Magnum Dimensions CSW Series User manual

Owner’s Manual
CSW Series (12-volt models)
Pure Sine Wave Inverter

© 2017 Sensata Technologies i
Disclaimer of Liability
Since the use of this manual and the conditions or methods of installation,
operation, use and maintenance of the CSW Series inverter is beyond the
control of Sensata Technologies, this company does not assume responsibility
and expressly disclaims liability for loss, damage or expense, whether direct,
indirect, consequential or incidental, arising out of or in any way connected
with such installation, operation, use, or maintenance.
Every precaution has been taken to ensure the accuracy of the contents
of this manual, however the specifications and product functionality may
change without notice. We assume no responsibility for errors or omissions.
Restrictions on Use
The CSW Series inverter may only be used in life-support devices or systems
with the express written approval of Sensata Technologies. Failure of the
CSW Series inverter can reasonably be expected to cause the failure of that
life-support device or system, or to affect the safety or effectiveness of that
device or system. If the CSW Series inverter fails, the health of the user or
other persons may be endangered.
Copyright Notice
Copyright © 2017 by Sensata Technologies. All rights reserved. Permission
to copy, distribute, and/or modify this document is prohibited without
express written permission from Sensata.
Document Information
Description – CSW 12V Series Owner’s Manual
Part Number and Revision – 64-0063 Rev F
Date Published – August 2017
This manual is printed without color for cost savings. The entire manual
is available with many of the figures in color and can be downloaded at
www.SensataPower.com.
Contact Information
For Magnum-Dimensions products:
Sensata Technologies
Phone: [phone], Fax: [phone]
Web: www.SensataPower.com
Thank you for purchasing this CSW Series inverter. The CSW Series are
all under the Magnum-Dimensions brand from Sensata Technologies. We
understand that you have many purchasing options in the marketplace and
are pleased that you have decided on this product.
At Sensata, we are committed to providing you with quality products and
services, and hope that your experience with us is pleasant and professional.
Record the unit’s model and serial number in case you need to provide
this information in the future. It is much easier to record this information
now, instead of trying to gather it after the unit has been installed.
Model: Serial Number:
CSW412 BE
CSW1012 AU
CSW2012 BD

ii © 2017 Sensata Technologies
IMPORTANT PRODUCT SAFETY INSTRUCTIONS
This manual contains safety instructions that must be followed during the
installation and operation of this product. Read all instructions and safety
information on the inverter and in this manual before installing or using.
Safety Symbols
To reduce the risk of electrical shock, fire, or other safety hazard, the
following safety symbols have been placed throughout this manual to
indicate dangerous situations and important safety instructions.
WARNING: Indicates that failure to take a specified action could
result in physical harm to the user.
CAUTION: Indicates that failure to take a specified action could result
in damage to the equipment.
Info: Indicates information that emphasizes or supplements important
points of the main text.
Product Safety Warnings
WARNINGS: Failure to follow the instructions below and in this
manual can result in death or serious injury.
• All electrical work must be performed in accordance with local, state and
federal electric codes.
• This product is designed for indoor use only. Do not expose to rain,
snow, moisture, or liquids of any type.
• Use insulated tools to reduce the chance of electrical shock or accidental
short circuits. Remove all jewelry such as rings, watches, bracelets,
etc., when installing or performing maintenance on the inverter.
• Always disconnect the batteries or energy source prior to installing or
performing maintenance on the inverter. Live power may be present at
more than one point since an inverter utilizes both batteries and AC.
• Do not cover or obstruct any air vent openings and/or install in a zero-
clearance compartment. Always operate the unit in an open area.
• When working with electrical equipment or lead acid batteries, have
someone nearby in case of an emergency.
• Study and follow all the battery manufacturer’s specific precautions when
installing, using, and servicing the battery connected to the inverter.
• When working with batteries wear eye protection and gloves, and avoid
touching your eyes. Have fresh water and soap nearby in case battery
acid comes in contact with eyes. If this occurs, cleanse right away with
soap and water for a minimum of 15 minutes and seek medical attention.
• Batteries produce explosive gases, DO NOT smoke or have an open
spark or fire near the system.
• Avoid dropping any metal tool or object on the battery. Doing so could
create a spark or short circuit which goes through the battery or another
electrical tool and may cause an explosion.
• Explosion hazard! DO NOT use this inverter in the vicinity of flammable
fumes or gases (such as propane tanks or large engines).
• These inverters contain no user-serviceable parts. See the Warranty
section for how to handle service issues.

