US Leisure Electrics Conversion/Update

Discussion in 'Mech Tech' started by F_Pantos, Jan 12, 2019.

  1. ginger ninja

    ginger ninja Supporter

    Cheers folks.
    Nice to know there are options here. Have you fitted yours yet Andy as I’d love to take a look seeing your just down the road.
     
  2. The US So-72 originally had a metal plate mounted on the other side of the power inlet, this keeps the wiring very short and easy to install once the bus had been imported; the electrics were, as far as I can tell, fitted stateside by Delta Industries.

    The plate hold two US household style sockets and a thermal cutout; it looks like this.

    WP_20190119_09_59_26_Pro.jpg

    The plan is to fit the UK double socket vertically on this plate, you can see my rough pencil marks of where it will go. A bit of care and attention is required to make sure the bigger surface area and deeper UK socket fits safely into the plate.
     
  3. Here's the socket, I went for Stainless Steel, have to see how that works out when its in use, on the bus.
    WP_20190119_10_12_21_Pro.jpg
     
    theBusmonkey likes this.
  4. The inlet housing fits flush with the metal plate that holds the sockets, in the US configuration there was no need for cables to pass thru into the rest of the bus, as a result, the housing lacked any cable holes.

    In the new configuration, two cables need to go to the CU which will be hidden under the rear seat.

    Here it is before:

    WP_20190112_09_33_17_Pro.jpg

    You can just about see a hole blanked off. I removed this but need a second for the other cable.

    Out with the trusty punch to make a second hole, one for the cable to the CU and the other for the cable from the CU to the 13A twin socket; two separate holes so they don't rub against each other.
    WP_20190119_12_30_32_Pro.jpg

    Add in suitable grommets and the inlet is almost ready for wiring up.

    WP_20190119_12_33_34_Pro.jpg
     
  5. So out with the trusty jigsaw and on with the safety specs and this
    WP_20190119_09_59_26_Pro.jpg

    becomes this....

    WP_20190119_14_32_58_Pro.jpg

    I cut the hole slightly smaller than a shallow depth wall box and used the wall box to clamp the sockets to the plate.

    WP_20190119_14_33_09_Pro.jpg

    Next up etch primer followed by Pastel Wiess top coat etc.
     
  6. WP_20190202_13_44_41_Pro.jpg Got a second plug to try on the thicker hookup cable.
     
    Valveandy likes this.
  7. ginger ninja

    ginger ninja Supporter

    Hello
    Thinking about ordering the connectors now. Did anyone decide what’s best in terms of the blue one that’s higher current rating or the other one that’s better suited to disconnecting if things were left on?

    Or is the jury still out?

    P.
     
  8. The metal work I have adapted for UK 13A sockets is now in paint. This leaves time to work on the next big challenge, what to do about the 120v fridge on hookup?

    The fridge is 3-way and appears in eminently service-able condition, 3-way is great for festivals and rough camping, although whether I'll have the guts to leave the fridge running on gas overnight is another matter; I have bought a CO alarm.

    Anyway. on hook-up these worries should go away, but how to get 120v to the fridge's heater element? My first thought was a transformer, but then I wondered how safe this would be? Working through the problems, I ended up with either an auto-former or a full isolation transformer as the only work-able solutions, but decided in both cases the 120v circuit would still need full safety protected, RCB/MCB. Still, I persevered and found an a suitable isolation transformer, it weighed in at 3kg :(

    Wow! This is all getting very complex...... and very heavy.

    The plan was always to fit an on board charger for the twin leisure batteries and I was busy looking at CTEK chargers and working out that I needed at least 15Amps minimum or more. I was originally going for a marine charger as it was cheaper and can be switched to trickle charge overnight to keep fan noise down. The CTEK M200 or M300 were looking like favourties.

