IBM 990 - Manual (Page 245)

Chapter 9. Environmental requirements 233
Table 9-2 Internal Battery Feature emergency power times
9.1.4 Emergency power-off
On the front of frame A is an emergency power-off switch that will immediately disconnect
utility and battery power from the server when activated. This causes all volatile data in the
server to be lost.
In case a server is connected to a machine room emergency power-off switch, and the
Internal Battery Feature is installed, the batteries will take over if the switch is engaged.
It is possible to connect the machine room emergency power-off switch to the server
power-off switch. In that case, when the machine room emergency power-off switch is
engaged, all power will be disconnected from the line cords and the Internal Battery Features.
This causes all volatile data in the server to be lost.
9.1.5 Cooling requirements
The z990 requires chilled air from under the raised floor to fulfill the air-cooling requirements.
The chilled air usually is provided through perforated floor tiles. The amount of chilled air
needed in the computer room is indicated in the IMPP for a variety of underfloor
temperatures.
At an underfloor temperature of 20
o
Celsius (68
o
Fahrenheit), the cooling airflow
requirements with maximum populated I/O cages are listed in Table 9-3.
Table 9-3 Underfloor cooling airflow requirements (C/FM)
9.2 Weights
Since there may be a large number of cables connected to a z990 installation, a raised floor is
mandatory. In the IMPP, weight distribution and floor loading tables are published, to be used
together with the maximum frame weight, frame width, and frame depth to calculate the floor
loading for the z990 system.
Table 9-4 on page 234 indicates the minimum and maximum system weights for all models.
The weight ranges are base on configuration models with one and three I/O cages.
Model One I/O cage Two I/O cages Three I/O cages
IBM 2084 model A08 8 minutes 13 minutes 12 minutes
IBM 2084 model B16 13 minutes 8.5 minutes 10.5 minutes
IBM 2084 model C24 8.5 minutes 11 minutes 9 minutes
IBM 2084 model D32 13 minutes 8.5 minutes 7.5 minutes
Model One I/O cage Two I/O cages Three I/O cages
IBM 2084-A08 1050 1350 1750
IBM 2084-B16 1350 1750 2200
IBM 2084-C24 1750 2200 2600
IBM 2084-D32 1750 2200 2600