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Old 09-13-2011, 12:22 PM   #1
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Default Smart Meters

In my area, all of the electric meters are being replaced by "Smart meters". I guess they can be monitored remotely, so no more meter man.

I had a friend's new property that had no power. I checked the main, and told him the Poco probably disconnected power in the hand hole.

I learned today, that power was on to the property, and that there is a black button on the new meters that needs to be reset. The Poco probably can disconnect power remotely also.
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Old 09-13-2011, 03:03 PM   #2
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Not sure about that reset button theory, for most of the one's I've seen the button is used to scroll through the different display options (Kwh, KVA, Amps, Total Kwh, etc.) and Edison is so cheap I kinda doubt they paid extra for the remote power disconnect option.

Are you sure that you didn't simply push on the meter seating it properly? The installers up here had messed up on quite a few up here.

Finally, even with the remote disconnect option, I also seriously doubt that they would make restoration so easy....but then again....

EDIT: I'll go outside later today and take a closer look at my new smart meter..since Dronai and I have the same POCO they should be the same.

Last edited by guest; 09-13-2011 at 05:27 PM. Reason: See above
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Old 09-13-2011, 05:19 PM   #3
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The smart meter we have is kind of addicting. I keep going outside and checking my KW usage. The house draws .8 with all of the appliances and TVs off. Computers running of course, several small UPS units.

Goes up to 5kw or so when everybody is home.

I can go on line and see my usage hour by hour if I want, the data lags by two days.

Is it a benefit for me to have my voltage around 246 volts? It seems high to me and I know my water heater, as a resistive load, will draw more KW. My highest and of course year round load is my AC condenser.

Theory aside, and as a practical application, will the higher voltage reduce the kw usage of my condenser?

Just a practical application observation to open up some discussion. We are all well seasoned electricians so I don't need to hear any snide remarks.
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Old 09-13-2011, 05:25 PM   #4
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Quote:
Originally Posted by jrannis View Post
The smart meter we have is kind of addicting. I keep going outside and checking my KW usage. The house draws .8 with all of the appliances and TVs off. Computers running of course, several small UPS units.

Goes up to 5kw or so when everybody is home.

I can go on line and see my usage hour by hour if I want, the data lags by two days.

Is it a benefit for me to have my voltage around 246 volts? It seems high to me and I know my water heater, as a resistive load, will draw more KW. My highest and of course year round load is my AC condenser.

Theory aside, and as a practical application, will the higher voltage reduce the kw usage of my condenser?

Just a practical application observation to open up some discussion. We are all well seasoned electricians so I don't need to hear any snide remarks.

My understanding of how watthour meters work is that they are, to some extent, not sensitive to the voltage but rather the wattage, so I feel that the small percentage change in "efficiency" from the extra six volts would NOT translate into a tangible difference in your kwh usage.

And such a small percentage of "overvoltage" would not, IMHO, translate into the same percentage of efficiency change on your condenser.
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Old 09-13-2011, 05:59 PM   #5
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I guess a couple volts will not add up to much in a Ohm's law calculation but in a practical way is the higher voltage something healthy or unhealthy for my compressor?
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Old 09-13-2011, 06:01 PM   #6
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A poco close to me has smart meters they can turn on and off. When they reconnect you have to go out and push a button... People that forget the button look dumb when we turn it on
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Old 09-13-2011, 06:40 PM   #7
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Quote:
Originally Posted by mxslick View Post

EDIT: I'll go outside later today and take a closer look at my new smart meter..since Dronai and I have the same POCO they should be the same.
My city is split, and I have SDG&E

Quote:
Originally Posted by jrannis View Post
The smart meter we have is kind of addicting. I keep going outside and checking my KW usage. The house draws .8 with all of the appliances and TVs off. Computers running of course, several small UPS units.

Goes up to 5kw or so when everybody is home. That's pretty cool, I'll have to check mine out !

I can go on line and see my usage hour by hour if I want, the data lags by two days. Online, really

Is it a benefit for me to have my voltage around 246 volts? It seems high to me and I know my water heater, as a resistive load, will draw more KW. My highest and of course year round load is my AC condenser.

Theory aside, and as a practical application, will the higher voltage reduce the kw usage of my condenser?

