When doing electrical work near gas meters, you may be told that you need to bond the lines. While this is a pretty common practice in some areas, it’s possible that you’ve previously worked on jobs where it wasn’t required. If you’re not familiar with why you should use bonding wires on gas lines or when bonding is used, here’s a quick rundown to get you up to speed.
Bonding Gas Lines
If you’re not familiar with the term, bonding gas lines is simply the process of attaching a grounding wire to the lines to keep them from holding a charge. You’ll often see this with the metal gas lines that connect to the gas meter, many of which will have a green ground wire looped up and connected to a fitting attached to the pipe. By attaching this ground wire, it eliminates the possibility of shorts in the meter or other current passing through the gas line and potentially causing a spark. The wire is bonded on the load side of the meter, where there is the greatest chance of a current overflow or short.
In most places, electrical code doesn’t allow metal gas pipes to be used for conductive purposes; though it may seem easier to simply drive a length of blocked steel gas line into the ground as a grounding point, this would almost certainly result in a code violation. Instead, the use of bonding wires connected to gas lines as they come out of the meter provides a code-friendly option to help prevent shorts and sparks.
When to Bond Lines
As mentioned, gas lines are bonded when there is a risk that a current might connect to the metal pipe used in the line. Given how serious the risk of sparks are in a gas line, it should be obvious why one would want to ground those lines. However, unless there is a specific risk of a short in the meter or electrical lines running too close to the gas lines, bonding isn’t always necessary. There is one exception to this, however; the use of corrugated stainless-steel tubing (CSST) almost always calls for a grounding wire due to a flaw within that tubing’s design.
Is Bonding Allowed?
In many areas, adding ground wires to gas lines isn’t an issue. There are some localities where ordinances might prohibit the practice, however. In other cases, bonding may be limited to situations where there is a specific threat of short and disallowed at other times. As with most electrical work, make sure that you are familiar with local and state requirements before assuming that adding grounding wires to gas lines is allowed on your job.
Is Bonding Required?
Along the same lines as to whether bonding is allowed, it’s important to remember that there are situations where bonding lines are required in many areas. The biggest among these is when CSST was used inside of the house. While CSST was once hailed as a game-changer due to its flexibility and the ease with which it is installed, lightning strikes near the home could penetrate the jacket of the CSST and cause combustion within the gas line. In places where CSST is still in use, the lines must be bonded to prevent fires.
Have you ever grounded the gas lines on a job, or perhaps been explicitly told that you shouldn’t?