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I still wonder how electrocution is not a big issue. My local electricity codes say absolutely no electricity within zone 0. I get a bit nervous about hooking

I still wonder how electrocution is not a big issue. My local electricity codes say absolutely no electricity within zone 0. I get a bit nervous about hooking up IP 65 rated lights to a IP X4 rated switchbox a meter away from the shower head

Alupis 2y ago
There's a reason you don't see this type of water heater in most of the world.
- mikedelfino 2y ago
  I wonder, though, why there are so few incidents where this type of shower is prevalent, given that people not used to it are so worried. If the fatality rate were 0.0001%, hundreds of people would die every day.
  - Alupis 2y ago
    Just in this thread alone we've found several stories of people being mildly shocked by these devices while on vacation. It's not that people die every day from these devices, it's that in general this isn't a great way to heat water if you have alternatives available. I don't know about you, but I would prefer not to receive a shock, no matter how minor it might be, when I step into the shower...
- kragen 2y ago
  yes, and that reason is mostly the kind of people who were asking the original poster how he made it to adulthood
  - Alupis 2y ago
    Right, I'm sure it has nothing to do with the plethora of "shocking" tales regarding these water heaters. I can count on zero hands the number of times my shower has given me a jolt, even a minor one. We mostly see these types of devices in relatively poor countries without the means to install more modern and safer alternatives, such as whole house water heaters.
    - kragen 2y ago
      no? i mean it's the same reason most people in the usa don't have a bidet in their house; it's not because they're too poor to afford one. technology adoption is path-dependent and mostly random, and fear makes people conservative. yes, there are a few people who are familiar with the actual risks and rewards of the different technologies, but they're vastly outnumbered by the pre-galilean minds who are entirely guided by conventional wisdom most people in the usa can count on zero hands the number of times they've sprayed water on the bathroom ceiling from their bidet, too
      - Alupis 2y ago
        This assumes a bidet is objectively better than a regular toilet. That is debatable. It's not debatable these electric showerheads are objectively better, just because some poorer communities around the world use them.
        kragen 2y ago
        well, it only assumes that bidets are subjectively better to many people, which they certainly are; it doesn't rely on the assumption of an objective, observer-independent scale of valuation in the way you're describing (bidets aren't an alternative to a regular toilet, and the fact that you think they are is a minor indicator of why it's difficult for even widespread, highly beneficial innovations to become universal even after centuries) not only is it debatable whether or not electric showers are better in that sense, i have in fact debated it; i refer you to https://news.ycombinator.com/item?id=41250642 https://news.ycombinator.com/item?id=41250642 and eagerly await your opinion
        Alupis 2y ago
        If given the option, free of charge, to continue using electrified showerheads or using whole-home water heating... how many would continue to use electrified showerheads? The fact that they are only common in poor and impoverished areas, tells you everything you need to know. This argument is a lot like asserting instant-coffee is better than fresh brewed coffee because some people have no alternative choice.
michaelt 2y ago
Electric showers are very common in the UK - although the heater is in a wall-mounted unit, with the head on a hose, rather than the heater being in the head itself. The heating element has three layers - innermost, a wire that gets hot. Around that, a ceramic insulator. And outermost, a metal cover to protect the ceramic insulator. Then the heating element is mounted in a small water tank. And that, along with some other components, is put into a suitably waterproof outer plastic box. The insulation is of course all tested at the factory. The tank, heating element outer, and all the pipework in the general vicinity is then grounded, and the power supply passes through an RCD (our equivalent to a GFCI). There are also two or three temperature sensors, and a water pressure sensor. Installers also have to have an up-to-date electrical safety license - so for they know better than to (for example) compromise the waterproofing of the enclosure by adding extra holes to make the wiring simpler.
- kragen 2y ago
  i'm pretty sure that the electric showers i've used didn't have the sealed magnesia insulating layer you're describing, nor were they connected to an rcd/gfci i do agree that the measures you're describing would make them much safer
- mikedelfino 2y ago
  In some countries, electric showers use a metal coil as a heating element, similar to a spring, located directly in the showerhead. When you turn on the faucet, water fills the showerhead and touches the metal, effectively bringing the positive and negative wires into contact. The coil then heats the water as it flows out. Occasionally, the coil can oxidize or break if there's not enough water running to keep it cool. When that happens, most people replace it themselves.
- extraduder_ire 2y ago
  A lot of things involving electricity in places with type-G plugs seem more dangerous if you don't know/assume that almost everything is grounded. Took me a while to realize that hairdrier he mentioned in the blogpost likely didn't have a ground connection in the plug. In the case of a toaster with a grounded frame, the most likely route for a short is straight to earth which will trip the RCD on that set of plugs.
alvah 2y ago
Your local codes almost certainly say no electrical outlets in that zone, not no electricity. The assumption being hardwired devices installed by professionals are not a huge risk.
userbinator 2y ago
Electricity takes the path of least resistance. If things are done right, that means through the metal heating element and the ground wire, and not through your body.
- mistercow 2y ago
  This is a dangerous myth. Electricity takes all available paths, with less current flowing through the paths with greater resistance. As far as I understand, the main reason people don’t get electrocuted even with improperly grounded shower head heaters is that (as noted in the post), tap water is generally not very conductive in the first place, so you’ve effectively got a gigantic resistor between you and the wires (assuming there’s a continuous path through the water at all). So even if the least resistance path is through you, the amount of current will be tiny due to Ohm’s law.
  - userbinator 2y ago
    It's not a myth. Your second paragraph basically agrees with me and contradicts itself. so you’ve effectively got a gigantic resistor between you and the wires (assuming there’s a continuous path through the water at all). So even if the least resistance path is through you, the amount of current will be tiny due to Ohm’s law. That is, by definition, NOT the "least resistance path".
    - mistercow 2y ago
      > It's not a myth. Yes it is. A tip: if someone tells you something is a myth, your next step should be to google it. This is intro level parallel circuit stuff. Hell, just think about the circuitry in your house. If you have your phone charging on one outlet, and you plug a hair dryer into the adjacent outlet, does the phone stop charging? Does the hair dryer not run? Do you think those things have exactly equal resistance? Of course not. Current flows to both of them, but more current flows to the hair dryer. > That is, by definition, NOT the "least resistance path". I don’t think you know what “by definition” means. You could be the only path for the electricity to flow, and if there’s high enough resistance, it won’t hurt you. Please stop repeating this nonsensical folk wisdom. It can get people killed.