© 2017 Sensata Technologies iii
Table of Contents
1.0 Introduction.......................................................................... 1
1.1 Front/Back Features – CSW1012 and CSW2012 ........................ 1
1.2 Front/Back Features – CSW412............................................... 3
1.3 Regulatory Compliance .......................................................... 4
2.0 Installation ........................................................................... 5
2.1 Pre-Installation ..................................................................... 5
2.1.1 Installation Guidelines ........................................................ 5
2.1.2 Unpacking and Inspection ................................................... 5
2.1.3 Tools Required................................................................... 5
2.2 Locating and Mounting the Inverter ......................................... 8
2.3 Wiring the Inverter – General Requirements ........................... 11
2.3.1 Wiring Requirements ........................................................ 11
2.3.2 Torque Requirements ....................................................... 11
2.4 DC Wiring .......................................................................... 12
2.4.1 DC Wire Sizing................................................................. 13
2.4.2 DC Overcurrent Protection................................................. 14
2.4.3 DC Grounding.................................................................. 14
2.4.4 DC Cable Connections....................................................... 14
2.4.5 Wiring the Battery Bank.................................................... 15
2.4.6 Wiring the Inverter to the Battery Bank .............................. 15
2.4.7 Appliances and Run Time .................................................. 17
2.5 Testing the Inverter ............................................................ 18
2.5.1 Inverter Functional Test .................................................... 18
2.5.2 GFCI Function Test........................................................... 18
3.0 Operation............................................................................ 19
3.1 CSW412 Operation.............................................................. 19
3.2 CSW1012 and CSW2012 Operation........................................ 19
3.3 Understanding Loads ........................................................... 20
3.4 System Maintenance ........................................................... 21
4.0 Troubleshooting.................................................................. 22
5.0 Specifications...................................................................... 23
6.0 Limited Warranty................................................................ 24
6.1 How to Receive Warranty Service .......................................... 24

iv © 2017 Sensata Technologies
List of Figures
Figure 1-1, Front Panel Features (CSW1012 and CSW2012) .................... 1
Figure 1-2, Back Panel Features (CSW1012) ......................................... 2
Figure 1-3, Back Panel Features (CSW2012) ......................................... 2
Figure 1-4, Front Panel Features (CSW412) .......................................... 3
Figure 1-5, Back Panel Features (CSW412) ........................................... 4
Figure 2-1, Basic System Diagram ....................................................... 6
Figure 2-2, RV OEM System Diagram ................................................... 7
Figure 2-3, Mounting Positions ............................................................ 9
Figure 2-4, CSW412 Dimensions.......................................................... 9
Figure 2-5, CSW1012 Dimensions...................................................... 10
Figure 2-6, CSW2012 Dimensions...................................................... 10
Figure 2-7, DC Cable to Battery Terminals .......................................... 16
Figure 2-8, DC Cable to Inverter’s DC Terminals .................................. 17
List of Tables
Table 2-1, DC Terminal – Torque Requirements ................................... 11
Table 2-2, DC Wire/Overcurrent Device for Rated Use .......................... 13
Table 2-3, Appliance Power Consumption and Run Time........................ 17
Table 3-1, Examples of Digital Display Readings .................................. 20
Table 4-1, Troubleshooting Guide ...................................................... 22
Table 4-2, CSW1012 and CSW2012 Inverter Error Codes ...................... 22
Table 5-1, CSW Series Specifications.................................................. 23

