nicknorman

It’s worth mentioning that the top of the flue should be able to slide a bit in the deck collar as otherwise thermal expansion of the flue will put a big force on the top of the stove and maybe crack it. Also note in the envirograf instructions, no flame to be playing directly on to it. So you use glass stove rope to pack the bottom of the flue pipe / stove interface. The silicone goes on top of that to seal and look tidy.

It’s basically fire cement vs high temperature silicone. A lot of people use fire cement but IMO it only lasts a year then it cracks. It is terrible stuff! I use high temperature silicone which lasts as new until for some reason you need to remove the flue. Ie probably 10 years. This stuff. https://www.ebay.co.uk/itm/251723362373 The only people who prefer fire cement are people who have never tried the envirograf silicone

In house world you don't have a smoke detector in the kitchen, you have a heat detector. Trouble with narrowboats is that kitchen and living space tend to be one and the same.

You didn’t explicitly say it so I’m going to: many of the above topics are different within the confines of a narrow boat vs a house, which is why there is a separate ticket for marine lpg

Ah OK thanks for the clarification. Back to plan A! I've thought more about it and I think you are right. Put that on your mantlepiece!😱

I was thinking that as I typed. So I guess it must have been a nationwide thing assuming Scotland and Englandshire’s grids were connected back in the 1970s. But they did have the clock and he did talk about the cumulative time error.

A friend of mine worked in one of the hydroelectric control rooms in the Scottish Highlands and gave me the tour. Turbine machines would be taken on and off line according to demand and it had exactly the phase meters that you describe. The other thing it had was a domestic mains clock - driven by a synchronous motor which was normal at the time. As the load varied the frequency would change slightly and they would compare the synchronous clock to real time. I think the allowed short term error was quite big (as in a few seconds) but of course the long term error had to be zero, Of course you were there! After all you had just invented electricity and designed the research lab! So in one post you said same voltage, in another you said different voltage. Which post was wrong?

No it definitely isn't trying to generate a slightly higher voltage, it is as I said all about pushing the phase. The phase doesn't actually change significantly of course. You nearly touched on it when you originally said "What it actually does is to try generate the same voltage* and phase as the incoming mains but also dump in-phase current into the load to generate power. " * make your mind up, either the same voltage or, as you said later, a slightly higher voltage. It is the dumping of in phase current as you say. But that is done not by increasing the peak voltage, but by adding the current slightly ahead of the phase - what I would call pushing the phase. It is of course "in phase" because the phase is the summation of the shore power and the inverter power, and with the low circuit resitances only the tiniest of phase differences is needed to radically alter the balance of currents.

This is just another way of saying what I said. The voltage and phase of both sources is the same when they are connected together (has to be, otherwise it doesn't make sense, in the same way that 2 batteries in parallel have to have the same voltage (local tiny resistive losses excepted), however if one source tries to "push" the phase ahead of the other source, this requires a lot of current to advance the phase of the whole system by a very small amount and the current from the other source will decrease. I don't know if you have ever played with parallelled 3 phase ac generator machines but it is the same idea. If you put more torque on one, the torque required on the other decreases (to maintain constant frequency) - and of course they are phase locked by the electromagnetics. That's not quite what I said! I said "tries to advance" but since everything is connected in parallel, the actual phase of both sources must be the same. But one might be "pushing harder" and thus supplying more current. Obviously one scenario is where the inverter is not contributing at all, and yet at the terminals there is still the 240vac 50Hz or whatever, but no current is flowing in/out of the inverter. And then the inverter can start "pushing" by adding current. The current only flows because the desired phase of the inverter circuitry is slightly ahead of that of the shore power. Ultimately it could push hard enough that the current from the shore falls to zero, even though there is of course still 240v or whatever at the shore bollard. Another analogy is a tandem bicycle. Both sets of pedals are rotating at the same speed and same phase (instantaneous rotational position), but one person might be pushing harder and one less hard.

I've been thinking about this a bit more. So previously, you started the generator then turned the switch to shore power, the RCD tripped. Then you reset the RCD - several times - and eventually it worked and continued to do so. But of course after the first trip of the RCD, the changeover action of the switch is not relevant because it was already set to shore power (I presume?). This makes me think it is more likely to be a leak to earth somewhere between the RCD and the switch (cable, shore plug/socket, wiring to switch etc). What could be happening is that the current leaking through whatever the source of the leak is (damp leaf, spider, general damp gunge etc) to earth has a slight heating effect on whatever the source of the leak is, which dries it out a bit so that after a few moments of current flowing, it becomes too dry to conduct the 30mA required to trip the breaker. It would be interesting to consider if there is any correlation between the propensity to trip, and the relative humidity of the air. And also whether there is any correlation between propensity to trip and whatever else is plugged in (battery chargers and any other ac consumers in the boat). If you can identify that it only trips when x device is plugged in, there is your problem. Of course the tripping might well not be down to just one thing, there might be several sources of slight leakage which add up to the 30mA required to trip the RCD.

