Re: Have power usage data - now what (Excel question ?)

["David Chapman" <david@xxxxxxxxxx>]

Thanks for the Excel info, I'm going to need to work out how to split the
file into days as the time cycles back to 00:00 but should be able to. It
would be great if I could run the Mastech acquisition software from a
command line (so I could script it) but it doesn't do that.

Re the setup. I've got a 10 quid clamp meter from Ebay (Can't remember the
make - tiger chicken or something similar!) Break the clamp part off and
put
it round the main positive feed into the consumer unit - mine is actually
in
the meter box as it was easier. I then extend it back to the clamp meter
with thin screened cable (doesn't affect the accuracy) I then route the
screened cable through a Mastech MAS-345 meter. This meter has RS232 output
which I send (down CAT5 for 20 metres) to my PC. The software with the
meter
isn't great but outputs as a .csv for Excel. All works fine. Both meters
are
run from a single 9v PSU with a couple off PP3 clips on the output.

The MAS-345 reads current in the loop (AC 400ma scale) typically shows 1ma
when house is using 20amps. The actual value doesn't matter as it appears
to
be linear so I just use a fixed value in Excel as a multiplier to show real
amps and calibrate this using a few appliances I've measured with an
accurate Digital multimeter.

The clamp meters are easy to get, the MAS-345 was sold by Maplin last year
and there were loads on Ebay but a quick search doesn't show any at the
moment, it may be there is a replacement that does the same job.

Hope that helps.

David C