Alupis 2y ago

There's a reason you don't see this type of water heater in most of the world.

mikedelfino 2y ago
I wonder, though, why there are so few incidents where this type of shower is prevalent, given that people not used to it are so worried. If the fatality rate were 0.0001%, hundreds of people would die every day.
- Alupis 2y ago
  Just in this thread alone we've found several stories of people being mildly shocked by these devices while on vacation. It's not that people die every day from these devices, it's that in general this isn't a great way to heat water if you have alternatives available. I don't know about you, but I would prefer not to receive a shock, no matter how minor it might be, when I step into the shower...
kragen 2y ago
yes, and that reason is mostly the kind of people who were asking the original poster how he made it to adulthood
- Alupis 2y ago
  Right, I'm sure it has nothing to do with the plethora of "shocking" tales regarding these water heaters. I can count on zero hands the number of times my shower has given me a jolt, even a minor one. We mostly see these types of devices in relatively poor countries without the means to install more modern and safer alternatives, such as whole house water heaters.
  - kragen 2y ago
    no? i mean it's the same reason most people in the usa don't have a bidet in their house; it's not because they're too poor to afford one. technology adoption is path-dependent and mostly random, and fear makes people conservative. yes, there are a few people who are familiar with the actual risks and rewards of the different technologies, but they're vastly outnumbered by the pre-galilean minds who are entirely guided by conventional wisdom most people in the usa can count on zero hands the number of times they've sprayed water on the bathroom ceiling from their bidet, too
    - Alupis 2y ago
      This assumes a bidet is objectively better than a regular toilet. That is debatable. It's not debatable these electric showerheads are objectively better, just because some poorer communities around the world use them.
      - kragen 2y ago
        well, it only assumes that bidets are subjectively better to many people, which they certainly are; it doesn't rely on the assumption of an objective, observer-independent scale of valuation in the way you're describing (bidets aren't an alternative to a regular toilet, and the fact that you think they are is a minor indicator of why it's difficult for even widespread, highly beneficial innovations to become universal even after centuries) not only is it debatable whether or not electric showers are better in that sense, i have in fact debated it; i refer you to https://news.ycombinator.com/item?id=41250642 https://news.ycombinator.com/item?id=41250642 and eagerly await your opinion
        Alupis 2y ago
        If given the option, free of charge, to continue using electrified showerheads or using whole-home water heating... how many would continue to use electrified showerheads? The fact that they are only common in poor and impoverished areas, tells you everything you need to know. This argument is a lot like asserting instant-coffee is better than fresh brewed coffee because some people have no alternative choice.