© 2017 Sensata Technologies 1
Introduction
1.0 Introduction
Congratulations on your purchase of the CSW Series pure sine wave inverter.
The CSW Series includes the CSW412, CSW1012 and CSW2012 inverters;
under the Magnum-Dimensions brand from Sensata Technologies. The CSW
Series inverters are “pure” sine wave inverters designed to be powerful, yet
simple to operate, and will provide you with reliable AC power for trouble-
free use. Please read the Introduction section to familiarize yourself with the
features and benefits of your CSW Series inverter.
1.1 Front/Back Features – CSW1012 and CSW2012
The front panels of the CSW1012 and CSW2012 inverters are similar and are
equipped with the following features (see Figure 1-1):
1. Serial Number – the unique identification number assigned to each
unit (with a model-specific prefix).
Note: Enter your inverter’s serial number in the table on page i. It is to
easier to record this information now, instead of trying to gather it after the
unit has been installed.
2. GFCI – a Ground Fault Circuit Interrupter protected AC outlet. The GFCI
outlet quickly stops the flow of electricity in the event a ground fault
occurs on the device that is plugged into the inverter.
3. Status Indicator – an at-a-glance LED that provides the inverter’s
status—lights green, red, or amber (see Section 3.0 Operation).
4. Digital Display – a three-character alphanumeric display that shows
the inverter’s measured battery voltage, total AC output power, and any
error or warning codes.
5. Power/Select Button – a momentary button switch that allows the
inverter to be quickly turned on or off.
6. Remote Port – a RJ12 connector that allows an optional remote switch
to be connected via a remote cable.
Note: Remote switch is sold separately (PN: CSW-RS).
7. USB Port – allows USB-enabled devices to be powered and charged.
6
7
2
3
4
5
1
Figure 1-1, Front Panel Features (CSW1012 and CSW2012)

2 © 2017 Sensata Technologies
Introduction
The back panels of the CSW1012 and CSW2012 inverters are equipped with
the following features (See Figure 1-2 and Figure 1-3, respectively):
8. Cooling Fan(s) – an intake cooling fan(s) that automatically turns on
when the inverter’s internal temperature rises above a safe level, and
turns off when the inverter’s internal temperature falls to a safe level.
9. Mounting Flanges (front and rear) – used to mount and secure the
inverter to a shelf/wall.
10. DC Negative Terminal (black) – the inverter’s connection to the
negative terminal on the 12 VDC battery bank.
11. DC Positive Terminal (red) – the inverter’s connection to the positive
terminal on the 12 VDC battery bank.
12. Model Number – the model number of the inverter (i.e., CSW1012),
and other information.
13. DC Chassis Ground Connection – the connection that is used to tie
the exposed chassis of the inverter to the DC grounding system. The DC
grounding system could be the vehicle’s chassis, the DC grounding bus,
or to the engine’s negative bus.
Figure 1-3, Back Panel Features (CSW2012)
12
9
13
11
10 8
Figure 1-2, Back Panel Features (CSW1012)
8
10
11
12
13
9

© 2017 Sensata Technologies 3
Introduction
Figure 1-4, Front Panel Features (CSW412)
2
1
3
4
5
6
1.2 Front/Back Features – CSW412
The CSW412 is equipped with the following front panel features (Figure 1-4):
1. Power Indicator – an at-a-glance LED that lights green when the
inverter is on. (see Section 3.0 Operation).
2. Fault Indicator – an at-a-glance LED that comes on to indicate an
inverter fault (see Section 4.0 Troubleshooting).
3. USB Port – allows USB-enabled devices to be powered and charged.
4. ON/OFF Power Switch – a 2-position switch that turns the inverter
on and off.
5. Serial Number – the unique identification number assigned to each
unit (with a model-specific prefix).
Note: Enter the inverter’s serial number in the table on page i. It is to easier
to record this information now, instead of trying to gather it after the unit
has been installed.
6. GFCI – a Ground Fault Circuit Interrupter protected AC outlet. The GFCI
outlet quickly stops the flow of electricity in the event a ground fault
occurs on the device that is plugged into the inverter.

4 © 2017 Sensata Technologies
Introduction
Figure 1-5, Back Panel Features (CSW412)
11
710
8
9
The back panel of the CSW412 inverter is equipped with the following
features (see Figure 1-5):
7. Cooling Fan – an intake cooling fan that automatically turns on when
the inverter’s internal temperature is >122°F (50°C). The fan turns off
when the inverter’s internal temperature falls below 122°F (50°C).
8. DC Negative Terminal (black) – the inverter’s connection to the
negative terminal on the 12 VDC battery bank.
9. Mounting Flanges (front and rear) – used to mount and secure the
inverter to a shelf/wall.
10. Model Number – the model number of the inverter (i.e., CSW412),
and regulatory compliance information.
11. DC Positive Terminal (red) – the inverter’s connection to the positive
terminal on the 12 VDC battery bank.
1.3 Regulatory Compliance
The CSW Series inverters are intended to be used for land vehicles (RVs
or trucks) or marine craft. They are listed to UL Standard 458, 5th Edition
(Power Converters/Inverters and Power Converter/Inverter Systems for
Land Vehicles and Marine Crafts) for use in the US; and are also certified to
CSA Standard C22.2 No. 107.1-01 (General Use Power Supplies) for use in
Canada.
These inverters have been tested and certified to product safety standards by
Intertek Testing Services (known as ETL), which is a Nationally Recognized
Testing Laboratory (NRTL). NRTLs are qualified organizations that meet
Occupational Safety and Health Administration (OSHA) regulations to
perform independent safety testing and product certification.

