SIELCO srl
- Via Toscana, 57/59 - 20090 BUCCINASCO (Mi) - ITALY - tel. 02 - 45713300 - www.sielco.org
EXC/RTX19 - USER & MAINTENANCE MANUAL - rev.1.5 - 05/16
Page 14
BATTERY OR D.C. SUPPLY
The EXC/RTX19 include a low voltage d.c. power supply input with battery management,
to permit continuous d.c. power supply or back-up in case of mains failure. This input, whose
nominal voltage is 24 V negative grounded, accepts a dc supply which may range 22 ÷ 28 V
in absence of mains supply. It delivers a reg27.6V to permit battery charging, when
mains supply is present.
Front panel switch do not acts on d.c. supply, which is always on when applied to its
terminals on the rear panel. There is no switch in series to this supply but only a diode and a
self-reset fuse to protect from polarity reversal.
Voltage higher than 28Vdc applied to or current sunk from this input for different
purpose than battery charging may seriously impair the equipment power supply.
Notes on battery and wiring
Any kind of battery may be used, provided it has the correct voltage ( 24 V, nominal) and
an adequate capacity. Price / performance considerations may suggest plumb batteries, regular
or sealed.
We suggest using sealed batteries for small systems, 20 to 40 A/hour rated. Higher capacities,
like 40 ÷ 100 A/hour and more, may be achieved at low cost from car-type batteries: in this
case always install the batteries in a well vented place, because acid gas produced during
battery charging may damage the electronic equipment.
EXC19 and RTX19 battery inputs may be wired together to the same battery array, provided
they both are internally preset to 27.6V, as regular. In this case the power supplies appear to
be in parallel (with some redundancy) and they both charge the battery array at a higher rate.
Plumb batteries are usually made up to 12 V nominal voltage, so two batteries are required
in series. Wire them with proper section wire: 1 sq. mm is usually enough to connect them to
the transmitter and/or the receiver; bigger sections may be used in case of long wiring.
Install batteries capable of sustaining the system for the maximum foreseen period of
mains failure. Avoid to completely discharging the batteries or permanent damage may
occur to them. Even if the battery manager disconnects the battery when the voltage is
lower than 22V, a small test current, nearly 10-15mA is sunk by the circuitry in absence
of mains power. This current is capable to deeply discharge the battery array in case of
prolonged mains absence. Always remove the battery array if the system is off-line