System Power; Peripheral Bays - NEC EXPRESS5800/180Ra-7 User Manual

System Power

The BSU may be configured with up to three 750-Watt power supplies. Each supply
has autoranging input 50/60 Hz and automatically switches between the following input
voltage ranges:
100-120 VAC at 50/60 Hz; 12.0 A maximum current
!
200-240 VAC at 50/60 Hz; 7.0 A maximum current
!
All output grounds connect to the power supply chassis and to earth ground through the
AC line cord. Each supply has:
Individual AC input line cord that plugs into the external side of the power supply
!
Isolating device on each DC output so that the failure of one supply does not affect
!
the operation of the others
Cooling fan integral with each power supply enclosure. The fan circuit implements
!
fan failure detection.
In a system, power is drawn equally from all supplies installed. A four processor system
with one power supply or an eight processor with two power power supplies can be
fully loaded (all drive bays and add-in board slots filled). The power supplies use a
forced current-sharing technique that ensures the supplies share within 10 percent at full
load. In a high-access system with two or three power supplies, the additional supply
gives redundancy, because the load is redistributed if one supply fails.
The DEU may be configured with up to two power supplies. If the second power supply
is installed for power system redundancy, the power supplies are now hot-swappable
and can be easily installed or removed from the back of the DEU without turning
system power off.

Peripheral Bays

The system supports a variety of standard PC AT-compatible peripheral devices. The
chassis includes these peripheral bays:
A 3.5-inch front panel bay for mounting the standard 3.5" diskette drive (supports
!
720 KB and 1.44 MB diskette media)
Two 5.25-inch removable media front panel bays for mounting half-height 5.25-inch
!
peripheral devices: optional tape drives and optional additional CD ROM drive, etc.
A front panel bay for mounting the standard slim (low-profile) CD-ROM drive.
!
Two hot-swap SCSI hard disk drive bays for mounting up to two SCSI hard disk
!
drives in easily removable drive carriers. Each drive has a set of three lights to
indicate the fault or other status: power-on (green LED), activity (green LED, and
fault (yellow LED).
Note:
plane that require an 80-pin single connector attachment (SCA)
connector on the drives that you install.
1-24 System Overview
The SCSI hard disk drive bays contain a hot-swap back