Hoover

 Last week the cordless Hoover made so much noise even ear defenders where not enough.

It was vibrating so much the dust box was coming off on its own.

Opening up didnt reveal anything, and the vortex/motor assembly was quiet once removed.

It was bought 8/6/2020. 2.5 years later and the fan blade was thick dust.

Motor part number.

Never did get to the bottom of the noise.

A new power project

If you're after a piece of gear that is reasonably expensive, and you see a lightly fire damaged one on Ebay, keep searching. Or allow plenty of time.

We want to be more grid independent, so was looking at power wall solutions. The biggest players such as SMA and Studer not only want stupid money, but if you want to see a some pretty graphs you have to use their gear $$$$$. Enter Victron and the Multiplus II

A good range of voltages and powers. In 2022 a 3kVA/48V or 24V version can be found for 1200€. Having spent 260€, I got this

Yep, I saved ~1000€ and gained a claimed working inverter. And a fair amount of work, but that's part of the fun, right?

Before 

After

See the melted wires and connectors?

There is also a fan (blades melted) , a support PCB and trafo. The trafo just wiped clean.

Cleaning was pretty basic. A tap water rinse with plenty of directed jets. Then to displace the water 99% ethanol in a sprayer and a child's toothbrush, plus other small brushes. 

You'll read plenty on line saying soot is magnetic, but none of this soot was. The nylon bristles on the a toothbrush are ethanol safe, but the handle may melt. ESD precautions were followed; no vacuuming, and no compressed air. A wet nylon brush is OK.

 A (lithium) battery fire that caught the OSB on fire. Note the power available light.  The owner confirmed it was still working after the fire. I suspect that the wiring was too small as the 10mm battery tails were still connected. 50mm recommended.

 A load of stuff to replace, the worst of which is the main power terminals. These terminal are designed to take 70A at 230V. Imagine the size of pcb track and the amount of heat to melt the solder.

This product is repairable with large soldering irons and experience. There are 5 PCBs; a SMPS; a logic board; logic board daughter module; 2 mosfet gate drivers.

The day after cleaning, with the PCB stored at room temperature, I powered it up. It worked fine with all of the suppression caps missing and a melted fuse left it. And not earthed. 

28/2/23 Finally ordered the spares from Mouser and replaced anything dodgy. The hardest part was removing and soldering back the parts. The PCB is likely 4oz copper and whilst it has lands, it took a large soldering iron bit and a 50W iron.

The new cap at the front was slightly taller. You can't really see, but the 3 at the rear were slightly bulging. The worst had gained 1.6ohms of ESR and lost 10% capacitance. The others seemed ok. All replaced along with the 3 red ones on the PCB. 3 X caps were changed. 2 charred relays work fine. The terminals are fine, just ugly. They are around 40€ to replace with Wurth, but still 10€ from no-name. I decided that there was little point as they were not going to get out the PCB easily, and I didn't want to grind/cut them out.

The fan was replaced with a similar flow unit (Noctua NF-F12 iPPC-24V-3000 Q100 IP67 PWM), but controlled with a pic using Intel PWM commands to the fan. There are a lot of posts in the Victron community with one dealer swapping out the fan before delivery with a quieter one with half the flow. The MP commands the fan to 40% on with only 1kW load in a room at 20C. It doesn't stay on long, but I think half flow is too marginal. It's a 20mm unit vs the original 30mm. It's held on with special anti vibration mounts at the bottom and a bit of wire at the top. Moving air makes noise; there is little vibration from this fan.

21/8/2024 When I installed this hard-wired into the house wiring, I decided to limit the scope of the inverter output. The AC input, which is what ESS drives ie charge from solar, and back-feed battery to grid is connected to 1 of 4 RCDs in the main board. I jiggled a few circuits around on another RCD and this has lighting, electric gates, some kitchen sockets, some lounge sockets and some bedroom sockets. Downstream of this RCD I fitted a manual change-over between grid and the multiplus AV output. The multiplus has a built-in bypass, so during normal operation you can tell it to disconnect from the grid. However, if it fails, or you switch it off, you have no power to parts of the house. Sure you can flick the manual bypass, but you have to be there for that. So I swapped it out for an automatic transfer switch. I bought this one

Not the fastest (50ms) and an electrical life of 1500 ops. It has a warning not to connect it onto a dead short, so you need to be careful! But at 25€ it will keep the fridge running if the multiplus dies and we're away. I've got it set with the multiplus as the priority supply - no point having grid as main, then waiting 50ms for the inverter to connect when it fails!

Look carefully at the size. I got it in my board, but it's tight. 10mm2 fine strand wire helped a lot

I'm pretty sure they make these for other brands, but the CE certificate has the Geya name on.