Just a practical application observation to open up some discussion. We are all well seasoned electricians so I don't need to hear any snide remarks.
Quote:
Originally Posted by jrannis View Post
I guess a couple volts will not add up to much in a Ohm's law calculation but in a practical way is the higher voltage something healthy or unhealthy for my compressor?
Remember that post about lowering the voltage in New York City to save electricity ? Lower Voltage equals lower wattage. Use Ohms law for resistance and check it out.
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Old 09-13-2011, 07:29 PM   #8
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Up here they had "technicians" come by and install the new smart meters. I've gone out to a few service calls where the improperly installed meters have caused issues.

I've heard that once fully operational they can remotely turn them on/off and will send an alert out when removed.

I'm still seeing the plastic covers on these meters when the PoCo cut someones power so I guess its still not up and running.
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Old 09-13-2011, 08:04 PM   #9
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Do the smart meters let hydro know that they are removed?
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Old 09-13-2011, 09:02 PM   #10
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Quote:
Originally Posted by CanadianSparky
Do the smart meters let hydro know that they are removed?
Our
Meters send a signal every 15 minutes if they fail to signal twice an automatic service call is generated and a truck dispatched
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Old 09-13-2011, 09:22 PM   #11
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Not only do smart meters have the capability to remote disconect power but they can also sence bypasses and being tilted or removed such as in situations where tampering is taking place to steal power.
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Old 09-13-2011, 09:25 PM   #12
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you mean I can't do panel changes illegally anymore?
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Old 09-13-2011, 09:32 PM   #13
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Originally Posted by DiegoXJ View Post
Up here they had "technicians" come by and install the new smart meters. I've gone out to a few service calls where the improperly installed meters have caused issues.

I've heard that once fully operational they can remotely turn them on/off and will send an alert out when removed.

I'm still seeing the plastic covers on these meters when the PoCo cut someones power so I guess its still not up and running.
I picked up some side work with these guys. They practically ripped the meter can off the houses pulling the old meters. The guy that did my house didn't use the jumpers when he removed the meter and the spikes smoked my network adapter card. I got $600 from them for that.
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Old 09-13-2011, 11:04 PM   #14
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Quote:
Originally Posted by meadow View Post
Not only do smart meters have the capability to remote disconnect power but they can also sence bypasses and being tilted or removed such as in situations where tampering is taking place to steal power.
Ours only alarm when removed.
Quote:
Originally Posted by DiegoXJ View Post
Up here they had "technicians" come by and install the new smart meters. I've gone out to a few service calls where the improperly installed meters have caused issues.

I've heard that once fully operational they can remotely turn them on/off and will send an alert out when removed.

I'm still seeing the plastic covers on these meters when the PoCo cut someones power so I guess its still not up and running.
Yep can remotely disconnect.
Quote:
Originally Posted by mxslick View Post
Not sure about that reset button theory, for most of the one's I've seen the button is used to scroll through the different display options (Kwh, KVA, Amps, Total Kwh, etc.) and Edison is so cheap I kinda doubt they paid extra for the remote power disconnect option.

Are you sure that you didn't simply push on the meter seating it properly? The installers up here had messed up on quite a few up here.

Finally, even with the remote disconnect option, I also seriously doubt that they would make restoration so easy....but then again....

EDIT: I'll go outside later today and take a closer look at my new smart meter..since Dronai and I have the same POCO they should be the same.
Ours you can go on line and see your usage in 15min increments.
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Old 09-13-2011, 11:25 PM   #15
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Are you guys sure they have a disconnect in those smart meters? I can't imagine there is room for a 200a contactor inside
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Old 09-13-2011, 11:31 PM   #16
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Are you guys sure they have a disconnect in those smart meters? I can't imagine there is room for a 200a contactor inside
They use a set of solid-state triacs, if they have disconnect ability.
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Old 09-13-2011, 11:46 PM   #17
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Quote:
Originally Posted by randas View Post
Are you guys sure they have a disconnect in those smart meters? I can't imagine there is room for a 200a contactor inside
Yep my company has the contract to do the repairs for the southern region automatic meter upgrade in this area. I had to learn a bunch about them, customers have million questions concerning the new meters. Like mxslick said its solid state. What have trouble believing is that a meter can pass up to 550 amps.
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Old 09-14-2011, 06:10 AM   #18
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i want a meter that yells at the kids to turn stuff off.....

