Habitation 12 volt system

Hello all

We are currently on my first trip out in our 2011 Broadway EK after PXing  a Nuevo ES last October.
Stopped for a brew on services on M6 on way to Melrose CC site and checked the operation of the fridge and kept the engine running.
All ok but to my surprise, I noticed the 12v habitation electrics were fully functional.
The Nuevo whilst engine running only ran the fridge.
Should I be overly worried about this and does anybody have any ideas what's going on?

Thanks

JT

Totally different van, but I can run with, or without habitation 12v, depending whether or not the 12v switch on the zig unit is switched on or off. The fridge is independent of the 12v zig switch.....I thought all vans were the same, in this respect.     
Then again, I could be totally wrong..           wouldn't be the first time.      

I am surprised!  On my 2012, with the Sargent EC328, habitation 12v is off as soon as engine starts. Maybe the previous owner modified it.

From what I have read on the Sargent website, the 12 volt system (apart from the fridge) should be off when the engine is running so as to meet EMC requirements.

My Nuevo is the same year as yours so I think the 12V electrics should be disabled automatically by the Sargent control as soon as the engine is started.

One thing to check is whether the leisure battery is being charged while the engine is running. If the "engine run" input is not working, the split charge won't be on a typical recent Sargent unit. You may find that the fuse on this input is hidden away somewhere, depending on the model of power control unit, as it's external on some common models.

Spospe wrote:From what I have read on the Sargent website, the 12 volt system (apart from the fridge) should be off when the engine is running so as to meet EMC requirements.

What is "EMC requirements"..........more European red tape useless input ??   

Hi  

logburner wrote:What is "EMC requirements"..........more European red tape useless input ??    

A simple question with a very complicated answer but certainly not just red tape.

For EMC read “electrical interference” It’s a massive problem nowadays but generally not well understood by people not involved with it on a day to day basis. Why should it be? You can’t see it or feel it but it has been responsible all sorts of equipment malfunctions, some trivial, some more serious  and some the cause of fatal accidents.

These effects are much more common than you may think but would undoubtedly be even more common if it wasn’t for the effort and expense that goes into understanding it and designing equipment to cope with it (to defined levels anyway) as well as testing for compliance to the standards.

These days we define the level of interference a piece of equipment is allowed to emit and perhaps more importantly (particularly for safety critical systems) the level of interference it must withstand before it fails.

http://www.emcuk.co.uk/awareness/Pages/InterferenceExamples/Automotive.htm

If you read the papers you could be forgiven for thinking that someone in Europe sits a desk thinking up daft rules. Not true, in fact these regulations apply in some form in most parts of the world and each region has various organizations responsible for accessing the problems as well as defining and implementing standards. In Europe the main organisation is probably CENELEC. You can think of the EU as the publisher /controller rather than the originator.

Cenelec itself is composed of members from various countries for example for example the British Standards Organization (BSI) in the UK.

http://www.cenelec.eu/aboutcenelec/whatwedo/factsandfigures/index.html

In the case of motorhomes when they say they ”turn of the electrics to comply with the regulations” perhaps they should say “we’re turning of the electrics because we don’t comply with the regulations”. That wouldn’t sound so good though would it?

Brod

But!! If you buy a European motor home the habitation electrics are available at all times.
These motor homes are identical eg same base vehicle,same fridges, heating systems etc etc.
Where would we find their compliance and in what form??

Mojo and Peter, you are on to something.

The display panel for the Sargent EC325 shows 13.8v  to 14.4v for the vehicle battery and 12.6v for the leisure when engine running.
Additionally, the panel shows "mains supply off" but all 230v works, then when you turn the charger on the EC325 the lcd shows "mains supply on"
I can alternate between on  and off by flicking the charger switch, but all all times all the AC sockets are live on hook up.
When the charger is on it charges both batteries whenever I select the relevant battery.

May be the previous owner wanted any rear passengers to watch TV whilst traveling.
From my point of view, the drawback is not charging the Leisure battery from the alternator if I wild camp.
Were would you look first?

