Jump to content

IanD

PatronDonate to Canal World
  • Posts

    12,108
  • Joined

  • Last visited

  • Days Won

    93

Everything posted by IanD

  1. We've had the debate about separate inverter/charger vs. combis before, and as usual there as pros and cons of both... A combi makes dealing with power under BMS control -- especially in a boat with LFP -- much simpler, and can do things which separate units can't. It's also likely to cost less and be more reliable and compact (no needless circuit duplication) than 2 separate units --- especially at higher power levels -- but as you say when it goes wrong you lose everything. However most separate charger/inverters have the same problem that they don't fall back to feeding shore power through if they die, you need external changeover switching in both cases. And they'd have done the same thing faced with an over-range input voltage, they disconnect to protect themselves and the circuits connected to the output. I believe the default overvoltage threshold is 265V but it can be set at up to 270V -- either way, it should not have had a problem with 255V, unless the installer lowered it. There have been very occasional deaths on stage due to electrocution for many years, but for sure far fewer than all the other rock'n'roll causes of death -- drugs, drink, car crashes, bizarre gardening accidents, choking to death on vomit***... 😉 *** somebody else's vomit, obvs.
  2. This post cannot be displayed because it is in a forum which requires at least 10 posts to view.
  3. Plus the time needed to get all the band members to bring their kit in when some live miles away -- basically, most of a day that could be better spent doing other things. Twice as long as a gig but for no money... 😞 And given that all the risk is to the band members not the public and we're happy not to bother, it seems pretty pointless. The only issues we've ever had have not been with our kit but with venue supply problems, one of which actually blew up our guitarist's rather nice valve amp... 😞
  4. Understood, reversing (and repeating several times) often clears things -- but not always especially if whatever you've picked up is big, by the time you've realised what's happened it's usually too late. It takes ages to cut a keep net off once all the hoops and mesh are tangled round the prop... 😞
  5. That sounds strange, most Victron gear like inverters is fine up to 270Vac input. It needs to be because if you use an IT this has 5% stepup at no-load -- with 253V input (UK limit) this gives 266V at the inverter input -- and I saw this at Uplands marina sometimes. It could be that the maximum input voltage limit was set lower than this since it's programmable...
  6. Not sure how that helps stop getting stuff wrapped round the prop though -- some canals are just bad for it, and some boats seem more prone to pickup than others. Getting something nasty irremovably wrapped round the prop seems more like bad luck than anything else, for example the infamous Rochdale crossings last year where other boaters got multiple prop fouls including razor wire and a mattress and I got one carrier bag...
  7. There is no legal requirement, but many venues won't let you bring in your own equipment -- not just PA but also things like backline instrument amps -- unless you can provide proof of PAT testing. (yes I know this is like ATM machines, but it's what everyone calls it) We did exactly what you said (except the tester was borrowed) but it's still a PITA when you've got a lot of gear -- which we had with a 10-piece band with full PA and 6 foldback channels and lots of backline... 😞
  8. That does depend on what heavy bits of equipment are placed where in the boat. If there's a lot in the stern (like mine) then a heavy baseplate would make the boat too stern-heavy...
  9. No, you do need a suitable pan base, but most reasonably modern pans are fine, they're designed to be induction-hob compatible -- which are not exactly a new invention. Most hybrids (including mine) use a 230Vac generator connected to one input of a Victron Quattro with the shoreline connected to the other, then normal thickness mains cables can be used for the connection even if the generator is in the bows. This allows the Quattro (controlled by the BMS) to deal with all switchover/control/charging functions, and gives a backup 230Vac source in the rare case that the Quattro inverter fails. A nominally 6kVA generator really isn't big enough by the time you consider system losses, actual continuous generator capacity, temperature heatsoak, required charging rates, and wanting to keep running times down. I'd say you need 9-10kVA depending on the generator spec, and a Quattro 48/10000 (8kW continuous output, 7kW battery charging if you can keep it cool enough). Whether this goes in the bow or stern is a matter of choice, both have advantages. You need to think how you're going to heat the boat and hot water, if you have a diesel boiler this (and a dual-coil calorifier, and the fuel tank) all need to be next to the generator (and silencers, and skin tank...) at one end or the other. My boat has everything including batteries (except BT) at the stern, others split them between bow and stern -- both work, like everything to do with boats there are pros and cons both ways. I'm not saying that hybrids are perfect or suitable for everyone, and they are more expensive -- but do offer some significant advantages in return if they meet your requirements. They'd be much more attractive in future if there were network-wide charging bollards, but unlike EVs there's no thought-through plan to make this happen any time soon... 😞
  10. Most pans work fine with induction hobs, but not all. Redundancy is an argument for having gas, especially if you don't have an onboard generator (I do) which can provide 230Vac even if the inverter fails (with some rewiring). I don't think going electric for cooking -- hob or oven or even kettle -- makes sense on a diesel-powered boat, which is why most people don't do it and stick to gas. It does make sense on a hybrid/electric boat where you already have a huge battery bank with a lot of electrical power (big inverter) and a generator and lots of solar, because these are all needed anyway for propulsion. But this is an expensive option today (and in the near future with no charging bollards), you've got to be willing to pay a lot for the silent cruising benefits, and most people aren't (or can't).