© 2017 Sensata Technologies 5
Installation
2.0 Installation
Review this section and all safety instructions before proceeding with the
installation of your inverter.
WARNING: Installations should be performed by qualified
personnel, such as a licensed or certified electrician. The installer
determines which safety codes apply and ensures all applicable
installation requirements are followed. Applicable installation codes
vary depending on the specific location and application.
WARNING: Before installing, review the “Important Product Safety
Information” on page ii and adhere to all cautionary markings located
on the inverter and on the batteries.
2.1 Pre-Installation
Before proceeding, read the entire Installation section to determine how
best to install your CSW Series inverter. The more thorough you plan in the
beginning, the better your inverter needs will be met. Depending on your
application, there are simplified system diagrams shown in Figure 2-1 and
Figure 2-2. These should be reviewed to assist you in planning and designing
your installation. These drawings are not intended to override or to restrict
any national or local electrical codes, and should not be the determining
factor as to whether the installation is compliant, that is the responsibility of
the electrician and the onsite inspector.
2.1.1 Installation Guidelines
• Before connecting any wires, determine the cable routes throughout the
vehicle or boat, both to and from the inverter.
• Always check for existing electrical, plumbing, or other areas of potential
damage BEFORE drilling or cutting into walls.
• Ensure all wires have a smooth bend radius and do not become kinked.
• If installing this inverter in a boat, RV or truck, ensure the conductors
passing through walls, bulkheads, or other structural members are
protected. This minimizes insulation damage (such as chafing), which
can be caused by vibration or constant rubbing.
2.1.2 Unpacking and Inspection
Carefully remove the inverter from its shipping container and inspect all
contents. Verify the following items are included:
• CSW Series inverter
• CSW Series (12-volt models) Owner’s Manual
If items appear to be missing or damaged, contact your authorized Magnum-
Dimensions dealer or Sensata Technologies directly.
*** Save your proof-of-purchase as a record of your ownership; it
is needed if the unit should require in-warranty service. ***
2.1.3 Tools Required
Installing the inverter is simple and requires the following:
• Adjustable wrench (10-13 mm) • Level • Drill
• #10 Mounting screws (x4) • Pencil • Drill bits
• Phillips screwdriver

6 © 2017 Sensata Technologies
Installation
Figure 2-1, Basic System Diagram
AC OUT
CSW-TS15
Transfer Switch
CSW Series
Inverter
AC Loads
(15A max)
DVD
Tools
TV
AC
Sub-Panel
AC
Outlet
DC
Disconnect
Fuse
DC
Ground
(Vehicle
chassis, DC
ground bus,
or engine
negative bus)
AC
Main Panel
(Branch Circuit
Breaker to
Transfer Switch:
15A max)
AC IN
AC Source
(120VAC, 60 Hz Sinewave)
Note: A 12-volt charging
system is required to charge
the battery bank when the
battery is discharged.

