Inverter Through EHU

Discussion in 'The Beginner' started by Enjoy_Yourself, Aug 22, 2011.

  1. Enjoy_Yourself

    Enjoy_Yourself Read Only Funster

    Joined:
    Jul 1, 2010
    Messages:
    86
    Likes Received:
    25
    Location:
    Pontypool, South Wales
    Hi

    Finally decided to go with solar panel and inverter option for wild camping power. Bought 350W inverter on Sunday at Malvern but now looking at how to connect everything up.

    Pretty happy with connecting inverter to batteries and I think I have a simple option for connecting appliances. (Thanks to electrician brother-in-law!). Thing is it sounds too simple to be true!

    Going to connect inverter to external EHU socket, shut off circuit breakers for fridge and boiler, and use existing 240V socket for appliances.

    Anyone done the same or see any drawbacks with this?

    Thanks in anticipation as always.
     
  2. MikeandCarolyn

    MikeandCarolyn Read Only Funster

    Joined:
    Mar 18, 2008
    Messages:
    2,171
    Likes Received:
    1,463
    Location:
    Worle,North Somerset
    As I understand it,an inverter converts 12v to 240v-the EHU will be 240v,so,whats the point in connecting the inverter to it ?
    I also seem to remember something from the info that came with my 350w inverter saying that it was not a good idea to use it when connected to mains.
    I could well be wrong-and no doubt someone with more knowledge will come along shortly :BigGrin:

    Mike
     
  3. CHRI$

    CHRI$ Funster

    Joined:
    Jul 26, 2009
    Messages:
    5,595
    Likes Received:
    7,096
    Location:
    england
    i have done the same with my inverter but you must switch off your 12v charger as it will try to charge your battery from the inverter:thumb:
    and just connect it to your ehu socket so its only surplying your socket's:thumb:
     
  4. scotjimland

    scotjimland Funster Life Member

    Joined:
    Jul 25, 2007
    Messages:
    28,934
    Likes Received:
    25,574
    Location:
    .
    Just to clarify ... Are you going to use the EHU socket .. ie plug the inverter into the inlet ? If so that is ok .. and as Chris advises .. switch off the charger.

    IF NOT...

    How do protect against having both mains and inverter supply on at the same time .. perhaps your electrician can explain what protection he proposes.. ?

    Will this be automatic or will it depend on you remembering to physically disconnect the inverter supply before plugging in the EHU and visa versa .. If this is not automatic one day it will go bang ..

    If you never intend to use EHU again that is a different story .. but ensure that the EHU socket is physically disconnected from the distribution board.. and preferably removed or blanked over.
     
    • Like Like x 1
  5. CHRI$

    CHRI$ Funster

    Joined:
    Jul 26, 2009
    Messages:
    5,595
    Likes Received:
    7,096
    Location:
    england
    what iv done is just made up a fly lead that plugs into the inverter and the other end plugs into the ehu socket,and rewired my circuit breaker so i can flick a switch and turn off all but the sockets,including the charger:thumb:
    and when i need ehu i just pull out the plug from the inverter fly lead and plug in the ehu:thumb:
    and flick the switch back on that surply's the fridge and waterheater and charger:thumb:
     
  6. Enjoy_Yourself

    Enjoy_Yourself Read Only Funster

    Joined:
    Jul 1, 2010
    Messages:
    86
    Likes Received:
    25
    Location:
    Pontypool, South Wales
    Hi Mike

    Just want to use 240v wiring and sockets already in van. Inverter will be in garage with batteries so no direct access to socket on inverter.

    Cheers

    Neil
     
  7. Enjoy_Yourself

    Enjoy_Yourself Read Only Funster

    Joined:
    Jul 1, 2010
    Messages:
    86
    Likes Received:
    25
    Location:
    Pontypool, South Wales
     
  8. scotjimland

    scotjimland Funster Life Member

    Joined:
    Jul 25, 2007
    Messages:
    28,934
    Likes Received:
    25,574
    Location:
    .
    you have it sorted then :thumb:
     
  9. Enjoy_Yourself

    Enjoy_Yourself Read Only Funster

    Joined:
    Jul 1, 2010
    Messages:
    86
    Likes Received:
    25
    Location:
    Pontypool, South Wales
    Thanks Chris

    Great idea regarding fly cable.......wasn't looking forward to wrestling with EHU cable every time the wife wanted to do her hair!

