dmr

Intuitively this is what I would think, but having more mass right at the bottom will increase the moment of inertia so mass distribution could also be a factor, so I need to learn a bit more about this.

It could be raising the centre of gravity (centre of mass?), or maybe its increasing the moment of intertia. I should try to learn about this stuff. However there is a limit on how much one person can learn, I note that my BMI puts me well into obese. This might be due to a long body or short legs, but I suspect its the weight of useless information in my brain 😀

We are a big heavy boat but putting a builders bag worth of wood on the roof makes a significant change to the stability. I also wonder about marginal changes to centre of gravity and moment of inertia. Last year I removed and replaced all the ballast under the back cabin, and went from steel laying on concrete slabs to steel (almost) directly on the baseplate, plus lead on the steel to replace the weight of the slabs. I am almost sure this has made the boat a bit less stable, or at least more inclined to roll as we step on and off. I have probably dropped the CofG by a couple of inches.

I remember that it was pretty common for plug tops to run quite warm when running an electric fan heater. After all the trouble we go to on boats to crimp everything and make really good connections I am a bit surprised about how basic a lot of mains wiring is. When I was redo-ing my consumer unit I observed that the earth bus bar is just a small brass strip with a single little screw securing each wire. Do domestic electricians now fit ferrules? and should they be used in 13 amp plug tops? (though wiring plug tops is pretty must history these days) Are these any good? Any first hand forum experience? I am tempted to get them. I note these are not genuine Wago but a brand that I have not heard of.

We managed without ferrules for many years, so it is a bit odd that its now seen as insanity not to use them. Some appliances would arrive without a plug top for you to fit one yourself, and quite often the strands of the pre-stripped flex were..........soldered 😀 The newer Victron Orion DC DC charger puts what some people feel is a reckless amount of current through a small screw connector. The manual states that the use of a ferrule is optional.

There is also a difference between ignorance/poor workmanship, and making an informed decision to deviate from the rules. I like to solder things, but I know how to solder. I have some 240volt and 12volt cables running next to each other under the gunnel (previous owner stuff), but I know they are there and would turn the 240 off before messing with the 12. We have a sink drain very close to the waterline, so the hose is all done correctly inside the boat etc etc.

A few weeks ago we pumped al the s**t out of the holding tank and are now replacing it with new and very different s**t, do we need a survey and paperwork ? 😀

Will investigate further tomoro, especially the observation from moominpapa, maybe I got it wrong, but ultimately I observe things rather than following ISO regulations, because some boat stuff goes against normal domestic practice, but still uses domestic equipment there is always a potential for things to wrong. Have just looked at my old MCB's (Doepke) and the terminals do screw upwards to clamp but the thread is such that its still righty tighty. All interesting stuff.

Data sheet says 25mm2 in and 10mm2 out. The10mm out could be two wires of 2.5 plus some to spare. Not sure why the in is 25mm, but suspect there is a good reason. Could be to join a whole load together. Do most modern consumer units have a live busbar???

I mostly like ferrules but prefer them on thicker cables, about 2.5mm minimum. They are ok on 1.5 but if used with a choc bloc they can snap off if you have to undo/redo them a few times. They are in effect turning a soft copper wire into a more brittle structure, though I suspect some are better than others.

Pretty sure I got it right, I had a good look inside the terminals, but I will have another look tomorow. They are big holes. I did download the spec and they can take some pretty hefty cables, but I think the spec said 1.5 minimum and I am doing 2.5. Not sure why domestic stuff takes such big wires, unless they are intended to take several wires into each connector.

I tried a ferrule of the correct size, crimped onto the wire. My crimp was fine (I have worked with electricity all of my life 😀). The terminal just couldn't get a decent grip onto the ferrule, though ferules worked fine on the earth commoning strip. My guess is that these terminals need to work with a softer metal like copper to get a good grip. I was very tempted to solder the strands but decided against it as everybody hates soldering these days. Yes, looks like MK was a bad decision, maybe I should have gone for proper Chinese like Chint??? I wanted double pole (or at least "+N") and wanted in at the bottom and out at the top so the MK looked just right.

Its an old consumer unit (in a tight space) and does not have commoning strips for the live and neutral. I have used large chocolate blocks to common up the 4 wires (one in, three out) for now as I judged this to be much safer than having multiple wires into a single terminal. I will get some of the lever ones from your link.

Yes, they are square "tunnels" with a flat bottom and flat clamp. One of the clamps (neutral?) has fine ridges on it, the other is smooth, which is a bit odd. The clamp does grip the wire but not with nearly as much force as I would like. The old ones that I took out had a more rounded tunnel and this worked much better.

I have just redone my consumer unit with RCBO's (mcb and rcd combined). These were from a "reputable" company, MK, though looked to be very chinese. I have had great difficulty getting the contacts to get a good grip on the cables, even when tight I can still pull them out with moderate force. Maybe this is normal but I don't like it. The www tells me I am not alone here. I wonder if these contacts are intended for solid copper, or thick strands of copper, as used for conventional mains wiring, and if our boaty use of fine stranded cable is actually counter productive here and creating a potential hazzard ???😀. The best method is to spread the freshly cut strands out into a fan, twisting is no good at all, bootlace ferules are worse than useless, and its strictly one cable per connector which is not really viable in my consumer unit.