© 2017 Sensata Technologies 7
Installation
Figure 2-2, RV OEM System Diagram
AC
Main Panel
(Branch Circuit
Breaker to
Transfer Switch:
15A max)
AC IN
AC OUT
AC Source
(120VAC, 60 Hz Sinewave)
CSW-TS15
Transfer Switch
CSW Series
Inverter
Notes: The NEC requires overcurrent
protection for wiring and equipment
in both AC and DC circuits. As shown
in this diagram, the RVIA allows the
following application where an
inverter is installed in a RV.
Pass-thru mode: When the AC source
(generator or shore power) powers
loads thru a transfer switch (i.e.,
pass-thru mode), the conductor from
the transfer switch to the dedicated
load will be protected as long as the
branch rated circuit breaker at the
AC source does not exceed the
ampacity of the conductor feeding
the dedicated load.
Inverter mode: When the inverter is
powering loads using power from the
battery (i.e., Inverter mode), the
conductor from the inverter output to
the dedicated load will be protected
as long as the ampacity of the
conductor is sized based on the
inverter’s AC output rating. In
Inverter mode, the inverter has
overcurrent protection to limit the
output current and to protect the
conductor.
Dedicated
AC Load
(15A max)
DC
Disconnect
Fuse
DC
Ground
(Vehicle
chassis, DC
ground bus,
or engine
negative bus)
Note: A 12-volt charging
system is required to charge
the battery bank when the
battery is discharged.

8 © 2017 Sensata Technologies
Installation
2.2 Locating and Mounting the Inverter
DANGER: Explosion hazard!
• Do not use the unit in the vicinity of flammable fumes or gases
(such as propane tanks or large engines).
• Avoid covering the ventilation openings. Always operate unit in
an open area.
• Prolonged contact to high heat or freezing temperatures will
decrease the working life of the unit.
• Do not connect AC power source like utility power or generator to
the AC outputs of the unit. It will damage the unit and may cause
fire; and is not covered by warranty.
Install and mount in a location that meets the following requirements:
Clean and dry – The inverter is rated “For indoor use only”. It should not
be installed in an area that allows dust, fumes, insects, or rodents to enter
or block the inverter’s ventilation openings. This area also must be free from
any risk of condensation, water, or any other liquid that can enter or fall on
the inverter. Inverter failure under these conditions is not covered under
warranty.
Cool – The inverter should be protected from direct exposure to the sun or
to any equipment that produces extreme heat. The ambient temperature
should be between 32°F (0°C) and 104°F (40°C); note that the inverter’s
output specifications are rated at 77°F (25°C), so the cooler the better.
Ventilated – In order for the inverter to provide full output power and
avoid over-temperature fault conditions, do not cover or block the inverter’s
ventilation openings, or install this inverter in an area with limited airflow.
Allow a minimum airspace clearance of 3” (7.6 cm) around the unit to
provide optimum ventilation.
Safe – Do not mount the inverter near any flammable or combustible fluid or
components, or in locations that require ignition-protected devices.
Close to the battery bank – As with any inverter, it should be located as
close to the batteries as possible. Long DC wires tend to lose efficiency and
reduce the overall performance of an inverter. However, the unit should not
be installed in the same compartment as the batteries or mounted where it
will be exposed to gases produced by the batteries. These gases are corrosive
and will damage the inverter; also, if these gases are not ventilated and if
allowed to collect, they could ignite and cause an explosion.
Accessible – Do not block access to the front or back of the inverter. Allow
room to view any indictors or digital display and to access the AC and DC
wiring connections—they will need to be checked and tightened periodically.
Orienting the inverter – This inverter has no restriction on the direction
on which it can be mounted. It can be mounted on/underneath a horizontal
surface (shelf or table), on a vertical surface (wall or bulkhead) with the DC
terminals facing left or right, or towards the top or bottom (see Figure 2-3).
Use the base of the inverter’s chassis as a template to mark your mounting
screw locations (or, refer to the dimensions in Figures 2-4 thru 2-6). If this
unit is used in a mobile application, you may want to place flexible washers
or bushings between the mounting surface and the inverter’s mounting
flanges to reduce vibration.

© 2017 Sensata Technologies 9
Installation
Figure 2-3, Mounting Positions
DC terminals towards the
bottom, right, top or the left.
Flat on a
horizontal surface
(right side up
or up side down).
Figure 2-4, CSW412 Dimensions
Top
5.8’’ (14.7 cm)
6.3’’ (16.1 cm)
6.9’’ (17.5 cm)
7.9’’ (20 cm)
Front (AC Side) Back (DC Side)
3.4’’
(8.7 cm)

