Electricity Consumption monitoring - was Maplin Wattage & Current Meter

["Kevin Hawkins" <lists@xxxxxxx>]

Hello Neil,



            Thanks f= or the info here. Ideally what I would like to do is
have some cost effective metering on each of my fused outputs from the
distribution panel but there are a lot =96 about 15 so if there is no cost<= BR> effective means of doing this =96 meaning that the sensors had to be
attached to each output but the main control electronics was one then I
will probably go the =91feed=92 measuring route. However I would like to ge= t
both the KWHr and at any point an instantaneous power level reading ,
although perhaps for the latter a current would do. I really want to be
able to detect that a load has indeed =91come on=92 after being instructed<= BR> to do so and would therefore like resolvability to say 60W or 250ma.



            I have b= een looking at RS Components product=85



http://rswww.com/cgi-bin/bv/browse/Module.jsp?BV_SessionID=3D@@= @@097009914
0.1042206662@@@@
<http://rswww.com/cgi-bin/bv/browse/Module.jsp?BV_SessionID= =3D@@@@09700991
40.1042206662@@@@&BV_EngineID=3Dccchadchejldhhfcfngcfkmdgkldfhg.0&3= 2196594
76=3D3219659476&stockNo=3D2489017&prmstocknum=3D2489017&prodoid= =3D270839>
&BV_EngineID=3Dccchadchejldhhfcfngcfkmdgkldfhg.0&3219659476=3D32196= 59476&sto
ckNo=3D2489017&prmstocknum=3D2489017&prodoid=3D270839



            This lin= k may need a bit of cut and pasting to work ! It
looks very nice but as with all RS bits it tends to be top price but I
couldn=92t determine the manufacturer or find it elsewhere. Actually it
has more features than I need. All I really want is the pulsed output at a fairly high resolution. This seems to provide 100 pulse per KWHr =96 I would have really like 1000 pulses =96 I guess I can measure the period of<= BR> the pulses to get instantaneous power but it will not be very accurate.
A trickle load of say 2KW means 200 pulses per hour or a period of 18
seconds between pulses moving to 2060 KWHr (one light) alters the period to 17.47 S but it takes me that long to know the power has increased =96 (actually it takes me almost twice as long to get an accurate figure) so it=92s not really suitable =96 I guess I need current metering for this.


            Do you k= now of a low cost, high resolution (displayless)
product that has pulse resolution of 100 /Kwhr or better (1000/Kwhr),
preferably with integrated current transformer or direct through
connection coping to say 100A =96 although am I fused at 63 A possibly.
Any other links to products much appreciated.



            Kevin


-----Original Message-----
From: Neil Fuller [mailto:neil@xxxxxxx]
Sent: 04 January 2003 17:35
To: ukha_d@xxxxxxx Subject: Re: [ukha_d] Maplin Wattage & Current Meter



Commercially, energy consumption, monitoring and targetting is a huge
part of the BMS industry.

There are many meters available ranging from simple single phase meters
with pulse outputs all the way through to highly complicated meters
providing details of individual phase currents, voltages, power, power
factor, harmonic content etc etc!

The simple meters provide a VFC to interface to almost any BMS
controller.

It's then simply a matter of scaling the number of pulses over a fixed
time period.

Most people count the pulses in a 15 minute segment (to give
kW/15minutes) and then x4 to give kWh. This is done to provide a means
of analysing data in 15 minute segments (many commercial BMS log data at 15 minute intervals). If you count the pulses in 1 hour time increments, it will give the same answer but you can't see the change in loads
during the hour. Counting the pulses in too small a time frame does not
provide easy determination of max demand (another big concern
commercially).

Commercial meters start at around =A360 - =A370. They are normally designed=
to be panel mounted (on DIN rail) and are directly connected for up to
about 100 amps. Beyond that, CT's are used.

I've not really come accross a meter that would be suitable (read cost
effective) for sub circuits in a domestic environment and I know of
nothing (apart from the maplin jobby) for appliance level power
consumption measurement.

Using a clamp meter (CT) is OK for current measurement but does not
provide power measurement. To measure power, you also need to measure
the voltage (and the better meters take in to account the power factor
too).

If you want details of meter suppliers, post back and i'll dig out some
contacts.

Regards

Neil
  ----- Original Message -----
  From: Kevin Hawkins
  To: ukha_d@xxxxxxx
  Sent: Saturday, January 04, 2003 2:22 PM
  Subject: RE: [ukha_d] Maplin Wattage & Current Meter


  They seem like good little devices - it's a shame that the design is=
  such that the plug cable passes over the display window though. Also=
  means that mounting in sockets near to the floor is impossible.



            &nb= sp; What would be really nice is if someone could adapt these
to
  provide data out in some form (RS232 ?) and then you could use them<= BR> for
  HA electricity consumption monitoring (bearing in mind 13A max). On<= BR> that
  subject does anyone do this at the whole house level and is so how -=
  sort of looking at current transformers at the moment having just go= t
my
  electricity bill.



