Bonding and Floating Your Generator’s Neutral

Choosing a generator isn’t an easy task. A lot can go wrong if you neglect your research and you might even end up buying a product that doesn’t suit your needs – perhaps with the wrong neutral type.

Given that you are reading this article, this may have already happened to you. So, what should you do if you get stuck with a generator which has an unsuitable neutral?

First, Don’t Panic!

You don’t have to return your generator just yet! Follow this article and see how easy it can be to bond and unbond your generator’s neutral.

Precaution: Always turn off the generator, disconnect the spark plug wire and ensure that the generator has cooled down before making any changes to it.

Converting a Bonded Neutral to a Floating Neutral

Why or When do I Need This Conversion?

First things first, why or when would you need to convert from a bonded to a floating neutral?

Let’s consider that you have a generator with a bonded neutral. You want to connect this generator to a system that already has a bonded neutral e.g., a home electrical panel. For this connection, you have a transfer switch that does not transfer the neutral.

According to the safety standards of NEC article 250, the neutral must be grounded once, but no more than once.

This leaves you in a complex situation. You can’t force the transfer switch to transfer the neutral, nor is it financially advisable to go out and buy a new generator.

However, you can modify the neutral connections of your generator to comply with the safety regulations!

The Process

Picture of the neutral ground wire and the bonded jumper wire of an alternator

Your owner’s manual may already explain you how to convert the neutral. Source: owner’s manual of the WGen9500DF

Before proceeding, you must do a little bit of research on your own to find the exact location of the generator connections and identify the neutral and the ground. The best way to do so is to consult the manufacturer’s manual.

If such information is not available in the manual, contact the manufacturer or consult a licensed electrician.

Once you have identified these connections, follow these steps to float the neutral.

Tools required: A screwdriver or a wrench, and an electrical insulation tape.

Steps:

  1. Once you have identified the neutral and the ground connections, locate the bonded jumper wire.
  2. Using a screwdriver or a wrench, remove the screw or bolt from either one of the neutral or the ground connections and disconnect the bonded jumper wire from it.
  3. Keep the respective ground or neutral connection intact and tighten the bolt.
  4. Wrap electrical insulation tape around the open end of the bonding jumper wire so that it does not pose a safety hazard.
  5. After the modification, put a label on the generator which clearly indicates the changes made, so that you don’t forget it in case you want to use it for any other application in the future.

Please note that if your generator is equipped with GFCI receptacles, removing the bonded neutral may not allow their proper operation. Therefore, it is advised to always keep the jumper wire in case it is needed for future use.

Converting a Floating Neutral to a Bonded Neutral

Why or When do I Need This Conversion?

Let’s now assume the opposite scenario. You have a generator that has a floating neutral and you want to connect it to your home’s electrical panel, using a transfer switch that transfers the neutral. Per NEC 250 article, its neutral must be grounded at least once – but it isn’t!

Example number 2: Consider using a floating neutral generator at a construction site to power tools and other equipment, connected via supply cords and plugs.

Such a system, according to the NEC, is considered a “separately derived” system, which must have its neutral bonded to the ground. However, you are stuck with an unbond, floating neutral generator. What now?

It’s time to get your tools and bond the neutral!

The Process

Tools Required: Screwdriver or a wrench and a jumper wire.

Steps:

  1. Locate and identify the neutral and the ground connections on the generator as explained previously.
  2. Once the connections are identified, insert a jumper wire between the neutral and the ground connections.
  3. Using a wrench or a screwdriver, remove the screw or bolt from both the neutral and the ground connections.
  4. Insert the bonding jumper wire into the connections.
  5. Tighten the screws or bolts again.
  6. Once the conversion is done, put a label on the generator which clearly indicates the changes made.

Conclusion

Buying a generator can be confusing, as different applications may require a different type of neutral.

Therefore, one must invest time to understand the differences between a bonded and a floating neutral generator, to understand which is more suitable for them.

In case you are stuck with the wrong neutral type, follow the instructions in this article. However, do remember that any modification to the generator connections should only be done by a licensed electrician.

Paul

Paul

Manager & Editor of generatorbible.com. Early retired from the OPE industry, living in South Carolina. He now mostly spends his time traveling and taking care of his wife and grand-children.

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