Inhaltsverzeichnis
Werbung
METRO
ELECTRIC SYSTEM
Batteries
Check the battery charge condition
Since the specifi c weight of the electrolyte is proportional to the battery's charge condition, measuring the specifi c weight of the electrolyte is an effective, accurate way of checking the
charge of the battery. When the battery is charged and in normal conditions, with the electrolyte at the correct level, its density will be about 1.260 (30° Bè) at 30°C. If the density is between
1.26 (30° Bè) and 1.20 (24° Bè), the battery is partially fl at, while if the density is below 1.14 (18° Bè) the battery is completely fl at.
Measuring the density
Measuring the density of the electrolyte is the most important check to be made on a battery, so this measurement must be made with the greatest care, using a densimeter. Insert the
syringe densimeter and draw in enough electrolitye to raise the fl oat. Check that the tip of the fl oat does not touch the rubber element, or stick to the glass sides. If the density has to be
measured after distilled water has been added, wait until the density of all the liquid in the element has become uniform.
Topping up with water
Add distilled water to every single cell of the battery after charging the batteries, to bring the level to 6 mm above the plates. Initially, do this every time the batteries are charged.
Subsequently, top-ups may become less frequently on the basis of the manager's experience, but must take place at least once a week.
Charge limits
There is no need to recharge the battery if the density at the end of the working day has not dropped below 1.24 (28° Bè).
Overcharging is the most common error in the use of drive batteries. If the batteries are continuously overcharged, their lifetime may be drastically shortened.
The maximum recommended temperature is 45°C. If the electrolyte temperature rises more than 10-12°C over the ambient temperature, overcharging may occur regardless of the actual
temperature reached. If there is a 5-10% residual battery charge indicated on the dashboard, it is only possible to vacuum, the brushes will stop.
Battery charging premises
The gases developed during battery charging represent explosion hazard; it is therefore necessary to ensure adequate ventilation during charging, and fi rm contacts on the terminals to
prevent any sparks. The premises in which storage batteries are charged mut be well ventilated and the temperature must not exceed 40-45°C. If ventilation through the windows is not
adequate, use special vent ducts, which mut not be connected to the ordinary chimneys. When necessary, use suitable fans to provide faster air exchange.
No continuous service or out of use
If the battery is not used continuously, it must be given a «refresher» charge at least once a month, even if the specifi c weight of the electrolyte is still high. If the battery is out of use for
long periods, it must be stored in a cool, dry place. It must be charged completely once a month until lively gas bubbles are seen in all the elements and the voltage and specifi c weight
readings remain constant for 3-4 hours. In all cases, before a battery which has been out of use for a long time is put back into service, it must be recharged and the elecrolyte level must
be checked.
Installing the batteries
Fit the batteries into the compartment provided. Check them carefully before installation, ensuring that the elements are not broken. Never add electrolyte if the batteris have been in use
for one week or longer. The mating surfaces for battery connection must be clean; apply a fi lm of grease or vaseline to the terminals or connections. The batteries may have lost a little
charge in transit; in this case, charge them before using them on the machine.
Installing the battery charger
This must be installed in a dry, well ventilated place, well away from heat sources and corrosive environments. Ensure that the voltages correspond (see nameplate on battery charger).
Protect the system with a delayed switch or a fuse rated above the maximum power absorption of the battery charger. Always ensure the polarity is correct when connecting the battery
socket.
58
Werbung
Inhaltsverzeichnis
