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And you're to blame, You give solar a bad name! Meant to be safer than a cheater cord, power cord with shrouded banana plugs + Similar wire and banana connected to equipment under test. Now it's easy to stack banana plugs and plug in HV scope probe. It's just as easy to mix up Line and...

Transformers aren't well understood by most people who use them. It is well known that centertap "Neutral" connection carries the difference between L1 and L2, but that is not at all true for autotransformers. It is only true for the case of an isolation transformer where all power is delivered...

A while back I bragged about creative use of heater hose as tough, large size insulation for electrical terminals: https://diysolarforum.com/threads/fire-never-cover-lifepo4-with-wood.19373/page-12#post-238207 It seemed like a good idea at the time. More recently, I was wiring up...

After watching a video (sorry can’t find it now) showing resistance testing of cheap fuses and name-brand ones, I decided I’d better test the ones I’ve put in our cars. In the video, it was said that previously Harbor Freight sold fuses, but later recalled them and didn’t carry anymore. Fuses...

Showing a work-in-progress assembling 3-phase SMA system. 3x SI-5048-US are configured for 3-phase and produce 120/208Y, rated 15 kW continuous. Sunny TriPower 30000TL-US-10 is 480V delta (or 277/480Y), rated 30 kW. TriPower combiner box will be used, but for now just one string being connected...

Lawyers Share The Stupidest Cases They Had To Deal With (thesportsdrop.com) " 53. The Show Is About To Begin I was arguing for my client to be released on his own. The judge asks him where he is going to live. “With my fiancée,” he says. He spins a lovely tale about how wonderful his fiancée...

I picked up 24x FullRiver DC250-6 AGM batteries, somewhat used. They had powered a couple Tuk-tuk for tourists. 76 lbs. each, so 1800 lbs. https://fullriverbattery.com/batteries/part-dc250-6/ Most measured 6.26 ~ 6.29V, but a couple were lower, lowest being 6.05V (40% SoC per manual) I set...

After reading of someone tripping battery breakers at well below rating, I realized that could be due to pulses of current drawn by the inverter. Ideally capacitors would smooth out current draw so high frequency switching pulses and 60 Hz draw all came from the caps, and current from batteries...

Raspberry Pico, a microcontroller to handle overhead without using a massive computer like the Raspberry Pi itself. Programmable in Python, it seems. https://www.theverge.com/circuitbreaker/2021/1/21/22242619/raspberry-pi-pico-microcontroller-tiny-computer-diy-projects "Raspberry Pi on its...

Came across the following blog. It includes the company's installed system numbers and failure rates for SolarEdge, Fronius, Enphase. Also, information on limitations and best use of optimizers. https://www.mcelectrical.com.au/solaredge-inverter-optimiser-review/

https://www.livescience.com/spinal-implant-for-walking-after-paralysis

Apparently we have been mislead, and tin foil hats actually make us more susceptible to the government's microwave transmissions from space: https://web.archive.org/web/20100708230258/http://people.csail.mit.edu/rahimi/helmet/ Of course, the government itself was behind the misinformation...

Because I have suitable equipment I'm going to put up measurements I've taken, might help someone with planning a system or general education. Motors draw a startup surge of considerably more amps than they draw while running. With grid power you may see the lights dim briefly, but if you have...

https://www.visiontimes.com/2021/10/14/uk-vaccine-surveillance-report-98-percent-antibodies-majority-breakthrough-cases.html When I hear such claims, I try to look for references, see what if anything is behind it. Turns out this one is true. The key contributor is probably given in the...

In the interest of science ;) I have captured waveforms drawn by a high frequency inverter from the battery. This could give some insight to how a BMS might react. About 25 years ago I found myself with idle hands and some money ($800?) burning a hole in my pocket. I wandered into Quement...

Surge arrestors are used on AC and DC side of PV inverters for protection, to clamp high voltage transients. One inverter I have (actually several) are in the SMA family SUNNY BOY 5000-US / 6000-US / 7000-US / 8000-US. These come with a kit of MOV to protect the DC side: The MOVs are about...

Here is a new record low price for solar panels, just $0.0231 per watt! https://www.ebay.com/itm/224443956635

My upright Frigidaire deep-freeze wasn't freezing anything more concentrated than ice cubes any more. Things were mushy and spoiling. Maybe it just needs a refrigerant recharge; I'll look into that later. Went to the store and found they all have 60 or 90 day delivery. Only come out of China...

Harbor Freight has their 12V 4A automatic battery charger on sale for $25 https://www.harborfreight.com/4-amp-fully-automatic-microprocessor-controlled-battery-chargermaintainer-63350.html I use this for FLA and AGM batteries, to bring to nominally charged and keep at float. For a battery...

The Pandemic is over. It is no longer a novel corona virus. Virtually the entire population is no longer "Covid naïve", having been vaccinated, infected, or both. Variants that are spreading widely don't attack the lungs like the original (killing the Wuhan doctor, for instance.) What I got was...

I've been using Delta Lightning Arrestors on my system since they were spec'd by Real Goods as part of the package I bought from them. I now have a surge capacitor on the AC input as well, which is supposed to slow rising edge of voltage so it doesn't get as high before the Silicon Oxide...

When I hung my original 2.5 kW SWR-2500U inverters 17 years ago, I was probably stronger and they were only 75 lbs. I was able to carry them up a stepladder and hang them head high. Taking them down to upgrade was doable, but difficult When I hung 75 lb transformerless 10000TLUS under the deck...

So you think you can backfeed a transformer secondary, either as step-up or as auto-transformer? Turns out these things aren't so ideal and reversible as one might expect. It isn't just the greater inrush (primary is often wound outside secondary to reduce inrush current), but also idle current...

I've built myself a circuit breaker tester. I assembled three transformers into a 3-phase wye auto-transformer, and by means of a breaker and cord/plug it can be repurposed into a current multiplier. A breaker connects X1 to H2 and H3, providing 4.7x current boost on X2 paralleled with X3...

Got SMA WebBox connected. It is able to see the SB5000 and SI-6048 I'm using, display and presumably alter their parameters. My unit has RS-485 for communication with inverters and Ethernet for PC/network (other models have Bluetooth but lack legacy networks.) Reading that it supports FTP with...

I suppose I could buy a solar panel tester like Will reviewed, but that doesn't feel DIY enough to me. Besides, I'm a cheapskate, and I try to do things in the most difficult (and expensive if the equipment wasn't on hand) way. I'm presently working on an underperforming string of Sharp 165W...

No "Hot Work" permit required!

SMA just announced Sunny Boy Smart Energy hybrid, SBSE7.7-US-50 and lower wattage models now on California's CEC website. (Larger up to 11.4kW not yet available.) This makes them available for approval by PG&E (Haven't tried yet, might take time for their system to be updated.) This inverter...

https://news.yahoo.com/us-electric-power-sector-halfway-122900988.html The projected increase didn't happen. We're only half as bad as we thought we would be! (In other news, Congress is 50% of the way to balancing the budget.)

I tested the effect of a 9kVA toroid auto-transformer connected to 120/240V split-phase low-frequency inverters. Inverters are SMA Sunny Island 6048-US, four wired series parallel. I also turned off output breakers to test with two wires in series. Imbalanced load was applied with four...