Smart meter causing damage to electronics?

[gar]

130517-0832 EDT

kwired:

I would agree that a power company assumes a 200 A service is unlikely to be loaded to 200 A. But in the design of equipment it is still necessary assume that that load may be present.

A solid-state switch will have a very short time constant that it can tolerate an overload. Milliseconds in some cases, seconds with moderate heatsinking, and possibly a minute with very massive and special cooling.

I don't have any reference on overloading of a mechanical contact.

In contrast transformers and motors have overload time constants that are much longer many minutes to hours.

All of these times are a function of the type of device and the criteria used in the design.

In a machine design class that I once had one question was on the design of an automotive drum brake. My design resulted in a brake shoe about 12" wide, whereas a typical brake is about 2" wide. Why the difference? Because the equation required a service factor element. I had no data (tables) on this constant for automotive service, and thus I used the only table available and that was for industrial service. Obviously quite different criteria for industrial vs automotive.

.

 

[kwired]

130517-0832 EDT

kwired:

I would agree that a power company assumes a 200 A service is unlikely to be loaded to 200 A. But in the design of equipment it is still necessary assume that that load may be present.

A solid-state switch will have a very short time constant that it can tolerate an overload. Milliseconds in some cases, seconds with moderate heatsinking, and possibly a minute with very massive and special cooling.

I don't have any reference on overloading of a mechanical contact.

In contrast transformers and motors have overload time constants that are much longer many minutes to hours.

All of these times are a function of the type of device and the criteria used in the design.

In a machine design class that I once had one question was on the design of an automotive drum brake. My design resulted in a brake shoe about 12" wide, whereas a typical brake is about 2" wide. Why the difference? Because the equation required a service factor element. I had no data (tables) on this constant for automotive service, and thus I used the only table available and that was for industrial service. Obviously quite different criteria for industrial vs automotive.

.

I was not assuming a solid state switch. I can see a contact that is rather light duty being used under the assumption that it:

1: will not be loaded to 200 amps all that frequently

2: will not be actually switching all that frequently

Both conditions would apply well to most typical residential services.

 

[GoldDigger]

I was not assuming a solid state switch. I can see a contact that is rather light duty being used under the assumption that it:

1: will not be loaded to 200 amps all that frequently

2: will not be actually switching all that frequently

Both conditions would apply well to most typical residential services.

Add one more condition, also met, just for completeness:
3. It will not be required to interrupt a fault.

 

[kwired]

Add one more condition, also met, just for completeness:
3. It will not be required to interrupt a fault.

I guess it depends on exactly what you mean here. Interrupting a fault is one thing and closing a circuit with a fault condition are not exactly the same thing, but closing that switch when there is a fault condition will not do it any good if there is a high available fault current, especially if it has a somewhat light duty contact.

 

[eHunter]

I found some additional info and specs on the smart meter.
Itron CENTRON II w/OpenWay
Specs
https://www.itron.com/na/PublishedContent/CENTRON II C2SXD.pdf

Picture of the Service Switch on Page 18
https://www.itron.com/na/PublishedContent/CENTRON II.pdf

An Itron website article described the integrated Service Switch as having the following chatacteristics:
Integrated Service Switch
> Meets ANSI C12.20 specifications
> Switch Ratings are 200 amps (Form 1S included)
> Rated for >6000 amps fault current withstand
> Rated for >2.5kV basic impulse level withstand
> Rated for 30,000 mechanical cycles under no load
> Rated for 5000 mechanical cycles under full load
> Meter remains energized and records ?zero consumption?
> Monitors load side voltage
> Load Limiting capability
> Manual arming button on meter cover
> Capability to reconnect by utility or customer interaction

 

[kwired]

I found some additional info and specs on the smart meter.
Itron CENTRON II w/OpenWay
Specs
https://www.itron.com/na/PublishedContent/CENTRON II C2SXD.pdf

Picture of the Service Switch on Page 18
https://www.itron.com/na/PublishedContent/CENTRON II.pdf

