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ArgMeMatey

join:2001-08-09
Milwaukee, WI
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reply to Frink

Re: Generator doesn't work with Power Vent Hot Water Heater

After seeing the where this thread has gone, I'm glad I insisted on the Direct Vent instead of the power vent that the plumber recommended!

We can probably agree that this thread reflects many different risk tolerances. We've all seen the redneck solution websites and the state-of-the-art, cost-is-no-object installations. This is neither, but the subject of interlocks is not even remotely a gray area.

We can also agree that once something has become a matter of law, violating that law increases the risk of being found criminally or civilly liable in the unlikely case that property damage, injury or death occurs because of your actions.

So the only advice I'll give is, get umbrella liability and be glad the prosecution will have a tough time compelling your family to testify in a criminal trial. Because somewhere on the East Coast right now, somebody is unintentionally backfeeding a power line, and somebody else is going to get shocked. Let's hope they can let go.
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garys_2k
Premium
join:2004-05-07
Farmington, MI
Reviews:
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said by ArgMeMatey:

After seeing the where this thread has gone, I'm glad I insisted on the Direct Vent instead of the power vent that the plumber recommended!

We can probably agree that this thread reflects many different risk tolerances. We've all seen the redneck solution websites and the state-of-the-art, cost-is-no-object installations. This is neither, but the subject of interlocks is not even remotely a gray area.

We can also agree that once something has become a matter of law, violating that law increases the risk of being found criminally or civilly liable in the unlikely case that property damage, injury or death occurs because of your actions.

So the only advice I'll give is, get umbrella liability and be glad the prosecution will have a tough time compelling your family to testify in a criminal trial. Because somewhere on the East Coast right now, somebody is unintentionally backfeeding a power line, and somebody else is going to get shocked. Let's hope they can let go.

Nobody is talking (here) about connecting between the house wiring and a generator, other than the ground. This is about using a generator with an unbonded ground-neutral on a load that requires that bond.

Regarding interconnection, I'm with you. Do it right with an interlock or transfer switch.

As for the linemen, they treat all wires as hot and short the primaries together and then to ground before messing with them. They're well aware of the risks and realities of improperly connected generators.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1
Not connecting to the house wiring? When the water heater is plugged into the extension cord with the bonded neutral / ground, it will connect the generator neutral into the entire wiring system of the house on both the house neutral as well as ground systems.


Jack_in_VA
Premium
join:2007-11-26
North, VA
kudos:1
Not if it's not connected to the house wiring in any way. Just life the 10-2 and ground wire from the heater.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1
said by Jack_in_VA:

Not if it's not connected to the house wiring in any way. Just life the 10-2 and ground wire from the heater.

Ok, so if the water heater is connected to the plumbing system by plastic pipe and not directly bonded to the ground system then it would't be connected. My guess is that at this point in time, the majority of homes in the US have metal pipe.


Jack_in_VA
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North, VA
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said by robbin:

said by Jack_in_VA:

Not if it's not connected to the house wiring in any way. Just life the 10-2 and ground wire from the heater.

Ok, so if the water heater is connected to the plumbing system by plastic pipe and not directly bonded to the ground system then it would't be connected. My guess is that at this point in time, the majority of homes in the US have metal pipe.
[/BQUOTE

Majority? Maybe but definitely not all.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1
said by Jack_in_VA:

Majority? Maybe but definitely not all.

True, but all gas water heaters are connected by a metal gas line and that line is bonded to the ground system. Same difference, still connected.


Jack_in_VA
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said by robbin:

said by Jack_in_VA:

Majority? Maybe but definitely not all.

True, but all gas water heaters are connected by a metal gas line and that line is bonded to the ground system. Same difference, still connected.

I don't recall specifying that I was talking about a gas fired water heater. More specifically I was using my electric water heater.

robbin
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join:2000-09-21
Leander, TX
kudos:1
said by Jack_in_VA:

I don't recall specifying that I was talking about a gas fired water heater.

That's what the thread is about. I responded to gary2k and then you responded to what I said.

Gas water heater / generator / extension cord / neutral ground bond. It connects to the electric system of the house. It is not isolated.

garys_2k
Premium
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Farmington, MI
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said by robbin:

said by Jack_in_VA:

I don't recall specifying that I was talking about a gas fired water heater.

That's what the thread is about. I responded to gary2k and then you responded to what I said.

Gas water heater / generator / extension cord / neutral ground bond. It connects to the electric system of the house. It is not isolated.