10 © 2017 Sensata Technologies
Installation
Figure 2-5, CSW1012 Dimensions
Figure 2-6, CSW2012 Dimensions
Top
10.3’’ (26.2 cm)
6.3’’ (16.1 cm)
6.9’’ (17.5 cm)
12.6’’ (32.1 cm)
Front (AC Side) Back (DC Side)
3.4’’
(8.4 cm)
Top
13.4’’ (34 cm)
8.5’’ (21.6 cm)
9.1’’ (23 cm)
16.5’’ (41.9 cm)
Front (AC Side) Back (DC Side)
4.3’’
(11 cm)

© 2017 Sensata Technologies 11
Installation
2.3 Wiring the Inverter – General Requirements
This section describes the requirements and recommendations for wiring the
CSW Series inverter. Before wiring the inverter, carefully read all instructions.
WARNING: Wiring should meet all local codes/standards and be
performed by qualified personnel (i.e., licensed electrician).
2.3.1 Wiring Requirements
• All conductors that are at risk for physical damage must be protected by
tape or placed in a raceway.
• Always check for existing electrical, plumbing, or other areas of potential
damage prior to making cuts in structural surfaces or walls.
• Where DC wiring must cross AC or vice-versa, try to make the wires at
the crossing point perpendicular (90 degrees) to one another.
• DC overcurrent protection must be provided as part of the installation.
• Use only copper wires with a minimum temp rating of 167°F (75°C).
• Ensure all conductor insulation is of a type that is approved for the
voltage, operation, temperature and location of use.
2.3.2 Torque Requirements
All wiring to the DC terminals and DC ground connection should be checked
periodically (once a month) for proper tightness. For the torque requirements,
refer to Table 2-1. If you don’t have a torque wrench, ensure all connections
are tight.
Table 2-1, DC Terminal – Torque Requirements
Inverter
Model DC
Terminals Torque Requirements Torque Wrench Size Needed
CSW412 Hex Cap
screws
52 to 58 lbf-in
(5.9 to 6.5 N-m) 12 mm wrench
CSW1012 M6 x 1.0
Hex nuts
79 to 96 lbf-in
(8.9 to 10.9 N-m) 10 mm wrench
CSW2012 M8 x 1.25
Hex nuts
16 to 21 lbf-ft
(22 to 28 N-m) 13 mm wrench

12 © 2017 Sensata Technologies
Installation
2.4 DC Wiring
This section describes the inverter’s required DC wire sizes, the recommended
disconnect/overcurrent protection, and how to make the DC connections to
the inverter and the battery bank.
WARNING: Even though DC voltage can be regarded as “low
voltage”, significant hazards may be present, particularly from short
circuits of the battery system.
CAUTION: The inverter is NOT reverse polarity protected—if the
negative and positive battery voltage is connected to the inverter
backwards, the inverter will likely be damaged. Use a voltmeter to
verify the correct polarity BEFORE connecting the DC wires.
CAUTION: DO NOT connect the battery cables to the inverter until
all wiring is complete and the correct DC voltage and polarity have
been verified.
Refer to Figure 2-7 when connecting the DC wires to the battery, and to
Figure 2-8 when connecting to the inverter. Also, consider the following
requirements to ensure maximum performance:
The inverter’s DC positive and negative cables from the battery bank should
be tied together with wire ties/straps or electrical tape approximately every
6 inches (15.3 cm). This helps improve the surge capability and reduces the
effects of inductance, which improves the inverter waveform and reduces
the wear of the inverter’s filter capacitors. Keeping the battery cables close
together also reduces the chance of radio frequency interference.
Be aware that over-tightening or misthreading the nuts on the DC terminals
can cause the bolts to strip and snap/break off.
Make sure cables have a smooth bend radius and do not become kinked.
Follow existing wire runs where possible.
Crimped and sealed copper ring terminal lugs with at least a 6 mm (1/4”)
bolt hole to connect the DC wires to the inverter’s DC terminals.
The battery bank voltage MUST be between 10.5 – 15.5 (10.5 – 15.75 for
the CSW412) for the inverter to operate. If the voltage exceeds 16.0V, the
inverter may be damaged.
To ensure the maximum performance from the inverter, all connections from
the battery bank to the inverter should be minimized. The exceptions are the
DC fuse and disconnect, or the DC circuit breaker—required at the battery to
protect the DC wiring—in the positive line. Any other additional connection
will contribute to additional voltage drops, and these extra connection points
may loosen during use.
A brief spark or arc may occur when connecting the battery cables to the
inverter DC terminals; this is normal and due to the inverter’s internal
capacitors being charged.
Before routing the wiring, color code the DC cables/wires with colored tape
or heat shrink tubing: RED for positive (+); WHITE for negative (–); and
GREEN (or bare copper) for DC ground, to avoid polarity problems.
A cable should be connected directly from the inverter negative terminal
to the battery negative connection; this ensures the inverter has a reliable
return path directly to the battery. Do not use the chassis in place of the
battery negative connection to the inverter.

