AC Service Ground and Bonding Connections

groundtermination Service Ground/Bonding Connections: Bonding and grounding are actually two subjects, but for the purpose of this article, “Bonding” serves to protect the individual from electrical shock where “Grounding” can provide a fault path for stray electrical current that might originate from a faulty electrical device or an electrical storm.  Both work hand in hand.

Near the meter base, there should be a small wire about the size of a small straw or bigger, connected to a metal (copper/copper clad) rod. The wire could be solid, stranded with a plastic sheath or bare copper. The AC Service Panel will dictate the size of this conductor.

Visually follow the wire to see where it goes.  This wire may go to a ground rod and/or  water pipe. Typically you should find a ground conductor attached to both as well as the electrical panel it self.  It should be firmly attached. Normally this ground wire should not have any electrical current passing through it and should be safe to touch. If the attachment is clean of corrosion and secure, no further action is required. If you find the conductor(s) cut, severed or disconnected, they must be reattached or replaced. If the conductor is completely severed, replacement is about your only choice as the NEC (National Electric Code) does not allow splicing of this conductor.  If the ground termination has signs of excessive corrosion, it should be cleaned and tightened. TIP: Clean the corrosion in the same method you would clean a automotive battery terminal. This is a very important part of the electrical system and its integrity is for your safety and your home. If you are unable to replace the conductor, hiring a professional is probably your only choice.

Coming from the telecommunications industry, bonding and grounding was near religion. Resources were dedicated to inspect, validate and correct grounding/bonding issues regularly in large facilities. Within that plan there was typically a grounding schematic detailing proper grounding/bonding for that office. Even though every office was different, the schematic was still the same.  As we bring more sophisticated electronics into our house, a similar method is being adopted for the house. If you are a real techno-nerd and have lots of electronic gizmo’s in your house, having your house well grounded  is imperative in ensuring your equipment works well and protected from faults that may occur.  Be sure and read AC Service Ground and Bonding Connections Part II Also if you are really bored look at this Surge Protectiondocument  from the National Institute of Standards and Technology (NIST).

With more electronics in the house, the National Electric Code (NEC) now includes the use of a bonding collection device in the current 2008 code for this purpose bringing all these ancillary grounding terminations to one location.  You will probably not have one of these devices in your house as will take the industry some time to catch up. Granted, you don’t need the device to comply with the code or complete a good grounding system but it does meet the specific need. 

Surges and faults are typically blamed on the electrical utility but in reality the Telephone and CATV are just as large of contributor.

You may find several ground terminations throughout your household associated with TV or Radio antennas, cable, satellite television and telephone services. Typically they will be attached to the ground system and/or the cold water pipe as this water pipe should be connected to the ground/bonding system. TIP: These devices might be connected at various locations in different ways, so don’t be surprised if you see them bonded to the AC Service Mast or piggy backed onto the ground wire with a stirrup or saddle clamp. Regardless of their location, their integrity is important to your safety and the safety of your home as well as the electrical equipment  you own.  Inspect these ground termination in the same respect as the electrical service grounding/bonding termination. In a perfect world all cables would attach to the same side of the house and the ground wires would be short and fairly straight and bringing them through the house to collect them would be avoided as any surge event will travel through the house to get to the other side and will reek havoc along the way on its search to the ground source.

With the increased use of highly sensitive electronics found in the home, proper grounding is becoming even more important. Look for a future article on surge protection and TVSS devices.

Key Inspection Points and Corrective Action

  1. Visually check the ground conductor(s) for physical integrity.
  2. If the conductor is completely severed, it must be replaced.
  3. Visually inspect all ancillary connections (cable, telephone, etc.).
  4. Are all ground terminations clean, secure and tight? Excessive corrosion at the terminations should be cleaned.  

 

 

 

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3 Responses to AC Service Ground and Bonding Connections

  1. […] discussed without stressing the importance of  a grounding network for your house. My article on bonding & grounding covers how to identify and inspect your system, but the subject warrants a bit more discussion. The […]

  2. […] may also want to read: Electrical Switches and Outlets, AC Service Ground and Bonding, AC Service Ground Part […]

  3. […] voltage issue by creating additional doorways into the equipment. As we saw  in the AC Ground and Bonding article, external surges can enter the house as easily through the Telephone line, CATV or […]

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