3 ms·

Hmm you sure they are pulling in series? Depends on the design on the plug but I imagine it works the same way as any other multi-socket (pulling it in parallel

by ErrantX 16y ago

Hmm you sure they are pulling in series? Depends on the design on the plug but I imagine it works the same way as any other multi-socket (pulling it in parallel), why would they set it up to work in series (that would be a big design flaw). One imagines that once this made it to the engineering level (this is just design, right) this would be sorted out. If we're talking 'light' consumers, say below a 100W or so you might get away with it but if a 'heavy' consumer would be plugged in as the last element in a series of 'light' ones you'd be concentrating an awful lot of energy in to a small spot. Think about what is likely to have these sorts of plugs; Laptops, for example, usually pull under 2A. Which means you could have 10 plugged in before it starts to be a problem, and even pulling 20A to your socket (which is a common rating for mains sockets) still leaves plenty of leeway. I'm not sure what my iPhone or radio alarm clock is rated for (am at work atm) but I can't imagine they add up to more than 1A draw. As I mentioned, the problem on mains networks overloading comes, usually, from a faulty trip switch. If it is doing its job the most that you can do is trip it (and maybe fry some equipment that isn't earthed/fused properly). Stocking up a plug is pretty safe; again, as mentioned, it is easy (and more common) to overload the whole circuit via a number of plugs :) EDIT: meh, it's impossible, anyway, for it to be set up in series, otherwise you wouldn't be able to pull power correctly. with 5 plugs 'ganged' up Uh, there are three plugs in the design? But this is a reasonable concern (the heat issue). In practice it is not too much of a worry, if a device is demanding 2KW this plug is clearly unsuitable (for a number of reasons).

jacquesm 16y ago
> Hmm you sure they are pulling in series? The contacts are in series: live->socket1->socket2->socket3->socket4->socket5->load | | neut<-socket1<-socket2<-socket3<-socket4<-socket5<-load So the current for the last load passes through all the intermediary sockets. It does not pass through their wiring but it does pass from pin-to-pin. It would have to and no engineering trick will get you around that when you're piggybacking stuff. > Think about what is likely to have these sorts of plugs; Laptops, for example, usually pull under 2A. Which means you could have 10 plugged in before it starts to be a problem, and even pulling 20A to your socket (which is a common rating for mains sockets) still leaves plenty of leeway. Until someone plugs their hairdryer or fryer in to the last one, which is possible because it is still valid socket.
- ErrantX 16y ago
  Hmm.... yes, I see what you mean. But it comes back to the same issue; which is that if you are overloading it to the degree that it passes the rated value then the trip switch is the failsafe. The socket is at just as much risk. You wouldn't (in the UK anyway) be able to sell these if they were rated less than the socket.
  - jacquesm 16y ago
    That's the whole point I'm making. You would be doing something that seems safe, that will not trip the breaker but that will cause a problem. Just the fact that you can gang a bunch of stuff that is rated does not mean that there aren't any hidden variables here, and contact resistance is exactly that. Very easy to overlook. That's why 'three way' connectors were outlawed in many countries (but not in all): http://www.rapidonline.com/1/1/8248-3-way-mains-adaptor.html http://www.rapidonline.com/1/1/8248-3-way-mains-adaptor.html That's the UK version, there are others for different places. The euro-plug variety of them has been outlawed for so long that I can't even find an image of one. People would get up to all kinds of creative uses for these, such as 'wonder why I can't plug on three-way in to another', and if that works why not several. They're also known as 'firestarters', any idea why ;)?
    - ErrantX 16y ago
      I'm still unconvinced.. the way overloading usually causes fires is heating cables till they short and cause sparks/fire. But that is by the by, my main issues: If all of the mini-sockets are low rated there is no danger, because of how the socket is set up, if you use the other socket for something with a big draw (i.e. if you have a dual socket and plug one of these into it next to something with a big load it will not overload it). If you overload this device or the socket it will trip the circuit breaker. Same as if you plug all the devices into different sockets on the main. Heat is unlikely to be an issue, even with contact resistance it is related to the device it is powering - and I contend that this is not a plug you would use, rate, recommend or legally allow for high power devices. If you're powering three laptops it works out to about 1W for the whole device (rember, while the cable goes to each socket the pins are part of the device circuit, the parallel branch, not the main series).

by ErrantX 16y ago

jacquesm 16y ago

> Hmm you sure they are pulling in series? The contacts are in series: live->socket1->socket2->socket3->socket4->socket5->load | | neut<-socket1<-socket2<-socket3<-socket4<-socket5<-load So the current for the last load passes through all the intermediary sockets. It does not pass through their wiring but it does pass from pin-to-pin. It would have to and no engineering trick will get you around that when you're piggybacking stuff. > Think about what is likely to have these sorts of plugs; Laptops, for example, usually pull under 2A. Which means you could have 10 plugged in before it starts to be a problem, and even pulling 20A to your socket (which is a common rating for mains sockets) still leaves plenty of leeway. Until someone plugs their hairdryer or fryer in to the last one, which is possible because it is still valid socket.

ErrantX 16y ago
Hmm.... yes, I see what you mean. But it comes back to the same issue; which is that if you are overloading it to the degree that it passes the rated value then the trip switch is the failsafe. The socket is at just as much risk. You wouldn't (in the UK anyway) be able to sell these if they were rated less than the socket.
- jacquesm 16y ago
  That's the whole point I'm making. You would be doing something that seems safe, that will not trip the breaker but that will cause a problem. Just the fact that you can gang a bunch of stuff that is rated does not mean that there aren't any hidden variables here, and contact resistance is exactly that. Very easy to overlook. That's why 'three way' connectors were outlawed in many countries (but not in all): http://www.rapidonline.com/1/1/8248-3-way-mains-adaptor.html http://www.rapidonline.com/1/1/8248-3-way-mains-adaptor.html That's the UK version, there are others for different places. The euro-plug variety of them has been outlawed for so long that I can't even find an image of one. People would get up to all kinds of creative uses for these, such as 'wonder why I can't plug on three-way in to another', and if that works why not several. They're also known as 'firestarters', any idea why ;)?
  - ErrantX 16y ago
    I'm still unconvinced.. the way overloading usually causes fires is heating cables till they short and cause sparks/fire. But that is by the by, my main issues: If all of the mini-sockets are low rated there is no danger, because of how the socket is set up, if you use the other socket for something with a big draw (i.e. if you have a dual socket and plug one of these into it next to something with a big load it will not overload it). If you overload this device or the socket it will trip the circuit breaker. Same as if you plug all the devices into different sockets on the main. Heat is unlikely to be an issue, even with contact resistance it is related to the device it is powering - and I contend that this is not a plug you would use, rate, recommend or legally allow for high power devices. If you're powering three laptops it works out to about 1W for the whole device (rember, while the cable goes to each socket the pins are part of the device circuit, the parallel branch, not the main series).