IBM DS4700 manual Low Range High Range

vCircuit overloading – Power circuits and associated circuit breakers must provide sufficient power and overload protection. To prevent possible damage to the unit, isolate its power source from large switching loads (such as air conditioning motors, elevator motors, and factory loads).

vPower failures – If a total power failure occurs, the unit automatically performs a power-up recovery sequence without operator intervention after power is restored.

Table 20. DS4700 Express ac power requirements

	Low Range	High Range
Nominal Voltage	90 to 136 VAC	198 to 264 VAC
Frequency (Hertz)	50 to 60 Hz	50 to 60 Hz
Idle Current	3.86 Aa	2.05 Ab
Maximum Operating Current	4 A/4.54 Aa c	2.12 A/2.41 Ab c
Maximum Surge Current	5.04 Aa	2.67 Ab

a.Typical voltage: 115 V ac, 60 Hz, assumes 72% power-supply efficiency and 0.99 power factor

b.Typical voltage: 230 V ac, 60 Hz, assumes 72% power-supply efficiency and 0.99 power factor

c.The higher number in this range applies when all of the drives are placed in Selfseek mode.

Table 21. DS4700 Express dc power requirements

	Requirement
Operating Voltage	-42	V to -60 V
Nominal Voltage	-48	V
Idle Current	11.8 A
Maximum Operating Current	15.8 A
Maximum Surge Current	16 A

Power and site wiring requirements for models with ac power supply and fan units

The storage subsystem uses wide-ranging redundant power supplies that automatically accommodate voltages to the ac power source. The ac power supplies operate within the ranges specified in Table 20. The ac power supplies meet standard voltage requirements for both domestic (inside USA) and international (outside USA) operation. They use standard industrial wiring with line-to-neutral or line-to-line power connections.

The agency ratings for the DS4700 Express Storage Subsystem (ac models) are 6 amps at 100 VAC and 2.5 amps at 240 VAC. These are the overall maximum operating currents for the DS4700 Express Storage Subsystem with ac power supply and fan unit CRUs.

AC power recovery: After a total ac power failure, after normal power is restored, the storage subsystem performs power-up recovery procedures automatically without operator intervention.

Power cords and receptacles: The storage subsystem ships with two jumper cords used to connect to the rack PDU. You must purchase the power cords that

Chapter 1. Introduction 27