© 2017 Sensata Technologies 13
Installation
2.4.1 DC Wire Sizing
It is important to use the correct sized DC wire to achieve maximum
efficiency from the system and to reduce fire hazards associated with
overheating. Always keep your wire runs as short as practical to prevent
low voltage shutdowns and to keep the DC breaker from nuisance tripping
(or open fuses) because of increased current draw. See Table 2-2 to select
the minimum DC wire size (and corresponding overcurrent device) required
based on your inverter model. The cable sizes listed in this table are required
in order to reduce stress on the inverter, minimize voltage drops, increase
system efficiency, and ensure the inverter’s ability to surge heavy loads.
If the distance from the inverter to the battery is >5 feet (1.5 m), the
DC wire will need to be increased. Longer cable distances affect inverter
performance. See Table 2-2 to determine the minimum DC wire size needed
for various distances greater than 5 feet—based on your inverter model.
DC Wire Size Exception: In an OEM RV application, smaller DC wire (with
appropriate overcurrent protection) may be used if the inverter will only be
connected to a dedicated load (as shown in Figure 2-2), and the inverter and
dedicated load have been thoroughly tested and sold together by the OEM
as a complete system.
Table 2-2, DC Wire/Overcurrent Device for Rated Use
CSW412 CSW1012 CSW2012
Full Load Current 38 amps 94 amps 187 amps
Maximum
Continuous Current146 amps 113 amps 224 amps
Minimum DC
Ground Wire Size2#8 AWG
(8.36 mm2)
#8 AWG
(8.36 mm2)
#8 AWG
(8.36 mm2)
Minimum DC
Wire Size
[75°C rating in free air]3
#10 AWG
(5.26 mm2)
[50 amps]
#2 AWG
(33.6 mm2)
[170 amps]
#3/0 AWG
(85 mm2)
[310 amps]
Maximum DC
Fuse Size 50 amps with time delay
150 amps with
time delay
300 amps with
time delay
Increased
size for
longer
distance
5 – 10 ft
(1.5 – 3 m) #8 AWG (8.4 mm2)
#1 AWG
(42.4 mm2)
#4/0 AWG
(107 mm2)
10 – 15 ft
(3 – 4.6 m) #6 AWG (13.3 mm2)
#1/0 AWG
(53.5 mm2)
Not
recommended
Note1:Maximum Continuous Current is based on the inverter’s continuous power
rating at the lowest input voltage with an efficiency factor.
Note2:The grounding conductor for the DC system shall meet the sizing
requirements specified in the NEC for the application, but must be no smaller
than 8 AWG (8.4 mm2)copper. In some applications, the DC grounding conductor
is required to be no less than the wire size for the DC positive/negative cables.
Note3:Copper wire rated with 167°F (75°C) insulation at an ambient temperature
of 86°F (30°C), with a multiple cable fill factor (0.8) derating (if needed).