How's that? If the water heater is disconnected from the breaker, then connected to the generator via an extension cord, the generator's ground and neutral are bonded and then the generator's frame is connected (bonded, ideally) to the house ground, HOW are they "not isolated?"


ArgMeMatey

join:2001-08-09
Milwaukee, WI
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reply to garys_2k
said by garys_2k:

Nobody is talking (here) about connecting between the house wiring and a generator, other than the ground.
...
As for the linemen, they treat all wires as hot and short the primaries together and then to ground before messing with them. They're well aware of the risks and realities of improperly connected generators.

1) I was referring to this subthread and similar posts ... »Re: Generator doesn't work with Direct Vent Hot Water Heater

2) I was thinking about places where a secondary cable feeds more than one home. If one customer connects their generator and fails to turn off the main, the secondary is backfed. I am guessing this would often just trip the generator breaker because of the loads that are still connected, but if it didn't, another customer doing their own hot-wire setup, not thinking like a professional line worker, could get a shock.
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garys_2k
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Oh, I forgot about THAT suggestion, yeah, bad bad bad. So easy to mix up the switching, kind of like 1) drop the magazine, then 2) clear the chamber. Don't mix those up, either!

I've also thought that it'd be likely that a home generator would just drop its breaker if the main was thrown, may be more of a real safety hazard in rural areas where there may be only one house on a long stretch of line. In any case, it's not anything that should be possible to happen, even by mistake.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1
reply to garys_2k
said by garys_2k:

said by robbin:

Gas water heater / generator / extension cord / neutral ground bond. It connects to the electric system of the house. It is not isolated.

How's that? If the water heater is disconnected from the breaker, then connected to the generator via an extension cord, the generator's ground and neutral are bonded and then the generator's frame is connected (bonded, ideally) to the house ground, HOW are they "not isolated?"

Well, I can quote you multiple times in this thread where you stated that a proper bond to ground was not required. However my original point, which you would know if you had read my prior posts, is that the water heater is still connected to the house via the ground system on metal water pipes as well as the gas line. This creates hazards. Especially with multiple extension cords laying around.

said by garys_2k:

Nobody is talking (here) about connecting between the house wiring and a generator, other than the ground.

Why do you believe that the generator neutral is not connected to the entire house ground and neutral via the neutral / ground bond as I have described??


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by robbin:

However my original point, which you would know if you had read my prior posts, is that the water heater is still connected to the house via the ground system on metal water pipes as well as the gas line. This creates hazards. Especially with multiple extension cords laying around.

Why do you believe that the generator neutral is not connected to the entire house ground and neutral via the neutral / ground bond as I have described??

1 - Multiple extension cords laying around, but plugged in the generator, is a hazard by itself.

2 - Yes the generator would be effectively bonded to the house's ground through the copper pipes of the water heater. But what's your point? All ground systems should be bonded, even if they are from separately derived systems.

2.1 - Maybe you're thinking that the house's N/G bond is considered as a SECOND N/G bond, but that's incorrect, because the generator's neutral isn't connected to the house's neutral through a second line.

robbin
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join:2000-09-21
Leander, TX
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1 edit
said by alkizmo:

2 - Yes the generator would be effectively bonded to the house's ground through the copper pipes of the water heater. But what's your point? All ground systems should be bonded, even if they are from separately derived systems.

The safety of a floating neutral generator is inherent in the design as since there is no ground, there is no shock or electrocution hazard from say standing in a wet puddle. The only way to be part of the current path is by touching both hot and neutral. Once the generator has a neutral ground bond added, this is no longer the case. My point is that the water heater is not isolated from the house as was posted. The entire house ground system is now energized. As a result, there are now many ways to receive an unhealthy or killing shock.

The fact that the Power Vent water heater only draws about 2 amps virtually guarantees that other devices will be powered concurrently with the water heater. As the generator has not been fully installed as code would require means that there is no shock protection for the house residents. Yes, every outlet in your kitchen has GFCI protection, but that extension cord coming in through the window does not (floating neutral generators do not have GFCI protection).