    At this point, I noticed that some of the chargers, albeit the more expensive ones, can also act as power supplies, the MSX25 which is a so-called pro-workshop charger; it also has a temp sensors for the connectors, cool or what?

    https://www.ctek.com/products/professional/mxs-25

    I had a eureka moment (no out-of-bath images implied please) and thought why not use the charger to power the fridge in the charger's "supply" mode? The fridge on DC requires 110watts, this is within the 300watts that the charger in supply mode is capable of and, as far as my background reading has taken me, the charger has a on-board fan to keep it cool :cool:

    I will probably mount the charger onto the bodywork which can act as a heatsink.

    CTEK seem well designed and well constructed. I may add a fuse in the live but I imagine CTEK already have something similar inside the charger, add in the temp sensor and the CTEK's fan, and, I think, this might be a viable solution.

    I will have to see how this works out and if the CTEK is capable of delivering the required power over extended periods without overheating or dying but since I was buying a charger anyway its worth a try and I can always fallback to the transformer solution or buying a new fridge, either way the charger isn't wasted money.
     
  9. theBusmonkey

    theBusmonkey Sponsor

    The ctek supply mode is primarily designed to allow technicians to remove a battery from a modern vehicle and not loose codes etc
    Connect the charger to the battery in the normal way, preferably close to keep the cable runs short and with crimped ring terminals in place of the clips.
    Connect the dc positive of the fridge into your dc fuse box and earth to chassis.
    This way the charger will satisfy all demand on the leisure battery, including the 10amps or so required by the fridge.
    Make sure the interconnects you get for the fridge, fuse box included, can handle the current rating. A lot of the generally available stuff is woefully borderline as load increases.
    I have been using a ctek MXS 10 exactly like this for years to power a Westy fridge that draws 8-9 amps through its dc element. I have used the power supply mode but to be honest there is no point as in normal smart mode the charger adapts to load on the battery automatically.:thumbsup:
     
  10. theBusmonkey

    theBusmonkey Sponsor

    Actually, @F_Pantos , the fridge supply on Chip is connected to a +bus bar in the engine bay that in turn comes direct off the LB. Fused cable obviously.
    The bus bar feeds the dc fuse box under the r&r as well.
    It just makes isolating stuff a bit easier in our set up.
     
    F_Pantos likes this.
  11. Sorry, didin't see this. I think either would work fine, but if you believe you'll be in a situation where the cable is disconnected from the bus end first when the bus' circuits is under load then the second one we found is probably a better bet.
     
    ginger ninja likes this.
  12. Bought the CTEK today already got the fridge on test just using the mains supply in the garage and the supplied croc-clips to see how well, or not, it all works..

    To be honest, I probably could have got away with a 15A CTEK but when I add in the LED roof lights, the gas heater, the stereo and a few other bits and bobs it was getting uncomfortable close to to 15Amps, and while the 25 Amp CTEK is bigger it is also very well made and I can confirm it does have its own fan :)

    Just working out where to put it now. Under the back seat is probably best, near the leisure fuse box, I did worry that the the gas heater is under there and that the extra temp would make life harder for the CTEK , but the likelihood of the heater being on when the outside temp is high and the CTEK is going full chat is next to nil.
     
    theBusmonkey likes this.
  13. theBusmonkey

    theBusmonkey Sponsor

    It'll work!
    It certainly won't take long to charge the LB on site.
    Our system makes ice on the fridge evaporator.:D
     
    F_Pantos likes this.
  14. Ice for a nice cold drink? That I could live with, total luxury.
     
  15. theBusmonkey

    theBusmonkey Sponsor

    Here's ours.
    Bit of an untidy picture as it was taken during the build but I didn't want it buried under all the carp we carry inside...You can also make out the bus bars for + & - . Bad earths cause so many issues!
    P1040595.jpg
     
    pkrboo likes this.

  16. That's a good spot for it, nice and out of the way, I'll consider that one in my thinking, if I may?

    Meantime, your prediction about ice on the evaporator seems to have some merit (mind you it was only just +6 degrees in the garage).

    WP_20190209_15_27_46_Pro.jpg
     
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