorted SCRs (if applicable)
2
Inverter DC Breaker Trips
Capacitor Pre-Charge Circuitry Improperly Used
Defective C1, C2, or C4 Capacitor
Defective S2A-167S Oscillator/Line Sync Board
Defective S2A-297/S2A-306 IGBT Drive Board
Defective IGBT Module
Shorted Wiring
Incorrect Battery Connected
Shorted Battery Cells
3
Lockout (No AC Output)
Low or No DC Voltage Input
Defective Inverter AC Breaker
Defective Inverter DC Breaker
Broken Wire
Shorted or Open C1 Capacitor
Low or High DC Voltage Shutdown Activated or
Improperly Set
Open F2 Fuse
Open Fuse on S2A-297/S2A-306 IGBT Drive
Board
4
F2 Fuse Clears
Defective S2A-167S Oscillator/Line Sync. Board
Defective S2A-297/S2A-306 IGBT Drive Board
5
Bypass AC Breaker Tripped
AC Bypass Line Overload Condition
Shorted SCRs (if applicable)
6
READY LED for Pre-Charge Circuitry Not
Illuminating
Defective C2 Capacitor
Defective READY LED
Improper Connection to S2A-172 Reverse Polarity
Board
No or Low DC Voltage Input
Inverter ON/OFF Switch set to ON
Defective IGBT Module
Defective C4 Capacitor
Open Pre-Charge Resistor
Defective Batteries
7
Inverter’s AC Load Supplied by Wrong Source
Defective SCR Module
Defective Static Switch
Overloaded Prime Source

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Ordering Replacement Parts
Contact La Marche to place an order for spare or replacement parts. To order replacement parts; please provide
the model and serial number of the battery inverter, the parts needed, and the quantity required.
SCR Modules
The procedure for checking the SCR module is as follows:
➢Disconnect the wiring going to the module.
➢Using an ohmmeter, the three main terminals (A1K2, K1, A2) you should read high resistance in both
directions on your meter.
➢Gate (G1) should read a high resistance between the top (A1K2), bottom (A2) terminals and a low resistance
(10 Ohm - 40 Ohm) to the middle (K1) terminal.
➢Gate (G2) should read a high resistance between the middle (K1) and (A2) terminal and a low resistance
between terminal (A1K2).
NOTE: A wiring diagram of the module is located on the side of the component.
IGBT Modules
➢With an ohmmeter, measure the resistance between Terminal 1 (collector) and Terminal 2 (emitter) negative
lead on Terminal 1 should read, low resistance. Reverse the meter leads and it should read a high resistance.
➢With negative lead on one, measure to Terminal 3, it should read high resistance.
➢With negative lead on Terminal 1, measure to Terminal 5, it should read a low resistance.
➢When the S2A-297 or S2A-306 card is removed, jump the gate and emitter of the IGBT with copper wire to
protect from ESD damage.
C1, Resonating Capacitors 560 VAC –660 VAC (approximately)
➢With an ohmmeter, the meter should deflect to low resistance, then gradually rise to high resistance.

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Appendix A: A31 Specifications
ELECTRICAL
DC Input Voltages
24VDC: 21 –30VDC
48VDC: 42 –60VDC
120VDC: 105 –150VDC
Voltage Range: ± 10% from nominal
AC Output
AC Output Voltage: 1 Phase –120VAC (Standard), 208VAC, 220VAC, 240VAC
AC Output Power: 1000VA –15000VA (0.8 lagging factor)
Regulation
Line Regulation: ±3% over DC battery range
Load Regulation: ±4% from no load to full load
Frequency Regulation: ±0.5% (Quartz Clock)
Approximate
Efficiency
24VDC: 70 –75%
48VDC: 85 –90%
120VDC: 85 –90%
Total Harmonic
Distortion
Approximately 5% at nominal DC input & full load. Less than 3% for any single
harmonic
Meters
Options 06C/06D –Analog DC Ammeter & DC Voltmeter ± 2% Accuracy
Option 22D –Digital DC Ammeter & DC Voltmeter ± 1% Accuracy
PROTECTION
Current Limit
Approximately 150%, protected by AC Output Breaker
Input/ Output
Input: DC Breaker, Reverse Polarity Protection Indicator, Filter Pre-Charge Circuit
Output: AC Breaker, AC Bypass Line Fuse
ENVIRONMENTAL
Audible Noise
Less than 65dBA at any point 5 feet from any vertical surface
Operating
Temperature
32 to 122˚F (0 to 50˚C)
Storage
Temperature
-40 to 140°F (-40 to 60°C)
Relative Humidity
0 to 95% (non-condensing)
Cooling
Convection Cooled (4000VA and larger inverters are fan-assisted)
Shock
The inverter in its shipping container withstands shock developed when one edge
of the container is dropped six inches while the opposite edge is resting on the
ground, or it is dropped two inches without any physical damage or degradation of
the electrical performance.
