Samlexpower PST-15S-12E Owner's manual - Section 8 |
34 | SAMLEX AMERICA INC.
oil resistant, multi-stranded copper wire cables rated at 90ºC / 194°f minimum. Do not use
aluminum cable as it has higher resistance per unit length. Cables can be bought at a marine
/ welding supply store. Effects of low voltage on common electrical loads are given below:
•
Lighting circuits - incandescent and Quartz Halogen: A 5% voltage drop causes an
approximate 10% loss in light output. This is because the bulb not only receives
less power, but the cooler filament drops from white-hot towards red-hot, emitting
much less visible light.
•
Lighting circuits - fluorescent: Voltage drop causes a nearly proportional drop in
light output.
•
Ac induction motors - These are commonly found in power tools, appliances, well
pumps etc. They exhibit very high surge demands when starting. Significant volt-
age drop in these circuits may cause failure to start and possible motor damage.
•
PV battery charging circuits - These are critical because voltage drop can cause a
disproportionate loss of charge current to charge a battery. A voltage drop greater
than 5% can reduce charge current to the battery by a much greater percentage.
8.4.4 Fuse Protection in the Battery circuit
A battery is an unlimited source of current. Under short circuit conditions, a battery can
supply thousands of Amperes of current. If there is a short circuit along the length of
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 cable will
become red-hot, the insulation will melt and the cable will ultimately break. This inter-
ruption 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
conditions, the fuse used in the battery circuit should limit the current (should be "Cur-
rent Limiting Type"), blow in a very short time (should be fast Blow Type) and at the
same time, quench the arc in a safe manner. for this purpose, fuse Type UL Class-T (as
per UL standard UL 248-15) / Type "HRC" (as per BS88-2 or as per IEC 60269-2) should be
used. 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 fuse or equivalent
should be installed within 7” of the battery Plus (+) terminal (Please see Table 8.2 for
fuse sizing). Marine Rated Battery fuses, MRBf-xxx Series made by Cooper Bussmann
may also be used. These fuses comply with ISO 8820-6 for road vehicles.
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
cables. Please note that the internal DC side fuses are designed to protect the
internal components of the inverter against DC side overloading. These fuses
will not blow if there is a short circuit along the length of wires connecting the
battery and the inverter.