Page198 of 544 Powersupplies
553-3011-100 Standard14.00 January 2002
AC power supply featu res . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
Voltage . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Over-voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Under-voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Introduction
This chapter describes the Option 11C AC/DC power supplies (NTAK04,
NTAK05, NTDK72, and NTDK78) reserve power requirements, and the
operation of the Power Fail Transfer Unit (PFTU). The NTDK15 power
supply for the Option 11C Mini is described on page204.
Features of the Option 11C power supplyDimensions and weight
The AC/DC and DC power supplies measure approximately 12.5 inches
(305mm) high, 5 inches (127 mm) wide and 10 inches (245 mm) deep.
It weighs approximately 12 lb (5.5 kg), while the DC power supply weighs
approximately 8 lb (3.5 kg).
AC/DC power supply features
The NTAK04and NTDK78 AC/DC power supply has the following features:
•A current limiting circuit which l imits the surge of current on the i nput
line when the system is first switched on.
•Accommodates a reserve power system. The system continues to operate
on DC reserve power in case of AC power failure.
Note: The NTAK04or NTDK78 AC/DC power supply cannot power up
on battery alone. If the NTAK04or NTDK78 is powered down while
operating on DC reserve power, then AC power is required to power up
the system.
•Battery charging for the reserve power system. Charging current in a
worst-case scenario (when Meridian Mail is installed) is 1.0 amp.
•Power (± 15V) for one attendant console.
•Generation of a system line transfer signal and power (-52V) for the
Power Fail Transfer Unit (250 MA maximum).