Data center infrastructure is constantly evolving. Increases in computer room and data center density and diversity are driving change in the power and cooling systems that business critical servers and communications devices depend on for their performance and reliability.
As equipment density rises, hardware becomes mission critical because the each application deployed increases business dependence on data center IT systems. At the same time, entire facilities, as well as individual
Density is an issue felt across all business, according to a 2006 Data Center Users Group study released in October. Heat density and power density represented two of the top three issues driving change in the data center as more than 40% of the respondents noted these as top trends related to infrastructure.
For many organizations, the IT infrastructure has evolved into an interdependent business critical network with the data center as the hub. A power failure at any point along the network can impact the entire operation -- and have serious consequences for the business.
As a result, there exists a valuable opportunity for resellers to work closely with customers to proactively identify problems within their power systems that could adversely affect availability of their critical systems and operational performance of their facility.
Preventive maintenance usually requires a shut-down to ensure electrical connection integrity. Most preventive maintenance measures should only be attempted by qualified personnel.
The following are preventive maintenance tips for resellers to use when reviewing a customer's power systems:
- Small UPS devices should be inspected annually.
- Medium and large UPS systems should be inspected twice a year to ensure proper operation and confirm that the unit is operating within the manufacturer's specifications.
Data center semi-annual service
- Perform temperature checks on all breakers, connections and associated controls. Repair and/or report all high temperature areas.
- Perform complete visual inspection of equipment including subassemblies, wiring harnesses, contacts, cables and major components. Check air filters for cleanliness.
- Check modules for the following:
- Rectifier and inverter snubber boards for discoloration.
- Power capacitors for swelling or leaking oil.
- DC capacitor vent caps that have extruded more than 1/8".
- Record all voltage and current meter readings on module control cabinet or system control cabinet.
- Measure and record harmonic trap filter currents.
Data center annual services
- Check inverter and rectifier snubbers for burned or broken wires.
- Ensure all nuts, bolts, screws, and connectors for tightness and heat discoloration.
- Verify fuses on the DC capacitor deck for continuity (if applicable).
- With customer approval, perform operational test of the system, including unit transfer and battery discharge.
- Calibrate and record all electronics to system specifications.
- Install or perform Engineering Field Change Notices (FCN), as necessary.
- Measure and record all low-voltage power supply levels.
- Measure and record phase to phase input voltage and currents.
- Review system performance with customer to address any questions and to schedule any repairs.
Data center battery inspection service
This visual inspection should be performed during the UPS semi-annual and annual preventive maintenance services.
- Check integrity of battery cabinet (if applicable).
- Visual inspection of the battery cabinet or room to include:
- Check for NO-OX grease or oil on all connections.
- Check battery jars for proper liquid level (if flooded cells).
- Check for corrosion on all terminals and cables.
- Examine physical cleanliness of battery room and jars.
- Measure and record DC bus ripple voltage.
- Measure and record total battery float voltage.
Data center preventive maintenance service on power management systems
- Perform complete visual inspection of internal sub-assemblies, wiring harnesses, contactors, cables, major components, and check for proper clearance around the unit.
- Examine all transformer, terminal block and ground/neutral bus bar connections, as well as input and output breakers for tightness.
- Inspect high and low voltage junction box terminals for tightness.
- Inspect all option wiring for tightness. (Spike suppressor, ground fault, phase rotation/loss).
- Inspect all capacitor bank connections for a solid fit.
- Verify that all cooling fans are functional and air ducts are open.
- Confirm continuity of all fuses and that they are correctly rated.
- Measure input and output phase to phase voltage.
- Determine the output, neutral and ground current.
- Verify kVA load and capacity per phase.
- Validate grounding electrode conductor and any isolated grounds.
- Measure all filter capacitor currents at no load for all three phases.
- Measure primary, secondary, second harmonic and third harmonic (if applicable). All should be balanced within 2.5% deviation.
- Verify EPO lamps are illuminated.
- Check that local and remote EPOs are functioning properly if permitted.
- Confirm that monitor is recording within +/- 2% of those values measured.
- Activate transformer over-temp alarm and shutdown circuits to confirm proper operation if permitted.
- Verify operation of any option for alarm or shutdown sequence if permitted and of any customer alarm circuits and specified messages.
- Make sure of specified restart capabilities either manual or auto-restart.
- Verify operation of the bypass switch and the bypass transformer over temp alarm.
About the author:Omar McKee is
the service product manager for the service business of Emerson Network Power.
This was first published in June 2007