The Signals section is a bit hidden under Settings > System, near the bottom, but it’s a great tool to better understand what’s going on with your Sense Monitor and your home. A few things to know:
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Closest to the Details Inside Your Monitor - The Signals section contains the most detailed real-time results streaming from your Sense Monitor, that users are able to see. I say “results” rather than “data" because, as I have already described here, the raw data the monitor acquired has already been substantially transformed into something simpler by the time it reaches your app (or web app). The Signals section shows the real-time power flowing through each sensor (CT-current transformer) plus the voltage on each of the two “legs” or passes in your home, plus the measured frequency of your alternating current (AC - hopefully around 60 Hertz). Non-solar Sense users will see 2 power values, 2 voltage values, plus frequency. Users with solar will see two additional power values. It should be noted that for solar installs, the mains power in the Signals section will reflect the Total Usage flowing into your house, even if your sensors/CT are on the mains flowing out of your meter.
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Great for Debugging - If you are seeing strange results in your Power Meter or Now bubbles, the Signals section is one of the best places to start debugging because it shows the details. A few things to look for in all the detailed power, voltage and frequency values:
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Dashes for all of the values - indicates your Sense is offline, and not talking to the Sense mothership.
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Zeros for any of the values, except perhaps solar power at night - indicates there’s some kind of measurement problem. If the voltage is zero for a leg, it’s likely the corresponding mains and solar for that leg will be zero as well (that’s how the calculation works).
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Negative values - Properly configured, the Sense monitor should never produce negative values, except possibly for some very small negative values on the solar legs on at night (mine are -2W at night). If you encounter this issue, Sense support can typically validate and re-configure remotely. Negative values make a real mess out of the Now bubbles and Power Meter, because everything displayed is expected to be positive.
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Voltages more than 10% below or above 120V - If you see this, take a look at the Power Quality view under Sense Labs. If you see erratic voltage levels, you might want to try a power cycle “reboot” of your Sense monitor.
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Frequency more than a few Hertz away from 60. If the frequency is off by more than a few cycles per second, you might want to try a power cycle “reboot” of your Sense monitor. If that doesn’t clear the problem check in with Sense support.
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Highly unbalanced values between legs - Unless your home is wired very strangely, the power on each leg should be relatively close, within 20% of the whole house load, unless you have a very power-intensive 120V device running on one of the legs. A typical solar install should show both legs being very close, within 100W. FYI - Sense has an internal tool used by support and R&D that offers a “Power Meter-like” display of all 2/4 power components one sees in the Signals section. That helps them diagnose any issues you might have, but only with your permission to access your data.
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Solar deviations - if you have Sense and a solar install, your solar must be measured with Sense, in most cases, for your grid signals to be measured correctly. Your two solar signals should display roughly the same amount of wattage at any given time. If you notice a dramatic deviation of over 50 to 100 W or more, then there is likely an issue with your solar not being measured correctly. This may have the knock-on effect of causing solar to be measured in your main lines, causing measurement and device detection issues. If you notice this, please make sure to contact support so we can verify any possible issues and work to provide you with suggestions on how to make adjustments.
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Cannot be Screenshotted on Android App - Currently, there is a known issue that Settings > System view cannot be screenshotted in the Android App for security reasons. An easy workaround for screenshotting the Signals section is to go to the same Signals view in the web app (home.sense.com) or in the Power Quality view under Sense Labs.
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Accessible via the informal Sense API - There’s an informal Sense API that enables Python-savvy users to read all the Signal section real-time values within user-created apps, via the "update_runtime()” call. I have found this useful for doing real-time alerts plus charting when voltage or frequency goes outside normal range. Here’s a simple example - note that it is important to limit how often you call update_realtime to every 60 seconds or longer.
- Available in Home Assistant - The Home Assistant home hub used with the Sense integration employs the same “update_runtime()” call to log the same data. So you can generate charts of separate L1/ L2 power and voltage directly from within Home Assistant, instead of writing your own code.
The Signals section is a real wealth of information.
