
Siemens Industry, Inc.
Building Technologies Division
P/N 315-099321-72
• Supplies 6.2VDC @ 2A (power limited) to the system bus
• Supplies 24VDC @ 2A (power limited) to the system bus (subject to a 12A
total current limit)
• Communicates via HNET protocol
• Four programmable relays with 2A ratings
OPERATION The PSC-12 occupies one network address in the HNET network and has four functional
components: the Controller, the Charger, the Power Supply and the Interface Board.
The Controller determines the activation of the Charger and monitors the status of
the Power Supply (ground fault conditions, loss of network communication, 24VDC
terminal overload and the status of the battery).
The Power Supply has an Offline switch mode power converter and power factor
correction circuit to improve conductive RF emission at low frequency. It is designed
to take voltage inputs of 120VAC-240VAC at 50Hz/60Hz and has one resettable
circuit breaker that can also be used as a battery power switch.
The Charger monitors and maintains the battery. This circuitry utilizes three charge
modes, depending upon the state of the batteries: Bulk (Full) Charge State, Trickle
Charge State and Float (maintenance) State. The Charger monitors the batteries and
determines which of the charging modes to activate. It also has the capability to
check the state of the battery through diagnostic testing.
Terminal Blocks, The PSC-12 has one reset switch, seven LEDs, three address switches, one circuit
breaker, four terminal blocks, four terminal connections and two 60 pin flat ribbon
connections as shown in Figure 2.
A reset switch is located on the top of the front panel. Pushing the reset switch re-
initializes the PSC-12 operation.
The LEDs located at the top left of the module are defined as follows:
POWER - (Green or Blue) Normally ON. When illuminated, indicates
that the PSC-12 is powered from the AC
mains. When flashing, indicates that the
PSC-12 is powered from the battery.
MODULE FAIL - (Yellow) Normally OFF. When illuminated indicates
that the module microprocessor has failed.
CAN FAIL - (Yellow) Normally OFF. Not used in this applica-
tion.
HNET FAIL - (Yellow) Normally OFF. When illuminated, indicates
that the HNET communication with the
PSC-12 has terminated and the card goes
to degrade mode (applicable only when
the card resides in the HNET network).
GND FAULT - (Yellow) Normally OFF. When illuminated, indi-
cates that the PSC-12 has detected
either a negative or positive ground fault
on its outputs.
Controls and Indicators