Newbie - 220 Volts single phase

Hello, my name and is Alexander and I’m from Chile. I have been a Sense user for 3 weeks. The truth is that I bought the product without being sure that it would work on my single phase 220 Volts network.

Well, after several attempts with different connection options, the device began to work. I am attaching an image of the connection that is currently working. The first few days I was able to identify that the consumption readings were quite accurate. After a few days I realized that the device had not completed the calibration so I requested help to support team who responded very quickly and completed the calibration remotely. In recent days I realized that the energy totalizer was not correctly adding consumption in some cases, especially in abrupt increases in consumption such as the hair dryer, for example. Instead of adding up to 2000 watts, the totalizer metric shows an increase of about twice the consumption. I reported the problem to support, but this time I wasn’t so lucky anymore.
My fear became concrete, Sense does not have compatibility with 220 Volts networks in a single phase and i was



informed me that unfortunately there is no international support yet. Even so, I am very satisfied with the insights that I have identified through Sense and while I hope that at some point the compatibility that I require will be enabled, I would like to ask you if any member of the forum has any situation similar to mine and has resolved it in any way. I appreciate in advance any help or tip. Regards.

Two thoughts.

  1. If your house is only using a single phase, unlike the US split-phase, you should only be using a single CT. The CT on your neutral is essentially doubling your current and power. I’m guessing that now that you are finished with setup, you could remove one of the CTs from a wire and leave it empty. Before you do that, you might want to share a screenshot of you Settings > My Home > Monitor > Signals information to confirm that’s what is happening.

  2. Not sure of your math using the tagged power transitions, but I wouldn’t use those as a reference for usage. Better to use the whole house usage (Sense Power Meter) vs. your meter if possible.

Hi Kevin, thanks for your answer. Attached requested screen capture.

Agree about using whole house usage instead graph totalizer.

I appreciate if you can confirm that the signals displayed are within the expected ranges.

Thanks again for your help.

Alexander Cepeda R.

@arlequin71, this view confirms my theory. Sense is built and reports on split-phases - that’s what you see in the two Mains and Voltage columns. In the US both the Voltage columns would be close to 120V, but not necessarily the same. The Mains would show the power used by each phase - they could be close if the house load is well balanced or very different if you are using a large load on just one phase/leg.

You are seeing the same exact Voltage and Mains on each phase, though you really only have a single phase. Unless Sense did something to cut the number in half, your Sense is showing double power.

Ok @kevin1 then the option here is to disconnect one of CT’s isn’t it?

Yes - that’s what I would suggest. Probably take it off of the Neutral wire ? Then take a look at the Signals section again.

Ok, this is how it looks by disconnecting one CT.

The numbers make sense :wink:

That should be your real single-phase usage. Time to start comparing against your meter. Not sure how that looks in Chile, but different techniques you can use in the US.

@kevin1 i just repeated the test with the hair dryer and now the total sum is consistent with the chart values as shown in the attached image.

Thanks so much for your help i really appreciate it.

As you recommended now I’m able to start comparison against the energy provider measurement.

Regards.

Alexander Cepeda R.

1 Like

Suggestion:
I think you should try to create a “virtual” split phase system to let sense work.

L1 ----[RESISTOR]--------[VIRTUAL NEUTRAL FOR SENSE WHITE WIRE]-------[RESISTOR]-------NEUTRAL

That would divide the 240 volt in 2 x 120 volt.
The sense would see all usage on both phases all the time and this should take care [TM famous last words] of the double counting.
Now to the value of the resistors: i would try 2 x 220k ohm resistors.
Each resistor would dissipate about 0.065 watt.
A “normal” resistor is able to dissipate 0.25 watt so we should be within safety rules
Everything will carry lethal voltages so put it in a well protected box, away from accidental touching with big warning signs on it!

No guarantees this will work but this has a good change or working.
This make the sense see all your loads as 240 volt which is correct and use both CT’s to measure the exact same signal.

Interesting approach, thanks @dannyterhaar i would try it if after my analysis i detected relevant inconsistencies. Thanks for your advicice.