14 © 2017 Sensata Technologies
Installation
2.4.2 DC Overcurrent Protection
For safety reasons and to comply with electrical code regulations, DC
overcurrent protection must be provided as part of the installation. The DC
overcurrent protection device must be installed in the positive DC cable line,
it can be a fuse (with a disconnect switch) or a circuit breaker and must
be DC-rated. It must be correctly sized according to the size of DC cables
being used, which means it is required to open before the cable reaches its
maximum current carrying capability, thereby preventing a fire. The NEC
requires both overcurrent protection and a disconnect switch.
Because batteries can deliver thousands of amps in an instant during a
short, you are required to install a DC-rated fuse (or circuit breaker) that
has a interrupt current rating (known as Amps Interrupting Current or AIC)
that can withstand the short-circuit current without explosion or damage.
If a fuse is used as an overcurrent device, a Class-T type or equivalent is
highly recommended when used with inverters. A Class-T fuse is rated for
DC operation, can handle very high short-circuit currents (up to 100,000
amps), and has a time delay that allows for momentary current surges from
the inverter without opening the fuse. In some installations, if the combined
short-circuit current of all the batteries in the bank is determined to be
2,700 amps or less, then an ANL type of fuse may be used—if in doubt, use
a Class-T fuse. See Table 2-2 for the fuse size (coordinated with the DC wire
size) recommended for your CSW inverter.
2.4.3 DC Grounding
The inverter should always be connected to a permanent, grounded
wiring system. The idea is to connect the metallic chassis of the various
enclosures together to have them at the same voltage potential, to reduce
the possibility for electric shock. For most installations, the inverter chassis
and the negative battery conductor are connected to the system’s ground
bond via a safety grounding conductor (bare wire or green insulated wire)
at only one point in the system. The grounding conductor for the DC system
shall meet the sizing requirements specified in the NEC for the application,
but must be no smaller than 8 AWG copper.
Example: An inverter used in a marine application under ABYC guidelines
requires the size of the DC grounding conductor to be of an ampacity equal
to or one size less than that of the DC positive conductor.
See Table 2-2 for the minimum ground wire size recommended for your
inverter.
Info: If the inverter is installed in a vehicle, connect the battery
negative cable directly to the inverter’s negative terminal. DO NOT
connect the negative battery cable meant for the inverter to the
vehicle’s frame/safety ground.
2.4.4 DC Cable Connections
Do not put anything between the battery cable ring lug and the battery
post (see Figure 2-7), or the flat metal part of the inverter’s DC terminal
(see Figure 2-8). When connecting the battery cable, it should be placed
directly against the battery post or inverter terminal. Incorrectly installed
hardware causes a high resistance connection which could lead to poor
inverter performance, and may melt the cable and terminal connections.
See Table 2-1 for the torque requirements.

© 2017 Sensata Technologies 15
Installation
Info: The DC terminal/Hex nuts on the CSW1012 and CSW2012
are made of stainless steel, which has a high likelihood of galling
or thread seizing while being tightened—causing the bolts to
strip or to snap/break off. Use an anti-seize lubricant, tighten the
fasteners slowly (@low rpms) without interruption, and apply only
light pressure.
2.4.5 Wiring the Battery Bank
WARNING: Lethal currents will be present if the positive and
negative cables attached to the battery bank touch each other.
During the installation and wiring process, ensure the cable ends
are insulated or covered to prevent touching/shorting the cables.
Info: DO NOT connect the DC wires from the battery bank to
the inverter until 1) all DC wiring is complete, 2) the correct DC
overcurrent protection has been installed, and 3) the correct DC
voltage and polarity have been verified.
Depending upon the voltage of the batteries (6 or 12 VDC), the batteries
must be wired in series, parallel, or series-parallel to provide the correct
voltage. The interconnecting DC wires must be sized and rated exactly the
same as those used between the battery bank and the inverter.
Place the batteries as close as practical to the inverter, preferably in an
insulated and ventilated enclosure. Allow adequate space above the batteries
to access the terminals and vent caps (as applicable). Also, allow at least 1”
(2.5 cm) of space between the batteries to provide good air flow. DO NOT
mount the batteries directly under the inverter.
CAUTION: Install batteries in a well ventilated area. Batteries
can produce explosive gasses. For compartment or enclosure
installations, always vent batteries to the outside.
Info: To ensure the best performance from your inverter system,
batteries should be of the same size, type, rating, and age. Do not
use old or untested batteries.
2.4.6 Wiring the Inverter to the Battery Bank
CAUTION: The inverter is NOT reverse polarity protected—if the
positive terminal of the battery is connected to the negative terminal
of the inverter and vice versa, severe damage to the inverter will
occur and this will void the warranty. Before connecting the DC
wires from the batteries to the inverter, verify the correct battery
voltage and polarity using a voltmeter. If necessary, color code
the cables (with colored tape): red for positive (+), and white for
negative (-) to avoid polarity confusion.
Info: The DC overcurrent device (i.e., circuit breaker or fuse) must
be placed in the positive (red) DC cable line between the inverter’s
positive DC terminal and the battery’s positive terminal (red)—as
close to the battery as possible. For maximum protection, install it
within 18 inches (45 cm) of the battery.