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[Stephen Swaffer]

I was needing a hot shower so I disconnected the voltage feeds to the old hot water heater. As soon as I removed the first hot wire (black) the voltage on my hot water pipes dropped to nothing. Even though my NCVT said the shower was safe, i disconnected the other hot wire (red), just to be super safe...  I am not sure why the voltage leak wouldn't persist with the one hot lead still connected feeding through the heat element to the voltage leak?

It wouldn't surprise me to see the element burnt-but one end shorted to ground so you would only get power from one of the leads.

I helped my mainteneance techs troubshoot a heat zone on a blow molder today-an 8000-12000 watt element feed from 480 that kept overheating a zone.  One hot lead showed 0 ohms to ground-the other open to ground.  Since the shorted lead was not controlled by the t-stat the zone ran away. If that element was not grounded, touching it would give a very noticeable tingle.

[Scott Holtzman]

The link I sent is not a tankless hot water heater. It's just the opposite since there's a 50 gallon tank. In addition to a standard high-wattage heater element, it also has a heat pump on the top. So it only draws about 5 amperes or so to heat the water instead 20 amps like a conventional hot water heater. It also dehumidifies the room while it heats the water. This reduces electrical costs considerably, just like a heat pump on your house is much cheaper to run than electric baseboard heating. 

Learned something new. Sorry for not reading the link. 

[John Roberts {JR}]

More drama.... This morning I get ready to swap out my old hot water heater and find the copper plumbing sweated into the top nipples, so not getting the old one out without a torch. 

Just called a real plumber so my DIY repair is off the table. 

I am leaning toward connecting the loose 240 wires into the old dryer outlet,,,  I'll need to look up the wiring pattern, I suspect the middle blade is neutral/ground (don't worry I'll look it up).

I doubt the white wire inside the 240V cable is connected to anything (black and red are hot).

JR

[Mike Sokol]

More drama.... This morning I get ready to swap out my old hot water heater and find the copper plumbing sweated into the top nipples, so not getting the old one out without a torch. 

Just called a real plumber so my DIY repair is off the table. 

I am leaning toward connecting the loose 240 wires into the old dryer outlet,,,  I'll need to look up the wiring pattern, I suspect the middle blade is neutral/ground (don't worry I'll look it up).

I doubt the white wire inside the 240V cable is connected to anything (black and red are hot).

JR

Just make sure the EGC is properly connected.... But you know that already. 

[John Roberts {JR}]

Just make sure the EGC is properly connected.... But you know that already. 

Yes it seems an EGC could be most useful for these kind of products that mix electricity with water...  I finally grounded my washing machine and dishwasher..last weekend.

Hot water heater is next.

JR

[Kevin Maxwell]

JR, glad you are ok and didn’t get electrocuted.

I am probably showing my lack of understanding of proper grounding with this question. Would it be a good idea to put a clamp and a ground wire on the water pipes (assuming they are metal) as close to the shower/tub that then gets run to the earth ground? In my case the earth ground is the main water pipe where it enters the house. Then if there is a fault in the electric water heater it should trip the breaker. Or is there a reason not to do this as an added safety? All of my water pipes in the house are copper. I would have assumed that the ground of the cold water pipe would carry thru to the metal faucet assembly in the tub. Since the cold and hot water pipes join together in that faucet assembly then shouldn’t the hot water side also be grounded in my house? If the water pipes in someone’s house are plastic is there at least a metal faucet assembly to ground to?

I have an electric water heater that is supplied by the electric company and I pay a small rental fee each month. It is then their responsibility. A few years ago a brand new one that they put in to replace an older one of theirs leaked and flooded my basement after having it for only a few months. It was a defect at one of the heater core assemblies, not the tank itself. They fixed it and paid for the cleanup or at least their insurance company did.

[John Roberts {JR}]

JR, glad you are ok and didn’t get electrocuted.

Me too.... even if I wasn't completely fried, it could have caused me to fall in the shower (another undesirable statistic).

I am probably showing my lack of understanding of proper grounding with this question. Would it be a good idea to put a clamp and a ground wire on the water pipes (assuming they are metal) as close to the shower/tub that then gets run to the earth ground? In my case the earth ground is the main water pipe where it enters the house.