~CS~
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Old 09-14-2011, 06:46 AM   #19
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Quote:
Originally Posted by dronai View Post
My city is split, and I have SDG&E




Remember that post about lowering the voltage in New York City to save electricity ? Lower Voltage equals lower wattage. Use Ohms law for resistance and check it out.
I remember that post but, if voltage increases and resistance stays the same, the amperage increases.

I still need to understand how a higher voltage will effect a motor. Oh wait, how about Google..

ELECTRIC MOTORS AND VOLTAGE

The effect of low voltage on electric motors is pretty widely known and understood but, the effect of high voltage on motors is frequently misunderstood. This paper will try to describe the effects of both low and high voltage and to describe the related performance changes that can be expected when voltages other than nameplate voltages are utilized.
LOW VOLTAGE
When electric motors are subjected to voltages, below the nameplate rating, some of the characteristics will change slightly and others will change more dramatically. A basic point is, to drive a fixed mechanical load connected to the shaft, a motor must draw a fixed amount of power from the power line. The amount of power the motor draws is roughly related to the voltage times current (amps). Thus, when voltage gets low, the current must get higher to provide the same amount of power. The fact that current gets higher is not alarming unless it exceeds the nameplate current rating of the motor. When amps go above the nameplate rating, it is safe to assume that the buildup of heat within the motor will become damaging if it is left unchecked. If a motor is lightly loaded and the voltage drops, the current will increase in roughly the same proportion that the voltage decreases.
For example, a 10% voltage decrease would cause a 10% amperage increase. This would not be damaging if the motor current stays below the nameplate value. However, if a motor is heavily loaded and a voltage reduction occurs, the current would go up from a fairly high value to a new value which might be in excess of the full load rated amps. This could be damaging. It can be safely said that low voltage in itself is not a problem unless the motor amperage is pushed beyond the nameplate rating.
Aside from the possibility of over-temperature and shortened life created by low voltage, some other important items need to be understood. The first is that the starting torque, pull-up torque, and pull-out torque of induction motors, all change based on the applied voltage squared . Thus, a 10% reduction from nameplate voltage (100% to 90%, 230 volts to 207 volts) would reduce the starting torque, pull-up torque, and pull-out torque by a factor of .9 x .9. The resulting values would be 81% of the full voltage values. At 80% voltage, the result would be .8 x .8, or a value of 64% of the full voltage value.
In this case, it is easy to see why it would be difficult to start “hard-to-start” loads if the voltage happens to be low. Similarly the motor’s pull-out torque would be much lower than it would be under normal voltage conditions.
To summarize the situation, low voltage can cause high currents and overheating which will subsequently shorten motor life. Low voltage can also reduce the motor’s ability to get started and its values of pull-up and pull-out torque. On lightly loaded motors with easy-to-start loads, reducing the voltage will not have any appreciable effect except that it might help reduce the light load losses and improve the efficiency under this condition. This is the principle that is used in the so-called Nola devices that are sold as efficiency improving add-on equipment to motors.
EFFECTS OF HIGH VOLTAGE
One of the basic things that people assume is, since low voltage increases the amperage draw on motors, then by the same reasoning, high voltage would tend to reduce the amperage draw and heating of the motor. This is not the case. High voltage on a motor tends to push the magnetic portion of the motor into saturation. This causes the motor to draw excessive current in an effort to magnetize the iron beyond the point to which it can easily be magnetized. This generally means that the motors will tolerate a certain change in voltage above the design voltage but extremes above the designed voltage will cause the amperage to go up with a corresponding increase in heating and a shortening of motor life. For example, older motors were rated at 220/440 and had a tolerance band of plus/minus 10%. Thus, the voltage range that they can tolerate on the high voltage connections would be 396 to 484. Even though this is the so-called tolerance band, the best performance would occur at the rated voltage. The extreme ends, either high or low, would be putting unnecessary stress on the motor.
Generally speaking, these tolerance bands are in existence not to set a standard that can be used all the time but rather to set a range that can be used to accommodate the normal hour-to-hour swings in plant voltage. Operation on a continuous basis at either the high extreme or the low extreme will shorten the life of the motor.
Although this paper covers the effects of high and low voltage on motors, the operation of other magnetic devices are effected in similar ways. Solenoids and coils used in relays and starters are punished by high voltage more than they are by low voltage. This is also true of ballasts in fluorescent, mercury, and high pressure sodium light fixtures. Transformers of all types, including welding transformers, are punished in the same way. Incandescent lights are especially susceptible to high voltage conditions. A 5% increase in voltage results in a 50% reduction in bulb life. A 10% increase in voltage above the rating reduces incandescent bulb life by 70%.
Overall, it is definitely in the equipment’s best interest to have the utility company change the taps on incoming transformers to optimize the voltage on the plant floor to something that is very close to the equipment ratings. In older plants, some compromises may have to be made because of the differences in the standards on old motors (220/440) and the newer “T” frame standards (230/460), but a voltage in the middle of these two voltages, something like 225 or 450 volts, will generally result in the best overall performance. High voltage will always tend to reduce power factor and increase the losses in the system which results in higher operating costs for the equipment and the system.