  11. They should test them regularly (like appliances should be PAT tested -- a PITA for bands...) but I bet most don't. An RCD tester is a good idea for general safety testing, they also report any wiring errors which as you say are not unknown 🙂 However given that a live steel hull is going to leak far more than 30mA -- even allowing for paint! -- any shoreside RCD that isn't totally defunct or has contacts welded shut would still trip in the much-argued case above. Assuming the one on the boat doesn't trip, obviously... 😉
  12. I was always a firm supporter of gas hobs until I got an induction one, and many chefs have found the same... 😉 The one thing they're not so good at is cooking with a wok, a 6kW gas wok burner takes some beating -- yes you can get induction wok burners, but mostly 3kW and costing more than two grand... 😞 Having said that, you can get the same power with a flat-bottomed wok on a conventional induction hob, but you still get a smaller "hot area" than a big gas burner...
  13. This post cannot be displayed because it is in a forum which requires at least 10 posts to view.
  14. Electric cooking on a boat -- oven and/or hob -- is expensive to provide the power for (and recharge the batteries), unless you're doing this anyway for a hybrid/electric boat. In which case you might as well go all-electric (which is what I did) and get rid of the gas installation, which not only needs bottles but also costs to install, needs extra ventilation and safety devices, and causes more condensation when cooking. IMHO a gas hob and electric oven is the worst of both worlds, you need both the high power electrics/recharging and gas bottles/installation.
  15. And almost certainly a lot less efficient than a screw propeller, just like a paddlewheel...
  16. Also that this relies on a good shoreside ground connection, which is not always guaranteed. And that the transformer actually has an interwinding shield, which many don't (there are good reasons for this). The quality of the shield ground connection on the boat is in your control, the one on shore isn't. And to quote from Gibbo's webpage: "The hull of the boat now has 230 volts on it with respect to the actual ground outside. As this current has to travel through the water to return to earth, it is far from certain (particularly in fresh water) that sufficient current will flow to blow the incoming shorepower fuse. Obviously this situation is highly dangerous. If an RCD is fitted to the shorepower then this may well trip, but again it is far from certain. It is however highly likely. " It's more than highly likely, it's damn well certain given actual values for freshwater conductivity -- which I gave but you've ignored, and presumably Gibbo didn't look up either, he just "assumed". I'm pretty sure that all UK shorepower points (in marinas and canalside) have to be fitted with an RCD for obvious safety reasons, and the current via a live hull will be way *way* bigger than needed to trip these -- and probably even big enough to trip a fuse, but this doesn't matter. Given that he got this simple fact wrong, excuse me if I don't take everything he writes as gospel... 😉 Of course there is an RCD on the boat, as ISO and BSS require/recommend 🙂 Not me, Victron and other IT suppliers. I'm happy to be in the same boat (ho ho...) as thousands of other customers, using equipment designed and reviewed by experts at a reputable supplier and tested by all the certification authorities, and that they almost certainly know better than you and your guru Gibbo whose opinion -- with some basic errors in his assumptions, see above -- is that on balance it's better his/your way. But if you think Victron are wrong, I suggest you write to them and point out the error of their ways -- I'm sure they'd be grateful to know that they've sold thousands of ITs with an inbuilt safely issue that you and Gibbo have spotted but they and the regulatory bodies didn't... 😉
  17. That's definitely changed (and not Lees!) since we were last there but that was several years ago (2016?) -- gone upmarket is an understatement...
  18. Like I said, there are thousands of boats around the world with Victron ITs in them, all wired like mine -- oh yes, and not in plastic cases for good reasons. You'd better write to Victron and tell them they've been doing it wrong all these years, and you're absolutely sure of this because a website says so. You can't get a strong electric field in the water without lots of volts on the hull, which will cause large leakage current to ground via the water and trip the RCD, either in the bollard or on the boat. At least, unless Ohm's Law was repealed when I wasn't looking... 😉
  19. IIRC it's a Lees pub with their standard menu and beer -- OK but nothing special...
  20. That's why more power just makes the stern squat down more in shallow water as the prop sucks water from under the boat -- a steeper hill to climb, more power used but no more speed...
  21. Yes but it's not the drag from weeds in the current -- on canal bed or boat -- that causes most of the drag, it's "going uphill".
  22. And that's where most of the drag comes from -- for the water to flow backwards past the hull quite fast, it has to drop in level from bow to stern, this can be several inches as you can see looking at the bank. Which means the ~18ton boat is essentially having to be pushed uphill and that's what takes all the extra energy, not the surface drag which is what weed makes worse but which is low on low-speed canals anyway.
  23. This post cannot be displayed because it is in a forum which requires at least 10 posts to view.
  24. It has, but that's mainly because power goes up with speed^3, and in most canals by far the biggest source of the drag is from the narrow/shallow channels, not hull surface drag. I found I can use double the power in return for half the speed on a narrow/shallow canal like the Peak Forest compared to a wide/deep one like the Sheffield and South Yorkshire...
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.