To some extent it depends on the nature of what is being supplied. If it is a resistive load eg a heater or kettle, then a phase jump is not an issue. But if it has a transformer or motor it’s another matter. People don’t understand how ac works, for example if you ask people how a Combi Inverter supplements incoming shore power in “power assist” mode, they will tell you that, well, I guess it supplies the ac at a slightly higher voltage than the shore power or something…. Which is of course total BS! The inverter will supplement the shore power by supplying at the same voltage but trying to advance the phase of its supply vs the shore supply’s phase. Phase is king when it comes to ac systems! Anyway, let us know the outcome of starting the genny with the ac selector switch already set to that way and inverter already off. It will prove or disprove the point. Not if it is a double pole break before make, which apparently it is. The Inverter neutral is not connected to anything when the switch is set to shore power. And assuming the NE bond is the inverter side of the switch, which it must be otherwise the RCD would be tripping all the time.

Switching near-instantly from an ac source at a certain phase, to a different ac source at a random and different phase, is quite a brutal thing to do. Although I can’t immediately see why it would trip the RCD, I would suggest the following test: switch off the inverter first, then changeover the switch, then start the generator. This eliminates the transient “shock” of a near instantaneous major phase change. If that trips the breaker then there is an earth leakage fault but if it doesn’t, then I think the issue is the inadvisability of nearly instantly changing to a supply of different phase. As background, a Combi inverter charger can instantly switch between say shore power and, when shore power is unplugged, inverter power. But the inverter circuitry has been “tracking” the phase and frequency of the shore power so that when it suddenly needs to supply power the phase and frequency are matched for a seamless transition. The same applies in reverse (shore power suddenly plugged in, inverter no longer needed) - there is a few seconds delay before the switchover happens whilst the inverter adjusts its frequency and phase to match the shore power, again resulting in a seamless transition.

I can't count both ways at the same time because the electrons aren't going both ways at the same time! Electrons coming from the solar will split, some will go into the battery and some will not go near the battery, instead being diverted to run the boat services (fridge etc). You can't expect the battery or the battery shunt to know about electrons that don't visit it! The MPPT gives the value because all the electrons generated by the MPPT leave the MPPT, and that is all it knows about. It doesn't care where they go. Similarly you could have a monitor to count all the electrons coming from the engine alternator, one for the electrons coming from the generator/battery charger etc etc. But as you say, it is probably not worth the hassle!

I disagree. If you select a 40C wash and fill with water at 45C, the heater will never kick in.

Unforunately I think the two compact makes Candy and Zanussi are no longer made, and like you I am struggling to find an alternative.

There is no such thing as a 1.5v rechargeable lithium cell, the chemistry can’t do it. The 1.5v AA batteries have 3.6v Li cells and boost/buck/bms circuit to convert between the cell voltage and the 1.5v output and give the usual protections. Probably the major manufacturers think this is too difficult and unreliable. As to whether safe, you are into the area of exploding lithium polymer cells. Probably ok if the electronics hold up and you use the purpose designed charger, but I would want to charge them outside the boat.

Can’t remember exactly, but it was something along the lines of this https://www.amazon.co.uk/heating-foil-130Watt-underfloor-laminate/dp/B07DL1Y79M

it would be easier and less Ah-consuming to place heating mats under the battery, like wot I did. Plus a bit of insulation so the heating doesn’t disappear downwards.

Yes it’s funny how seeing a windlass left on the spindle of a raised paddle makes one cringe! I did notice the volockie removed it when the presenter walked away to talk to the other person.

I think the heater is only enabled at 0C. In any case, it doesn’t use current from the battery, it only uses charging current coming eg from the solar. So you would for example see a few amps charge from the solar controller or shunt, but no charge current on the BMS. It diverts any available charge current to the heaters, until the battery is a few degrees above zero. The battery is warmer than outside due to the canal water. Even when the surface of the canal is zero, the steel hull which is fairly heat-conductive, can transfer some heat up from the water at the bottom of the hull which will be warmer, plus some heat transferred from the living quarters.

Well, there is the usual 14 days. But no short term restrictions.

Do you really need it on the roof, as opposed to a front or rear bulkhead? A vertical surface is going to be less prone to collecting water and leaking, and bear in mind the aerial needs to be easy to reach when you want to align it. Have you considered terrestrial tv vs satellite? The latter has the advantage of working anywhere in the country and with the signal always in the same direction, but the disadvantage that the signal is completely blocked by any sort of foliage or buildings in the line of sight to the satellite.

Yes. Cold water weeping out of the PRV at the cold water inlet. The pressure of course deriving from heating the water further up. But the pressure in a non-flowing liquid is the same throughout (discounting head). It doesn’t matter where the PRV is located, it can vent any excess pressure.

The OP stated no accumulator fitted. So the whole water system is one sealed thing (nrv in the water pump). Having the PRV in the cold side has the benefit of not wasting hot water out of the PRV.