The graph shown in Figure 1 is widely used to illustrate the general effects of high and low voltage on the performance of “T” frame motors. It is okay to use the graph to show “general” effects but, bear in mind that it represents only a single motor and there is a great deal of variation from one motor design to the next.
For example, the lowest point on the full load amp line does not always occur at 2-1/2% above rated voltage. On some motors it might occur at a point below rated voltage. Also the rise in full load amps at voltages above rated, tends to be steeper for some motor winding designs than others.
Some general guidelines might be useful.
1. Small motors tend to be more sensitive to over-voltage and saturation than large motors.
2. Single phase motors tend to be more sensitive to over-voltage than three phase motors.
3. U-frame motors are less sensitive to over-voltage than “T” frames.
4. Premium efficiency Super-E motors are less sensitive to over-voltage than standard efficiency motors.
5. Two pole and four pole motors tend to be less sensitive to high voltage than six pole and eight pole designs.
6. Over-voltage can drive up amperage and temperature even on lightly loaded motors. Thus, motor life can be shortened by high voltage.
7. Full load efficiency drops with either high or low voltage.
8. Power factor improves with lower voltage and drops sharply with high voltage.
9. Inrush current goes up with higher voltage.
SUMMARY
There are very few desirable and many undesirable things that happen to electric motors and other electrical equipment as a result of operating a power system at or near the ends of voltage limits. The best life and most efficient operation usually occurs when motors are operated at voltages close to the nameplate ratings.


Reference:
http://www.motorsanddrives.com/cowern/motorterms12.html
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Old 09-14-2011, 11:46 AM   #20
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[quote=jrannis;537054]I remember that post but, if voltage increases and resistance stays the same, the amperage increases.

I still need to understand how a higher voltage will effect a motor. Oh wait, how about Google..

ELECTRIC MOTORS AND VOLTAGE

The effect of low voltage on electric motors is pretty widely known and understood but, the effect of high voltage on motors is frequently misunderstood. This paper will try to describe the effects of both low and high voltage and to describe the related performance changes that can be expected when voltages other than nameplate voltages are utilized.
LOW VOLTAGE
When electric motors are subjected to voltages, below the nameplate rating, some of the characteristics will change slightly and others will change more dramatically. A basic point is, to drive a fixed mechanical load connected to the shaft, a motor must draw a fixed amount of power from the power line. The amount of power the motor draws is roughly related to the voltage times current (amps). Thus, when voltage gets low, the current must get higher to provide the same amount of power. The fact that current gets higher is not alarming unless it exceeds the nameplate current rating of the motor. When amps go above the nameplate rating, it is safe to assume that the buildup of heat within the motor will become damaging if it is left unchecked. If a motor is lightly loaded and the voltage drops, the current will increase in roughly the same proportion that the voltage decreases.
For example, a 10% voltage decrease would cause a 10% amperage increase. This would not be damaging if the motor current stays below the nameplate value. However, if a motor is heavily loaded and a voltage reduction occurs, the current would go up from a fairly high value to a new value which might be in excess of the full load rated amps. This could be damaging. It can be safely said that low voltage in itself is not a problem unless the motor amperage is pushed beyond the nameplate rating.

I can't find the thread but, someone pointed out using something like this example:

Formula P= E 2 /R Heater rated 2400W @ 240V R = 24ohms

@ 240V 57600/24= 2400W @230V 52900/24= 2204W

I think this applies to Resistive, and not inductive loads.
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