Site Preparation Guide, Fourth Editon - HP Integrity rx7620 Server

Appendix B
General Site Preparation Guidelines
Electrical Factors
31
• Circuit breakers
• An emergency power cutoff switch
• Devices specific to the geographic location, such as earthquake protection
Lighting Requirements for Equipment Servicing
Adequate lighting and utility outlets in a computer room reduce the possibility of accidents during equipment
servicing. Safer servicing is also more efficient and, therefore, less costly.
For example, it is difficult to see cable connection points on the hardware if lighting is inadequate. Adequate
lighting reduces the chances of connector damage when cables are installed or removed.
The minimum recommended illumination level is 70 foot-candles (756 lumens per square meter) when the
light level is measured at 30 inches (76.2 cm) above the floor.
Working Space for Server Access
The recommended working space for performing maintenance on the server is three feet. The work space will
permit at least a 90 degree opening of equipment doors or hinged panels. When planning for the working
space area, consider whether access to the server will be at the front, the side, or the rear of the server.
Power Consumption
When determining power requirements, you must consider any peripheral equipment that will be installed
during initial installation or as a later update. Refer to the applicable documentation for such devices to
determine the power required to support these devices.
Electrical Load Requirements (Circuit Breaker Sizing)
NOTE LAHJ and should make the final decision regarding adherence to country-specific electrical
codes and guidelines.
It is good practice to derate power distribution systems for the following reasons:
• To avoid nuisance tripping from load shifts or power transients, circuit protection devices should never be
run above 80% of their root-mean-square (RMS) current ratings.
• Safety agencies derate most power connectors to 80% of their RMS current ratings.
Power Quality
The server is designed to operate over a wide range of voltages and frequencies. The server has been tested
and shown to comply with EMC Specification EN50082. However, damage can occur if these ranges are
exceeded. Severe electrical disturbances can exceed the design specifications of the equipment.
Sources of Voltage Fluctuations
Voltage fluctuations, sometimes called glitches, affect the quality of electrical power. Common sources of
these disturbances are:
• Fluctuations occurring within the facility’s distribution system
• Utility service low-voltage conditions (such as sags or brownouts)
• Wide and rapid variations in input voltage levels