That was the headline five years ago when an electrician was working in a data center accidentally touched a high voltage live terminal and was killed while installing an uninterruptible power supply. Five years later the courts have found the electrical contractor negligent in the accident because of failures in communication and management.

The electrical contractor claimed to have been under pressure from the difficult and demanding client, but as the health and safety inspector stated, “they cannot be excused for having lost sight of the need for the effective control of risks arising from the work being carried out under their control at the data center.”

Reading the recent court decision is a sad reminder of the risk data centers electrical system represent. The article made me think of a few of the tenants we professed in our data center.

Never Trust Always Test
• Turn it off
• Secure against accidentally being turned on (Lock out/Tag out)
• Test for voltage
• Ground the wires: Be especially careful with equipment that has capacitors, such as UPS systems. Capacitors can hold a charge long after the power is shut off.

• One person and one person only should be in charge of a project involving electrical wiring. Their job is to make sure all of the people involved are made aware of the tasks to be performed, and all safety precautions are being observed.
• Always have your single-line diagrams out and reviewed by everyone before making any changes or upgrades. Make sure everyone completely understands the diagrams and how they apply to the job at hand.
• Always implement lock out tag out devices where applicable before beginning the work.
• Prepare a safety checklist before beginning any work.
• When live testing is required, I’d recommend using a load bank to do the testing rather than using the actual equipment. When using load banks, you will have to take the extra steps to unhook and attach power to the load banks forcing everyone to be more aware of what they are doing.
• Follow guidelines outlined in NFPA 70E for when and where to wear personal protective equipment.

Regardless of all precautions taken to create a safe environment when working on electrical equipment, always assume it is energized before beginning the work. Always check it with a voltmeter and remember an energized piece of equipment looks no different than one that is not.

Ken Koty,