Checking Electrical Grounds
The purpose of grounding | Checking ground impedance | Checking for centralized grounding | Grounding cable and phone lines | More information about power quality
A good ground is essential to the safe and reliable operation of all home electrical equipment. This topic discusses
- the purpose of grounding
- checking ground ability
- checking for centralized grounding and
- grounding cable and phone lines.
The purpose of grounding
Electrical grounding prevents shortages from passing through electrical equipment.
The ground is the primary path through which a surge protector dissipates energy from a voltage spike.
Checking ground impedance
The ability of grounding systems to dissipate electricity is measured in ohms. Properly installed grounding systems require 25 ohms or less. Check to make sure your system achieves this minimum requirement. This should be done by a qualified electrical contractor using a ground impedance testing device.
Checking for centralized grounding
Most building codes require that all wires and pipes entering the home bond to a single ground point. Make sure that electrical conductors connect from the grounding rod to the
- water and
- telephone systems.
Grounding cable and phone lines
Since the 1980s National Electrical Code has required the bonding and grounding of all lines (power, phone, cable TV, communications lines) together before they enter the building. This is typically done at the ground by the electric meter where all lines should be bonded to the wire leading to the driven ground rod. If you have a centralized grounding system and the cable or phone lines are not bonded to it,
- contact the appropriate utility and
- have them check the system.
In most areas, it is the utility's responsibility.
More information about power quality
Visit the topics below to learn more about solutions to power quality problems in electrical systems.