Vibration
The inverter in its shipping container, withstands vibration encountered in shipping
without physical damage or degradation of the electrical performance.
Altitude
This inverter is capable of operation at altitudes up to 3,300 feet at an ambient
temperature of up to +50°C (122°F) and 10,000 feet at an ambient temperature of
up to +40°C (104°F).
Ventilation
The inverter should be mounted so that ventilating openings are not blocked and
air entering the cabinet does not exceed 50° C (122°F).

14
Appendix B: Power Wiring Guide
Use the following formulas and table to determine proper wire size for minimal voltage drop. At distances
exceeding 10 feet, the DC wire size should be chosen to keep the voltage difference between the inverter’s DC
input terminals and the battery at less than 1/2 volt when the inverter is fully loaded.
Table of Conventions:
CMA = Cross section of wire in circular MIL area
A= Ultimate drain in amps
LF = Conductor loop feet
MaxAmp= Maximum allowable amps for given voltage drop
AVD = Allowable voltage drop
K = 11.1 for commercial (TW) copper wire
= 17.4 for aluminum
Calculating Wire Size Requirements:
AVD KLFA
CMA  =
Table 5 –Wire Size/Area Table
Calculating Current Carrying Capacity of Wire:
KLF AVDCMA
MaxAmp 

=
Size
(AWG)
Area
CIR.MILS
Size
(MCM)
Area
CIR.MILS
18
1620
250
250000
16
2580
300
300000
14
4110
350
350000
12
6530
400
400000
10
10380
500
500000
8
16510
600
600000
6
26240
700
700000
4
41740
750
750000
3
52620
800
800000
2
66360
900
900000
1
83690
1000
1000000
0
105600
1250
1250000
00
133100
1500
1500000
000
167800
1750
1750000
0000
211600
2000
2000000

15
Appendix C: Manufacturer’s Standard Warranty
(IF THE INVOICE SHOWS THAT YOU HAVE PURCHASED THE EXTENDED PARTS WARRANTY OR IF YOU ARE INTERESTED IN
PURCHASING THE EXTENDED PARTS WARRANTY,SEE THE MANUFACTURER’S EXTENDED PARTS WARRANTY)
All La Marche Manufacturing Co. equipment has been thoroughly tested and found to be in proper operating
condition upon shipment from the factory and is warranted to be free from any defect in workmanship and
material that may develop within one year from date of purchase. In addition to the standard one (1) year
warranty, La Marche warrants its magnetics and power diodes on a parts replacement basis only for nine (9)
more years under normal use.
Any part or parts of the equipment (except protective devices, DC connectors and other wear-related items) that
prove defective within a one (1) year period shall be replaced without charge providing such defect, in our opinion,
is due to faulty material or workmanship and not caused by tampering, abuse, misapplication or improper
installation. Magnetics and power diodes are warranted for ten (10) years after date of purchase. During the
last nine (9) years of this ten (10) year warranty period, the warranty covers parts replacement only, no labor or
other services are provided by La Marche, nor is La Marche obligated to reimburse the owner or any other person
for work performed.
