Adverse Voltage Protection

It is a misconception that it is the power company's responsibility to protect its Members’ appliances, electronics, and other equipment from lightning and adverse voltage conditions. Though Members benefit from CoServ using lightning arrestors, it is the Member's responsibility to protect their homes, businesses and contents. It is not possible for CoServ to eliminate all risks simply because some voltage fluctuations are generated from inside the Member’s own home. Protection from the meter into the home is the Member's responsibility.

What is adverse voltage?

Adverse voltage is an abnormal change in voltage, known as a sag when the voltage dips or a spike when the voltage rises. Fluctuations vary in magnitude and duration typically lasting for a few milliseconds and ranging from a few volts to several thousand volts. Any fluctuation above an appliance’s or electronic device’s normal operating voltage generates an electrical arc inside the device causing excessive heat. The excessive heat will cause damage to the circuit boards inside the device, shortening the life span of the device.

Where do power fluctuations come from?

The most common and typically most destructive cause of voltage fluctuations is lightning. Fluctuations also come from normal utility grid fluctuation as well as from inside the Member’s home when large appliances such as HVAC units cycle. With lightning, a Member may incur damage at the time of the strike but may also notice that other appliances or electronics malfunction months after the initial incident. This happens because the lightning strike may only weaken some circuitry while completely destroying others. The smaller fluctuations most likely occur without the Member ever knowing about them, yet they take a toll on electronic circuit boards and reduce the life span of the device. Eventually, the device fails short of its expected life span, generating costly repairs or replacements that could have been prevented.

How do Members protect against adverse voltage conditions?

It is nearly impossible to eliminate every single type of adverse voltage situation, but there are ways that can greatly reduce the risk of equipment damage or failure. A multi-staging protection process has proven to be very successful in eliminating most harmful fluctuation. This process requires several steps to be successful:

  1. Protection at the point of electric entry.
  2. Protecting the telephone and cable television entry.
  3. Installing high quality, point-of-use surge protectors on sensitive equipment.

Based on the fact that every home is different, it may be best to have a reputable company perform an assessment to ensure all areas are protected properly.

What to look for in protective devices:

  • Indicator Lights (LED)—Ensure that each unit has a light showing valid protection. Protective devices are designed to discharge voltage fluctuations which weaken them and will eventually offer no protection at all. An indicator will let you know when it is time to replace the protector.
  • UL 1449 Listed—Look for the UL 1449 listing on the device. Under UL 1449, protective devices are required to pass three durability tests that determine the performance of the device. This will also help ensure a quality protector.
  • Energy Specifications—Make sure that the maximum impulse level the protector can withstand is labeled on the device. The range should fall between 10-100 kilojouless—the higher the joule rating the better the protector.
  • Clamping Voltage—Look for the clamping voltage to be listed on the protective device. The range will be from 330 volts up to 600 volts for a 120-volt nominal service. Four hundred volts will provide adequate protection.

For more information on electrical safety, visit our Safety section.