HP Modular Cooling System Generation 2 site preparation guide - Technical white paper

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Voltage fluctuations and outages
The HP MCS G2 is designed to provide immunity to power outages of less than one cycle. However,
testing cannot conclusively rule out loss of service. Therefore, adherence to the following guidelines
provides the best possible performance of power distribution systems for HP equipment:
 Dedicated power source—isolates the power distribution system from other circuits in the facility.
 Missing-phase and low-voltage detectors—shuts equipment down automatically when a severe
power disruption occurs. For peripheral equipment, these devices are recommended but optional.
 Online uninterruptible power supply—keeps input voltage to devices constant and should be
considered if outages of one-half cycle or more are common. Refer to qualified contractors or
consultants for each situation.
The HP MCS G2 can be protected from the sources of many electrical disturbances by using:
 An isolated power distribution system
 Power conditioning equipment
 Over- and undervoltage detection and protection circuits
 Protection to reduce high-frequency electrical energy radiation
 Surge protective devices on power cables to protect equipment against electrical storms
Electrical planning around water-handling components
Because of potential condensation on noninsulated water connections or leaking water connections
around water-based cooling systems, a few issues must be considered during the electrical planning:
• Waterproofed connectors
• Watertight conduits for cables
• Leak detection systems
Caution:
In case water is in contact with the power cables, shut down the main
breaker before cleaning up water in this area.
To identify waterproofed connectors, it is recommended to look at the IP rating of the connector based
on the international standard IEC 60529. HP recommends a connector that is rated at least IP 67.
Cable conduits are available in different styles, depending on flexibility and materials. The common
materials are plastic, metal, nylon, or mostly a composition of these materials. Watertight conduits are
available in both flexible and hard material, depending on the application.
A leak detection system for a data center usually uses leak sensor cables, which are installed on the
subfloor in a raised floor and connected to a facility management system.
Connecting to facility AC power
The HP MCS G2 accepts AC power through two C20-type power receptacles located at the top rear
patch panel. The HP MCS ships with two sets of AC power cords for connecting to redundant AC
power buses, if available. Figure 13 shows the two types of power cords shipped with the HP MCS
G2. The NEMA L6-20 power cord uses a NEMA L6-20 male plug for connecting to a facility AC feed
connector common to North America and Japan. The IEC 309 power cord uses an IEC 309 male
plug for connecting to a facility AC feed connector common in various international regions.