Common Power Problems

Data Center Best Practices | Common Power Problems

Common Power Problems

Common Power Problems are a direct result of utility power that is rarely clean, consistent power. Power companies are constantly faced with inconsistencies in generation sources, emerging green power generation technologies, old grids, and increased demand for electricity. Couple those stresses with extreme temperatures and other forces of Mother Nature, and the result is utility power coming into your facility that can contain spikes, sags, brownouts and even blackouts. These power quality problems damage valuable equipment, cause expensive and frustrating downtime and even, in some settings, put lives at risk. 

The good news is that you can prevent, or mitigate, these problems by incorporating the right power equipment into the power path of your facility to protect critical load. In addition to this review of Common Power Problems, and their possible solutions, see our “Common Power Problems and Solutions” Whitepaper for more in-depth information.

Power Surges

A power surge takes place when the voltage is 110% or more above normal. The most common cause is heavy electrical equipment being turned off. Under these conditions, computer systems and other high tech equipment can experience flickering lights, equipment shutoff, errors or memory loss.

Possible SolutionsSurge SuppressorsVoltage RegulatorsUninterruptable Power SuppliesPower Conditioners

High-Voltage Spikes

High-voltage spikes occur when there is a sudden voltage peak of up to 6,000 volts. These power problems are usually the result of nearby lightning strikes, but there can be other causes as well. The effects on vulnerable electronic systems can include loss of data and burned circuit boards.

Possible SolutionsSurge SuppressorsVoltage RegulatorsUninterruptable Power SuppliesPower Conditioners

Did You Know?

Voltage Regulators and Power Conditioners can be separate instruments but both Line Interactive UPS and Online Double-Conversion UPS provide some level of built-in power conditioning. Line Interactive UPS systems also have automatic voltage regulation (AVR). Online double-conversion UPS provides 100% power conditioning, zero transfer time to battery, no change in output voltage and better transient suppression.


Transients are potentially the most damaging type of power quality disturbance that you may encounter. Transients are defined as sudden, but significant deviations from normal voltage or current levels that typically last from 200 millionths of a second to half a second and are often caused by lightning, electrostatic discharge, load switching, or faulty wiring.  Transients can fall into two categories:

  • Impulsive: a sudden, non–power frequency change in the steady-state condition of voltage, current, or both that is unidirectional in polarity (primarily either positive or negative).
  • Oscillatory: a sudden, non-power frequency change in the steady- state condition of voltage, current, or both, that includes both positive and negative polarity values.  

Possible SolutionsSurge SuppressorsVoltage RegulatorsUninterruptable Power SuppliesPower Conditioners

Frequency Variation

A frequency variation involves a change in frequency from the normally stable utility frequency of 50 or 60 Hz, depending on your geographic location. This may be caused by erratic operation of emergency generators or unstable frequency power sources. For sensitive equipment, the results can be data loss, program failure, equipment lock-up or complete shut down.

Possible SolutionsVoltage RegulatorsPower Conditioners

Power Sag

A sag is the reduction of AC Voltage at a given frequency for the duration of 0.5 cycles to 1 minute’s time.  Sages are usually caused by system faults, and often the result of switching on loads with high demand startup currents.

Possible SolutionsVoltage RegulatorsUninterruptable Power SuppliesPower Conditioners

Electrical Line Noise

Electrical line noise is defined as Radio Frequency Interference (RFI) and Electromagnetic Interference (EMI) and causes unwanted effects in the circuits of computer systems. Sources of the problems include motors, relays, motor control devices, broadcast transmissions, microwave radiation, and distant electrical storms. RFI, EMI and other frequency problems can cause equipment to lock-up, and data error or loss.

Possible SolutionsVoltage RegulatorsUninterruptable Power SuppliesPower Conditioners


A brownout is a steady lower voltage state. An example of a brownout is what happens during peak electrical demand in the summer, when utilities can’t always meet the requirements and must lower the voltage to limit maximum power. When this happens, systems can experience glitches, data loss and equipment failure.

Possible SolutionsVoltage RegulatorsUninterruptable Power SuppliesPower Conditioners


A power failure or blackout is a zero-voltage condition that lasts for more than two cycles. It may be caused by tripping a circuit breaker, power distribution failure or utility power failure. A blackout can cause data loss or corruption and equipment damage. When you pair a UPS with a generator, when power goes out, the UPS will kick in first giving the generator time to start up which is ideal for mission critical applications that cannot go without power. 

Possible Solutions: Generators


Possible Solutions: What You Need to Know

Surge Suppressors:  While a surge suppressor can protect smaller devices against spikes and surges, if your equipment is mission critical, or your facility experiences frequent power outages, a surge suppressor may not be enough protection.

Voltage Regulators: These devices keep the voltage from the power source within a safe range for your equipment but do not provide battery back-up.

Power Conditioners: These can protect against surges and brownouts and may include built-in voltage regulators. They continuously monitor power and condition it as needed to protect your equipment. 

UPS: In addition to battery back-up, UPS equipment may include surge suppression, voltage regulation and power conditioning depending on the UPS topology.  

For more in-depth information about how to solve Common Power Problems, and the equipment to utilize, see our “Common Power Problems and Solutions” Whitepaper.

For more information about solving Common Power Problems,
call 800-876-9373 or email [email protected].