• Internal Relay

    Are smart meters fitted with an internal relay which if it fails, or the meter is hacked, could disconnect my electricity supply ?
    Tap below to see the best answer
    0
  • Are smart meters fitted with an internal relay which if it fails, or the meter is hacked, could disconnect my electricity supply ?
    Tap below to see the best answer


  • Best Answer

    hi Foxmeister
    There obviously is a valve in gas meters or pay as you go wouldn't be possible, and yes there is a relay in Smart electric meters.
    ​They are designed to fail safe, although that's not 100% certain as I suppose it depends on the failure.
    As far as hacking goes, I don't think there's been a reported case yet, I think the hackers are more interested in your bank account than your gas (or electric) meter, but never say never...

    ​disclaimer
    If it ain't broke don't fix it...
    Quote Originally Posted by Foxmeister View Post
    Are smart meters fitted with an internal relay which if it fails, or the meter is hacked, could disconnect my electricity supply ?
    Last edited by woz; 11-06-19 at 13:04.
    0
  • hi Foxmeister
    There obviously is a valve in gas meters or pay as you go wouldn't be possible, and yes there is a relay in Smart electric meters.
    ​They are designed to fail safe, although that's not 100% certain as I suppose it depends on the failure.
    As far as hacking goes, I don't think there's been a reported case yet, I think the hackers are more interested in your bank account than your gas (or electric) meter, but never say never...

    ​disclaimer
    If it ain't broke don't fix it...
    Quote Originally Posted by Foxmeister View Post
    Are smart meters fitted with an internal relay which if it fails, or the meter is hacked, could disconnect my electricity supply ?


  • Hi Woz, thanks for your reply. I agree totally that 'if its not broke we should'nt fix it' My existing electric meter doesn't have an internal disconnect relay or switch, so why would anyone design a smart meter that might include one? Regarding 'failing safe' if the relay contacts fail the electricity supply to the property would be disconnected. It's for this reason that I raised the question. As for there being no reports of smart meters being hacked yet I believe that any miscreant would probably wait until the numbers installed and working were large enough to make it worth their while. I hope you're right and that nobody does so.
    1
  • Hi Woz, thanks for your reply. I agree totally that 'if its not broke we should'nt fix it' My existing electric meter doesn't have an internal disconnect relay or switch, so why would anyone design a smart meter that might include one? Regarding 'failing safe' if the relay contacts fail the electricity supply to the property would be disconnected. It's for this reason that I raised the question. As for there being no reports of smart meters being hacked yet I believe that any miscreant would probably wait until the numbers installed and working were large enough to make it worth their while. I hope you're right and that nobody does so.


  • Contact failure is massively more likely under 2 circumstances, (I'm hoping the contacts are normally closed by the way but I don't know for sure) 1. arcing caused by constant operation (which there isn't normally) and 2. Contamination/oxidation caused by pollutants and excessive humidity (think swimming baths or having your tumble dryer venting onto the meter). I'm not saying it won't happen just that if it was an issue I think we'd have known by now. More likely to be an issue is the installers not torquing the tails to an appropriate tightness thus causing high resistance and heat generation. We shall see....
    The hacking is more likely to come from malice, but I think they will go for the infrastructure first..in which case we're all screwed...
    Quote Originally Posted by Foxmeister View Post
    Hi Woz, thanks for your reply. I agree totally that 'if its not broke we should'nt fix it' My existing electric meter doesn't have an internal disconnect relay or switch, so why would anyone design a smart meter that might include one? Regarding 'failing safe' if the relay contacts fail the electricity supply to the property would be disconnected. It's for this reason that I raised the question. As for there being no reports of smart meters being hacked yet I believe that any miscreant would probably wait until the numbers installed and working were large enough to make it worth their while. I hope you're right and that nobody does so.
    0
  • Contact failure is massively more likely under 2 circumstances, (I'm hoping the contacts are normally closed by the way but I don't know for sure) 1. arcing caused by constant operation (which there isn't normally) and 2. Contamination/oxidation caused by pollutants and excessive humidity (think swimming baths or having your tumble dryer venting onto the meter). I'm not saying it won't happen just that if it was an issue I think we'd have known by now. More likely to be an issue is the installers not torquing the tails to an appropriate tightness thus causing high resistance and heat generation. We shall see....
    The hacking is more likely to come from malice, but I think they will go for the infrastructure first..in which case we're all screwed...
    Quote Originally Posted by Foxmeister View Post
    Hi Woz, thanks for your reply. I agree totally that 'if its not broke we should'nt fix it' My existing electric meter doesn't have an internal disconnect relay or switch, so why would anyone design a smart meter that might include one? Regarding 'failing safe' if the relay contacts fail the electricity supply to the property would be disconnected. It's for this reason that I raised the question. As for there being no reports of smart meters being hacked yet I believe that any miscreant would probably wait until the numbers installed and working were large enough to make it worth their while. I hope you're right and that nobody does so.


