AT&T 555-230-894 manual Power Arrangements for DC Power, Parameter Requirements

Locate and Lay Out the Equipment Room

Power Arrangements for DC Power

The following table shows the input DC requirements for the system -48 VDC Input Power Requirements

Parameter	Requirements
Static Voltage	-48 VDC nominal, -42.5 VDC minimum, -52.5 VDC maximum
	(measured at input to System cabinet) under normal
	operating conditions.
Dynamic	Transient change in voltage— +/- 5% of steady state
Voltage	voltage. Allowed transient duration—Up to 200
	milliseconds.
AC Ripple	Maximum wideband AC ripple— 450 mvpp (mill ivolts peak-
Voltage	to-peak) in the 3 kHZ to 20 MHZ band.
Low Voltage	Automatic disconnect—Occurs when input voltage is less
Disconnect	than -42.5 VDC (control provided with battery plant).
Overvoltage	Input voltage at switching cabinets shall not exceed -52.5
Protection	VDC.
Voltage Drop	Maximum drop—M ust not exceed 0.5 VDC one way on
	feeder cables between the power board and the System
	cabinet. Feeders must be Underwriter Laboratories (UL)
	approved (or equivalent) and Canadian Safety Association
	(CSA) certified. Recommended -48 VDC feeder cable—
	Royal Electric #X4905 or equivalent No. 1 AWG is required
	for distances up to 50 feet (15 meters). Cable resistance
	must be equal to or less than 0.1290 ohms per 1000 feet
	304 meters).
Current Draw	The battery plant rectifiers must be capable of providing
	current for the System including that required for System
	holdover and for charging the batteries. In addition, this may
	include DC current required for an inverter that provides
	Occupier to peripheral equipment if it is installed and for
	future growth.
Circuit Breaker	An Underwriter Laboratories (UL) listed and Canadian
	Safety Association (CSA) certified circuit breaker must be
	provided at the battery plant power board for each System
	cabinet feeder. The recommended circuit breakers are 75
	ampere Airpax UPL-1-1REC2-52-753 or Heinemann AM1-
	B2-A-75-2.
Redundancy	Redundancy of the battery chargers/rectifiers should be
	considered. This would also provide the additional current
	necessary to recharge the batteries after being fully
	discharged.

Issue 1 September 1995 2-7