There’s a small AC-line device that has received a lot of favorable media coverage lately. It’s called Ting from Whisker Labs, Inc. and its purpose is to monitor the home AC line, Figure 1. It then alerts the homeowner via smartphone to surges, brownouts, and arcing (arc faults) which could lead to house fires. It’s even getting glowing click-bait testimonials such as “This Device Saved My House From an Electrical Fire. And You Might Be Able to Get It for Free.” Let’s face it, accolades don’t get much better than that.

Figure 1 The Ting voltage monitor is a small, plug-in box with no user buttons except a reset. Source: Wisker Labs

(“Arcing”—which can ignite nearby flammable substances—occurs when electrical energy jumps across a gap between conductors; it usually but not always occurs at a connector and is often accompanied by sparks, buzzing sounds, and overheating; if it’s in a wall or basement, you might not know about it.)

The $99 device plugs into any convenient outlet—more formally, a receptacle—and once set up with your smartphone, it continuously monitors the AC line for conditions which may be detrimental. It needs no additional sensors or special wiring and looks like any other plug-in device. The vendor claims over a million homes have been protected, aggregating over 980,000 “home years” of coverage and that four of five electrical fires have been prevented.

When the Ting unit identifies a problem it recognizes, the owner receives an alert through the Ting app that provides advice on what to do, Figure 2. Depending on the issue, a live member of the company’s Fire Safety Team may contact you to walk you through whatever remediation steps might be required. In addition, if Ting finds a problem, the company will coordinate service by a licensed electrician and cover costs to remedy the problem up to $1,000.

Figure 2 All interaction between the homeowner and the Ting unit for alerts and reporting is via a Wi-Fi to a smartphone. Source: Wirecutter/New York Times

It all seems so straightforward and beneficial. However, whenever you are dealing with the AC line, there’s lots of room for oversimplification, misunderstanding, and confusion. Just look at the National Electrical Code (NEC) in the US (other countries have similar codes) and you’ll see that there’s more to safety in wiring than just using the appropriate gauge wire, making solid connection, and insulating obvious points. The code is complicated and there are good reasons for its many requirements and mandates.

My first thought on seeing this was “this is a great idea.” Then my natural skepticism kicked in and I wondered: does it really do what they claim? Exactly what does it do, and is that actually meaningful? And then the extra credit question: what else does it do that might not be so good or desirable?

For example, some home-insurance companies are offering it for free, and waive the monthly fee for the first year. That’s a tradeoff users might consider, or is it a clever subscription-service hook?

There is lots of laudatory and flowery language associated with the marketing of this device, but solid technical details are scant, see “How Ting Works.” They state, “Ting pinpoints and identifies the unique signals generated by tiny electrical arcs, the precursors to imminent fire risks. These signals are incredibly small but are clearly visible thanks to Ting’s advanced detection technology.”

Other online postings say that Ting samples the at 30 megasamples/second, looking for anomalies. When it identifies a problem it recognizes, the owner receives an alert through the Ting app that provides advice on what to do.

Let’s face it: the real-world AC line looks nothing like the smoothly undulating textbook sine wave with a steady RMS value. Instead, these are some voltage level variations which the vendor says Ting captured, Figure 3.

Figure 3 The real-world AC line has voltage variation, spikes, surges, and dropouts. Source: F150 Lightning Forum

As for arcing, that’s more complicated than just a low or high-voltage assessment, as it produces RF emissions which can be captured and analyzed.

I was about to sign up to try one out myself but realized the pointlessness of that. First, a sample of one doesn’t prove much. Also, how could I “inject” known faults into the system (my house wiring) to evaluate it? That would be difficult, risky, foolish, and almost meaningless.

Consider the split supply phases

Instead, I looked around the web to see what others said, knowing that you can’t believe everything you read there. One electrician noted that it is only monitoring one side of the two split phases feeding the house, so there’s a significant coverage gap. Another one responded by saying that it was true, but most issues come across on the neutral wire that is shared by both phases.

Even Ting addressed this “one side” concern with a semi-technical response: “The signals that Ting is looking for can be detected throughout the home’s electrical system even though it is installed on a single 120V phase. Fundamentally, Ting is designed to detect the tiny electro-magnetic emissions associated with micro-arcing characteristics of potential electrical faults and does so at very high frequencies. At high frequencies, your home wiring acts like a communications network.”

They continued: “Since each phase shares a common neutral back at your main breaker panel, arcing signals from one phase can be detected by Ting even if it is on the opposite phase. Thus, each outlet in the home will see the signal no matter its location of origin to some degree. With its sensitive detector and powerful post-processing algorithms, Ting can separate the signal from the noise and detect if there is unusual electrical activity. So, you only need one Ting for your home.”

