Sun Microsystems 96257 manual Equipment Grounding, Source Power Input

Site Readiness Planning

Equipment Grounding

For safety and ESD protection, VSM5 system equipment must be properly grounded. VTSS cabinet power cables contain an insulated green/yellow grounding wire that con- nects the frame to the ground terminal at the AC source power outlet. A similar insulated green or green/yellow wire ground, of at least the same diameter as the phase wire, is re- quired between the branch circuit panel and the power receptacle that attaches to each cabinet.

Source Power Input

Voltage and frequency ranges at the AC source power receptacle(s) that will supply power to VSM5 system equipment must be measured and verified to meet the specifications shown in Table 4-2.

Table 4-2. Source Power Requirements for VSM5 Equipment

Source Power	Voltage Range	Frequency Range (Hz)
AC, single-phase, 3-wire	170-240	47-63

Dual Independent Source Power Supplies

VSM5-VTSS cabinets have a redundant power distribution architecture designed to pre- vent disruption of system operations from single-source power failures.

To enable this capability, the two VTSS cabinet power-strip cables must be connected to separate, independent power sources that are unlikely to fail simultaneously (e.g., one to local utility power, the other to an uninterruptible power supply (UPS) system). Connecting both cabinet power-strip cables to the same power source will not enable this redundant power capability.

Transient Electrical Noise and Power Line Disturbances

Reliable AC source power free from interference or disturbance is required for optimum performance of VSM5 system equipment. Most utility companies provide power that can properly operate system equipment. However, equipment errors or failures can be caused when outside (radiated or conducted) transient electrical noise signals are superimposed on power provided to equipment.

Additionally, while VSM5 system equipment is designed to withstand most common types of power line disturbances with little or no effect on operations, extreme power disturbanc- es such as lightning strikes can cause equipment power failures or errors if steps are not taken to mitigate such disturbances.

To mitigate the effects of outside electrical noise signals and power disturbances, data center source power panels should be equipped with a transient grounding plate similar to that shown in Figure 4-2on page 4-51.

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