An Itron website article described the integrated Service Switch as having the following chatacteristics:
Integrated Service Switch
> Meets ANSI C12.20 specifications
> Switch Ratings are 200 amps (Form 1S included)
> Rated for >6000 amps fault current withstand
> Rated for >2.5kV basic impulse level withstand
> Rated for 30,000 mechanical cycles under no load
> Rated for 5000 mechanical cycles under full load
> Meter remains energized and records “zero consumption”
> Monitors load side voltage
> Load Limiting capability
> Manual arming button on meter cover
> Capability to reconnect by utility or customer interaction

Looks like the contact device is not much different than the tabs that plug into the meter socket. Not really intended to operate frequently at full load rating like a real contactor, and if it were to close into a fault there is good chance it will need replaced.

Even with that in mind, most POCO probably see it as an easy and inexpensive way to connect/disconnect non pay customers vs sending someone out to do connects and disconnects. Chances are they will not be operating it at anywhere near full load or closing into a fault on these type of operations, and the frequency of operating it will be once a month (at the most) and not hundreds or thousands of cycles a month or even more.

 

[eHunter]

Looks like the contact device is not much different than the tabs that plug into the meter socket. Not really intended to operate frequently at full load rating like a real contactor, and if it were to close into a fault there is good chance it will need replaced.

Even with that in mind, most POCO probably see it as an easy and inexpensive way to connect/disconnect non pay customers vs sending someone out to do connects and disconnects. Chances are they will not be operating it at anywhere near full load or closing into a fault on these type of operations, and the frequency of operating it will be once a month (at the most) and not hundreds or thousands of cycles a month or even more.

I agree. From the pictures I have seen, there is no arc barrier between the service switch contacts and the surrounding electronic PCBs.
That to me spells integrity disaster in the event of trying to close into a fault. There is no apparent protection in the meter head which leaves only the upstream poco transformer primary cutout or a conductor failure to stop a nasty situation in the meter socket and or on the side of the structure. All unsupervised by a human to call the FD.

 

[GoldDigger]

I agree. From the pictures I have seen, there is no arc barrier between the service switch contacts and the surrounding electronic PCBs.
That to me spells integrity disaster in the event of trying to close into a fault. There is no apparent protection in the meter head which leaves only the upstream poco transformer primary cutout or a conductor failure to stop a nasty situation in the meter socket and or on the side of the structure. All unsupervised by a human to call the FD.

I only have one experience with this, and the POCO central service agent, before he plugged the re-connect order in to the computer (to be sent to the meter any time in the next 60 minutes), asked whether somebody would be on site from that moment until the service had been restored. Not as good as having a POCO employee or an electrician, but enough to dial 911.

 

[hurk27]

I only have one experience with this, and the POCO central service agent, before he plugged the re-connect order in to the computer (to be sent to the meter any time in the next 60 minutes), asked whether somebody would be on site from that moment until the service had been restored. Not as good as having a POCO employee or an electrician, but enough to dial 911.

I can see another problem with storm damage that could happen when there is no one to visually check to see if all the conductors of the service drop are intact, I bring this up because we had a case where the line man restored power to a house that had a pulled apart neutral at the service head from storm damage, the pole the drop came from had to be replaced but the houses drop was still intact except for the neutral, they never looked at the house side and just reconnected the supply end of the drop which fried much of the homeowners electronics as well as the smoke detectors and GFCI's, I can see this happening more often where no one will be there to check the drops at houses before the power is restored.

Of course it would still happen if the neutral was pulled apart if the power was still on, but in this case the whole area was already out of power when the damage happened on this block and the wife was home at the time the pole was replaced and when they restored the power she freaked out when all the smoke started coming out of all these appliances. the house next door was worse as not only was the neutral pulled apart, the hots were shorted in the meter housing because the lugs broke off and caught fire as it burned free, one conductor was left touching the meter housing or riser pipe which heated up all the grounding in the house and the home owner was electrocuted when he went to grab the hose bib to put water on the burning meter housing, he survived but was in the hospital for a few days.