The generator as shipped by the manufacturer does not need to be grounded as it is isolated by design. There is nothing unsafe about using the generator without grounding it if it is used as it was designed to be used -- with extension cords only. Remember, the reason we need protection from ground faults is that our electrical distribution system is an earthed system, meaning that ground is part of the entire system. This is not the case with a portable, floating neutral generator. Generators which come with ground bonds also come with GFCI protection.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by robbin:

The entire house ground system is now energized. As a result, there are now many ways to receive an unhealthy or killing shock.

it would normally trip the breaker on the generator (Or stall the generator) as the current would be flowing back to the neutral.

said by robbin:

The only way to be part of the current path is by touching both hot and neutral.

See I never knew that. I thought that no matter the source of current, you'd get shocked (Unless you were completely rubber proofed from touching anything that would conduct current to the ground).

I guess a precaution would be a GFCI protected extension cord.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
kudos:1
said by alkizmo:

said by robbin:

The entire house ground system is now energized. As a result, there are now many ways to receive an unhealthy or killing shock.

it would normally trip the breaker on the generator (Or stall the generator) as the current would be flowing back to the neutral.

Breakers provide overcurrent protection to prevent fires. They do not protect human life.

said by alkizmo:

said by robbin:

The only way to be part of the current path is by touching both hot and neutral.

See I never knew that. I thought that no matter the source of current, you'd get shocked (Unless you were completely rubber proofed from touching anything that would conduct current to the ground).

There was no ground and no need for it until the user followed your advice. Forget about ground, you need two conductors to complete a circuit. Ground is not one of them with a floating neutral generator.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by robbin:

Breakers provide overcurrent protection to prevent fires. They do not protect human life.

Right, but unless the short occurs while your touching something grounded, the breaker would trip quickly.

You're describing something that can happen with utility power in house circuits.

robbin
Premium,MVM
join:2000-09-21
Leander, TX
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I am talking about human life. What you recommended provides no safety. It is dangerous.

No, it cannot happen to the same degree with utility power if the house is less than 30 years old. They have GFCI protection on at least some circuits. You have both a baby and inlaws from out of the country in your home. Would you want either of them exposed to the shock hazard I have described? Put another way, if your house had no GFCIs in either the kitchen or the bathroom, would you feel comfortable with your family's safety?

sk1939
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reply to alkizmo
said by alkizmo:

said by robbin:

Breakers provide overcurrent protection to prevent fires. They do not protect human life.

Right, but unless the short occurs while your touching something grounded, the breaker would trip quickly.

You're describing something that can happen with utility power in house circuits.

No, actually breakers don't trip unless you ground the circuit or overload the circuit. It takes very little current to stop your heart, which is why GFCI's trip so low. You get shocked when you complete the circuit by providing a path to ground. Ground potential is important here.

Generator and utility power isn't that different.


pike
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join:2001-02-01
Washington, DC
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reply to alkizmo
said by alkizmo:

See I never knew that.

Precisely why you should refrain from dispensing electrical advice on a home improvement forum.

itguy05

join:2005-06-17
Carlisle, PA
reply to robbin
said by robbin:

Put another way, if your house had no GFCIs in either the kitchen or the bathroom, would you feel comfortable with your family's safety?

Yup. Why? Cause when I grew up in the 70's and 80's there were no GFCIs in the kitchen or bathroom. You learned real quick to be careful with electricity. May sound harsh but you could call it survival of the fittest.

Even used some home brew extension cords which were some heavy gauge wire and a steel box with a socket in the end. All the while using a 3 prong "cheater" adapter.


Jack_in_VA
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North, VA
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reply to pike
said by pike:

said by alkizmo:

See I never knew that.

Precisely why you should refrain from dispensing electrical advice on a home improvement forum.

I hope you are addressing that to a bunch of other posters and not just singling out alkizmo

robbin
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join:2000-09-21
Leander, TX
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reply to itguy05
said by itguy05:

May sound harsh but you could call it survival of the fittest

That's what you think we do here -- cull the herd?


djrobx
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reply to itguy05
said by itguy05:

said by robbin:

Put another way, if your house had no GFCIs in either the kitchen or the bathroom, would you feel comfortable with your family's safety?

Yup. Why? Cause when I grew up in the 70's and 80's there were no GFCIs in the kitchen or bathroom. You learned real quick to be careful with electricity. May sound harsh but you could call it survival of the fittest.

Even used some home brew extension cords which were some heavy gauge wire and a steel box with a socket in the end. All the while using a 3 prong "cheater" adapter.

This.

The funniest part is that we had tons of those cheater adapters, because some brainiac thought it was a good idea to replace a good number of our home's three prong outlets with two-prong child safety plugs. *Smacks forehead*. They were spring loaded. You'd have to plug in sideways, twist 90 degrees, then fully insert.

