Measuring Electricity Meter Usage

Hi

Does anyone know if there is such a device that will link to a serial port of a PC and report on the electricity meter reading for a domestic property?

Many thanks

Charles

Reply to
Charles
Loading thread data ...

Webcam. (USerialB)

Reply to
Ian Stirling

Yes, but they are far to dangerous for anyone to connect up. And I ain't joking.

Reply to
BigWallop

It would depend on if your meter is equiped with any radio telemetry capability to enable it to be remotely read. There is presuablably kit designed to read this. Could well be expensive though.

If not, your best bet would probably be a clamp meter with a data logging capability and a serial port, connected round one of the meter tails. That would let you log current over time. Some UPSes will log voltage over time for you as well. Given the two it would be easy enough drop the results into a spreadsheet and get power useage.

Reply to
John Rumm

On 22 Jun 2005 13:35:35 -0700,it is alleged that "Charles" spake thusly in uk.d-i-y:

Yes, I recall seeing a website about them, it depends on the type of meter how you hook it up, but none of it involves anything electrical with the meter, if I recall correctly it involved counting either the flashes of the LED on the electronic meters, or counting the times the black part of the disk went past on the old meters. It also involved blu-tack to attach the sensor :-)

However,

1) the electric company may get all fussy about something stuck to their meter, especially so now they have non-technical personnel reading the meters

2) I can't find the website now. Should have bookmarked it, dang.

3) it was highly hands on electronics and soldering and poking wires into the back of the computer's serial port, then writing your own program to do the arithmetic etc.

The general gist was quite simple in concept though, if 800 flashes of your LED on the meter = 1kwh, count the flashes, divide by 800, and Bob's a distant relative; the older style meter was more involved because of needing to 'see' the black section of the disk with a photosensor.

Anything more 'connected' to the meter than that is probably illegal, and almost certainly potentially lethal.

If you are looking at doing for a more serious reason than curiosity/easier home bookkeeping, I am sure there are data logging secondary meters available, but likely to be very expensive and require an electrician to fit, possibly with the electric company's co-operation.

Reply to
Chip

The only practical way to do this without serious expense is to get someone in electronics to make up a light sensor that can be stuck on the meter in front of the disk and read the black mark every time it passes.

A friend did this years ago and it worked quite well, he used an old tachometer and all he had to do was remove the sensor and put it on a long wire to the circuit board and then to an A/D convertor with a Basic program reading the pulses produced.

Reply to
EricP

One thing to keep in mind with solutions like this is that you are still relying on the meters measurements. If the purpose of the exercise is to validate the accuracy of the meter then this will not help. ;-)

Reply to
John Rumm

This may be what you're after:

formatting link

Reply to
Alex

That's why I was saying that these things can be to dangerous to tamper with on the mains. The only accurate way to measure what's actually going through the meter is to place probes on the input and output leads. On mains voltage, this has to be done very carefully of course.

Reply to
BigWallop

On Thu, 23 Jun 2005 09:54:39 +0100,it is alleged that Alex spake thusly in uk.d-i-y:

Reply to
Chip

That is why I suggested a clamp meter for measuring the current - no physical connection required. Again using a UPS for monitoring voltage requires no probing etc.

Reply to
John Rumm

From an ease of programming perspective, I would take it to one of the handshake lines on the serial port rather than the strobe on the parallel port these days. Under WinNT/2K/XP it is easy enough to get visibility of the status of these lines, but no as easy to peek the status of the parallel port as it was under Win9x.

Reply to
John Rumm

The voltage is easy, the clamp meter is not likely to be very accurate. However the phase angle is unknown so the energy consumption is unknown.

Reply to
Ed Sirett

formatting link

Reply to
Aaron

a "True RMS" meter helps. If the point of the exercise is to validate the accuracy of the meter though you can control the loads applied while taking your test readings - thus eliminating any reactive loads.

Reply to
John Rumm

Err, if the purpose of the exercise is to check the accuracy of the meter, a good starting point is to have an accurately known load of say 1kw at

230v. A quick check on supply voltage to apply a correction factor, and then counting the flashes or disc rotations over a period of time will have some relevance.

That's how the REC's (used to[1]) make their initial checks on meter accuracy.

[1] It's been some time since I had anything to do with metering so things might have moved on....
Reply to
The Wanderer

I can supply meters with a pulse out that can be counted.

Email me.

Alan Jones

Reply to
alan

HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.