Yes, this is a common situation with portable generators marketed as "floating neutral" even when they have a bond between neutral and the generator's "ground" (Equipment Grounding Conductor or EGC) at the receptacle. The key is understanding what "floating" really means, and why they are doing this.Here's a breakdown of the situation

Understanding Floating Neutral:
Traditionally

A true floating neutral means the neutral conductor is not electrically connected to the generator frame or the equipment grounding conductor (EGC) at any point within the generator. This is sometimes referred to as "unbonded."

Why Floating?

A truly floating neutral is safer for connecting to RV's and some older appliances. When connected to a generator, appliances normally receive ground through the grounding pin on their plug. If the appliances are already properly grounded, say through connection to your home's electrical system, they now have two paths to ground, one through the normal means and one through the generator. This creates a ground loop. Ground loops can cause nuisance tripping of ground-fault circuit interrupters (GFCIs) or even potentially pose a minor shock hazard.

The "Problem"

Floating neutral generators, however, don't work well with GFCI outlets directly connected to the generator. GFCI breakers and outlets trip by looking for an imbalance in current between the hot and neutral wires. They assume any current that is not returning on the neutral is leaking to ground, and therefore, must be a fault. If the neutral is floating, they can't detect this fault.

What DuroMax is Doing (and Why It's Confusing)



Neutral-to-Stator Bond

DuroMax (and other manufacturers) are bonding the neutral to the stator housing inside the generator. The stator housing is the metal enclosure of the generator.

Insulated Stator Mounts

Crucially, the stator housing is not bonded directly to the generator's frame. Instead, the stator housing is mounted to the frame via rubber isolators/motor mounts. This creates a scenario where the neutral is connected to a metal part, but that metal part is electrically isolated from the overall generator frame and external grounding system until you plug something in with a ground.



Continuity at the Receptacle

When you check with a multimeter, you will find continuity between the neutral pin and the ground (EGC) pin on the receptacles. This is because electricity flows through the bond to the stator and then can flow to the EGC due to the proximity and normal operation of the machine.

Why the "Floating" Designation despite Continuity?

Limited Ground Fault Protection

The intention is to provide a limited form of protection for people that use tools such as drills with grounded cords. In the event of a short, the user has a ground. It is not, however, a "safety" ground and cannot be relied upon.

Marketing/Compliance

This configuration allows them to market the generator as "floating neutral" for RV compatibility, while also providing some limited ground fault protection.

Technically Accurate (Sort Of)

Their explanation is technically accurate, as the current flows to the stator and then is able to go to ground. This is a "floating" ground as it doesn't have a solid ground until there is current.

The Implications and Potential Issues



GFCI Issues (Sometimes)

While this configuration can work with GFCIs better than a completely floating neutral, it's not guaranteed. A weak ground, a long run of wire, or a high-resistance connection can still cause nuisance tripping of GFCI outlets.

Misunderstanding

The biggest issue is the potential for misunderstanding. Users might assume that because there's continuity between neutral and ground at the receptacle, they have a proper, robust ground. This can lead to unsafe practices. If you are using GFCIs directly connected to the generator, use caution.

Potential for Damage with 220v (Depending on Configuration)

In some cases, with a 220v load, it can attempt to get ground through the neutral and damage the generator.

In summary

DuroMax (and other manufacturers) are using a "quasi-floating" neutral design. They create a bond between neutral and stator, and then isolate the stator from the frame. This allows them to market the generator as "floating neutral" while providing some degree of ground fault protection. It can lead to confusion and potentially unsafe practices if not fully understood. It's crucial to understand the limitations of this configuration and to not assume you have a robust ground simply because there's continuity between neutral and ground at the receptacle.

Recommendations


Understand Your Generator's Configuration

Always refer to the generator's manual and contact the manufacturer if you have any questions about the neutral configuration.2.

Be Careful with GFCIs

Use caution when connecting GFCI devices directly to the generator. Test them regularly to ensure they are functioning properly.3.

Consider Bonding

If you need a reliable, bonded neutral configuration for a specific application, consider bonding the neutral to the frame of the generator yourself.

WARNING

This may void the warranty and you need to understand the electrical code for your area. Do not do this if you plan to connect it to the grid or an RV without understanding the implications.4.

Portable Transfer Switch: For home use, it's often best to use a proper portable generator interlock and transfer switch. This will ensure a safe and compliant connection to your home's electrical system and provide a proper ground.Always prioritize safety when working with electricity. If you are unsure about anything, consult with a qualified electrician. Flag for review