 

[jumper]

I can see another problem with storm damage that could happen when there is no one to visually check to see if all the conductors of the service drop are intact, I bring this up because we had a case where the line man restored power to a house that had a pulled apart neutral at the service head from storm damage, the pole the drop came from had to be replaced but the houses drop was still intact except for the neutral, they never looked at the house side and just reconnected the supply end of the drop which fried much of the homeowners electronics as well as the smoke detectors and GFCI's, I can see this happening more often where no one will be there to check the drops at houses before the power is restored.

Of course it would still happen if the neutral was pulled apart if the power was still on, but in this case the whole area was already out of power when the damage happened on this block and the wife was home at the time the pole was replaced and when they restored the power she freaked out when all the smoke started coming out of all these appliances. the house next door was worse as not only was the neutral pulled apart, the hots were shorted in the meter housing because the lugs broke off and caught fire as it burned free, one conductor was left touching the meter housing or riser pipe which heated up all the grounding in the house and the home owner was electrocuted when he went to grab the hose bib to put water on the burning meter housing, he survived but was in the hospital for a few days.

Er, Wayne-I am pretty sure no one survives electrocution. Maybe getting shocked perhaps.

 

[ATSman]

Some bedtime reading:

https://en.wikipedia.org/wiki/Smart_meter

 

[gar]

130520-1506 EDT

The wiki reference said nothing about the contactor.

Said little about complaints.

Thus, I entered the following search string
what are the know causes of smart meter fires
and this lead me to
http://emfsafetynetwork.org/?page_id=1280
and then to
http://emfsafetynetwork.org/?p=9013

Quite clearly there is a neutral problem when the smart meter is installed or the story is incomplete or inaccurate.

If the story is accurate, then both the power company and the electrician were incompetent.

Assuming the story is correct, then why is there a neutral problem when only a smart meter is installed and not when the electro-mechanical meter is installed.

Is it possible that the neutral passes thru the meter and that the smart meters did not have a neutral coupling bar or if one was present that it had a high impedance?

I have a smart meter (bolt on) and a meter base for a bolt on meter. I have no meter problems, and I believe the meter includes a contactor. Also have learned I am probably on a mesh network. So far I have not set up to measure when RF radiation occurs and the duration. I am told it is some time after midnight. Before the meter was installed I made some loaded voltage change measurements. After the smart meter was installed the experiment was repeated and there was no significant difference. My meter base does not route neutral thru the meter.

One can make effective use of smart meter data to reduce your electrical energy use, and possible by a large amount. But one has to make life style changes. One of which is to turn unused items off when not in use.

I am presently working on a set of notes to help users use their DTE Energy Smart Meter data to help reduce their bill.

.

 

[GoldDigger]

Quite clearly there is a neutral problem when the smart meter is installed or the story is incomplete or inaccurate.

If the story is accurate, then both the power company and the electrician were incompetent.

Assuming the story is correct, then why is there a neutral problem when only a smart meter is installed and not when the electro-mechanical meter is installed.

Is it possible that the neutral passes thru the meter and that the smart meters did not have a neutral coupling bar or if one was present that it had a high impedance?

Only a small number of the anecdotal incident reports had enough information to clearly identify the problem. But there seem to be three categories they fall into and the smart meters are taking the blame.

1. Old meter bases are failing when the meter was replaced. This might have happened even when replacing an analog meter with a new analog meter.

2. Old wiring to the meter base is defective and the disturbance caused by replacing the meter may have disturbed a loose contact or an insulation flaw.

3. The symptoms seem to include those we associate with a faulty neutral, that is surges of voltage, possibly associated with unseen motor loads turning on and off. Of the many reported incidents of this type in the list, only one of them seems to have been substantiated by swapping back and forth between analog and digital meters. The rest might actually have fallen into categories 1 or 2, given that the meter does have a connection to the neutral and other wiring to that connection could have been disturbed.
Another possibility in this particular subset may be cases where the defective neutral's function was somehow being taken over by a bond made by the original metal meter housing and collar, and the plastic shell of the new meter could not do that. Just a WAG based on logical analysis.