I only recently cleaned up most of this mess because we sold the home. Replaced them with proper 3 prong outlets and verified them with a tester, and installed GFCIs in the bathrooms, kitchen, and garage.
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alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
reply to pike
said by pike:

Precisely why you should refrain from dispensing electrical advice on a home improvement forum.

And I did state in my kludge plug trick that he should wait for an electrician to give input and that it's probably wrong/unsafe. If Frink chose to use my trick, then that's his choice.

After that, it's all discussion/debate as to WHAT the risks are.

You guys keep talking about return path through ground... yes, I know that now, but I don't see how it is less safe than the typical wiring in a house.

The generator might be wet, extension cords yet, but even if his whole plumbing became live because of a short, the current would flow back to the neutral and trip the breaker.

People with a transfer switch that switch the neutral have N/G bond at the generator, a generator that can run outside. What exactly is different in this scenario that makes the transfer switch setup safe, but not a N/G bond with extension cords?

I'm trying to understand, but no one is giving me comparisons as to how a short would kill someone with a generator, but not with normal house wiring (Again, don't mention GFCIs, they aren't everywhere). The only ADDED risk I see, is AT the generator, outside, in the rain.

Can someone tell me what can happen differently between N/G bond in the generator vs. house wiring/transfer switch.

robbin
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join:2000-09-21
Leander, TX
kudos:1
said by alkizmo:

I'm trying to understand, but no one is giving me comparisons as to how a short would kill someone with a generator, but not with normal house wiring (Again, don't mention GFCIs, they aren't everywhere). The only ADDED risk I see, is AT the generator, outside, in the rain.

You can't limit it unless you can convince the electrons not to take the path they choose. There are multiple risks added.. Either do it right or keep it separate.

said by nunya:

said by alkizmo:

Now I'll probably get grilled for this, but...

Now if it's "safe", I don't know, I just know it's not the proper way to do it

Don't do this. It's dangerous. Emergency or not. An "emergency" situation never constitutes doing stupid things. Quite the opposite. Don't create a "life or death" emergency trying to alleviate a "loss of comfort" situation...There are multiple things that could wrong using this cheat. Anything metallic connected to the WH could become energized by the generator in such a scenario. This includes the metallic case and any metallic piping (gas or water). This could electrocute anyone touching them.

Enough said


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
No not enough said and no real explanation/example was given as to why there are added risks to N/G bond with extension cords compared to N/G bond with transfer switch.

I want to know/learn/understand. Is it too much to ask or is this forum no longer about learning?

sk1939
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reply to alkizmo
said by alkizmo:

You guys keep talking about return path through ground... yes, I know that now, but I don't see how it is less safe than the typical wiring in a house.

The generator might be wet, extension cords yet, but even if his whole plumbing became live because of a short, the current would flow back to the neutral and trip the breaker.

No, it wouldn't necessarily trip the breaker, and it definately wouldn't trip before someone touched something metallic and electrictued themselves.

As far as the N/G bond, it's not at the generator with a transfer switch, it's bonded at the panel.

Additionally, a N/G bond with extension cords can't handle the current load put on it (30-50A).

AC current is NOT DC, which means that it goes and comes back forming a loop. If it dosen't find a return via the neutral and/or has a shorter path to ground, it will take that, be it through a water pipe or a human. This is why you need to have a neutral and why a ground bond in two places is bad.


alkizmo

join:2007-06-25
Pierrefonds, QC
kudos:1
said by sk1939:

As far as the N/G bond, it's not at the generator with a transfer switch, it's bonded at the panel.

Incorrect, it can be either in the panel OR at the generator.
Transfer switches can switch the neutral. Mine for example does such thing, so the bond is at the generator, as per an electrician's recommendation.

said by sk1939:

Additionally, a N/G bond with extension cords can't handle the current load put on it (30-50A).

Yes it IS a kludge, but that isn't what's being debated.

said by sk1939:

AC current is NOT DC, which means that it goes and comes back forming a loop. If it dosen't find a return via the neutral and/or has a shorter path to ground, it will take that, be it through a water pipe or a human. This is why you need to have a neutral and why a ground bond in two places is bad.

I'm going to assume you were still talking about N/G bond not being good at the generator with a transfer switch. So yes, you're right, 2 bonds is bad. But again... the bond CAN be at the generator and be the only bond.