Page 20
Precautions when working with batteries
Batteries contain very corrosive diluted sulphuric acid as electrolyte. Precautions
should be taken to prevent contact with skin, eyes or clothing
•
Batteries generate hydrogen and oxygen during charging resulting in evolution
of explosive gas mixture. Care should be taken to ventilate the battery area and
follow the battery manufacturer’s recommendations.
•
Never smoke or allow a spark or flame near the batteries.
•
Use caution to reduce the risk of dropping a metal tool on the battery. It could
spark or short circuit the battery or other electrical parts and could cause an
explosion.
•
Remove metal items like rings, bracelets and watches when working with
batteries. The batteries can produce a short circuit current high enough to weld a
ring or the like to metal and thus cause a severe burn.
•
If you need to remove a battery, always remove the ground terminal from the
battery first. Make sure that all the accessories are off so that you do not cause a
spark.
DC SIDE CONNECTIONS
The DC input power to the inverter is derived from deep cycle batteries of the
required capacity. Read under
“Specifying Batteries, Chargers and Alternators” on
page 14
for details on sizing and charging of batteries.
Preventing input over voltage
It is to be ensured that the input voltage of the inverter does not exceed 16.5 VDC
for PST-100S-12A or 33 VDC for PST-100S-24A to prevent permanent damage to the
inverter. Please observe the following precautions:
•
Ensure that the maximum charging voltage of the battery charger / alternator
/ solar charge controller is below 16.5 VDC for PST-100S-12A or 33 VDC for PST-
100S-24A
•
Do not use unregulated solar panels to charge a battery. Under cold ambient
temperatures, the output of the solar panel may exceed 18 V for 12V system or
36 V for 24V system. Always use a charge controller between the solar panel and
the battery.
•
Do not connect the inverter to a battery system with a voltage higher than the
rated battery input voltage.
Preventing reverse polarity on the input side
When making battery connection on the input side, make sure that the polarity of
battery connection is correct (Connect the positive of the battery to the positive
terminal of the inverter and the negative of the battery to the negative terminal of
the inverter). If the input is connected in reverse polarity, DC fuse(s) inside the inverter
will blow and may also cause permanent damage to the inverter
Connection from the batteries to the DC input side of the inverter – cable and fuse size
The flow of electric current in a conductor is opposed by the resistance of the
conductor. The resistance of the conductor is directly proportional to the length of
the conductor and inversely proportional to its cross-section (thickness). The resistance
in the conductor produces undesirable effects of voltage drop and heating.
Thus,
thicker and shorter conductors are desirable
. The size (thickness / cross-section) of the
conductors is designated by AWG (American Wire Gauge).
Please note that a smaller AWG # denotes a thicker size of the conductor up to AWG #1, e.g. AWG
#2 is thicker than AWG #4.
