Inexpensive Protection for Valuable Electronic Equipment

External Protection: This is designed to reduce externally generated surges before entering the house through the power line. Some of the things that cause external surges are lightning strikes, downed utility poles, limbs and other objects contacting the line. In most cases, only 20% or less of surges enter a house through the power line.

The hard wired 400-amp rated protector is installed by an electrician to the wires coming into the meter base. Blachly-Lane has a supply of the 400 amp hard wired protectors at a price of $140 each.

Note: Surge protection will not protect for under or over voltage situations.

Internal Protection: The purpose of using outlet protectors inside the home is to reduce surges generated inside the house or other stray surges such as heating and cooling systems cycling on and off. Another reason for internal protection is to catch the surges that can come into the house through the phone and cable TV lines. Most surges (80% or more) are generated by equipment inside the house. Sensitive electronics such as computers, TV's and entertainment centers should be plugged into a proper outlet protector. Most home improvement or electonic stores have quality surge protectors.

Here are some quidelines for selecting surge protection:

• Underwriters Laboratories Standard #1449 - Verify that the Surge Suppressor is Underwriter Laboratory (UL) listed for compliance with their standard #1449. This testing verifies compliance by including on the product; the product's identity (Transient Voltage Surge Suppressor), the UL symbol, and the word "listed," all in close proximity. Caution: UL listed means the device was tested and passed the testing. The words "UL Tested" mean only that the device was tested. The results of that test remain unknown. Additionally, UL Standard # 1449 only provides assurance that the device meets certain safety standards, it is not a guarantee of performance.
• Clamping Voltage - Various protection levels are covered under the UL 1449 listing, including 330, 400, 500, 600, 800 and six other levels up to 4,000 volts (only 330, 400, 500, and 600 apply to plug-in models). A lower clamping voltage is generally better. Where multi-stage surge suppression is being used, the TVSS at the service entrance usually has a higher clamping voltage (which in turn allows for a higher total energy dissipation) than the installed point-of-use devices. Have your electrician verify that the devices are "coordinated" so that they work together to provide the proper protection.
• Total Energy Dissipation - This is the maximum surge energy that the unit can handle without being damaged. A larger number is better.
• Maximum Continuous Operating Voltage (MCOV) - This is the maximum designated rms (root-mean-square) value of 60 Hz voltage that may be applied between the terminals of the arrester. Choose an MCOV rating capable of sustaining 125 percent of the nominal rms voltage without degradation. For example, if the nominal RMS voltage of the system is 120 volts, select a device with a MCOV of at least 150 volts.
• Maximum Continuous Operating Voltage = 120 volts x 1.25 = 150
• Common Mode and Normal Mode Disturbances - The TVSS devices should be designed to protect against transients in four electrical modes including common mode (line-to-ground V3, neutral-to-ground V2) and normal mode (line-to-neutral V1, line-to-line*) disturbances.
• Sine Wave Tracking - This technology tracks the AC sine wave, permitting instant response to minor spikes and transients that will pass through conventional protection. These devices cost significantly more than conventional TVSS technologies.

Quality Surge Protection Products may be purchased from:

Meter-Treater, Inc.

EFI Electronics

American Power Conversion