Euronet 50-50max

(Sorry for my english... Google translator, with minor corrections, and sure, major mistakes)

Greetings from Navarra. First of all introduce myself, I am part of a nonprofit association that promotes sustainability projects, energy saving and environmental protection. We are considering proposing several municipalities and schools in our area the implementation of the Euronet system max 50-50 (, our idea was complemented with a system for monitoring power consumption in schools, to detect any unnecessary applications. So we have analyzed different systems, some proprietaries and OEM. We like the idea of ​​using OEM, being open source, so that if necessary make an adaptation could be made, and can publish so that everyone will benefit, but we have several doubts, we'd like us aclararas (power user ).

1. Are you really prepared OEM for use in this project? (Most of the facilities are going to be three phase.

2nd. Detectors and sensors work well ??

3rd. It boils down to ... if you were us Do OEM would use for this project ??

Opps ... I forgot ... you can find us at:

If you want my email address is:

Robert Wall's picture

Re: Euronet 50-50max

[The post above was originally sent to me as a PM, however it is more appropriate as a forum discussion.]

The easy answers:

1. In the UK, where the OEM project is based, we generally only have a single phase supply for domestic consumers. Therefore the projects and the modules sold in the OEM Shop are principally intended for single phase use. However, many users have reported that it is possible to have reasonably accurate measurements of a three phase supply.

2. There are no problems at all with the ac adapter when used as a voltage sensor. The standard current transformer is reasonably accurate down to about 2% (2 A) but inaccuracies increase below that. You can buy better (and so more costly) current transformers. Optical sensors might not work well in bright light.

3. I do not know enough about what you want to do to be able to answer that. Your website says "50/50 empowers pupils to learn about energy and become energy smart." A proprietary system (that only provides you with energy readings) will enable you to do that, but it might not help you to teach the pupils how that data is collected and analysed. I think that an Open Source solution would be a very powerful tool for the pupils to learn both aspects.

helianto's picture

Re: Euronet 50-50max

The point is that some group members suggest the use of a tool like so we have 2 questions :

1 . We can use openenergymonitor simple way to measure current of three phases ?

2nd . The cost of the system ( it is not clear what to buy for measurement in this case) .

Robert Wall's picture

Re: Euronet 50-50max

I do not have detailed knowledge of those Efergy units, so I cannot comment on those particular ones. However, I know that older Efergy monitors only measured current, therefore they could only produce an estimate of real power and energy given assumptions for the voltage of the supply and the power factor of the load.

The emonTx does measure the voltage of one phase, so provided that the voltage balance between the three phases is good, it will give a good measurement of real power, apparent power and current for each phase, and the voltage. You will need to load a 3-phase sketch into your emonTx.

The Emon system is very flexible, so how much it will cost depends very much on what you want to do. The system is split into four sections: the sensors & measurement, transmitting the data, storing the data and displaying the data. The emonTx can accept voltage, current and pulse inputs and transmit the data either with a (short) serial connection or by radio. The serial connection or the radio signal is received by the emonBase (a Raspberry Pi with a radio module if required), and then sent to a web server running emonCMS. The server can be the Raspberry Pi (therefore the data is stored on an internal SD card or a connected hard disc), or it can be another computer on the LAN or elsewhere on the WWW.

Therefore, the minimum you will probably need is:
An emonTx V3
an AC adapter to power the emonTx and simultaneously monitor the voltage,
3 CTs (You can have 4 in total.)

You’ll need a programmer, to re-program the emonTx. I strongly recommend a
USB extension lead to use with the programmer

To record the data and be able to view it on-line, you need to add
a Raspberry Pi with a RFM69Pi board to receive the data from the emonTx,
or instead of those two items, a emonPi.

a 5 V USB adapter,
a power cable,
an Ethernet patch cable into your router - not available in the shop - or a WiFi adapter.

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