Preparing for Midwest winter storm. Generator question

[waltee1000]

I got a brand new generator that I will be testing and keep ready for the weekend storm. I plan to put an extension cord and only keep the pumps and heater going incase of a prolonged power outage. Do I need to connect the portable generator to a grounding rod to prevent electric current through the salt water? I tried googling and getting all kinds of answers.

 

[UncommonSense]

I got a brand new generator that I will be testing and keep ready for the weekend storm. I plan to put an extension cord and only keep the pumps and heater going incase of a prolonged power outage. Do I need to connect the portable generator to a grounding rod to prevent electric current through the salt water? I tried googling and getting all kinds of answers.

— GFCI protection (to keep you safe) does not work with typical portable (not wired into your house) backup power…

— Best practice when running a portable generator or UPS is treating the tank as “unsafe to work on” until you’re back on GFCI protected city power!

 

[Ryan - Serious Reefs]

— GFCI protection (to keep you safe) does not work with typical portable (not wired into your house) backup power…

— Best practice when running a portable generator or UPS is treating the tank as “unsafe to work on” until you’re back on GFCI protected city power!

This is new to me. Is there something specific about portable generators that makes them more dangerous, or is it mostly the lack of GFCI protection?

If I had to guess, I’d wager that 95% of reefers are running their tanks on standard outlets without GFCI simply because that’s what was there when they plugged everything in.

 

[jonelder68]

This is new to me. Is there something specific about portable generators that makes them more dangerous, or is it mostly the lack of GFCI protection?

If I had to guess, I’d wager that 95% of reefers are running their tanks on standard outlets without GFCI simply because that’s what was there when they plugged everything in.

Yes and it’s a huge issue I and many are working on trying to bring awareness to. We lost an amazing reefer and a friend to an electrical issue resulting in electrocution recently.

 

[UncommonSense]

Is there something specific about portable generators that makes them more dangerous, or is it mostly the lack of GFCI protection?

I’m definitely not an electrician, so this is likely far from a complete explanation…

As I understand it, a GFCI device looks for difference between hot and neutral… most (if not all) backup power solutions (short of those which are hard wired) have a floating neutral… apparently this means that a GFCI device cannot do its job (protecting you if an electrical fault occurs which would otherwise energize the water) if on a portable backup power supply!

(I’m sure this is a gross oversimplification, I’d love those with more experience in the field to chime in!)

 

[Gone Reefin’]

This is new to me. Is there something specific about portable generators that makes them more dangerous, or is it mostly the lack of GFCI protection?

If I had to guess, I’d wager that 95% of reefers are running their tanks on standard outlets without GFCI simply because that’s what was there when they plugged everything in.

Lack of GFCI. I hope that 95% figure is rapidly falling. Recent events on this forum have caused us all to take another look at electrical safety.

 

[jonelder68]

I got a brand new generator that I will be testing and keep ready for the weekend storm. I plan to put an extension cord and only keep the pumps and heater going incase of a prolonged power outage. Do I need to connect the portable generator to a grounding rod to prevent electric current through the salt water? I tried googling and getting all kinds of answers.

If working in the tank with battery back up or generator powering tank I would unhook all 120v supplies like heaters. Pumps if 120v and not DC lower voltage units.

Can also install an inline corded GFI

 

[Reefering1]

I would ground the generator. Ultimately nuetral and ground are bonded at the source. I learned this the 1st time using a generator. Everything worked fine but when I went to refuel, got quite the shock by touching the frame of the generator. The entire thing was electrified. If it has a ground connection, use it. I now have a 4' steel pipe drove into the ground to connect my generator to. Gfci will work as intended if unit is used as intended and gfci is properly connected to backup power source.

 

[jonelder68]

This is new to me. Is there something specific about portable generators that makes them more dangerous, or is it mostly the lack of GFCI protection?

If I had to guess, I’d wager that 95% of reefers are running their tanks on standard outlets without GFCI simply because that’s what was there when they plugged everything in.

Would make a great video for your new series if we can save a life it’s totally worth it! We’ve already lost one and that’s too many.

 

[UncommonSense]

Can also install an inline corded GFI

Therein lies the issue:

— an inline GFCI won’t trip in the event of an electrical fault when plugged into a portable generator… or at least that’s how I understand it!

 

[jonelder68]

Therein lies the issue:

— an inline GFCI won’t trip in the event of an electrical fault when plugged into a portable generator… or at least that’s how I understand it!

Depends on how the generator or battery supply is wired/made (floating or bonded neutral) Again just unplug all 120v/non DC regardless

 

[mfinn]

I have never worried about this issue ever and have not had a problem in 35 years of owning and running a generator for my tanks.
But, isn't a generator motor grounded to the frame which will be sitting on the ground?

 

[Reefering1]

But, isn't a generator motor grounded to the frame which will be sitting on the ground?

Sure, but then the question becomes- "how good is that connection to the earth?" Sand and rock aren't very good conductors and sitting on dirt is still questionable,at best.

 

[ros3to]

I have never worried about this issue ever and have not had a problem in 35 years of owning and running a generator for my tanks.
But, isn't a generator motor grounded to the frame which will be sitting on the ground?

Yes, and it's worth to mention that most modern portable generators are required to have gfci protection.

 

[jonelder68]

I have never worried about this issue ever and have not had a problem in 35 years of owning and running a generator for my tanks.
But, isn't a generator motor grounded to the frame which will be sitting on the ground?

But will it trip a breaker (if generator has one) before allowing you to become electrocuted once your hands are in the tank? No you will become the ground for the circuit. Hopefully it will then trip the breaker but most likely after you’ve already been electrocuted. GFCI protection is a must! GFCI is to prevent electrocution while a standard breakers purpose it to protect wiring.

