Safe to install 2-phase Vue on 3-phase house?

[jtolio]

Hello!

Up until about thirty minutes ago, I didn’t know that one phase vs two phase vs three phase electrical systems were even something that existed.

I ordered Amazon’s top seller for energy analysis, the Emporia 16 sensor Vue 2. Excited, I followed the instructions and was puzzled when I got to the mains hookup.

Trying to follow along, I followed the instructions with the 200A CTs and put one on my red main, one on my black main, and left the white main and the unshielded ground cable alone. I connected these into the B and C ports on the Vue 2, which is as far as I can tell what the picture in the app suggested.

Then the app asked me how many 200A CTs I installed and I said 2, and so I connected in the red and black power to 15A circuits, and connected blue and white to the neutral bar.

But I have three phase power, and had I had 3 200A CTs, I should have connected blue to another 15A circuit.

First off, is what I did safe? Everything seems okay. But secondly, after having read more now it appears I’m only observing 2/3s of the current entering the house? Is that right?

I ordered another 200A CT, and I need to find another 15A short cable and screw cap, but should I disconnect what I already did until that arrives?

Thanks

[yyzguy]

Where are you located?   I believe 3 phase is almost nonexistent for residential use.   Also, it sounds like you’re not very familiar with how electrical power works, so I’m concerned you might accidentally hurt yourself.  You can get the screw cap at any hardware store and while your there find a scrap piece of  romex and use one of the insulated wires to use for the short wire.  Are you sure you have a 3 phase system?

[djwakelee]

Please post a picture of your setup and electrical panel.  Typically residential is not 3 phase.  Based on the wire coloring, it sounds like you may have this installed in a sub panel, which would be standard 120/240V.  But a picture of your electrical panel (cover off) and showing the Vue2 and hookup will help us advise you correctly.

[jtolio]

I will post a photo when I can safely shut down the panel and open it up again hopefully later today, but in the meantime, is it possible for me to get the benefit of the doubt for the original question?

To answer some questions:
* No, I did not install this in a subpanel. I do have three panels, two are subpanels, and the panel I installed this in is not one of the two subpanels.
* I am in Northern Michigan.

Assuming my description is accurate (I still believe it is), is it safe to install a 2 phase Vue on a 3 phase system the way I did? It does work the way I described it for 3 phase systems with the Sense (https://help.sense.com/hc/en-us/articles/360043157054-Learn-more-Three-phase-installation).

• This reply was modified 2 years, 3 months ago by jtolio.

[djwakelee]

Is it safe, probably.  Is it correct and will it read accurate readings – can’t say until seeing the setup.  But everything you described doesn’t sound correct.  And residential in the US is rarely 3-phase, unless a mansion.   Shouldn’t be referencing the Sense documentation – as that’s a different product from a different company.

 

 

[jtolio]

[djwakelee]

That’s standard residential split phase 120/240 – not 3 phase.  The red and black are the hots, the white is the neutral, and the un-insulated wire likely goes to a ground rod.

In this standard setup, you’ll want your mains clamps plugged into to the A and B terminals of the Vue 2.  I think you mentioned hooking up to B and C – this is incorrect.  Your power connections are a bit hard to see, but the white and blue connected to the neutral bar is correct.   The red and black wires would need to do to a double pole breaker – not two individual circuits.  If you have room in the panel this is best done with a new 15A dual pole breaker, but if not you can tie off an existing dual pole 240V circuit.  Can’t tell if you did that or not.  The online manual details those two different scenarios.

After you connect things correctly (moving the mains from B/C to A/B), you’ll need to re-run setup for the Vue 2 be configured properly.

[jtolio]

Hi! Happy to be wrong about the 2 phase vs 3 phase thing. Thanks for checking out the photo!

In terms of the rest of the details, I followed the instructions very carefully. The reason I chose B and C is because of this photo in the instructions:

 

You’ll notice that this photo is oriented with the top of the Vue at the bottom of the picture. Specifically, if you were to be looking at the back of the Vue, A is to the left and C is to the right, which means that in this picture in the instructions, two 200A CT sensors are hooked up to B and C. Since the instructions didn’t specifically specify A and B, I went with the picture. But okay, I swapped to A and B as you suggest. It appears to not matter.

In terms of connecting the red and black wires to a double pole breaker, here your advice directly contradicts the official instructions for my case (no empty breaker, two 200A CTs), see below:

Your thoughts?

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