Xantrex Technology 120 VAC/60 - Manual (Page 37)

INSTALLATION
 2001 Xantrex Technology, Inc.
5916 - 195th Street N. E.
Arlington, WA 98223
Telephone: 360/435-8826
Fax: 360/435-2229
www.traceengineering.com
SW Series Inverter/Charger
Part No. 2031-5
Rev. C: February 2001
Page
29
GROUNDING VS. LIGHTNING
This information is intended to provide basic grounding techniques that will help prevent inverter damage
due to lightning. It is not intended to be a complete course on grounding or a guarantee against protection
during a lightning strike situation. The NEC is the ultimate authority as to legitimate grounding techniques
for your electrical system.
If an electrical system has components grounded at different points in the earth, large voltage differences
will exist between these points during a lightning strike (See Figure 15). If this voltage appears between
the AC and DC side of the inverter, it will fail. All Trace™ inverters are designed to withstand a minimum
of 1750 volts between AC and ground, and 500 volts between DC and ground.
ONE GROUND FOR ALL EQUIPMENT
The first step in inverter protection is to make sure that all equipment in the system is physically
grounded at the same location. This assures that there is no voltage potential between grounds in the
system (See Figure 15 and Figure 16). No voltage means no current flow through the system.
Practically speaking, this would mean connecting the generator and battery grounds together, as well
as the case or “safety” grounds in the system, and then attaching all to the same earth grounding rod
(See the NEC for specific information on grounding requirements, and hardware).
In severe conditions, the generator frame should physically be isolated from the earth by a wood
frame or some other insulating means. This assures that the single point ground system is
maintained.
KEEP EQUIPMENT CLOSE TOGETHER
All equipment involved in a system should physically be located as close as possible to one another.
This reduces the potential that is developed between the ground site and the individual components of
the system during a lightning strike. This single point grounding greatly reduces the potential for
lightning damage to electrical equipment.
If you are unable to achieve single-point grounding due to large distances between equipment or other
variables, other means of lightning protection must be considered. Consult a reputable lightning
protection company.
Figure 15, Multiple Point Ground System Figure 16, Single Point Ground System
Equipment all grounded at
same point. No voltage
across system, and no
current flow through
equipment and wiring.
Generator
Ground
Lightning
Strike
Zero Voltage Difference
across Component Grounds
GENERATOR INVERTER BATTERY
BANK
Inverter
Ground Battery
Ground
Voltage
Difference
Voltage
Difference
Equipment acts as a
conductor due to
voltage between the
grounds. Bad!
GENERATOR INVERTER BATTERY
BANK
Generator
Ground
Inverter
Ground Battery
Ground
Lightning
Strike