Power problems are the scourge of residential and commercial electronics, not to mention the toll they take on productivity and relaxation. Disruptions and irregularities in the power system, including voltage spikes (surges), voltage fluctuations (brownouts), dips (sags), total outages (blackouts) and noise (interference), affect electronic signal performance, damage electronic circuits and even create a fire risk depending on the severity and duration of the problem.

This article examines ten common power problems experienced in residential and commercial environments, including the power optimization products that address the issues.

Images were provided by Future Ready Solutions partner Xtreme Power Conversion.

 

 

Blackout

An AC blackout is a complete loss of power due to the absence of electricity. Also known as an outage, blackouts typically occur when there is a failure in the external power grid such as a downed line or blown transformer.

Blackouts don’t typically damage electronics during the power outage, but rather when the power is restored due to a sudden surge in voltage that can overload sensitive components within the electronics. Additionally, blackouts can be followed by intermittent drops in voltage and cycling power that also detrimentally affects circuits, motors, compressors and other sensitive components.

Perhaps most frustrating, however, is the total loss of power that typically leaves buildings — and everything inside — in the dark.

 

Power Sag

A power sag is a brief drop in voltage often due to turning on or off large loads, short circuits in power lines and loose connections. Also known as a voltage dip, power sags are common when large, power hungry devices such as air conditioners, power tools, vacuums, appliances, motors and other industrial machinery power on thereby reducing the normal power level by 10% or more.

Unlike brownouts, which we will discuss below, power sags are usually brief in nature; however, their impact on electronics can still be catastrophic. Power sags are known to cause electronics to fail and/or reboot due to the erratic power flow, computers can lose data or suffer corrupt files, electronics can suffer premature wear and tear, and devices can overheat leading to, in extreme cases, electrical fires.

 

Power Surge

A power surge is a sudden, brief spike in electrical voltage that exceeds normal power levels. Power surges are often caused by lightning strikes, power grid fluctuations (including the initial surge of power after a blackout), the powering on of large appliances or motors, and faulty wiring.

Power surges can be catastrophic to electronics and other electrical devices, as the short burst of high electricity can overload their circuits. Products with circuit boards (think TVs, hi-fi equipment, computers, connected appliances and most other modern devices) are particularly prone to power surge damage because they rely on a specific amount of regulated voltage; however, in extreme surge events any device connected to the power grid can experience damage including circuit failure and the melting of metal and plastic components. Overload from power surges often causes the “burning odor” in failed electronics.

As with other power problems, power surges can also lead to less visible device damage including premature wear and tear and file corruption.

 

Brownout

An AC brownout is a longer-term drop in voltage within an electrical power system. Brownouts are usually caused by a reduction in power during periods of peak energy usage, such as during extremely hot or cool weather. Utility companies intentionally induce brownouts to reduce stress on the power grid and prevent a more catastrophic overload and potential blackout. High population density areas are the most prone to brownouts, as are those regularly impacted by severe weather and temperatures.

Brownouts are often indicated by dimming lights when the voltage drops, and this voltage reduction is what typically damages sensitive electronic circuits. Ironically, the intermittent voltage from brownouts can often be more destructive than a surge or total blackout, and brownouts are known to cause a host of issues including device malfunction and failure from underpowered circuits, computer data loss and file corruption, premature wear and tear, device overheating and even electrical fires.

 

Overvoltage

Overvoltage is an increase in electrical voltage that exceeds normal power levels. Unlike a power surge which is a brief spike, overvoltage occurs on a longer, more regular basis and is often permanently present unless addressed in the power infrastructure or with conditioning equipment.

A major cause of overvoltage is electromagnetic interference (also known as EMI). EMI induces unwanted voltage spikes on electronic circuits through capacitive and inductive coupling by essentially “injecting” additional power into the circuit. Switching power supplies, motors, high-speed electronics, appliances and lighting fixtures are common sources of EMI, as are simple power lines with high current fluctuations.

Regardless of the source, overvoltages can cause significant damage to electronics leading to premature failure, data loss and expensive repairs.