 

[mfinn]

But will it trip a breaker (if generator has one) before allowing you to become electrocuted once your hands are in the tank? No you will become the ground for the circuit. Hopefully it will then trip the breaker but most likely after you’ve already been electrocuted.

Never, ever been a issue.
I can't explain it, but I'll bet countless others using a generator for their tanks, just power on the generator, plug in the tanks power needs and go.
Otherwise there would be huge warnings all over R2R about electrocution using a generator.

 

[mfinn]

But will it trip a breaker (if generator has one) before allowing you to become electrocuted once your hands are in the tank? No you will become the ground for the circuit. Hopefully it will then trip the breaker but most likely after you’ve already been electrocuted. GFCI protection is a must!

My guess is once the generator is grounded, it's grounded. For the water to be energized, there has to be a bad wired in the tank( heater or powerhead), then you might have a problem.

 

[jonelder68]

Never, ever been a issue.
I can't explain it, but I'll bet countless others using a generator for their tanks, just power on the generator, plug in the tanks power needs and go.
Otherwise there would be huge warnings all over R2R about electrocution using a generator.

Ensure your generator has GFCI protection at minimum. Double safety would be unplugging 120v/non-dc powered items while hands in tank.

After Miami Reef’s incident there has been much discussion here about electrical safety.

Aquarium and electrical safety

Wow! This has been a horrible week. First loosing my dog and now after taking a few day break from here R2R only to return and find out the tragedy my friend Baruch/ @Miami Reef has been lost 😭. Seems he has passed from an electrical incident while working in his tank. Unsure how this has...

www.reef2reef.com

 

[mfinn]

And for what it's worth while on the subject of generators, my current and past generator has had a separate gentran switch to by-pass my house electrical panel.
That is well worth the extra cost. My wife can do everything now if I'm not around.

 

[jonelder68]

From the electrical safety post! Great write up by Mr. Bean.

There is no “simple” or straightforward answer, and the explanation will probably confuse some people. Instead of giving direct advice, let me just try to explain how inverter (UPS) and portable-generator outputs differ from your utility power. Sorry, this will be long and a bit technical, there is no way around it.

Most consumer UPS units and small generators have a floating neutral.

That means the neutral isn’t tied to earth ground. Its only reference is the hot. In other words, the only place current can flow (in theory) is between the inverter’s HOT and its own derived NEUTRAL.

Think of a battery. The only place current can flow is between its two terminals. If you touch only the positive terminal, even standing in a puddle, nothing happens. A floating inverter output is basically the same idea (ignoring AC vs. DC). Its two output terminals can only (in theory) pass current between each other.

With your utility supply, the NEUTRAL is bonded (electrically connected) to EARTH GROUND at your service panel. So if you touch utility HOT while you’re grounded, current will flow from HOT through you to GROUND, partly or fully bypassing the neutral. That’s the fault path a GFCI is designed to detect.

With a floating source, touching HOT while grounded doesn’t create that path. There is no path to ground. So (in theory) you don’t get shocked.

---

“Hey Bean! That sounds great, my UPS or generator can’t shock me!”
No. It can absolutely shock you!!
If you grab HOT and NEUTRAL from the floating source, you will get shocked. You just become the load.

In a bonded system you would also get shocked if you grab hot and neutral. The difference is crucial to understand: if you are grounded, a GFCI would trip because some of the current leaks to ground. In a floating system, there is no neutral-to-ground reference at all, so the GFCI has nothing to compare and will not trip.

If you are grounded is a very important caveat. In a bonded system if you are insulated and touch hot and neutral, you also become the load and the GFCI can't help you.

So on one hand, the floating system can be called “safer” because the typical line-to-ground fault doesn’t exist. On the other hand, there is zero protection for a line-to-neutral fault, and the system is not GFCI protectable.

I leave it to you to decide if it is safer or more dangerous overall. I think many who understand these systems would argue that line-to-ground faults are more common (frayed hot wire, hand in water, feet on floor... or face against faulting fixture, hand in grounded tank) and these faults are far less likely in a floating system. They would likely point out that in a floating system, just as in a bonded system, the GFCI offers minimal protection for line-to-neutral contact and only helps in the line-to-neutral scenario if the person is also grounded.

---

“Hey Bean! What is all this ‘in theory’ nonsense?”

We say “in theory” because depending on how the source is built, some tiny amount of current can leak to ground — transistor base drive, generator excitation, internal filtering, other complex faults, etc. So even in a floating system chances of ground fault are not mathematically zero and from a safety perspective you should not treat the floating output any differently.

---

"Hey Bean! What about using them anyway for when the UPS or power station is delivering mains power?"

Well that depends on how your UPS or power center is built. You MUST check the documentation. Many UPS system will pass neutral through (bonded) when on Mains Power and switch to floating when on battery. So on mains power, the GFCI behaves as expected,

However many power centers like Jakery, or Bluetti or EcoFlow derive their outputs from their inverters 100% of the time, so they are always floating.

After a lot of research, it seems a GFI, even without a ground would work on a battery back up

So am I correct they only are concerned with current flow ie difference ?

They only care about the imbalance between hot and neutral. That part is correct.

But the key point (and why this gets confusing) is that a downstream GFCI can only see an imbalance if the system has a neutral-to-ground reference. On a bonded system, a line-to-ground fault creates that imbalance and the GFCI trips. On a floating UPS/generator output, there is no reference, so there’s no imbalance, so it won't typically trip. But back to the "in theory" part, as depending on how the device is built, there could be enough leakage current for it to trip.

The end...