Our most important job is to deliver safe, dependable power to your home. Due to a number of factors inside and outside your home, the voltage of your electric service will vary slightly. Most of the time you won’t even notice these voltage variations, but modern sophisticated electronic equipment can be very sensitive to even small, split-second electricity fluctuations, whatever the cause.

Sometimes events interrupt or vary your power supply. For example, a car hitting a utility pole, a neighbor overloading a circuit or a squirrel gnawing on a power line may result in power surges, sags or outages.

Common power quality symptoms and causes
No home or business is completely immune from power disturbances. However, there are steps you can take to protect your equipment. The table below describes the most common electrical disturbances in homes, typical causes and tips to help safeguard your equipment.

Typical power quality problems and solutions

A good first step toward correcting power quality problems in your home is to look for the source of the disturbance. Many times power quality problems occur as a result of inadequate or poor home wiring.

1. Check wiring and grounding
Proper wiring and grounding is essential for the smooth operation of sensitive electronic equipment.

• If a piece of equipment has operating problems, first check to see if it is plugged into a grounded outlet.

• Usually, a grounded outlet has two receptacles, each with three slots: two side-by-side vertical slots and one semicircular slot. A simple hand-held device available at most hardware stores can help you determine whether your outlets are properly grounded.

• A ground is often needed to meet safety standards because some appliances could otherwise be shock hazards. If your outlet does not have a ground, a licensed electrician should upgrade it.

• Check your appliances for loose or damaged plugs and connections, and repair or replace them.

2. Move your equipment to a dedicated circuit

• It’s generally a good idea to use separate circuits to isolate sensitive electronics from problem-causing appliances. In many cases, relocation is a simple, no-cost solution to a power quality problem in your house.

• Avoid putting sensitive devices (personal computers, modems, VCRs and stereo equipment) on the same circuit as furnaces, air conditioners and kitchen appliances.

3. Keep a power quality log
If disturbances happen, write down the date, time, duration and a description of what occurs. This will help you – and us – track down the cause.

4. Install a surge protector
Your entertainment system, television, VCR, CD player and stereo system are valuable items and need to be protected accordingly. Using a surge protector is one inexpensive way to protect this equipment from power fluctuations. The job of a surge protective device, sometimes called "transient voltage surge suppressor," is to reduce the magnitude of power surges to any equipment or appliance connected to it. Surge protectors direct the disturbance. Therefore, they protect equipment by re-routing excess energy from temporary over-voltages. However, this device will not eliminate power fluctuations.

You can find surge protectors at almost any store that sells electronic equipment. All surge protectors, however, are not created equal. Make sure you’re getting a surge protector, not just a power strip. Though they look very similar, power strips only offer multiple electrical outlets, not surge protection.

What to look for when buying a plug-in surge protector:

• UL TVSS 1449 rating – a certification label from an independent test lab such as UL (Underwriters Laboratories) or ETL (Electrical Testing Laboratories) on the package. Products with this certification label meet current industry safety standards.
• ANSI/IEEE C62.41, Category A (for higher exposure environments, use Category B) – The maximum amount of voltage that will reach your equipment as a result of having it connected to a surge protector.

• UL 330 voltage rating – This performance standard ensures that power disturbances are recognized and routed away from your equipment instantaneously, providing effective protection and keeping your equipment safe from damage.

• Catastrophic event protection for safety – a fast-acting fuse that reacts quickly and shuts down your system in the event of a dangerous wiring problem.

• Site-wiring fault indicator – indicates there may be a problem with the wiring of the outlet.

• Protection working indicator – lets you know that the surge protector is working as intended.

• Connection lines for phone lines, television cables and other data communication lines.  (Be aware that damaging power disturbances can also reach your equipment through cable and telephone lines.)

• Line-noise filters – otherwise this noise could disrupt your equipment’s performance.

• A lifetime product warranty and insurance coverage on connected equipment.

5. Consider main circuit panel protection
A surge protector installed at the main circuit panel safeguards your appliances from power fluctuations that originate outside your home. This type of surge protector requires installation by a professional electrician.

Main circuit panel surge protectors effectively block outside power disturbances before they have a chance to enter your home – protecting items such as built-in appliances, which you may not even know contain electronic components.

However, sensitive items such as computers and home entertainment equipment still need the protection of a plug-in surge-suppressor to shield them from variations that occur inside your home, as well as disturbances that may enter through cable and telephone lines.

6. Add an uninterruptible power supply (UPS) With the growth in the number of home-based offices, many at-home computer users would benefit from installing a battery back-up system, also known as an uninterruptible power supply (UPS). A UPS is designed to immediately switch your computer to emergency back-up power to allow you to work through brief power outages without data loss or downtime.

A UPS also provides protection from voltage sags. Sags are short-term decreases in the voltage level. Sags can cause frozen keyboards and system crashes. A UPS gives you time to save your files and shut down the computer safely in the event of an extended outage. Some UPSs come with software that automatically saves and shuts down your equipment. Make sure to check the UPS specifications you will need. Your computer’s monitor size and the type of CPU will affect the UPS’s battery run-time.

What to look for when buying a UPS:

• A UL 1778 rating
• The number and type of outlets you need
• Run-time – the bigger the VA (volt amps), the longer the run-time
• Length of battery life, battery replacement cost and availability
• Site-wiring fault indicator – indicates there may be a problem with the wiring of the outlet
• Connection lines for phone lines, television cables and other data communication lines – be aware that damaging power disturbances can also reach your equipment through cable and telephone lines
• A lifetime product warranty and insurance coverage on connected equipment