Alan Ambrose

Easiest way to try out is Arduino software or similar and the USB dongle which will present the 485 as standard serial. The manufacturer’s simple protocol is probably documented somewhere, otherwise it’ll be hard to guess unless you have a working example from somewhere. Post up docs here?

Congrats. You need the patience of a saint, no?

Re 5G routers - anyone have a recommendation for SIM providers? O2 has bolloxed our camera sims and talking to people at O2 and EE shops - they don't really support data sims. They say they will cut off any sim that doesn't have a voice call on it at least every 3 months. AI recommends EIOTCLUB, Transatel and other providers I've never heard of. I read there are some multi-network IOT data sims? Any experience? p.s. O2 & EE seems to be our best actual networks at the plot. Ditto 4/5G router/aerial recommendations?

Ah, that’s good - it includes the ‘not yet built’ database

Yeah, there’s a ‘new build database’ or something and the standard ‘actually exists’ database. My LPA insisted on putting us on the former. That means that all but a few switched-on merchants can’t see it. Annoying for deliveries.

Is there a vague 'requirement' for a fire-brigade-accessible PV-shutdown switch. I'm thinking a big red stop switch in an obvious place, probably wired to the inverter or a DC-contactor? Would this be sensible or is it completely OTT?

I'm meaning from a Part P / BC point-of-view? Yeah, I realise that this is industrial spec cable rather than domestic, but this is for 24V (i.e. ELV) ffs. Max current will be 3 x 14W 5m LED strips i.e. 2A. The braid will be used for EM shielding, given that dimmer control is fairly noisy. You could have the same is it / isn't it discussion for 24 or 48V PoE over CAT5/6/6a, of course, and pretty much nobody would think that falls under Part P.

Errrr, super-complicated, slow expensive torture by your LPA, utilities and various other suppliers who don't give a ....... monkey's and are often actively hostile. Will test all your considerable skills and patience. At least with a PhD you get a piece of paper at the end.

FYI, for MVHR, I used both the spreadsheet here on ‘t ‘ub and, for comparison, the Ubbink calculator. Then there’s a bit of common sense re air & duct routes, ceiling heights, valve positions. Detailed but not rocket surgery as they say.

A couple of questions: + anyone used ROTHOBLAAS air tight tapes instead of Pro Clima? e.g. https://insulationmerchant.com/products/rothoblaas-seal-band-60-airtightness-tape . I know their screws get proper SE reverence, so maybe their tape is pretty good also? and... + there's a bit of a fuss re CT1 being maybe less than magic: https://youtu.be/bwvE9FqjfQA - anyone have any views?

OK ta.

Should the max MPPT voltage be compared against the panel's open-circuit or max power voltage? For the panels I'm looking at (JAM54D41-445/LB) the max power voltage at 32.65V is only 83% of the open-circuit voltage of 39.1V. I'm pushing the max MPPT voltage with the number of panels I'm thinking of, hence the question.

I found a few scraps on info for anyone coming across this thread. Summary is that you can control either by linking up via Velux's propriety RF interface e.g. + Documentation - Velux | Loxone + Velux - Home Assistant Yuk. The more grown-up solution is via a custom PCB: + Controlling Velux windows | SmartHome.Exposed + Module VNX-A for interfacing VELUX® KMG100 window actuator drive Curiously, Google AI thinks this (which seems to be nonsense unless this is maybe for some non-retail Velux products): VELUX 24V control systems are Open System solutions for controlling electric windows, blinds, and vents via a ±24V DC signal, allowing integration into building management systems. This is different from the company's proprietary io-homecontrol system and is often used in commercial applications or with smart home systems that support this voltage. You typically need a compatible building management system and hardware like relays to control the devices. How it works Voltage: The system uses a low-voltage ±24V DC supply, which is a standard in building automation. Control signal: You send a polarity-based signal (positive or negative) to open or close the window or blind. Integration: This allows you to integrate VELUX products into your preferred smart home or building management system (BMS). Hardware: A building management system can control the devices through hardware with relays that switch the 24V DC signal. Devices like the Velux KLF 050 or KLF 200 interface can also be used for this purpose, or you can use a system like Loxone with appropriate relay extensions. Key components VELUX products: This includes electric or solar-powered windows, blinds, and ventilation modules equipped with a 24V actuator. Control unit: A building management system or a specific interface (like the Velux KLF series or a Cartelectronic interface) that sends the 24V DC commands. Power supply: A 24V DC power supply for the actuators and control system. Relays: In many cases, a relay is needed to switch the 24V DC polarity to control the motor. Example scenario A smart home system (like Loxone) is connected to VELUX windows via a relay. The system sends a signal to the relay, which then applies a 24V DC current to the window's actuator, opening or closing it based on the polarity. This allows for automated control of windows based on time, temperature, or other inputs within the smart home setup.

One of the next few Thursdays maybe? IP14-ish but feel free to make suggestions. Or maybe if we're very nice to @G and J he might resurrect his Woodbridge offer?

This is Artisan Electric's view of battery options from a year ago (below). I'm leaning towards the Sigenergy stuff. Anyone have a very different view or some more nuanced observations? I'm looking for single phase, adaptable 'open' system, to bolt into Home Assistant or similar. From: https://youtu.be/7xQGexleUfQ