Power Failure/Emergency Transfer - Toshiba Perfecptione Installation And Maintenance Manual

avoid power degradation by supplementing the -24
volts, maintaining a constant power level.
4. EXTENDED RESERVE POWER
4.00 The power supply is equipped, as a standard
feature, with an internal battery chargemnverter.
Full reserve power can be provided for any system
by connecting an appropriate, customer-supplied
24-volt battery pack. During normal operation, the
power supply chargemnverter will maintain the
proper charge in the battery pack. In the event of an
AC power failure, switchover to battery power will
be automatic. There will be no loss of system
operation as a result of power switchover. When
AC power is restored, switchback to the power
supply will be automatic.
4.01 Battery selection and size will depend on
system size and desired reserve operating time.
The maximum power consumption of the basic
cabinet is 11.5 amps at -24 VDC. For both a basic
and expansion cabinet configuration, the maxi-
mum will be 19 amps at -24 VDC. The selected
batteries must be compatible with the system' s
charger float voltage of 27.3 VDC.
INSTALLATION INSTRUCTIONS
SECTION 200-255-202
FEBRUARY1992
5. POWER FAILURE/EMERGENCY TRANSFER
5.00 The function of the Power Failure/Emergency
Transfer Unit (DPFT) is to automatically connect
selected trunks to selected standard telephones in
the event of system failure while permitting normal
operation when the system is in service (maximum
of 1 per cabinet).
5.01 The DPFT is a self-contained module that
mounts externally to the basic cabinet, typically on
the MDF. Connections to the trunks, stations and
basic cabinet are made via two 50-pin amphenol-
type connectors (Jl and J2) on the DPFT (see
functional diagram in Figure 2-6).
5.02 The module consists of eight relays that are
normally operated, connecting the telephones to
NSTU circuits and the trunks to NCOU circuits. If a
power failure (or other emergency) occurs, the
relays release, connecting the telephones directly
to the trunks. Calls can then be placed from the
telephones over the CO trunks, bypassing the
system (which is out of service).
5.03 Power Fail Transfer (PFT) telephones con-
I
J2 NCOU
CO LINE
I
I
TELEPHONE TELEPHONE
Notes: 1. One of eight DPFT circuits. Notes: 1. One of eight DPFT circuits.
2. Conditions of AC power on. 2. Conditions of AC power on.
FIGURE Z-6-DPFT FUNCTIONAL DIAGRAM
FIGURE Z-6-DPFT FUNCTIONAL DIAGRAM
2-3 2-3
C INDICATING C INDICATING
WER ON WER ON