Should a piece of equipment require major component replacement or repair during warranty period, these can
be handled in one of three ways:
1. If the Purchaser elects to take the responsibility of repairing the equipment and requests replacement part(s), Purchaser
or Sales Representative must contact Factory for return authorization and a purchase order must be issued. Replacement
part(s) will be promptly shipped and invoiced. After the defective part(s) are returned and inspected at the Factory, if the
defect(s) were due to faulty material or workmanship, credit will be issued.
2. The equipment can be returned to the La Marche factory to have the inspections, parts replacements and testing
performed by factory personnel. Should it be necessary to return a piece of equipment or parts to the factory, the
customer or sales representative must obtain authorization from the factory. If upon inspection at the factory, the defect
was due to faulty material or workmanship, all repairs will be made at no cost to the customer during the first year. If the
Extended Warranty is purchased, the parts required for repair will also be at no cost but La Marche will notify the Purchaser
of the costs of Labor to replace the defective part(s). A Purchase Order to cover this labor is required before repairs will
be initiated. Transportation charges or duties shall be borne by Purchaser.
3. If the purchaser elects not to return the equipment to the factory and wishes a factory service representative to make
adjustments and/or repairs at the equipment location, La Marche's field service labor rates will apply. A purchase order
to cover the labor and transportation cost is required prior to the deployment of the service representative.
In accepting delivery of the equipment, the purchaser assumes full responsibility for proper installation, installation
adjustments and service arrangements. Should minor adjustments be required, the local La Marche sales
representative should be contacted to provide this service only.
All sales are final. Only standard La Marche inverters will be considered for return. A 25% restocking fee is
charged when return is factory authorized. Special inverters are not returnable.
In no event shall La Marche Manufacturing Co. have any liability for consequential damages, or loss, damage or
expense directly or indirectly arising from the use of the products, or any inability to use them either separately
or in combination with other equipment or materials, or from any other cause. In addition, any alterations of
equipment made by anyone other than La Marche Manufacturing Co. renders this warranty null and void. Failure
to follow safety precautions specified by the manufacturer during replacement of components or verifications
renders this warranty null and void.
La Marche Manufacturing Co. reserves the right to make revisions in current production of equipment, and
assumes no obligation to incorporate these revisions in earlier models.
The failure of La Marche Manufacturing Co. to object to provisions contained in customers' purchase orders or
other communications shall not be deemed a waiver of the terms or conditions hereof, nor acceptance of such
provisions.
THE ABOVE WARRANTY IS EXCLUSIVE, SUPERSEDES AND IS IN LIEU OF ALL OTHER WARRANTIES,
EXPRESSED OR IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR
FITNESS. NO PERSON, AGENT, OR DEALER IS AUTHORIZED TO GIVE ANY WARRANTIES ON BEHALF
OF THE MANUFACTURER, OR TO ASSUME FOR THE MANUFACTURER ANY OTHER LIABILITY IN
CONNECTION WITH ANY OF ITS PRODUCTS UNLESS MADE IN WRITING AND SIGNED BY AN
OFFICIAL OF THE MANUFACTURER.

16
Appendix D: Manufacturer’s Extended Parts Warranty
(THIS IS YOUR WARRANTY IF YOU HAVE PURCHASED THE EXTENDED PARTS WARRANTY AS SHOWN ON OUR
INVOICE TO YOU OR IF YOU PURCHASE THE EXTENDED PARTS WARRANTY ANYTIME DURING THE FIRST 12 MONTHS
AFTER THE DATE OF OUR INVOICE)
All La Marche Manufacturing Co. equipment has been thoroughly tested and found to be in proper operating condition upon shipment
from the factory. Any part or parts of the equipment (except protective devices, d.c. connectors and other wear-related items) that
prove defective within a one (1) year period from the date of our invoice to you shall be replaced without charge providing such
defect, in our opinion, is due to faulty material or workmanship and not caused by tampering, abuse, misapplication or improper
installation. Labor and parts are covered during this one (1) year period.
