Grounding Guide for Phone System Installation

Purpose of Grounding the System 

• Fundamental to the safety of those installing, using, and servicing the electrical system
• Assures the system will work properly while preventing damage to the system
• All electrical systems serving structure must be bonded together including the following:
  • Electrical wiring system
  • Telephone system
  • Phone system
  • Burglar alarm system
  • Cable or satellite system

Grounding: The process of making a planned, continuous, connection between NONCURRENT CARRYING parts of the electrical wiring installation and the earth and some other conducting body. 

Grounded: Describes the act of being connected to the earth or some other conduction body that serves in place of the earth.

Bonding: Process in which all NON-CURRENT CARRYING METALLIC parts of the electrical wiring system are permanently joined together to form a CONTINUOUS grounding path.

Bonding 

• Reduces the differences in potential between each electrical system
• May be caused by power surges, lightning strikes or other types of ground fault type occurrences

 Parts of the Electrical System 

• Circuits
• Service Entrance Panel
• Metal Water Pipe
• Metal Gas pipe

 The Grounding Electrode System 

• All materials must be grounded using approved bonding and grounding electrode systems
• Check with local building code

Metallic Pipe 

• A cold running Water pipe must always be bonded to the service entrance panel, grounding electrode conductor, or grounding electrode
• Other metal pipe, such as gas pipe, which may become energized accidentally must be bonded to the electrical system grounded system
• Do not ground to sprinkler system pipes

Use of Bonding Jumper 

• To provide CONTINUOUS grounding path around devices such as water meters installed in metallic water pipe system 

Types of Grounding Electrodes
 

Metal Underground Water Pipe 

• Must be bonded to the supplemental grounding system electrode and to the neutral bus bar in the SEP
• Connection must be made within 5 feet of entering structure
• Water pipe must be in direct contact with the earth for at least 10 feet

 Concrete Encased Electrode 

• Electrode encased in foundation footing covered with at least 2 inches of concrete
• Electrodes must be at least 20 feet in length and consist of one or more ½” steel reinforcement bars

Ground Ring 

• Bare Copper
• At Least #2 AWG or larger
• Encircling residence for a length of 20 feet
• Buried at least 2 ½”

Metal Framework

Supplemental Electrodes 

• Typically made of metal rods, pipes, or plates

Rod and Pipe Electrodes 

• Iron or steel rod electrodes
• Must be 5/8” in diameter
• Pipe must be ¾” in diameter
• Galvanized or metal coated for corrosion resistance
• 8 feet in length
• Installed to a depth of 8” in direct contact with earth
• Nonferrous rods must be listed at no less than ½”
• Stainless Steel- ½” diameter
• Must be at or below ground level
• Must be protected from physical damage

 Exceptions 

• If electrode can not be driven more than 4” into the earth b/c of rock or other obstruction
• May be driven at an oblique and of no more than 45° from vertical
• At least 8” of the electrode must be in contact with earth

Multiple Grounding Rods 

When more than one electrode grounding rod is used:

• Must be installed not less than 6 feet apart
• Must be bonded together with an approved bonding jumper to form single grounding electrode system
• Plate Electrode 
• May be used in areas where it is not possible to use a grounding rod or ring
• Steel/Iron Plate electrode must be ¼” thick
• Non-ferrous metal plate must be 0.06” thick
• 2 feet square
• Buried at least 2 1/2’
• Grounding Electrode Conductor 
• Copper
• Aluminum
• Copper-clad
• AL and AL-CU may not be used in contact with masonry, corrosive, or in direct contact with the earth