Power Quality

Power Quality Concerns

When sizing up power quality issues, preventive measures are the first line of defense. Sometimes the solution is simply to tighten or clean a loose connection or follow one of the other steps suggested here. The services of a licensed electrician may be required to accomplish some of these, especially if you are not familiar with electrical systems.

Correct wiring and grounding difficulties

Proper wiring and grounding of your entire home is essential for today's electronic equipment to operate smoothly. The traditional "safety ground" protects people, but is sometimes inadequate for sensitive electronics.

Symptoms of home wiring problems include lights dimming or brightening noticeably, or problems with electronic equipment. Consider such problems as a warning to have a licensed electrician check for grounding that conforms to current National Electric Code (NEC) and local standards, as well as for adequate connections in your electrical system. Such problems sometimes mask more subtle difficulties that cannot be remedied without adequate wiring and grounding. In Hawaii, the salty and humid environment often corrodes metal, resulting in poor electrical connections. Damaged wiring may not only be a power quality problem but is a safety hazard as well! If you notice that the service wiring and/or connections leading up to your meter show signs of corrosion, wear, or damage, please call Maui Electric's Trouble Line is 871-7777, or toll-free from Molokai and Lanai at 1-877-871-8461, available 24 hours a day, 7 days a week.

Move offending equipment

A large appliance on the same circuit as your electronic equipment can produce spikes, power surges, sags, or noise. These disturbances can be a nuisance or even damaging to sensitive electronic equipment. Appliances especially likely to cause problems include shavers, hair dryers, laser printers, fax/copy machines, electric tools, electrified fences, burglar alarms, cordless phones, fish tank pumps, and heaters. Relocation of offending equipment to an outlet on a different circuit can often correct the problem.

Using separate circuits to isolate electronics from problem-causing appliances is always a good idea. If you are building a new home or remodeling, include circuits that are dedicated for your most sensitive equipment, to minimize interference.

A Special Note on Air Conditioning

For window air conditioners under 1 ton (12,000 BTUH), we recommend plugging the unit into a dedicated outlet. Do not use power strips or extension cords as they may overheat and become a fire hazard.

For all air conditioners greater than 1 ton of cooling, you should have a qualified electrician install a dedicated circuit for the unit. Before you make that purchase, consider contacting our Residential & Appliance Energy Info line at 543-7511 to have a Hawaiian Electric Customer Installations Department representative determine if your electrical service can accommodate the unit. When a large air conditioner starts, it will draw a large amount of inrush current that could cause power quality problems not only within your home but your neighbors' homes as well. Typical problems include voltage sags and flicker that may affect lights and sensitive electronic equipment. An upgrade to your electrical service may be in order and this upgrade could involve Hawaiian Electric's transformer and service wiring.

If an upgrade in electrical service is needed (upgrading from 60A or 100A to 200A for example), the customer is responsible for the following costs:

  • Purchase and installation of a new meter socket.
  • New meter socket must be rated for 200A.
  • New service drop (larger wires) to provide more capacity.
  • Specific requirements as per Customer Installations Department.

Please bear in mind that very large air conditioners above 3 tons of cooling may cause power quality problems that may not be resolved by a service upgrade. Instead of a single large unit to cool several rooms, consider installing smaller units to cool individual rooms. In addition to reducing inrush current and the resulting voltage drop in your home, this will save you energy by allowing you to cool only the rooms that you need to cool.

NOTE: Maui Electric works with residential developers to review the design of homes that will be equipped with air-conditioning.

Battery Backup

Buy appliances with battery backup, if they depend on a clock, internal timer, or programmed data. Examples are alarm clocks, coffee makers, and microwave ovens.

A one-second interruption is long enough to disturb a digital clock or timer that is not capable of retaining memory through brief pauses in electricity. Fortunately, some products are now equipped to "ride through" such interruptions. Computers, for example, have a built-in tolerance to voltage sags. However, the amount of ride-through capability in computers and other appliances varies among manufacturers and models.

For your computer, look for software that performs an automatic timed backup, and (most importantly) make sure the feature is activated. 

Take defensive measures when lights dim (or brighten) and stay dimmed (or bright)

If your lights dim or brighten noticeably and stay dim or bright, turn off your major appliances. If that causes the lights to return to normal, you may have an electrical problem that should be investigated by a qualified electrician or representative from Hawaiian Electric. If not, leave your appliances off until the lights return to normal, since equipment or other damage can occur under some circumstances.