©
2006 Magnum Energy Inc
.
DC Overcurrent Protection
For safety and to comply with electrical code regulations, you must
install a DC overcurrent protection device in the positive DC cable
line to protect your DC cables. This DC overcurrent device must be
DC rated and can be a fuse or circuit-breaker. 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.
See Table 1 to select
the DC overcurrent device needed based on the minimum wire size
according to your inverter model.
For electrical systems in AE applications, the NEC (National Electrical
Code) requires an overcurrent protection device. Mobile installations
typically do not require using a DC disconnect, although an
overcurrent protection device is still required. Because the DC
disconnect is not required, a fuse is usually used as the overcurrent
device in these installations. These installations also do not normally
use conduit, so the fuse
must be installed
in the ungrounded
conductor (usually the positive DC cable line)
within 18 inches of the
battery to protect the DC wiring system.
If using a fuse, we recommend using a
class-T type or equivalent. This
fuse type is rated for DC operation, can
handle the high short-circuit
currents and
allow for momentary current surges from the inverter
without opening.
DC Grounding
The inverter/charger 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, which reduces the possibility for electric shock.
For the
majority of 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. Per the NEC, the size for the grounding conductor
is usually based on the size of the overcurrent device used in the DC
system.
Refer to Table 1
to select the DC ground wire needed based
on the overcurrent device used for your inverter model,
If using this inverter in a vehicle, DO NOT connect the battery negative
(-) cable to the vehicle’s safety ground. Connect it only to the
inverter’s negative battery terminal. If there are any non-factory
installed DC appliances on board the vehicle, DO NOT ground them at
the safety ground. Ground them only at the negative buss of the DC
load center (as applicable).
2.0 Installation
13
http://www.wholesalesolar.com/inverters.html
http://www.wholesalesolar.com/inverters.html