 

Normal Mode Noise

Normal mode noise, also known as differential mode noise, is electrical noise that travels in opposite directions on a pair of wires. When normal mode noise is present the current is flowing in one direction on one wire and in the opposite direction on the other. This imbalance will often cancel each other out; however, in extreme cases normal mode noise will distort electrical signals and affect electronic device performance.

Normal mode noise is typically caused by poorly connected conductors, erratic noise in the power source or load components, improper ground currents or circuit imbalances. It’s also a common problem with low-cost switching power supplies and unbalanced signal transmission lines.

 

Common Mode Noise

Unlike normal mode noise, common mode noise travels in the same direction on a pair of wires. It’s known as “common mode” because the direction of the currents is the same on both the positive and negative sides of the circuit. In most buildings, common mode noise is present between the signal lines and reference ground, thereby creating an uneven ground potential in the electrical system.

Common mode noise tends to be more problematic than normal mode noise because it’s harder to filter out and can more easily spread to other circuits. It’s also a greater issue when dealing with long cable lengths and high-speed data signals.

Common mode noise is typically caused when signal wires run too close to ground planes, in large or older properties where multiple ground potentials are present, in areas prone to high electromagnetic interference and from poorly wired connections.

 

Frequency Variation

Electrical frequency variations occur when there is an imbalance between the amount of electricity being generated and the actual demand for power, causing the alternating current to cycle at a faster or slower rate than normal. Lower frequencies are present with higher demand than supply, and higher frequencies are present with lower demand than supply.

Frequency variations can cause flickering lights, motors to run slower or faster than specification, clocks to lose time and other electronic device and appliance failures. In extreme cases, excessive frequency variations will cause devices to operate inefficiently and generate excess heat, ultimately leading to expensive repairs and creating a fire risk.

 

Switching Transient

A switching transient is a short-lived voltage or current fluctuation that occurs in an electrical circuit when there is a change in circuit conditions. Switching transients are typically brief periods of instability, such as when a light switch is turned on or off or when a breaker is opened or closed.

Unlike a power surge, switching transients have oscillating wave forms and the power circuit typically quickly settles into a steady state.

However, like a power surge, switching transients can cause damage to sensitive electronics, motors and even the power infrastructure itself. Switching transients can exceed the insulation capabilities of components and cables, creating a power arc and short circuit and ultimately leading to premature device failure and fire risk.

 

Harmonic Distortion

Harmonic distortion occurs when the electrical voltage isn’t a smooth wave but has added spikes and irregularities due to the presence of additional frequencies. They are often caused by devices that draw power in pulses rather than a smooth sine wave, such as computers, hard drives, servers and LED lights.

Harmonic distortion can lead to the overheating of electronics, transformers, appliances and other devices with motors, ultimately leading to premature failure, data loss and expensive repairs.

 

 

Addressing Power Problems

In a perfect world, most power problems would be addressed outside the building by the utility company; however, as we’ve seen above, many issues are outside the utility provider’s control, originate within the building’s power infrastructure itself, or are even caused by the devices and appliances installed within the building.

In reality, it’s often up to the building owner and their integrator to plan for and address power issues at individual locations or for the building as a whole.

Historically, surge protectors, uninterruptible power supplies (UPS) and power conditioners were installed at locations where sensitive electronics were present; however, this distributed approach didn’t protect the broader power grid and the other devices throughout the building, nor did it address the root cause of most power problems.

Today, centralized whole-building UPS systems are being installed at the main power panel thereby providing power optimization to the broader building and all connected devices. Centralized UPS systems effectively provide battery backup, surge protection and power conditioning to all devices downstream, and a properly installed whole-building UPS often costs less than individual power components and the repairs to devices that aren’t protected.

Plus, centralized UPS systems ensure audio-visual and computer equipment operate within specification and output the ultra high-definition and high-fidelity signals you’re paying for.

Future Ready Solutions offers a variety of power protection and optimization products including centralized and point-of-service UPS systems, surge protectors, power conditioners and power distribution devices. Contact us to learn more.