 

[hurk27]

Ok guys, since when does a 120/240 single phase meter base (found on almost all dwellings) have any connection from the meter to the neutral, all the ones I have seen including the old A bases only have 4 stabs or jaws which only connected the incoming hots to the outgoing hots that go to the service disconnect, the neutral does not connect to the meter, they are installing smart meters around here and they do not change the base in any way, I have pulled many of these smart meters and they plug in just like the old meters and do not have any connection to the neutral?, here if we are a contractor on our utility's list who has been certified we can pull the meter as long as we call it in when we pull it and when we re-install it.

About the only meters here that have a neutral connection are the 5 jaw (grounded B 3-phase) and the 7 jaw 208/120 3-phase services, these would have a demand meter installed in them and most have been digital for the last 20 years that I can remember.

 

[kwired]

130520-1506 EDT

The wiki reference said nothing about the contactor.

Said little about complaints.

Thus, I entered the following search string
what are the know causes of smart meter fires
and this lead me to
http://emfsafetynetwork.org/?page_id=1280
and then to
http://emfsafetynetwork.org/?p=9013

Quite clearly there is a neutral problem when the smart meter is installed or the story is incomplete or inaccurate.

If the story is accurate, then both the power company and the electrician were incompetent.

Assuming the story is correct, then why is there a neutral problem when only a smart meter is installed and not when the electro-mechanical meter is installed.

Is it possible that the neutral passes thru the meter and that the smart meters did not have a neutral coupling bar or if one was present that it had a high impedance?

I have a smart meter (bolt on) and a meter base for a bolt on meter. I have no meter problems, and I believe the meter includes a contactor. Also have learned I am probably on a mesh network. So far I have not set up to measure when RF radiation occurs and the duration. I am told it is some time after midnight. Before the meter was installed I made some loaded voltage change measurements. After the smart meter was installed the experiment was repeated and there was no significant difference. My meter base does not route neutral thru the meter.

One can make effective use of smart meter data to reduce your electrical energy use, and possible by a large amount. But one has to make life style changes. One of which is to turn unused items off when not in use.

I am presently working on a set of notes to help users use their DTE Energy Smart Meter data to help reduce their bill.

.

Don't pay your bill, then you will get an opportunity to see what happens when they operate the contactor:happyyes:

About the only meters here that have a neutral connection are the 5 jaw (grounded B 3-phase) and the 7 jaw 208/120 3-phase services, these would have a demand meter installed in them and most have been digital for the last 20 years that I can remember.

A corner grounded delta system doesn't have a neutral to connect to:?

I have seen 5th jaw used on 208/120 where only two phases and the neutral are used.

 

[hurk27]

Don't pay your bill, then you will get an opportunity to see what happens when they operate the contactor:happyyes:

A corner grounded delta system doesn't have a neutral to connect to:?

I have seen 5th jaw used on 208/120 where only two phases and the neutral are used.

Ya got ta Get technical on me:rant:

Just kidding, I should have said grounded conductor but neutral is allot less typing:happyyes:

I have never seen a 5 jaw used on a WYE how can they possably caculate the third phase if it is not run through the meter for current, the 5th jaw does not give the meter any current on the neutral and is only for voltage referance, if this is the case you could use that third phase for line to neutral loads and the current would never be recorded:?

It works for a grounded B because you don't need the grounded conductor run through the meter, just what the voltage is at from the phase conductors to the B phase as any current on the B phase will be also summed on the other two conductors with a WYE 208/120 or 480/277 the meter would have to see the current in all three phases and just the voltage to the neutral from any phase, but without all three phases passing through the meter like I said, someone is getting off cheap as any line to neutral loads on the un metered phase will not be recorded.

If that is what you did see, then someone messed up and the utility didn't catch it, they will some day and well it will be a mess trying to figure out how to back charge for it, although if there are no line to neutral loads on that phase then all is well.

 

[kwired]

Ya got ta Get technical on me:rant:

Just kidding, I should have said grounded conductor but neutral is allot less typing:happyyes:

I have never seen a 5 jaw used on a WYE how can they possably caculate the third phase if it is not run through the meter for current, the 5th jaw does not give the meter any current on the neutral and is only for voltage referance, if this is the case you could use that third phase for line to neutral loads and the current would never be recorded:?