  • My experience of relay failures, but not related to a Smart Switch, is not that power is left in the off position but the opposite. I have been through three different types of device that can be controlled wirelessly and when used for one particular item the relay failed. Not robust enough. What caused the problem was a 40 amp PSU switching on when the remote switch was operated. Nothing connected to the PSU was switched on but I am assuming that the sudden surge required to get the capacitors up to full capacity ready to do the job when called upon, happening at the same time as the wireless socket/plug-in was operated, was too much. If I leave the PSU off and switch it on after the wireless socket is switched on there is no problem. But, in every single case of failure the wireless plug, socket or plug-in was left in the on position. I just could not operate it wirelessly any more. It is possible that the relay in the Smart Meter will behave the same way, perhaps to prevent power loss to the consumer.
    Richard
    1
  • My experience of relay failures, but not related to a Smart Switch, is not that power is left in the off position but the opposite. I have been through three different types of device that can be controlled wirelessly and when used for one particular item the relay failed. Not robust enough. What caused the problem was a 40 amp PSU switching on when the remote switch was operated. Nothing connected to the PSU was switched on but I am assuming that the sudden surge required to get the capacitors up to full capacity ready to do the job when called upon, happening at the same time as the wireless socket/plug-in was operated, was too much. If I leave the PSU off and switch it on after the wireless socket is switched on there is no problem. But, in every single case of failure the wireless plug, socket or plug-in was left in the on position. I just could not operate it wirelessly any more. It is possible that the relay in the Smart Meter will behave the same way, perhaps to prevent power loss to the consumer.
    Richard


  • That was my point, when the relay operates particularly when the current is high or when the waveform isn't clean, you get arcing, which sometimes welds the relay contacts shut. If the relay contacts get pitted you then get arcing after it's operated, same result.
    Dunno what your 40A device is/was (welder?) or perhaps you have a very powerful transmitter.
    I suppose the way forward is to use the remote switch to operate a contactor, but you already knew that.
    To date I've had relay and stat contacts welding together in an rf switch operating tv/audio relatively low load (repaired a few times now) but possible the Sub could have a fairly hefty surge on switch on, and a bathroom heater (not mine). It's a bugg*r that electrickery stuff.
    The contactor in my E7 changeover closes before the other contact opens, so no current to worry about.
    Perhaps MrSmart can tell us if the contacts in the SM are normally closed or normally open?

    Quote Originally Posted by G4RHL View Post
    My experience of relay failures, but not related to a Smart Switch, is not that power is left in the off position but the opposite. I have been through three different types of device that can be controlled wirelessly and when used for one particular item the relay failed. Not robust enough. What caused the problem was a 40 amp PSU switching on when the remote switch was operated. Nothing connected to the PSU was switched on but I am assuming that the sudden surge required to get the capacitors up to full capacity ready to do the job when called upon, happening at the same time as the wireless socket/plug-in was operated, was too much. If I leave the PSU off and switch it on after the wireless socket is switched on there is no problem. But, in every single case of failure the wireless plug, socket or plug-in was left in the on position. I just could not operate it wirelessly any more. It is possible that the relay in the Smart Meter will behave the same way, perhaps to prevent power loss to the consumer.
    Last edited by woz; 21-06-19 at 23:31.
    0
  • That was my point, when the relay operates particularly when the current is high or when the waveform isn't clean, you get arcing, which sometimes welds the relay contacts shut. If the relay contacts get pitted you then get arcing after it's operated, same result.
    Dunno what your 40A device is/was (welder?) or perhaps you have a very powerful transmitter.
    I suppose the way forward is to use the remote switch to operate a contactor, but you already knew that.
    To date I've had relay and stat contacts welding together in an rf switch operating tv/audio relatively low load (repaired a few times now) but possible the Sub could have a fairly hefty surge on switch on, and a bathroom heater (not mine). It's a bugg*r that electrickery stuff.
    The contactor in my E7 changeover closes before the other contact opens, so no current to worry about.
    Perhaps MrSmart can tell us if the contacts in the SM are normally closed or normally open?

    Quote Originally Posted by G4RHL View Post
    My experience of relay failures, but not related to a Smart Switch, is not that power is left in the off position but the opposite. I have been through three different types of device that can be controlled wirelessly and when used for one particular item the relay failed. Not robust enough. What caused the problem was a 40 amp PSU switching on when the remote switch was operated. Nothing connected to the PSU was switched on but I am assuming that the sudden surge required to get the capacitors up to full capacity ready to do the job when called upon, happening at the same time as the wireless socket/plug-in was operated, was too much. If I leave the PSU off and switch it on after the wireless socket is switched on there is no problem. But, in every single case of failure the wireless plug, socket or plug-in was left in the on position. I just could not operate it wirelessly any more. It is possible that the relay in the Smart Meter will behave the same way, perhaps to prevent power loss to the consumer.


