Registering the power consuption in my house

Hello all.

I have an S7-224XP PLC that I'm planing to use for registering the power consumption in my house. The wattmeter installed has a LED that blinks 1000 times per kW. This is a red standard LED, aprox. 3 cm. behind a transparent plastic housing. The blink is quite short but also bright. This is excelent for the counting input on the PLC.

So, to my problem: I have not found a suitable reciever for this blink and also outputing a 24 volt pulse for the counting input on my PLC. (In other words convert the red blink to an 24V pulse)
Does anybody have any suggestions where I can buy such a device (photo-transistor, photo-diode)?

Regards form
Knut A. B.

http://www.marktechopto.com/Engineering%20Services/leds-drivers-displays-application-notes-detailed/leds-drivers-displays-application-notes-photo-sensor.cfm

This link might help you get where you want to be! The power company in Norway not do a good job of metering your power?

Why not buy a CT (current transformer) and put it in your service leads going into your house. Then you could have real time readings and find your peaks, fid how much certain devices draw in your houses, would be much more useful, especially considering that the meter already does what your going to do. If the meter is innaccurate then the blinking of the LED will be too!

If the meter is innaccurate then the blinking of the LED will be too!

Click to expand...

Definately!!! I would purchase soemthing like a Crompton Instruments 1534 series power monitor with a pulse output - no need even for that, the meter has kWh on board and is a class 1 device I believe. This is far more accurate than the enrgy supplier's metering normally.

Has a Modbus RTU interface as well so you can pull out all sorts of things to a PC/PLC and trend the data (small SCADA?).

The blinking LED is not going to be anymore accurate than the meter itself and you may as well save yourself some money and just read the meter if you wish to monitor the LED.

Ahh so many ideas, so many possibilities. This gave me more to think about. Is there a link to the Crompton Instruments 1534?

-But so far I have written a program for the S7-200 using a large part of the V-memory to log data, so I have a history of every hour a week back, every day-total in an month back and every week-total in a year back. This I'm going to pass through the PC-Access program so I can display the data in Excel and have a slightly better history of power consumption than the quarterly-history-bargraph I get from the power company.
Later on I plan on adding a outdoor temperature sensor for a similiar recording so I can take that in consideration for the power consumption.

I will try this aproach for now since I have all the components I need (except for the photo sensor).

This forum is an excellent source for good ideas and knowledge, I have been lurking for a while now and found many good ideas and solutions, hope I can be of help later on, as I get more experienced in using this forum.

Here is a link to a pade where you select 1530 series from a drop down box and a pdf file will automatically down load for you.

http://www.crompton-instruments.com/integra.htm