Toshiba Strara CTX Series, Installation And Maintenance Manual, Page: 273 / 290

Peripheral Installation
8-27
Strata CTX I&M September 2002
Power Failure Options
In the event of a power failure, Strata CTX uses these options:
Reserve Power
For information on the Reserve Power Option, see in Chapter 1 , “CTX Primary AC and Reserve
Power Considerations” on Page 1-31 .
Power Failure Transfer Unit
An optional Power Failure Transfer Unit (DPFT) can be installed that automatically connects up to
eight selected Exchange lines directly to designated standard telephones in the event of a power
failure. The DPFT enables normal operation of the selected Exchange lines and standard telephones
when the system is in service. When power is restored, each telephone is independently reconnected to
system standard telephone circuit ports after it is finished with its direct Exchange line call. The DPFT
is normally installed on the MDF.
Figure 8-26 provides a circuit diagram of the DPFT.
Note The DPFT option is only available with annlogue exchange lines.
Figure 8-26 DPFT Circuit Diagram
J2-26
J2-1
J1-26
J1-1
Relay
J1-25
J1-50
J1-2
J1-27
J2-2
J2-27
Telephone Current
Detector
To TEL-A1
To TEL-B1
To Exchange
line -A1
To RSTU/PSTU-A1
To PCOU/RCOU/RCOS-A1
To PCOU/RCOU/RCOS-B1
DG (Input)
-24V (Input)
RSTU or PSTU
Control
1498
Notes
• Representation of first of eight circuits.
• Conditions shown with AC power (-24VDC) off.
To Exchange
line -B1
To RSTU/PSTU-B1