Howzit from muldersdrift - DIY install

That is correct, I shouldn’t be running more than 20-25A max

The one that I’m using in my setup looks like this

The female part one go’s on your wall and then you can plug in the the male plug into it. It’s got a flap that close it for safety.

I prefer the Male part to be on the wall and the female part on the Gen… That way you wont have live prongs sticking out while the gen is running and the plugs unpluged.

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agree 100% you don’t want a live plug from gen that can be touched, extremely dangerous.

It think this is an issue either way.
You could have it that the wall side is live as well depending on how that change over switch is installed. (It should switch all the pins, but you never know how it was wired).
This might be where proper procedure and labeling for switching over is very important.

the change over switch is break before make so wall plug will never be live.

edit: in other words its 3 position, mains/off/gen

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Makes sense yes. I used mine to run the inverter gridtie if I need to charge the batteries. This was on my old setup.

Hi Louis, the one on the wall will never be live unless its connected to the gen (Plugged in)

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You get male and female wall-mount sockets. You also get male and female plugs for the other end. Get the right stuff and you won’t have to worry.

Just randomly snapping some Gewiss stuff from the AC/DC website:


So something came up which I thought was worth mentioning in case someone else finds this useful.

Remember I got the sonof DB switch mentioned earlier in this thread. Its is in my Db and switches my geyser through a contactor. It is timed to go off at peak solar times during the day and remain off during the night. Now currently we having pretty rainy weather in JHB and my solar was struggling to keep up charging the batteries…I still haven’t installed my 12 new panels…
Now back to the sonof switch. Last night we had a stormy night with lots of lightning and something must have happened upstream on our fibre line and the internet went off. Somehow this messed with the sonof switch and it switched on the geyser at 4 in the morning as i can see on VRM. How this happened i have no idea as its working back to normal today and none of the timer functions are wrong. Switching on at 4am was bad as my battery was already depleted from the days rain and then was drained further with the geyser going off. so I started my day on battery 27%. If anyone know how the sonof switch got this wrong please let me know.

So to fix this problem in future I’m going to wire in a mechanical or even digital timer inline with the sonof switches so that they will never be able to come on after dark.

So exactly a month of testing has passed and it showed up a few areas to fix and also gave very good data for me to use and see where to improve. I will post some pics this weekend of the generator plugs installed and give feedback.

Does everyone else feel like we just racing to December, doesn’t feel like there is time for anything.

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I must say, a couple of extra months this year would really help me a lot… There is so many things I still want to complete before December.

Are you using your sonoff with the stock firmware?

They use ntp servers for time, without internet they cant update time constantly.
They will however keep time (with a little drift, milliseconds i believe)
If they rebooted while your fibre line was down they would have no idea what the time is as they cant contact the time servers.

Most people use sonoff’s with custom firmware like esphome/tasmota integrated into home assistant.
Gives better total control in my opinion.

Smarthome tech is great, but most people dont think about “internet outages”
Reminds me of when google was down and users couldnt turn on their smart lights.

Yes for now using the stock firmware. But I think you are right regarding it loosing the connection to its time server. For now going to use inline timer to protect system and will check out tasmota firmware one day.