    May get round to installing permanent socket one day but this seems best way to get up and running.

    Cheers

    Neil
     
    • Like Like x 1
  10. scotjimland

    scotjimland Funster Life Member

    Joined:
    Jul 25, 2007
    Messages:
    28,934
    Likes Received:
    25,574
    Location:
    .
    that's a good plan..

    it also, should the need arise, let you use the 230v socket while on the move .. say for example to charge a laptop / phone etc
     
  11. normanandsue

    normanandsue Funster

    Joined:
    Dec 31, 2010
    Messages:
    1,298
    Likes Received:
    3,888
    Location:
    Dunfermline - Scotland
    Chris, I am a little puzzled, not difficult for me! If you are wild camping why do you need to switch off your 12v charger, is it because by using the ehu socket the charger will assume its a 240v. supply?

    If this is the case then my next question is how do I turn off my 12v charger?

    Many thanks Chris.

    Norman
     
  12. haganap

    haganap Funster Life Member

    Joined:
    Dec 5, 2007
    Messages:
    11,069
    Likes Received:
    13,678
    Location:
    Heavan

    Hi Norman,
    Yes is the answer. When you plug in from a 240 source, ie home or at a site, the van will charge your batteries back to full state.
    Therefore, when you plug the inverter in to use, the van would asume you were pluggin in on hook up and start to charge the battery(s) and of course taking it's power to do so from the battery(s)

    My 12v charger switch is on my electroblok


    To the OP, two things spring to mind, I purchased a something to prevent me from having to switch off the 12v charger. Its called, a oh god dam im working late its 01-30 its a clear box 2 inches by 2 inches. Then when you plug your electric in as normal it will switch the power from the inverter to the hook up source. I never fitted it as it looked a little too complicated for me. My plan was to fit it behind the inlet for the hook up point, if it would be of use to you or moreso your electirician friend let me know and its yours.

    The other thing I would say though is this. 350w inverter aint going to give you much and that I promise. Mine wouldnt even charge laptops or run my sky box despite running 3 leisure batteries that were new. I opted for a 2000w inverter and aint looked back. I was also told that My wife wouldnt be able to dry hair or the batteries would be dead in 5 mins, not the case at all. It works real well and we rarely go on a site, I have solar's for recharging, never stop anywhere more than a couple of nights and a Honda 1kw Genny for those times in the middle of winter in the Alps.
    Works a treat.:thumb:

    good luck with it:thumb:


    Sorry, forgot to mention tha tin the end I opted to run my invertor direct to the battery bank, then ran a cable (fused) with 4 240 sockets on it to the rear of the van for power at the back. Anything else plugs straight in to the invertor (two sockets) at the front of the van, but to be honest, most of my stuff is all 12V even Nikki's new hair straightnes.
     
  13. Enjoy_Yourself

    Enjoy_Yourself Read Only Funster

    Joined:
    Jul 1, 2010
    Messages:
    86
    Likes Received:
    25
    Location:
    Pontypool, South Wales
    Hi Haganap

    The little 2 x 2" box, was that a relay? If so, would be very interested as I hope to achieve same sort of set up as you describe when time allows.

    12V hair straighteners........why didn't I think of that before!!

    Thanks for advice and enjoyed reading the blog.

    Cheers

    Neil
     
  14. haganap

    haganap Funster Life Member

    Joined:
    Dec 5, 2007
    Messages:
    11,069
    Likes Received:
    13,678
    Location:
    Heavan
    that's the thingy, will look in the garage for it later :Smile:
     
  15. JeanLuc

    JeanLuc Funster

    Joined:
    Nov 17, 2008
    Messages:
    2,782
    Likes Received:
    1,859
    Location:
    Warwickshire
    Just a few thoughts in case they are useful in deciding on your inverter layout.
    Concerning Haganap's comment that a 350W inverter would not charge a laptop, I am surprised at that. I manage very successfully with a Sterling 150W pure sine wave model. In fact it will charge a laptop (85W power supply) and run a speaker system at the same time. However, it would not work satisfactorily when plugged into a 12V "cigarette" socket as originally supplied. The cable run to the socket was too thin and resulted in voltage drop between battery and inverter. Once I had wired it in permanently with thick cable (via a relay on/off switch) all was sweetness and light.
    My choice was to install a dedicated 13 amp twin socket so I can use the inverter whilst travelling, and to prevent me having to deal with switch-trickery to connect it to existing sockets.
    If your van has an Electrobloc, and you switch it off at the main switch on the EBL, then if it is wired in the same way as mine, that will cause power to the Truma dump valve to be lost - the valve will open and the water will empty: not what you want whilst wild camping. In fact, I'm not sure that master switch prevents charging anyway.

