Compaq ProLiant BL e-Class System Overview and Planning

Compaq ProLiant BL e-Class System Overview and Planning 18
Power Planning
The following general guidelines should be followed when planning and installing a ProLiant
BL e-Class system:
High-voltage deployment is highly recommended (200-240VAC) because of lower current
requirements.
Both power supplies provided with your ProLiant BL e-Class server blade enclosure should be
plugged into an AC power source to assure full power supply redundancy.
Avoid single points of failure:
• Do not cable both enclosure power supplies to the same PDU (or power strip) to prevent
a single PDU failure causing loss of the enclosure.
• Do not cable multiple enclosures or PDUs to the same AC wall outlet (or AC breaker) to
prevent a single AC source failure causing loss of all enclosures.
• Each power supply should be supplied by different AC sources – ideally, different
municipal AC power networks
The ProLiant BL e-Class server blade enclosure’s two power supplies share the load
approximately 50/50%, but this can vary by ± 12% up to 44/56%. For example, a 1000 W load
could be shared 440/560 W.
Determine how many PDUs you need. For instance, a 16-A, low-voltage PDU can only meet the
requirements of one fully loaded, non-AC-redundant enclosure at 10 A. A 24-A high-voltage
PDU can support up to 4 fully loaded, non-AC-redundant enclosures at 4*5 = 20 A.
Decide what level of redundancy your environment needs (described in section “Redundancy and
Single Sources of Failure”). This requires a significantly different PDU configuration.
• Power supply redundancy (standard on ProLiant BL e-Class server blade enclosures)
• PDU redundancy
• AC source redundancy
Carefully review PDU or power strip current limitations to avoid the “domino effect” (described
below). If a power supply or AC source fails (or is unplugged), the remaining components must
have enough capacity to support the new power distribution.
The ProLiant BL e-Class server blade enclosure should always have two power supplies installed
to ensure proper airflow and adequate cooling. This is true even if only one power supply has AC
power.
ProLiant BL e-Class Enclosure Power Specification Summary
There is a 1000-W AC input for a fully loaded ProLiant BL e-Class server blade enclosure.
There is a 10-A maximum current draw at low voltage (100 V).
There is a 5-A maximum current draw at high voltage (200 V).
The enclosure supports power supply redundancy with 2 power supplies in a 1 + 1 configuration.