It works for a grounded B because you don't need the grounded conductor run through the meter, just what the voltage is at from the phase conductors to the B phase as any current on the B phase will be also summed on the other two conductors with a WYE 208/120 or 480/277 the meter would have to see the current in all three phases and just the voltage to the neutral from any phase, but without all three phases passing through the meter like I said, someone is getting off cheap as any line to neutral loads on the un metered phase will not be recorded.

If that is what you did see, then someone messed up and the utility didn't catch it, they will some day and well it will be a mess trying to figure out how to back charge for it, although if there are no line to neutral loads on that phase then all is well.

What I have seen is single phase meter with 5th jaw (neutral) used when the supply is two phase conductors and neutral conductor from a 208/120 Y. I don't know exactly how the meter works or if the neutral is needed to make it work. It was just a fifth jaw for reference and the neutral was not interrupted in any way by pulling the meter. The application was three phase supply to meter bank with single phase run to each tenant. POCO requested us to supply meter sockets with fifth jaw, but I don't know for certain that the meters actually used the fifth jaw.

 

[hurk27]

What I have seen is single phase meter with 5th jaw (neutral) used when the supply is two phase conductors and neutral conductor from a 208/120 Y. I don't know exactly how the meter works or if the neutral is needed to make it work. It was just a fifth jaw for reference and the neutral was not interrupted in any way by pulling the meter. The application was three phase supply to meter bank with single phase run to each tenant. POCO requested us to supply meter sockets with fifth jaw, but I don't know for certain that the meters actually used the fifth jaw.

That is a new one on me? I have set 208/120 volt services with single phase meters for each apartment but I used just regular 4 jaw meters and our utility never said a word? wonder if they used some kind of jumpers from their meters 5th stab to the neutral and just never said anything to us? these were 3 separate meter stacks with 16 meters in each stack each stack was fed from two of the three phase with all three stacks balanced across the phases, I would think it would be kind of hard to find meter stacks with 5 jaw meter bases in them? custom made I would suppose?

Wonder if it is because the neutral is always current carrying in a 4-wire WYE system? or is because of the WYE the meter must know the voltage of line to neutral to get an accurate reading?, I was told one time that the reason they needed the voltage info from the grounded phase of a corner grounded delta was the meter had to figure the KWH used with this info from the other two phase to know how much the load was on the grounded phase, so it might be something with a Polly phase system that at least the voltage of the phase that doesn't pass through the meter must be known to accurately figure the KWH's?

 

[kwired]

That is a new one on me? I have set 208/120 volt services with single phase meters for each apartment but I used just regular 4 jaw meters and our utility never said a word? wonder if they used some kind of jumpers from their meters 5th stab to the neutral and just never said anything to us? these were 3 separate meter stacks with 16 meters in each stack each stack was fed from two of the three phase with all three stacks balanced across the phases, I would think it would be kind of hard to find meter stacks with 5 jaw meter bases in them? custom made I would suppose?

Wonder if it is because the neutral is always current carrying in a 4-wire WYE system? or is because of the WYE the meter must know the voltage of line to neutral to get an accurate reading?, I was told one time that the reason they needed the voltage info from the grounded phase of a corner grounded delta was the meter had to figure the KWH used with this info from the other two phase to know how much the load was on the grounded phase, so it might be something with a Polly phase system that at least the voltage of the phase that doesn't pass through the meter must be known to accurately figure the KWH's?

I don't know a lot about meters, but I kind of assumed some of what you mentioned. Seems if you plugged a standard 240 volt meter into a socket supplied with two phases of a 208 system you could encounter inaccurate metering - especially inaccurate metering of 120 volt loads.

The meter sockets I had used were Square D - don't remember specifically which series but you just put another code letter in the catalog number to specify the fifth jaw.

 

[Sahib]

If the electronic devices were fed through a working UPS, they could not be damaged by any over voltages caused by break in upstream neutral. For the UPS would have tripped under such condition.
Dim and bright lights would have readily indicated neutral break condition but this was not mentioned by the OP.
Nor the tripping of the UPS feeding the electronic devices not damaged was reported by the OP.....