www.brultech.com

I started to look at a power meter solution first when we put our solar in but now that we are installing a (50a) car charger, I really got interested in seeing the breakdown of my power coming in, going out and used by the car

My Setup:
200A panel
60A 240v double breaker for our AC (warm in Arizona)
50A 240v double breaker for the car charger
50A 240v double breaker for the Stove
50A 240v double breaker for the Dryer
??A 240v double breaker for Incoming Solar (I will have to check on the breaker size)

I would like to track all these with one ECM-1240 and a Dashbox.

I am a little confused about how many CTs I need for the above. I read the piece about balance and unbalanced 240 but I am not quite sure I understood.

Also, is there any downside to using larger CTs than the load requires? Will they be less accurate?

My guess is that I will need
2*200A split CTs
10*80A core CTs
ECM-1240
Dashbox

And that I will require a power source for the Dashbox (outlet) as well as an Ethernet Connection to it. I also assumed the serial cable that comes with the Dashboard to be pretty short so the 1240 and Dashbox will have to be mounted relatively close (next to the breaker panel).

Could you please verify all this for me and tell me what the best/cheapest options is to purchase this (package vs. individual items)?
Any help is very much appreciated.

Thanks,
Rob

Rob,

A balanced 240 load circuit will have only 3 wires. Two wires are insulated (usually black and red or black and white) and the 3rd is a bare copper wire that serves as ground. Water heaters, stoves and dryers are typically balanced. If the cable supplying the appliance has 4 wires, the additional wire is a neutral, and would typically be considered an unbalanced load.

With all that, there is no harm at all with using 2 CT's on a balanced circuit, personally myself, I chose to use 2 CT's for each 240v circuit.

The micro 80 CT's are rate at typically better that 1.5% accuracy, the micro 100's are rated at 1% One consideration if using the 100's instead of the 80's is that the 100's are physically larger than the 80's. At the same time, they will accommodate a larger gauge of wire than the 80's will.

The Dashbox comes with it's own wall wart for power. You'll need a total of 3 receptacles, one for the dashbox, one for the ECM-1240 and one for the potential transformer. And you assumed correctly that the serial cable is relatively short and that the dashbox will need to mounted close to the ECM-1240.

I'm sure that Teken or Ben will be along to add to this.

Hi rlcrook,

Thank you for the quick response. I figured the Dahbox had a power adapter and I now guess the 1240 has its own adapter (requiring two outlets). You mentioned three outlets and a transformer. What would this be?

As to the CTs. I guess I should at least get one set of 100a as the car charger can take this amount even though we are only going to use it at 50a for now.

I understand the 100a CTs are a little bigger and probably harder to fit in the electric panel but they would be very "loose" around the wire. Would this not cause problems getting a good reading from them?

And as I am thinking about this more, I assume the CTs have a direction to them and that I need to make sure they are mounted correctly on my solar feed.

Can anyone from Brultech give me an idea of the turn around time?

Thanks for reviewing this. I am looking forward to getting this up and running

Rob

gjunky wrote:Hi rlcrook,

Thank you for the quick response. I figured the Dahbox had a power adapter and I now guess the 1240 has its own adapter (requiring two outlets). You mentioned three outlets and a transformer. What would this be?

As to the CTs. I guess I should at least get one set of 100a as the car charger can take this amount even though we are only going to use it at 50a for now.

I understand the 100a CTs are a little bigger and probably harder to fit in the electric panel but they would be very "loose" around the wire. Would this not cause problems getting a good reading from them?

And as I am thinking about this more, I assume the CTs have a direction to them and that I need to make sure they are mounted correctly on my solar feed.

Can anyone from Brultech give me an idea of the turn around time?

Thanks for reviewing this. I am looking forward to getting this up and running

Rob

Hello Rob,

The third transformer is called the PT (Potential Transformer) this is what allows the ECM-1240 to measure and know the line voltage coming into the home from the POCO.

The CT will have no problem measuring the voltage / current from the wires at all.

I sent an email to Sales to see how I can order this. There is a package #1 which is a bit cheaper than buying the individual parts but there doesn't seem to be a way to actually purchase it.