Thanks

JT

Hi  



This deviation from the original question probably merits a thread of its own but for now:

roger7webster wrote:But!! If you buy a European motor home the habitation electrics are available at all times.
These motor homes are identical eg same base vehicle,same fridges, heating systems etc etc. ??

It doesn’t matter which European country the van is manufactured in, the rules are the same. It probably depends on how much testing has been done.

roger7webster wrote:Where would we find their compliance and in what form??

Through a "Certificate of Conformity" The vehicle manufacturer themselves should (must) be able to provide that information.

Examples here:

https://www.eurococ.eu/en/certificate-of-conformity

As far as EMC is concerned the base vehicle will have undergone EMC testing and issued with a Certificate of Conformity by (probably) a test house e.g.

http://www.tracglobal.com/content/emc-testing-automotive

As I understand it, that certificate will then be used (with others covering other aspects of the regs) to get type approval, and in the UK this means going through the Vehicle Certification Agency (VCA).

http://www.dft.gov.uk/vca/additional/files/vehicle-type-approval/system--component-type-approval/vca045.pdf

As I read the rules the converter then has to re-submit the vehicle for approval as a motorhome so there's probably a clue in this little piece of text.

“For example; if a product can only be used when the vehicle is stationary (e.g. through an interlock device such as a power supply connection via a relay switch fed the parking brake warning light) then it would not need to have an approval.”

Only the vehicle convertor can give a definite answer (and probably won't) but I suspect that many disconnect their own installations so as not to require the complication and expense of re-testing for EMC.

As for the fridge point, most fridges already have their own certificate of compliance e.g. (page 6):

http://www.caravanfridges.co.uk/pdf-manuals/rm-rms-rml-operation-manual.pdf

EMC areas that may be affected by the installation are a grey area.

Brod

So it seems there is no actual difference between UK and continental built motorhomes and any emc produced.
Its all down to the compliance certificate.
Thanks Brod for the info

All very complicated.   
I haven't a hope of understanding it all.......   
I'll just make sure the 12v switch on the zig is turned off, when moving on.....
Then I don't need to understand it.......it'll all go away..       

I will report back after the weekend when I get back to sunny Cheshire.
My multimeter and long nose pliers were erroneously left at home.

Thank you all

Hi

roger7webster wrote:So it seems there is no actual difference between UK and continental built motorhomes and any emc produced.
Its all down to the compliance certificate.

Possibly (perhaps probably), but be careful, you can't say there is no actual difference because no certificate means that in all likelihood there  been no test.  Many engineers would say designing for EMC compliance is a black art. That's debatable but certainly very small differences can have a massive effect how sensitive a system is to interference.

Something as simple as moving a wire can make all the difference between complete failure and a pass. Secondly one van may have EMC filters ( a sort of suppressor) fitted in sensitive areas where as another outwardly similar van may not.

Brod

Hello all again

Now we are home I have taken some readings, and very nice Melrose CC site is too.
Engine not running and panel switched off reading from the leisure battery terminals 12.75 to 12.94v (30 watt PV on roof causing variance)
When engine running no perceivable difference in readings.
I can the turn the panel on with the engine running, introduce a load by turning on TV and lights and I can get a voltage drop to 12.3v

I can the select the vehicle battery and the lights and TV still on. The leisure battery returns to 12.75 volts and indicating no load and the habitation electrics are still live.
There is no voltage drop on the vehicle battery and presumably the supply is coming from the alternator circa 14 volts.

Perhaps of more concern is that when I hook up the mains the and select leisure battery, this is supplying the 12volt habitation system and exhibits the same voltage drop when I turn lights on etc. It appears the EC325 only supplies the 12 volt side when the charger is switched on. The "mains on" display only shows when the charger switched on.
I would not want to leave the charger switched on whilst on hook up all the time but otherwise I would be discharging the leisure battery.

Can I then conclude leisure battery the receives no charge when engine running and clearly a problem lies with the wiring to the EC50/ Sargent 325.?

I'd like to get an idea of what could have been either interfered with or possible failed.

Thank you,

JT

Ploughlin, You're a star.
But what a proverbial the notorious fuse 8 is to get to between drivers seat and seat panel.
It was not seated correctly.

Thank you very much

JT

Thanks Peter,

All is now fine.

Cheers

JT