HTU21D

The weather station is eating HTU21D humidity sensors. About 3-4 / year.

I'm beginning to think the sensors from Aliexpress aren't genuine

The temperature still works, but humidity stays at 0%

I wouldn't mind if I lived in the tropics and they were permanently wet, but the one that just failed hasn't seen proper rain for months.

Ive started covering them in PTFE tape which protected a genuine SHT for around 10 years.

Replacements

1/3/22 ? PTFE tape, otherwise open. A fair amount of verdi grée on the pins + pcb

30/10/22 sealed in acetic based clear silicone and PTFE tape

Fencing the garden

Cut the east hedge and installed 1m fence to keep the deer out. A couple of days, plus the shredding. A further afternoon for the south hedge, and 16/11 an afternoon cutting most of the north hedge.

Denver radio IR-135S

 A few internal shots. Nicely built.

The battery is a single 2000mAh 3.7V cell. 3 wires, the white marked NTC.

The USB consumption in standby/charging battery was ~0.6A. Turning the radio on increased consumption between 0.1 and 0.15A, meaning a battery life of around 9.5 hours.

Rear panel with led, usb & 2x 3.5mm jacks

30/4/24 The original 2Ah battery (from 12/2021, radio bought 8/22) is lasting less than a day. I think it used to be 4-5 days. Replaced it with 2 x 2.9Ah from BAK. 

The protection PCB from the original 1S now runs 2P. Charging current is 0.7A at 5V. Likely to be a 4-5 hour charge now. If the display is powered, it adds 0.05A. Running current adds 0.1A (TBA when charged)

Be sure to let the PCB cool down after soldering else the radio will think it's on fire from the embedded NTC (13k at 18C, W to BL)

A post I found with a good info

https://heyrick.eu/blog/entry/20230107

Dishwasher energy saving?

We basically have free hot water as surplus PV is diverted to a 65l tank. I noticed in the manual for the dishwasher that it can take cold water up to 30C. I had an old shower mixer, so I've shoe horned that into the cold and hot feeds under the sink. Early results show a 25% energy saving - the heating element is normally on 12 mins, and it's on 8 mins.

Before I start planning a cruise with the saved money, it's worth noting that it's 25% of the water heating phase. Why? Because the PV pays for the the period where the pump runs. Our modest PV will never cover the 2kW of the heater. Hover, this is the dominant cost of a dishwasher for most people. Today we are generating say 1kW. The DW heater plus other loads total around 2.1kW, so for a 12 minute period we pay for 1.1kW, or 220Wh. This happens twice for a 'run' so 440Wh. With hot water feed, the heater runs for 8 mins, so the 440W becomes 330Wh. Over a year assuming we run it every day and it's a sunny day that's 40kWh, or around 8€  saved! 

There are days when we have little or no PV, but still have hot water from the day before. In that case the savings, assuming 300W PV, on say 1.8kW are 360Wh x 2 = 720Wh * 0.25 * 365 = 66Wh / 13€

I'm not convinced the savings even paid for the PTFE tape and certainly not the 2 hours or so I spent, but it all helps. I'm still trying to find a way to offset the router which takes 20W 24/7 (35€) and push it into the daytime. It takes quite a big battery to run it from say 8pm to 8am. 

Some dishwashers, in particular Bosch and Smeg, can take cold water up to 60C which would almost double the savings.

~jan 2023. PSU failed. Threw in an old usb adapter.

12/11/23 Looks like the inlet valve is passing. Came to use the DW and found it had so much water in it, it flowed out when I opened the door. This tripped the flood alarm so I had to take it apart to dry it out. I have noticed increasingly that there is water in there and assumed that it wasnt pumping out correctly.

Lidl silvercrest induction hob SDI3500

Got a Lidl single ring induction hob.  Works well. However, about a year into the 3 year warranty it just stopped mid-use. Nothing. Rien. A fuse? Well yes, but not the obvious fuse near the inlet.

There is a thermal fuse built into a rubber piece which is in contact with the cooking top. It's easy to test. Pull the red connector and if there is no continuity, replace the thermal fuse. You can  short out the pcb connector and do a check that there is no other problem, but never run the appliance with safety items missing,

Bought a similar replacement Sefuse sk167R0. The thermal grease had all dried out and might have contributed to the over-heat triggering.

BTW the green connector is a 100k NTC thermistor.

I found this which has some photos and some other easy to fix problems.

https://academie.repaircafeparis.fr/index.php/reparer/electromenager/reparer-cuisine/44-plaques-de-cuisson/185-rca-91-une-plaque-a-induction-avec-un-fusible-thermique-defaillant