The Raritan Blog

Structuring a Reliable Power Distribution Equipment Maintenance Plan

Jessica Ciesla
March 7, 2019

The lack of a sound power distribution maintenance program can result in a catastrophic power failure that impacts system uptime or factory production. The initial power failure may be due to an unavoidable disaster, but an inability to quickly recover from such an occurrence is typically due to a data center manager’s unwillingness to view maintenance as an investment rather than an expense. The primary goal of a preventative maintenance plan for power distribution infrastructure is to minimize the impact that an equipment malfunction or power outage will have on business operations or service. This infrastructure includes but isn't limited to the following equipment:

•    Smart rack PDUs
•    Smart rack controllers
•    Service entrance switchgear
•    Rack transfer switches
•    Branch circuit monitors
•    Environment sensors
•    Power panels
•    Inline meters

Data center managers often rely on outside experts to help them develop a robust equipment maintenance plan. These experts are typically maintenance contractors, but they may also be original equipment manufacturers (OEMs) or electrical contractors. A comprehensive maintenance plan should cover all components related to the distribution of electrical power to ensure that this equipment continues to operate safely and reliably. The maintenance plan should address issues in the following areas:

•    Environment
•    Grounding systems
•    One-line diagrams
•    Equipment wear
•    Scheduled Interruptions


Environmental issues have a high potential for human error that could disrupt business operations. A licensed electrical engineer must perform a series of tests on power distribution equipment, which should include arc flash analyses, short circuit analyses and time/current coordination studies. These studies will ensure that the electrical equipment is properly labeled, rated and set, thus increasing uptime by identifying safety deficiencies in the power distribution system.

Grounding Systems

The neglect of grounding systems can result in phase-to-ground faults, which usually accounts for at least 95 percent of all electrical faults. Furthermore, this type of fault can affect half of a facilities power distribution system. A licensed electrical engineer can assist data center managers in selecting an electrical maintenance contractor who can inspect the data center’s grounding system, which will provide managers with peace of mind regarding electrical faults.

One-line Diagrams

The development of a maintenance plan will be hampered by a lack of current one-line electrical diagrams. A licensed electrical engineer is needed to create and maintain one-line diagrams, which should include equipment name plate data and the physical location of each piece of electrical equipment. A one-line diagram provides creates a baseline of electrical equipment that will allow a facility manager to develop a robust maintenance plan.

Equipment Wear

Electrical equipment suffers wear and tear over time, generally as a result of the combined effects of heat, moisture and dirt. This process can cause the equipment of an electrical system to quickly deteriorate, especially conductive materials, insulation and other protective components. Clean components in a temperature and humidity-controlled environment can help create the optimum conditions needed to maximize the life of electrical equipment. Proper maintenance of electrical equipment can lower its operational costs, thereby minimizing the equipment’s total cost of ownership.

Scheduled Interruptions

Electrical systems pose a potential threat to human safety, especially when cleaning, inspecting or servicing equipment that is still receiving power. These activities require a scheduled interruption of service, during which the manager must ensure the facility’s essential power requirements are temporarily met through alternate sources. This strategy will reduce the risk of electrical injuries.

Raritan initially developed KVM switches that allow IT professionals to remotely manage servers, and we are now a leading provider of intelligent rack PDUs. Our intelligent power and energy monitoring products are transforming the way companies manage their data center power chains. Our solutions increase the reliability and intelligence of data centers for 9 of the top 10 Fortune 500 technology companies.

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