            &nb= sp; Kevin



  -----Original Message-----
  From: jpm.egroup1@xxxxxxx [mailto:jpm.egroup1@xxxxxxx= m]

  Sent: 03 January 2003 16:56
  To: ukha_d@xxxxxxx   Subject: [ukha_d] Maplin Wattage & Current Meter



  Bought one of these (on-line from Maplin) with a few other bits to take
  it
  over the P&P limit.  The full order arrived in two days.
  Some useful bits of functionality:

  Shows the peak wattage & the time it occurs
  You can set the cost per KWh & it will display the cost of runni= ng
  device to
  date.

  I was surprised at the results, having tried it out on a couple of   devices
  in the home office:

  *  I have a couple of old Sun 20" monitors that I use with= the PCs.
  These
  monitors do have a power saving mode.
  In normal use they consume 120W (each), in standby, they consume 40W=
  (each).
  I will now try & remember to power them down when I do not use t= hem.

  *  Laptop in docking station consumes only 38W (good).

  I suppose I ought to do dishwasher, tumble drier & washing machi= ne...
  the
  cost of using them may be surprising to me.

  Overall, seems like a good investment.


  -----Original Message-----
  From: roaming@xxxxxxx [mailto:roaming@xxxxxxx]
  Sent: 02 January 2003 14:40
  To: ukha_d@xxxxxxx   Subject: Re: [ukha_d] [OT] Plamsa purchase - on the verge....


  Thanks Doogie, and thanks Stu for reminding me of dv-depot - there w= as
  some
  reason I didn't use them when I went looking for the disc - probably=
  they
  were
  out of stock :-(

  I know you've offered me a loan of the disk before Doogie, but I
really
  want
  my
  own copy as sods law dictates that I would want to borrow it again a= s
  soon
  as I
  returned it :-/

  DV depot have it in stock, @ 28 and a bit quid, so am ordering it as=
we
  speak...

  cheers,


  Tony

  Quoting Doogie Brodie <ukhad@xxxxxxx>:

  > Mark Harrison wrote:
  >
  > > Have you got a UK source for Video Essentials?
  > >
  > > (Assuming that that IS the Joe Kane thing)
  >
  > I have seen them for sale in HMV before in the obscure section.= ...
  might
  > be worth a shot.
  >
  > /me puts it in the drive and notes that it's a 3.32GB single la= yer
  disc
  >
  > Let me know if you still can't source one.... ;)
  >
  > --
  > Doogie
  >
  >
  >
  >
  > http://www.automated= home.co.uk
  > Post message: ukha_d@xxxxxxx   > Subscribe:  ukha_d-subscribe@xxxxxxx   > Unsubscribe:  ukha_d-unsubscribe@xxxxxxx   > List owner:  ukha_d-owner@xxxxxxx   >
  > List of UKHA Groups here -
  http://gr= oups.yahoo.com/group/UKHA_Grouplists/
  >
  > Your use of Yahoo! Groups is subject to
  http://docs.yahoo.com/= info/terms/

  http://www.automatedhome.= co.uk
  Post message: ukha_d@xxxxxxx   Subscribe:  ukha_d-subscribe@xxxxxxx   Unsubscribe:  ukha_d-unsubscribe@xxxxxxx   List owner:  ukha_d-owner@xxxxxxx
  List of UKHA Groups here -
  http://gr= oups.yahoo.com/group/UKHA_Grouplists/

  Your use of Yahoo! Groups is subject to
  http://docs.yahoo.com/= info/terms/







  Yahoo! Groups Sponsor



  ADVERTISEMENT


<http://rd.yahoo.com/M=3D234081.2814790.4175286.1925585/D= =3Degroupweb/S=3D1705

041992:HM/A=3D1327985/R=3D0/*http:/ad.doubleclick.net/clk;4870024;7586687;x= ?
  http://www.ameriquestmortgage.com/welcome.html?ad=3DYahoo01>



<http://us.adserver.yahoo.com/l?M=3D234081.2814790.4175286.= 1925585/D=3Degrou
  pmail/S=3D:HM/A=3D1327985/rand=3D174518597>


  http://www.automatedhome.= co.uk
  Post message: ukha_d@xxxxxxx
  Subscribe:  ukha_d-subscribe@xxxxxxx
  Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
  List owner:  ukha_d-owner@xxxxxxx
  List of UKHA Groups here -
  http://gr= oups.yahoo.com/group/UKHA_Grouplists/

  Your use of Yahoo! Groups is subject to the Yahoo!
  <http://docs.yahoo.= com/info/terms/>  Terms of Service.



  [Non-text portions of this message have been removed]


        Yahoo! Groups Sponsor
            &nb= sp; ADVERTISEMENT
                   
      

  http://www.automatedhome.= co.uk
  Post message: ukha_d@xxxxxxx
  Subscribe:  ukha_d-subscribe@xxxxxxx
  Unsubscribe:  ukha_d-unsubscribe@xxxxxxx
  List owner:  ukha_d-owner@xxxxxxx
  List of UKHA Groups here -
http://groups.ya= hoo.com/group/UKHA_Grouplists/

  Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.=


[Non-text portions of this message have been removed]