Be careful about such ASSumptions. My metal water line rusted out and started to leak a couple years back. Now the water pipe coming into my house is PVC, so not a ground. I am not even confident about the town's water lines, probably PVC too anywhere they leaked.

Then if there is a fault in the electric water heater it should trip the breaker.

There is a chassis ground screw on the new water heater, old one just had some wires sticking out a hole in the side. My wiring drop to the heater does not have a ground wire but I am putting this on my bucket list to jumper a ground wire over to the fuse panel a few feet away.

Or is there a reason not to do this as an added safety? All of my water pipes in the house are copper. I would have assumed that the ground of the cold water pipe would carry thru to the metal faucet assembly in the tub. Since the cold and hot water pipes join together in that faucet assembly then shouldn’t the hot water side also be grounded in my house? If the water pipes in someone’s house are plastic is there at least a metal faucet assembly to ground to?

My water pipes were never a decent ground surrogate (I checked when dealing with my ungrounded kitchen), but only recently a voltage hazard. I am tempted to bond them to my fuse box, just for general principles. My two other appliances that mix electricity with water (dishwasher and washing machine) are plugged into a grounded GFCI outlet. After I ground the heater chassis and plumbing I should be OK. 

I have an electric water heater that is supplied by the electric company and I pay a small rental fee each month. It is then their responsibility. A few years ago a brand new one that they put in to replace an older one of theirs leaked and flooded my basement after having it for only a few months. It was a defect at one of the heater core assemblies, not the tank itself. They fixed it and paid for the cleanup or at least their insurance company did.

Yup apparently water leaks are the common fault. There is a sacrificial metal rod (aluminum) anode inside to reduce internal corrosion. These rods are consumed over time and supposed to be checked annually. I never knew they even existed.   That's life for you, gives the test first, then the answers.

JR

PS: Yesterday I took a hot shower, just because i could.  A pretty expensive shower but owning a house is like a hole in the ground you throw money into.

[Mike Sokol]

Me too.... even if I wasn't completely fried, it could have caused me to fall in the shower (another undesirable statistic).

We often underestimate how dangerous the fall can be from getting shocked. If you're on the roof or up on a ladder and get shocked, you'll probably take a fall. Sometimes that fall can be fatal or at the least break some bones. When I did sound for Chumbawumba back in the 90's, I was given an ungrounded generator to supply power for the PA and band that were both up on the roof of a parking garage, 4 floors up. I measured 90 volts between the mic body and the railing around the edge. We had built a stage up on the roof so this railing wes now only about a foot above the stage, so a shock could have caused a musician to take a dive some 40 feet to the sidewalk below. And that's where my mixing console was positioned, 1 foot in front of the band and 40 feet below them on the sidewalk. With my luck they would have landed on my console. I grounded the generator and made it safe for the band to play, which took a load off my mind. Yes, I tested the voltage in advance of the show, which is what warned me of the hot grounds.

[Stephen Kirby]

I am probably showing my lack of understanding of proper grounding with this question. Would it be a good idea to put a clamp and a ground wire on the water pipes (assuming they are metal) as close to the shower/tub that then gets run to the earth ground?

Have to defer to the experts but I thought that doing this would cause leakage currents to go through the piping, accelerating corrosion at the very least.  Since the service entrance is bonded to the incoming water pipe as a ground, any other connections some distance from that point would create a circuit.

[John Roberts {JR}]

Have to defer to the experts but I thought that doing this would cause leakage currents to go through the piping, accelerating corrosion at the very least.  Since the service entrance is bonded to the incoming water pipe as a ground, any other connections some distance from that point would create a circuit.

My incoming PCV water main is not a very good ground.

I am buying a grounding pipe clamp, and will wire the water heater EGC, to cold(?) water pipe, then to fuse box ground. It looks like hot and cold pipes are bonded to each other, but now floating wrt ground.

Grounding the heater and plumbing seems prudent in light of my recent experience. 

JR

PS:  I asked the plumber about modern grounding practices regarding building plumbing and he said he still sees pipes bonded in some large commercial buildings but not residential, but I do not expect him to be an electrical code expert. 

[ProSoundWeb Community]