Samlex America PST-2000-24 - Manual (Page 32)

32 | SAMLEX AMERICA INC.
the cables that connects the battery to the inverter, thousands of Amperes of current
can flow from the battery to the point of shorting and that section of the wire will be-
come red-hot, the insulation will melt and the cable will ultimately break. This interrup-
tion of very high current will generate a hazardous, high temperature, high-energy arc
with accompanying high-pressure wave that may cause fire, damage nearby objects and
cause injury. To prevent occurrence of hazardous conditions under short circuit condi-
tions, an appropriate fuse should be used in the battery circuit that will limit the cur-
rent, blow in a very short time and quench the arc in a safe manner. for this purpose, UL
Class T fuse or equivalent with Ampere Interrupting Capacity (AIC) of at least 10,000A
should be used (As per UL Standard 248-15). This special purpose current limiting, very
fast acting fuse will blow in less than 8 ms under short circuit conditions. Appropriate
capacity of the above Class T fuse should be installed within 7” / 178mm of the battery
Plus (+) Terminal. The fuse will require a corresponding fuse holder.
WARninG!
Use of an appropriately sized external fuse as described above is mandatory to
provide safety against fire hazard due to accidental short circuit in the battery
wires. Please note that the DC side fuse(s) inside the unit are designed to pro-
vide protection to the internal components of the inverter. These fuses will NoT
blow if there is a short circuit along the length of wires connecting the battery
and the inverter.
Recommended Sizes of Wires and external Fuses
Table 8.2 (page 33) provides recommended sizing of DC input wires and external DC
input fuses based on the following considerations:
• Current in Amperes a conductor can carry continuously under the conditions of use
without exceeding its temperature rating is termed Ampacity (Ampere Capacity).
Conductor temperature rating of 105°C / 221°f, ambient temperature of 30°C / 86°f
and wiring in free air have been considered
• Wire size is indicated in American Wire Gauge (AWG). AWG of a stranded wire is de-
termined by the total cross-sectional area of the conductor. note: Because there are
also small gaps between the strands, stranded wire with higher number of strands
will always have a slightly larger overall diameter than a solid wire / wire with lesser
number of strands with the same AWG.
• The Ampacity of the recommended AWG of the wire is equal to or greater than the
designed DC input current at the rated continuous output power of the inverter.
• Distances 3 ft. (.91 meters) / 6 ft. (1.83 meters) / 10 ft. (3.05 meters) shown in Table 8.2
are the distances between the battery and the inverter. The running length of routing
of the wire should be considered if the wiring run is not straight but circuitous.
• Recommended AWG of wire will produce maximum continuous voltage drop =
(Designed DC input current at the rated continuous output power of the inverter) X
(Resistance of the length of wire). Length of wire is equal to 2 times the distance (to
cover the total length of the Positive and Negative wires). Table 8.1 (page 33) indi-
cates resistance of wire in ohm / ft. at 25°C / 77°f for calculating voltage drop.
seCtIOn 8 | Installation