Circuit Protection
Surge Protectors for Home Electronics
What is Surge Protector?
A surge protector is a device used to protect home electronics from surges in voltage by getting rid of excess voltage using a Metal
Oxide Varistor (MOV) or a Gas Discharge Arrestor(GDR), sending the excess current to ground.
Surge protector power outlet strips are a power outlet that have a built-in surge suppressors to protect all equipment plugged into the power strip,
reducing the risk of equipment damage or fire. Small variations in voltage can damage most electronics, appliances, or equipment.
Protectors - Surge Arresters for Data Communications
What is a Protector Surge Arrester?
A protector surge arrester is a device that limits voltage spikes in a communication circuit, "arresting" or discharging the current surge to protect the circuit
from excess current or excess voltage added to the system from sources outside the communication circuit.
Protector Surge Arrestors are typically permanently wired into commercial or industrial medium to high-voltage circuits. Surge arrestors can be used for protecting
communication circuits that could accidentally have contact with high-voltage lines.
Grounding Requirements for a Protector
What is Grounding?
Grounding a circuit is connecting the circuit to the ground of the earth. Connecting a communications circuit to the ground improves circuit
protection from unexpected excess current by allowing the earth, a large conductor, to absorb excess current, instead of allowing the excess current
to damage the circuit or spark to other nearby conductors causing a fire risk, damage to property, or risk to human life.
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Grounding conductors or bonding conduction for communications circuits must be copper or some other corrosion-resistant material,
and have insulation suitable for the area in which it is installed.
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Metal Sheaths of any communications cables must be grounded or interrupted with an insulating joint as close as practicable to the
point where they enter any building (such point of entrance being the place where the communications cable emerges through an exterior
wall or concrete floor slab, or from a grounded rigid or intermediate metal conduit).
- Communications grounding conductors may be no smaller than 14 AWG.
- The grounding conductor must be run as directly as possible to the grounding electrode, and be protected if necessary.
- If the grounding conductor is protected by a metal raceway, it must be bonded to the grounding conductor on both ends.
In a building with a grounding system, grounding electrodes for communications ground should be connected to the nearest of the
following:
- The grounding electrode of an electrical power system
- A grounded interior metal water piping system near the pipe's entrance to the building
- The nonflexible metal power service raceway
- The power service equipment enclosure
- A separate grounding electrode conductor
If the building being served has no grounding electrode system, the grounding electrode should be connected to one of the following:
- An acceptable individual grounding electrode
- A ground rod or pipe (minimum 1.5 m (5 ft) long and 12.7mm(1.2 in) in diameter) driven into the ground. Grounding rods should
be separated from all lightning protection system grounds or conductors.
Connections to grounding electrodes must be made with approved means. If the power and communications systems use separate grounding
electrodes, they must be bonded together with a bonding jumper copper conductor no smaller than 6 AWG.
For mobile homes, if there is no service equipment within 9m (30 feet) of the outside of the mobile home, the communications circuit must
be connected to a grounding electrode. In this case, or if the mobile home is connected with a cord and plug, the communications circuit protector
must be bonded to the mobile home metal frame or grounding terminal with a copper conductor no smaller than 12 AWG.
Available Surge Protective Devices
Consult the NEC® 800.100 for more detailed information on grounding methods for communications.
Warning: When using this information to perform electrical work, call a licensed electrician and consult the NEC® for safety.
All licensed electricians have passed examinations covering the National Electric Code®, know state and local building codes, and may carry
insurance to cover damages.