This response brought yet another online response: “monitoring the voltage of both sides of the split phase would be far more ideal. One of the more common types of electrical fires is a damaged or open neutral coming from the transformer. This could send one side of your split phase low and the other high frying equipment and starting fires. But if you’re only monitoring one side of the split phase, you will only see a high or low voltage and have no way of knowing if that is from a neutral issue or voltage sagging on the street.”

As for arcing, every house built since 1999 in the US has been required by code to use AFCI (arc fault circuit interrupter) outlets; those can stop an electrical fire in nearly all cases, not just report it. However, using a single Ting is less costly and presumably has some value for an older home that isn’t going to be renovated or updated to code.

How big is the problem?

Data on house fires is collected and analyzed by various organizations including the National Fire Protection Association (NFPA), individual insurance companies and industry-insurance consortiums. Are house first due to electrical faults a problem? The answer is that it depends on how you look at it.

Depending on who you ask and what you count, there are about 1.5 million fires each year—but many are outdoor barbeque or backyard wood-pile fires. The blog “Predict & Prevent: From Data to Practical Insight” from the Insurance Information Institute deals with electrical house fires and Ting in a generally favorable way (of course, you have to consider the blog’s source) with some interesting numbers: The 10 years from 2012 through 2021 saw reduced cooking, smoking, and heating fires; however, electrical fires saw an 11 percent increase over that same period, Figure 4. Fire ignitions with an undetermined cause also increased by 11 percent.  

Figure 4 The causes of house fires have changed in recent years; electrical fires have increased while others have decreased. Source: U.S. Fire Administration via the Insurance Information Institute

Specific hazards are also detailed, Figure 5:

Figure 5 For those fires whose source has been identified, connected devices and appliances are the source of about half while infrastructure wiring is at about one quarter. Source: Whisker Labs via Insurance Information Institute

The blog also points out that there are many misconceptions regarding electrical fires. It’s easy to assume that most fires are due to older home-wiring infrastructure. However, their data found that 50 percent of home electrical-fire hazards are due to failing or defective devices and appliances, with the other half attributed to home wiring and outlets.

Further, it seems obvious that older homes have higher risk. This may be true only if all other things are equal when considering the effects of age and use on existing wiring infrastructure, but they rarely are. The data shows that assumption is suspect when considering all other factors such as materials, build quality, and the standards and codes at that time.

Other implications

If you get this unit through an insurance company (free or semi-free), that means there’s yet another player the story in addition to the homeowner and Whisker Labs. First, one poster claimed “Digging through the web pages I found each device sends 160 megabytes back to Ting every month…So that means you have to have a stable WiFi router to do the upload. As far as I know, the homeowner does not get a copy of the report uploaded to Ting, but the insurance company does.”

Further, there’s a clause in the agreement between the insurance company that supplied the unit and the homeowner. It says they “may also use the data for purposes of insurance underwriting, pricing, claims handling, and other insurance uses.” Will this information be used to increase your rates or worse cancel your home insurance for imperfect wiring?

It’s not easy to say that the Ting project is a good or bad idea, as that assessment depends on many technical factors and personal preferences. One thing is clear: it may be very useful for collecting and analyzing “big data” across the wiring of millions of homes, AC-line performance, and the relationships between house specifics and electrical risks (hello, AI). However, it can be very tricky when it starts looking at microdata related to a single residence, as it can tell others more about your lifestyle than you would like others to know or how affects how the insurance company rates your house.

What’s your sense of this device and its technical validity?  What about larger-scale technical data-collection value? Finally, how do you feel about personal security and privacy implications?

Bill Schweber is an EE who has written three textbooks, hundreds of technical articles, opinion columns, and product features.

Related content

• Ground-fault interruption protection—without a ground?
• AC-DC adapters get their GaN shrink
• Cable Self-Heating: The Other Side of IR Drop
• ‘Mistakes Were Made’,” Even in a Simple 3-Wire AC Hookup

References

• The Wall Street Journal, “This (Possibly) Free Smart Device Listens to Your Home’s Wiring — and Could Prevent a Fire”
• Electrician Talk, “Ting Power Quality device”
• F150 Lightning Forum. “Ting Electrical Fire Safety Device”
• Insurance Information Institute, “Predict & Prevent: From Data to Practical Insight”
• Wirecutter, “This Device Saved My House From an Electrical Fire. And You Might Be Able to Get It for Free.”
• Reddit, “Does Ting actually work and if so, how?”
• Reddit, “Do you recommend Ting electrical monitors?”
• Wikipedia, “Arc-fault circuit interrupter”
• Rainbow Restoration Blog, “28 House Fire Statistics: How Common Are House Fires?”
• Whisker Labs, “2023 Data Analysis Update: Internet of Things (IoT) System Preventing 4 of 5 Home Electrical Fires”

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