michaelt 2y ago

Electric showers are very common in the UK - although the heater is in a wall-mounted unit, with the head on a hose, rather than the heater being in the head itself. The heating element has three layers - innermost, a wire that gets hot. Around that, a ceramic insulator. And outermost, a metal cover to protect the ceramic insulator. Then the heating element is mounted in a small water tank. And that, along with some other components, is put into a suitably waterproof outer plastic box. The insulation is of course all tested at the factory. The tank, heating element outer, and all the pipework in the general vicinity is then grounded, and the power supply passes through an RCD (our equivalent to a GFCI). There are also two or three temperature sensors, and a water pressure sensor. Installers also have to have an up-to-date electrical safety license - so for they know better than to (for example) compromise the waterproofing of the enclosure by adding extra holes to make the wiring simpler.

kragen 2y ago
i'm pretty sure that the electric showers i've used didn't have the sealed magnesia insulating layer you're describing, nor were they connected to an rcd/gfci i do agree that the measures you're describing would make them much safer
mikedelfino 2y ago
In some countries, electric showers use a metal coil as a heating element, similar to a spring, located directly in the showerhead. When you turn on the faucet, water fills the showerhead and touches the metal, effectively bringing the positive and negative wires into contact. The coil then heats the water as it flows out. Occasionally, the coil can oxidize or break if there's not enough water running to keep it cool. When that happens, most people replace it themselves.
extraduder_ire 2y ago
A lot of things involving electricity in places with type-G plugs seem more dangerous if you don't know/assume that almost everything is grounded. Took me a while to realize that hairdrier he mentioned in the blogpost likely didn't have a ground connection in the plug. In the case of a toaster with a grounded frame, the most likely route for a short is straight to earth which will trip the RCD on that set of plugs.

alvah 2y ago

Your local codes almost certainly say no electrical outlets in that zone, not no electricity. The assumption being hardwired devices installed by professionals are not a huge risk.

userbinator 2y ago

Electricity takes the path of least resistance. If things are done right, that means through the metal heating element and the ground wire, and not through your body.

mistercow 2y ago
This is a dangerous myth. Electricity takes all available paths, with less current flowing through the paths with greater resistance. As far as I understand, the main reason people don’t get electrocuted even with improperly grounded shower head heaters is that (as noted in the post), tap water is generally not very conductive in the first place, so you’ve effectively got a gigantic resistor between you and the wires (assuming there’s a continuous path through the water at all). So even if the least resistance path is through you, the amount of current will be tiny due to Ohm’s law.
- userbinator 2y ago
  It's not a myth. Your second paragraph basically agrees with me and contradicts itself. so you’ve effectively got a gigantic resistor between you and the wires (assuming there’s a continuous path through the water at all). So even if the least resistance path is through you, the amount of current will be tiny due to Ohm’s law. That is, by definition, NOT the "least resistance path".
  - mistercow 2y ago
    > It's not a myth. Yes it is. A tip: if someone tells you something is a myth, your next step should be to google it. This is intro level parallel circuit stuff. Hell, just think about the circuitry in your house. If you have your phone charging on one outlet, and you plug a hair dryer into the adjacent outlet, does the phone stop charging? Does the hair dryer not run? Do you think those things have exactly equal resistance? Of course not. Current flows to both of them, but more current flows to the hair dryer. > That is, by definition, NOT the "least resistance path". I don’t think you know what “by definition” means. You could be the only path for the electricity to flow, and if there’s high enough resistance, it won’t hurt you. Please stop repeating this nonsensical folk wisdom. It can get people killed.