For the next four (4) years after the expiration of the one-year warranty, on a parts replacement only basis, any part
or parts of the equipment (except protective devices, d.c. connectors and other wear-related items) that prove
defective within the additional four (4) year period shall be replaced providing such defect, in our opinion, is due to
faulty material or workmanship and not caused by tampering, abuse, misapplication or improper installation. During
this four (4) year period, the warranty covers parts replacement only, no labor or other services are provided by La
Marche, nor is La Marche obligated to reimburse the owner or any other person for work performed. If you return the
equipment to our factory (freight prepaid), we will repair and cover parts and labor.
In addition, magnetics and power diodes are warranted for ten (10) years after the date of our invoice to you. The defect in the
magnetics or power diodes must, in our opinion, be due to faulty material or workmanship and not caused by tampering, abuse
misapplication, or improper installation. Labor and replacement magnetics and power diodes are covered under the extended warranty
during the initial five (5) year period from the date of our invoice to you. During the next five (5) years of this ten (10) year warranty
period for magnetics and power diodes, the warranty covers parts replacement only, no labor or other services are provided b y La
Marche, nor is La Marche obligated to reimburse the owner or any other person for work performed.
Should a piece of equipment require major component replacement or repair during the extended warranty period, these can be
handled in one of three ways:
1. If the Purchaser elects to take the responsibility of repairing the equipment and requests replacement part(s), Purchaser or Sales
Representative must contact Factory for return authorization and a purchase order must be issued. Replacement part(s) will be promptly
shipped and invoiced. After the defective part(s) are returned and inspected at the Factory, if the defect(s) were due to faulty material
or workmanship, credit will be issued.
2. The equipment can be returned to the La Marche factory to have the inspections, parts replacements and testing performed by factory
personnel. Should it be necessary to return a piece of equipment or parts to the factory, the customer or sales representative must
obtain authorization from the factory. If upon inspection at the factory, the defect was due to faulty material or workmanship, all repairs
will be made at no cost to the customer under the Extended Warranty. Transportation charges or duties shall be borne by Purchaser.
3. If the purchaser elects not to return the equipment to the factory and wishes a factory service representative to make adjustments
and/or repairs at the equipment location, La Marche's field service labor rates will apply. A purchase order to cover the labor and
transportation cost is required prior to the deployment of the service representative.
In accepting delivery of the equipment, the purchaser assumes full responsibility for proper installation, installation adjustments and
service arrangements. Should minor adjustments be required, the local La Marche sales representative should be contacted to provide
this service only.
All sales are final. Only standard La Marche units will be considered for return. A 25% restocking fee is charged when return is factory
authorized. Special units are not returnable.
In no event shall La Marche Manufacturing Co. have any liability for consequential damages, or loss, damage or expense directly or
indirectly arising from the use of the products, or any inability to use them either separately or in combination with other equipment
or materials, or from any other cause. In addition, any alteration of equipment made by anyone other than La Marche Manufacturing
Co. renders this warranty null and void.
La Marche Manufacturing Co. reserves the right to make revisions in current production of equipment, and assumes no obligation to
incorporate these revisions in earlier models.
The failure of La Marche Manufacturing Co. to object to provisions contained in customers' purchase orders or other communications
shall not be deemed a waiver of the terms or conditions hereof, nor acceptance of such provisions.
THE ABOVE WARRANTY IS EXCLUSIVE, SUPERSEDES AND IS IN LIEU OF ALL OTHER WARRANTIES, EXPRESSED OR
IMPLIED, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS. NO PERSON, AGENT OR DEALER
IS AUTHORIZED TO GIVE ANY WARRANTIES ON BEHALF OF THE MANUFACTURER, OR TO ASSUME FOR THE
MANUFACTURER ANY OTHER LIABILITY IN CONNECTION WITH ANY OF ITS PRODUCTS UNLESS MADE IN WRITING
AND SIGNED BY AN OFFICIAL OF THE MANUFACTURER.