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nicknorman

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nicknorman last won the day on October 10

nicknorman had the most liked content!

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Profile Information

  • Gender
    Male
  • Location
    Aberdeen
  • Interests
    Electronics, gliding, motorbikes

Previous Fields

  • Occupation
    helicopter pilot - retired
  • Boat Name
    Telemachus
  • Boat Location
    Fazeley Mill Marina, Tamworth

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  1. nicknorman

    Round pin sockets for 12V

    Voltage drop is the same as power loss. Current down the wires doesn’t (can’t) change, high voltage at one end, lower voltage at the other = power loss dissipated as heat. Presuming the resistance of the grid, or cable, or 2A connector, is a fixed value, the power dissipated as heat is proportional to the square of the current and nothing to do with the system voltage. I^2R. Note the square term! In layman’s terms if you double the current you double the I in the VI formula for power and if you double the current across a fixed resistance you double the voltage drop, ie double the V in the VI formula too. Hence the square. System voltage drop affects the end using device, or if it’s constant power increases the current. Wastes power anyway. But the connector rating, like a cable rating, is about the heating effect from the current flowing through it and its resistance. As you say, modern materials allow low resistance connections that can pass high current for the size. Old fashioned 2 A mains connectors made of brass suffer from high contact resistance even when new, and higher still as they get a bit corroded, which generates heat.
  2. nicknorman

    Round pin sockets for 12V

    No only the current is relevant. Current causes heating when passed through a connector, circuit voltage doesn’t. Which is why power sent through the national grid is very high voltage and thus relatively low current.
  3. nicknorman

    Round pin sockets for 12V

    Just to mention that a lot of these modern devices are “fixed power” types. So they will take (in this case) 80w regardless (within reason) of the supply voltage. So if you get 12v at the socket which is at the end of the wiring, it will take 6.66 A. But on the other hand, if the voltage has dropped to 10v at the socket which is at the end of the wiring, due to thin cable, it will take 8A. Which of course makes the voltage drop worse!
  4. nicknorman

    Round pin sockets for 12V

    It’s not just about the sockets though, it is also about the wiring and the fusing. (Theoretically at least) the fuse should take into account the lowest common denominator, so if the wiring can take 6A and the socket is rated at 2A, the fuse should be 2A. If the wiring can take 1A and the socket 2A, the fuse should be 1A. That is the theory! In practice, who knows! Being practical about it I’d try the load you want, whilst monitoring the plug/socket temperature (and of course whether or not the fuse blows!)
  5. nicknorman

    I've 'arrived' - My own parking place.

    I don’t really know what the confusion is about. Clearly the space is for a fat bloke looking to steal a baby and make a quick getaway. Mind you, when you are that fat would one baby be enough? Ok, maybe for breakfast.
  6. nicknorman

    Webasto Thermotop C Delta T Query

    Have you never heard of a love triangle? That usually has several balls and an arrow shape or two, with a couple of lines (not to be crossed).
  7. nicknorman

    Webasto Thermotop C Delta T Query

    However the heat is only dissipated if a/ it’s delivered to the device and b/ it’s expelled from the device by the fan. So reducing the water flow and/or the air flow will reduce the heat output and thus leave some for the other things.
  8. nicknorman

    Webasto Thermotop C Delta T Query

    Good question! Cycling on and off is definitely bad. I’m not too sure about 1/2 to full power, I would guess that’s much less harmful. Anyway, that is certainly one huge heater!
  9. nicknorman

    Webasto Thermotop C Delta T Query

    Obviously it depends on the size of the “blower box” but we have a 1.7kw one installed on the step to keep steerer’s tootsies warm. https://www.kurandamarine.co.uk/kalori-heater-matrix/heater-matrix-units/kalori-silencio-fai-kk12014081-kalori In our case, run from the calorifier loop. But the heating power consumed obviously depends on the fan speed, so on a slow speed it will output a lot less than 1.7kw, the air will feel hot and the deltaT will be low. Even on fast fan though, on ours the air feels fairly hot. The deltaT can be controlled by adjusting the fan speed and water flow so I don’t see any system as being problematic provided the above parameters are reasonable.
  10. nicknorman

    Top up Orange PAYG phone

    We had an Orange sim in the remote control for the boat heating/battery voltage/temperature. Since it mostly received texts (to put the heating on) and rarely sent them, I only topped the SIM up once in the 7 or so years we had it. When it needed topping up last year I found I couldn’t. Can’t remember exactly why but I had to get an EE sim.
  11. nicknorman

    Training a new Smartgauge

    Only if you fit it and leave the default start up SoC at 75%. The SG will synchronise when the actual SoC falls to the indicated SoC. The indicated SoC doesn’t move upwards unless the batteries are being charged at a bulk or absorption voltage. Probably your charger is on float which isn’t enough to get the SG indication climbing. The first time you actually use your boat off mains for a day or two, taking the SoC down and up significantly, it will become synchronised. Had you set the indicated SoC to 100% when you installed it, it would have been fine straight away.
  12. nicknorman

    Training a new Smartgauge

    No, you don’t need any other gauge, I think you must be misreading the manual. Just fit and forget. It will read accurately when you need it to, so for example if you only cycle it between 95% and 100% it won’t “learn” as it really needs deeper cycles, but then again it’s reading doesn’t matter. If you fit it to fully charged batteries having set the SoC to roughly 100%, the first time you significantly discharge down to say 60-70% or lower it will read fairly accurately and certainly will let you know when you need to recharge. Further cycles will refine it but it will read fairly accurately on the first cycle, provided you set the correct battery type. The other thing to bear in mind is that new batteries can take a few cycles to settle down (a lot of cycles in the case of something like Trojans) so again, there is no point in expending energy trying to get the SG to “Learn” batteries that are still bedding in. Just fit and forget.
  13. nicknorman

    Stiff lock gates and paddles

    We did the S&W between Autherly and Gt Haywood a couple of weeks ago. Don’t remember any paddles being stiff. That is just the way it is, I’m afraid. If you want stiff paddles on narrow locks, try the Huddersfield Narrow. They really are stiff! As to the gates, there are a few difficult ones including the bottom ones at Gailey, due to having very short and angled balance beams because of the proximity of a bridge. The trick with gates generally is just to maintain a firm pressure using your backside if possible, rather than trying to jerk them. Anyway, cheaper than going to the gym to lift weights!
  14. nicknorman

    Mysterious 5amp drain

    Could you remove your 12v fuses / turn of breakers one by one until you find one that is passing the 5A. And, for the mains side, leave the inverter on but switch off the breakers in the consumer unit?
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