RS1500 detecting no voltage when power still on

[Anonymous user]

Ever since the power company upgraded my electrical and gas meters to Smart Meters, my RS1500 will detect a no-voltage condition while everything else in the house remains powered. At first, I thought it was just dirty power since it had the classic brief click/beep pattern to it. I reset the sensitivity of the unit with no luck. I then noticed that this occurs at very regular times of day, so I was able to grab the voltage info during these events twice this weekend. Both times, it said the current voltage was 0 volts but nothing else in the house so much as flickered. Checking the voltage at other times when the UPS is fine returns 119 to 121 volts, which is pretty much expected.

I suspect it is related to the Smart Meters calling home. If you are not familiar with them, basically Smart Meters have the capability to transmit usage data back to the power company at regular intervals. The Smart Meters installed at my home are using radio waves for sending their data. I do not know the frequency that they use other than it is the same frequency used by Casablanca remote controlled ceiling fans. I had the power company out on Thursday and they said the voltage on the line was fine, although they did not come out during one of the problem times like I asked. At this point, I suspect that either the Smart Meters are either a) causing dirty power even though they don't transmit data over the power lines or b) causing RF interference that is causing the RS1500 to mistakenly detect a "power out" event.

Has anyone experienced this? Or is there an electrical engineer out there who might be able to theorize why the Smart Meter would make the RS1500 thinks there is 0 volts when there is indeed power? I'm still trying to get the power company to step up and take responsibility for this problem, but it would help to have a better idea of what is happening in the first place. Right now, the only problem with the Smart Meters that they will acknowledge is that it operates on the same frequency as the Casablanca ceiling fans.

[BillP]

that is quite interesting. i am eager to also see what you find out. i wasnt aware of these "smart meters."

[Anonymous user]

I've done some more digging today and it seems the power company person from Thursday was somewhat mistaken about the Smart Meters. The gas meter does indeed use radio frequencies (450-470MHz) to transmit its data. However, the electric meter uses the TWACS protocol for data over power lines to transmit its data. I would chalk this all up to dirty power caused by the electric meter except that still doesn't explain why, when queried, the UPS says it is detecting 0 volts on the line during these events. I would expect to see high or low voltage spikes during a data over the power line transmission, but not 0 volts. Is there some modulation the TWACS unit might be doing that would fool the UPS into thinking the power had gone out?

[voidstar_apc]

I can't say anything definitive without testing the UPS with a TWACS energy meter.

In general, in order to determine the AC voltage, the UPS has to determine the frequency and phase of the input line. To do that, the UPS looks at the zero crossings where the voltage goes positive to negative or negative to positive.

Coincidentally, from what I can find online, it looks like TWACS modulates the line near the zero crossing.

[Anonymous user]

Can you log the voltage over time using PowerChute? It is possible the power line carrier is interfering with the UPS' detection. If it seems very cyclical, then the meter is likely the blame.

[Anonymous user · Accepted solution]

I have it set up to query the UPS on each on-battery event and log the results now. The logs show mostly 0 volts during the events, although occasionally it shows normal voltage (119-121V) but still "onbatt" status. I suspect the later occurs when the event is so brief that by the time the query is processed, it is over and the voltage is back to normal. The UPS does not have time to get through the whole click, 4 beep sequence of a normal power outage during most of these events because they are so brief.

Edited to add this paragraph: I also have it set up to log the voltage every 5 minutes. Those logs show a consistent voltage of 118-122V for the last 4 days (when I started that log). So far, no event has coincided with this every 5 minute logging.

Voidstar, is there any specific sort of testing to do to see if it is the meter? My dad works in the hardware side of computers (I'm purely a software/security person), so I can run over to his place over the weekend and borrow some of his tools to test the outlet. I just have no clue what to look for.

Message was edited by: Shwaine