HP SureStore E Disk Array 12H User's and Service Manual (C5445-90901, September 1999)

Appendix D. Back-to-Back Racking
Installation Procedure
242
Racking
Installation Procedure
1. Confirm power requirements
Ensure that the installation site meets the following requirements.
•
Input voltage: 200/230/240 VAC single phase
•
Input frequency: 50 Hz/60 Hz
•
Input current: 16 A maximum, operating (per PDU)
US installations
Standard 20A Square D circuit breakers are adequate for all authorized configurations of back-to-back
racking.
European circuit breakers
In Europe, some sites may require upgraded circuit breakers. This is because inrush current for a single disk
enclosure may be has high as 57.16 amps peak for up to three milliseconds.
Note the figures in the following comparison chart:
Tripping
characteristic code
Current
multiplier
Total trip current Back-to-Back Rack usability
B 6X 96A Do not use with BTBR
C 12X 192A Up to 5 redundant disk enclosures
D 25X 400A Up to 5 redundant disk enclosures or
up to 8 non-redundant disk
enclosures
Z 4X 64A Do not use with BTBR
K 17X 272A Up to 5 redundant disk enclosures or
8 non-redundant disk enclosures
In Europe, therefore, site preparation must include 16 amp circuit breakers, preferably with the D or K
tripping characteristic code.
CAUTION! Intermittent power losses will occur if improper circuit breakers are used.