infrastructure – Graves On SOHO Technology

Stormy Weather: An observation of POE Budget

Late the other afternoon we had a thunderstorm come through. Tis the season hereabouts. The wind picked up, pushing in dark clouds. The sky darkened quickly. Then the Unifi app on my Pixel 8 pinged to alert me to a network error. The network switch in our attic had exceeded its power-over-Ethernet (P.O.E.) budget.

What a novel set of events I thought. It was the first time I’d ever seen such a notification. I wonder why it occurred? It didn’t take long to work it out.

The device reporting the power problem is a Unifi USW Flex 5-port switch that lives in the attic. It receives power from the USW-24-POE main switch in the house. The POE+ (aka 802.11at) ports on the main switch can deliver up to 30 Watts over a single Ethernet cable. That is, up to its overall power budget of 95 Watts.

USW Flex can deliver up to 46 Watts when powered from a POE++ (aka 802.11bt) capable switch. When powered from mere POE+ the USW Flex is able to provide 20 Watts onward to network loads.

Deal Alert: Wen Parallel Kit Delivers 240v 50A (12 kW) for Household Backup Power

It was two years ago, after the crazy derecho and Hurricane Beryl that I did a deep dive into an affordable approach to whole home backup power. That effort documented our own strategy, which involves a Predator 9500, which is large portable inverter. This is in contrast to expensive, installed backup generators from Generac or similar.

Since then, I remain active in various online forums on related subjects. A question that often comes up involves connecting a pair of inverters in parallel to deliver more power. This comes up enough that I wrote an overview of parallel kits for the Predator 9500 and similar inverters.

In doing that I discovered that these parallel kits were in short supply. Some companies like Harbor Freight, simply don’t offer them. Duromax does, but was sold out for the longest time. So, I was happy to find that Wen has an attractive offer that’s currently on sale for just $62.

New Gear: Ubiquiti Unifi 5G Backup

Apologies for the lengthy preamble. Back in 2001 when we moved into this house we started with Comcast cable modem internet access that delivered 5/1 mbps. We were committed to Comcast for cable TV since we were a Tivo household. Tivo DVRs leveraged cable and the Cable Card decryption scheme.

It also happens that Comcast’s internet access was not very reliable. That caused me to get a DSL service installed as a backup. The DSL service provided by Sprint was modest. We are some 11,400 feet from the nearest central office, which meant that 1.5 Mbps / 768 kbps was the best we could achieve.

Over a number of years, Comcast’s cable modem service got both faster and (somewhat) more reliable. Still, I retained the relatively pokey DSL service as a backup. After Hurricane Ike in 2008 I felt vindicated in that choice. Throughout and after that terrible storm we had sustained phone and internet access via that DSL service. In contrast, Comcast was out for a month.

There came a time when I realized that I had not used the DSL in over a year. And 4G wireless broadband had become available, so I could tether to a phone in a pinch. That combination supported ending the DSL service, which suffered declining cost/performance.

All that is back-story. In all that time, we never had a “dual-WAN” arrangement. Failover between the ISPs was manual. Typically, repatch the WAN port of the router to the desired modem, then load a different WAN configuration. Not difficult. But manual.

Well, no longer! Last week I took delivery of the new Ubiquiti Unifi 5G Backup device. Newly introduced for just $99 this wee magic wand promises an affordable, automatic backup to a 5G wireless service. It’s not locked to any carrier. At the outset it works with AT&T, T-Mobile, and presumably their MVNOs.

Well, hello there big boy! Duromax offers a 28 kW portable Inverter

DuroMax 28,000 Watt Tri Fuel Portable Inverter Generator Duromax continues to lead the market for large, portable inverters. After launching a 16 kW model last year, they have recently introduced a portable inverter that delivers a whopping 28 kW (starting Watts) when running on gasoline. The XP28000 is available in two versions, supporting (iH) dual-fuel or (iHT) tri-fuel configurations.

It’s plainly a mighty beast, capable of delivering 16 – 22 kW of continuous power, depending upon fuel type. That puts it up there with the typical Cummins, Generac or Kohler permanently installed standby generators.

Sunday Afternoon at The Micro Center

Last weekend I ventured out to our local Micro Center. I hadn’t been there for several years. It was an interesting and enjoyable experience, even if I didn’t buy anything on this occasion. In some fashion, it was a grounding experience.

I have a long relationship with The Micro Center. When I first moved here from Toronto in 1998 it was an eye-opening place. That was before Amazon.com, when computer stores were still a thing, and software was bought on floppy disk or CD-ROM. The Micro Center was a place I could go and lay hands on things before making a purchase. As a lark, one day I was there with Stella and I hugged a fancy new computer. Thereafter, she started to call it “The Michael Center.”

On Sunday, August 10th, 2025 The Micro Center in Houston was busy! It had not occurred to me that this was the last weekend before kids started back to school. It was also a tax-free weekend for back to school supplies. The place was fully of families getting things their kids would need for school.

The Lenovo Twins

I was there just to look around the place, but I really wanted to lay hands on a Lenovo T14 laptop. It’s one model in the running to replace my 2019 X1 Carbon and my aged desktop. I found a T14 there on display along side a T16. This was enough to convince me that 16” is just too big a laptop for my tastes. I wish I’d brought my X1 Carbon with me. The T14 is markedly heavier, but had a built-in Ethernet port and is vastly more upgradable over time.

I came away from the Lenovo display wanting to get hands on their P14 model, which is a mobile workstation. Sadly, such was not available at The Micro Center.

It’s really difficult to move away from the X1 Carbon. It’s basically ideal for mobile applications. However, soldered in memory means that the only upgrade opportunity is the NVMe drive.

On “Solar Generators”

Hi. My name is Michael and I am a pedant. I don’t mean to be, but it really can’t be helped.

I come to this admission when faced with an online discussion of “Solar Generators.” I believe this term arises from really poor use of language.

There really is no such thing as a “solar generator.” Except perhaps the sort of installation found in Nevada’s Ivanpah Dry Lake.

Let me break this down a bit:

Generators

Burn some fuel to create motion, which in turn creates electrical energy.

Batteries