SECTION 8 |
oil resistant, multi-stranded copper wire cables rated at 105ºC / 77°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
much less visible light.
•
Lighting circuits
light output.
•
AC induction motors - These are commonly found in power tools, appliances, well
pumps etc. They exhibit very high surge demands when starting.
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
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
and cause injury. To prevent occurrence of hazardous conditions under short circuit con-
ditions, the fuse used in the battery circuit should limit the current (should be "Current
Limiting Type"), blow in a very short time (should be Fast Blow Type) and at the same
tim
e, quench the arc in a safe manner. This special purpose current limiting, very fast
acting fuse will blow in less than 8 ms under short circuit conditions. Appropriate ca-
pacity of the above Class T fuse or equivalent should be installed within 10 cm of the
battery Plus (+) Terminal (Please see Table 8.2 for fuse sizing).
WARNING!
Use of an appropriately sized external fuse as described above is mandatory to
cables. Please note that the internal DC side fuses are designed to protect ther
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.
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Installation
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