Bonding and Grounding Portable Generators
A few weeks ago I started a series of articles on bonding and grounding of portable generators when used with RVs. Those articles stirred up quite a bit of conversation which is a good thing. We still have a couple of subjects to cover in this discussion so let’s get started with checking your generator to determine if it is already bonded. Remember, when we talk about bonding in the context of this subject, we are talking about connecting the neutral of the generator to the ground of the generator. Also remember that this specific bonding is to be done in only one place according to national electrical code.
In order to determine if your generator is already bonded you will need a multimeter which is capable of checking ohms or continuity. Keep in mind that continuity is a specific check of resistance, except the resistance for “continuity” is zero or very low. Next you will have to identify the neutral and the ground contacts on the generator output. Most likely we are talking about a generator that has either 120vac, 20 amp output or 120vac, 30 amp output connectors. The typical 30 amp receptacle has three connections as shown in the photograph of a TT-30R. Looking at this receptacle, the ground connection is at the top and looks like it is round. The two slanted slots at the bottom are the hot and the neutral connections, with the neutral being the slot on the right and the hot being the slot on the left. In order to determine if your generator is bonded properly for use on an RV, you should check for continuity between the neutral connection and the ground connection. If you are using the ohms setting on the multimeter, set the meter to the lowest ohms range and check for zero ohms between the two connections.
If your generator is bonded properly per the above test, there is nothing else you need to do because your generator is bonded.
Next time we will explain how to accomplish the necessary bonding if needed and discuss proper grounding of a portable generator.