Archived Forum

Can you explain what you mean exactly by that?

The emonPi requires a power supply to operate. That supply is often protected by a circuit breaker.

If you want to measure electrical energy, it needs some means of monitoring current and, usually - for decent accuracy, voltage. Where on your system you measure the voltage is largely immaterial. Where you measure the current or currents is of paramount importance, because you can measure only the current flowing in the wire at the point where a current transformer is located. Current that is drawn off upstream doesn't get measured. The wire that the current transformer sits on is often protected by a circuit breaker too.

You might want to look at the Building Blocks article about using the emonTx in North America.

Hello Robert,

Thank you for the prompt response. Basically what I am wondering is do I need an electrician to install or can I install this myself, especially in the US

Basically what I am wondering is do I need an electrician to install or can I install this myself, especially in the US

Hi Justin,

If you're in the US, you'll need to check with your AHJ. That's the Authority Having Jurisdiction. That might be the City, or County you live in, the energy provider, etc. As a general rule, any work done inside a load center (circuit breaker panel) needs to be done by a licensed electrician. Your AHJ can give you the details regarding that requirement.

Regards,

Bill

Thanks Bill. I guess what I am wondering is does the EmonTx require some type of interaction with the circuit breaker or is there a work around solution so I can monitor the same current flow without touching the circuit breaker? Ideally, I would like to install this myself and not have to deal with an electrician. 

If you have access to a single-core cable carrying the current to be measured, then as there is no galvanic connection to the cable, you should be able to install it yourself (you can take the voltage from any nearby convenient socket outlet). If you can only get to a two- or three-core cable, the CT won't work as it must be on a single wire.

I've uploaded images which might make it easier to help us. We watched the video and found that the CT sensor can clamp onto the bottom of the breaker, shown in the video. Do you see something analogous in these images or compatible? We were hoping one of these wires ontop of the breaker is a place where we can put the clamps on.

Additionally, for the gateway device do you guys have range information and is it programmable? Apologies if this information is readily available; we are having trouble finding it.

As you can see, we currently have a TED installed, but we do not want to have to go into the circuit breaker, which was the case here. Let me know your thoughts. 

Thanks so far for your prompt responses. I appreciate your attention to this. This is an ideal and great product you guys have here, we just want to ensure it can be used in the US on this breaker and other breakers as well. 

Thanks,

Justin

Justin,

When you say "circuit breaker" are you referring to the circuit breaker panel, or an individual circuit breaker?

Do you want to monitor your whole house, just a few circuits, or many/all circuits individually?

Although the idea behind OEM is whole-house monitoring, the emonTX, version 3.4 could be used to monitor the whole house and two branch circuits, or four branch circuits if whole-house monitoring is not needed.

If whole-house monitoring is what you want to do, then your CTs must be attached to the main feed, which is usually done in the circuit breaker panel. (perhaps this was what you were asking about?) The CTs don't have to be attached to the main feed in the breaker panel, but as the National Electrical Code requires wiring to be in conduit, the breaker panel is usually the easier choice.

Your picture shows jacketed branch feeders and flexible armored cable. As Robert has mentioned, the Current Transformer (CT) must be placed around only one conductor of each branch circuit. (either hot or neutral, but not both) Since since the circuits shown in your picture are jacketed or armored, i.e. not possible to break out just one conductor, you won't be able to attach your CTs to the wires at that particular location.

We watched the video and found that the CT sensor can clamp onto the bottom of the breaker, shown in the video.

What video did you watch? You say the video mentions a CT on the "bottom of the breaker."  Was the video one you could post a link to? I'd like to take a look at it if I could.