    In case it is of any interest, I wrote a summary of my installation and put it in the downloads section. The procedure for a larger inverter would be the same but the cable might need to be thicker.
    http://www.motorhomefun.co.uk/downloads/miscellaneous/13/instal-small-inverter-pdf-102/
     
  16. haganap

    haganap Funster Life Member

    Joined:
    Dec 5, 2007
    Messages:
    11,069
    Likes Received:
    13,678
    Location:
    Heavan
    point taken Jeanluc, but, it was a 350w inverter from Argos. Wired directly in to the 12v socket and not in to the batteries. Remember I have 2 kids, 3 laptops, 4 phones, 2 DS's and a Ipod that need charging, oh and then there's the sky box. When I used the sky+ box or charged the laptop(s) through the inverter it would squeel like a lobster in a pot. :Wink:
    Now the OP mentioned hair drying, now, I know we have met and I have less hair than your avatar, but, my good lady has a fine head of hair to dry. I am not aware of a hairdryer that would do the job on a 350w inverter. :RollEyes:
    My second problem would be, if your going to hard wire an inverter in the manner and fashion suggested, it would be pertinent to do the job once and once only, ie go for a much bigger inverter to start with, one that would cater for the needs of all, hence the suggestion.
    for me the best method is everything 12v, big battery bank, solar's to charge, inverter for occasional charging of some items and drying Nikkis bonnet, 12v straightness to finish the job and a good Honda gennie for desperate winter dark days.
    This is a tried and tested method for the haganap family and we so rarely use electric hook up and go several days or even as much as a week touring withut even thinking about the genny.:thumb:
     
  17. JeanLuc

    JeanLuc Funster

    Joined:
    Nov 17, 2008
    Messages:
    2,782
    Likes Received:
    1,859
    Location:
    Warwickshire
    Paul, I agree absolutely about aiming to get everything to run directly from 12V wherever possible. Also to size the inverter "right first time": you clearly need a large inverter with the family. I think the OP also needs a decent sized one for hair drying. I was not suggesting that a 150W would be the right size for the OP, but the wiring regime I used for my small inverter would still be relevant for a big inverter - allowing for correctly-sized cables of course.

    Regarding your original problems with the 350W inverter "screaming" under load: that is exactly the problem I had with my 150W but I could identify my problem as voltage loss due to thin cables from the battery, not the small size of the inverter. I wonder whether the problem in your case was Argos? I realize it may sound a bit "sniffy" to suggest that the cheaper inverters may not be up to the job, but I have read of several people having problems with them. Sometimes the stated power output is in fact the maximum peak, whereas the pricier / premium brand versions usually have a peak capacity that is double the stated output. I am sure you know all this and, of course, your system is sorted now, but thought the information might be useful to the OP.
     
  18. Enjoy_Yourself

    Enjoy_Yourself Read Only Funster

    Joined:
    Jul 1, 2010
    Messages:
    86
    Likes Received:
    25
    Location:
    Pontypool, South Wales
    Philip

    We only need the inverter for hair starighteners that claim to be 45W (15 minutes to heat up would seem to confirm this!) and charging notebook and smartphone so I think 350W more than covers it. Everything else 12V or gas. Installation will be close to batteries using cable provided by manufacturer and 60A fuse on positive so hopefully losses should be minimal.

    I have already looked at your download on permanent installation and will try to emulate this over the winter. Very grateful for the simple way you have explained everything.

    100W Solar panel and second 125Ah battery being fitted tomorrow and then two weeks of off grid freedom in SW France to test our self sufficiency out. :Smile:

    Neil

    OP = ?
     
  19. CHRI$

    CHRI$ Funster

    Joined:
    Jul 26, 2009
    Messages:
    5,595
    Likes Received:
    7,096
    Location:
    england
    OP=original poster
     
  20. Enjoy_Yourself

    Enjoy_Yourself Read Only Funster

    Joined:
    Jul 1, 2010
    Messages:
    86
    Likes Received:
    25
    Location:
    Pontypool, South Wales
    Thanks Chris
     
    • Like Like x 1
Loading...

Share This Page