  • My 40 amp PSU is for a transmitter to ensure a smooth 12 volt or so DC current. The full 40 watts is never needed but it’s getting “up to speed” on switch on is in time too much for the relay in smart plugs. As you say, it creates arcing and then failure. What I have found is robust enough is a LightwaveRf plug-in socket. They seem to cope OK being switched on and the PSU coming on immediately. Not the LightwaveRf wireless sockets though, the relay in those fails after a few switching on and offs with the PSU in the on position. I tend to play safe and if I remember switch off the PSU manually. The other wireless plug I know can’t cope is the Eve Elgato one but for other general use I recommend them.

    I also found that a standard fluorescent strip light operated by a LightwaveRF socket blows the relay. Due to the capacitor in the strip light needing a sudden big current draw. I no longer have any strip lights of the old sort now. What I have now where they are useful are led strips. Commented on elsewhere in this forum.
    Richard
    0
  • My 40 amp PSU is for a transmitter to ensure a smooth 12 volt or so DC current. The full 40 watts is never needed but it’s getting “up to speed” on switch on is in time too much for the relay in smart plugs. As you say, it creates arcing and then failure. What I have found is robust enough is a LightwaveRf plug-in socket. They seem to cope OK being switched on and the PSU coming on immediately. Not the LightwaveRf wireless sockets though, the relay in those fails after a few switching on and offs with the PSU in the on position. I tend to play safe and if I remember switch off the PSU manually. The other wireless plug I know can’t cope is the Eve Elgato one but for other general use I recommend them.

    I also found that a standard fluorescent strip light operated by a LightwaveRF socket blows the relay. Due to the capacitor in the strip light needing a sudden big current draw. I no longer have any strip lights of the old sort now. What I have now where they are useful are led strips. Commented on elsewhere in this forum.
    Richard


  • ha...You need a variac... I always wanted one but could never justify it.
    Re the fluoros, interesting I never thought of that being a problem but I don't think the capacitor is causing the problem, it's there to correct the power factor, BUT there is a high voltage spike as the starter operates. I suppose it depends on the ballast, but hey, most people who are using smart tech like that are unlikely to have 50 year old fluoros with spiky surgey ballasts (me being the exception as I have some in the loft!)
    Quote Originally Posted by G4RHL View Post
    My 40 amp PSU is for a transmitter to ensure a smooth 12 volt or so DC current. The full 40 watts is never needed but it’s getting “up to speed” on switch on is in time too much for the relay in smart plugs. As you say, it creates arcing and then failure. What I have found is robust enough is a LightwaveRf plug-in socket. They seem to cope OK being switched on and the PSU coming on immediately. Not the LightwaveRf wireless sockets though, the relay in those fails after a few switching on and offs with the PSU in the on position. I tend to play safe and if I remember switch off the PSU manually. The other wireless plug I know can’t cope is the Eve Elgato one but for other general use I recommend them.

    I also found that a standard fluorescent strip light operated by a LightwaveRF socket blows the relay. Due to the capacitor in the strip light needing a sudden big current draw. I no longer have any strip lights of the old sort now. What I have now where they are useful are led strips. Commented on elsewhere in this forum.
    0
  • ha...You need a variac... I always wanted one but could never justify it.
    Re the fluoros, interesting I never thought of that being a problem but I don't think the capacitor is causing the problem, it's there to correct the power factor, BUT there is a high voltage spike as the starter operates. I suppose it depends on the ballast, but hey, most people who are using smart tech like that are unlikely to have 50 year old fluoros with spiky surgey ballasts (me being the exception as I have some in the loft!)
    Quote Originally Posted by G4RHL View Post
    My 40 amp PSU is for a transmitter to ensure a smooth 12 volt or so DC current. The full 40 watts is never needed but it’s getting “up to speed” on switch on is in time too much for the relay in smart plugs. As you say, it creates arcing and then failure. What I have found is robust enough is a LightwaveRf plug-in socket. They seem to cope OK being switched on and the PSU coming on immediately. Not the LightwaveRf wireless sockets though, the relay in those fails after a few switching on and offs with the PSU in the on position. I tend to play safe and if I remember switch off the PSU manually. The other wireless plug I know can’t cope is the Eve Elgato one but for other general use I recommend them.

    I also found that a standard fluorescent strip light operated by a LightwaveRF socket blows the relay. Due to the capacitor in the strip light needing a sudden big current draw. I no longer have any strip lights of the old sort now. What I have now where they are useful are led strips. Commented on elsewhere in this forum.