Keeping habitation electrics on.

[wheelie67]

Afternoon Guys,

So I'm trying to find the supposed relay that turns the habitation electrics off when the engine is running on our 2018 Bailey.

I've searched and searched but Google can't give me a definitive answer of where this relay is, or a wiring diagram, but I believe that the green alternator wire is the signal wire.

Today I've taken the 12v / 240v electric box under the seat apart, and inside, hidden in the wiring is a little black box with 'HALL CURRENT SENSOR' written on it.

Could this be the mischievious little monkey that I'm after, (although obvs it's not a relay) that senses a current and shuts the electrics down?

I've never come across one of these before in 30 years of building custom cars so not totally sure what it does.

Cheers Ears.

 

[Stu-cambs]

On mine which is an older Autotrail , I found a wiring diagram , and then found that the wire which fed the 12v to the fridge then carried on to the Sargeant unit to tell it that the engine was running and turn off the 12v hab. So in my case it was just a case of snipping the wire (a pink one) going into the unit (after the fridge!) and voila !! I would suspect though on yours a 2018 it may be more complicated ?

 

[wheelie67]

Why do they have to make things so difficult The power / fuse box appears to be a Bailey own make.

 

[Two on Tour]

Why do they have to make things so difficult The power / fuse box appears to be a Bailey own make.

No, Bailey just re-badge them. They are made by BCA and Elddis use the same units.

This is the CBE SRX 250 relay unit that switches the hab 12v electrics when the engine is running on our Elddis and it's located at the bottom of the drivers side "B" post and is triggered by the alternator D+ energising.

 

[OllyHughes]

On mine which is an older Autotrail , I found a wiring diagram , and then found that the wire which fed the 12v to the fridge then carried on to the Sargeant unit to tell it that the engine was running and turn off the 12v hab. So in my case it was just a case of snipping the wire (a pink one) going into the unit (after the fridge!) and voila !! I would suspect though on yours a 2018 it may be more complicated ?

Can I ask what year your M/H is

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[WildBunch]

Hi Wheelie67.
You do not say why you want to turn off the Hab electrics when the engine is running.
Is it to put more charge into the engine battery. If this is the case & you do succeed in being able to do this, notwithstanding the fridge & other essential circuits, you may be disappointed.
The alternator is designed to charge the engine battery quickly, initially at a high current rate. After a very short time the engine battery voltage will start to rise & the current output from the alternator will ramp back automatically in proportion to the higher voltage. So perversely the additional domestic load may cause the alternator to provide a longer period of high charging current by holding the voltage down. I found a lot of helpful technical guidance on the Sterling web site who sell among many products a interposing device to fool the alternator into thinking the engine battery is still flat thus improving the charging of the batteries. This was a product for boats, so I do not necessarily recommend it for modern motorhomes.

 

[Stu-cambs]

Can I ask what year your M/H is

It s a 2004 Autotrail Cheyenne 696 (Merc Sprinter based)

 

[XxAnthxX]

You do not say why you want to turn off the Hab electrics when the engine is running

The thread title indicates he wants to keep the hab power on......

 

[WildBunch]

I stand corrected, my Hymer runs most of the domestics when the engine is running, thus my misunderstanding.

 

[XxAnthxX]

I stand corrected, my Hymer runs most of the domestics when the engine is running, thus my misunderstanding.

....I think this crazy situation only affects UK manufactured vans......

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[Two on Tour]

....I think this crazy situation only affects UK manufactured vans......

Maybe it will change for new models now we are out of the EU and UK manufactures are not tied the the EU directive that require the nonsense.

 

[Pausim]

Maybe it will change for new models now we are out of the EU and UK manufactures are not tied the the EU directive that require the nonsense.

Not sure you can blame the EU for this one, doesn’t seem to happen on continental builds. Electronic items can stay live as long as they have the right accreditation. I think it is down to the UK NCC which seems to have difficulty distinguishing between a caravan and a motorhome.

 

[Two on Tour]

Not sure you can blame the EU for this one, doesn’t seem to happen on continental builds. Electronic items can stay live as long as they have the right accreditation. I think it is down to the UK NCC which seems to have difficulty distinguishing between a caravan and a motorhome.

It really depends on who abides by the EU directive https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:32014L0030&rid=4 and obviously those continental manufactures have decided not to where as the NCC has require UK manufactures to do so.

Why would you think the electrical equipment in a caravan would produce EMC any differentially to that in a motorhome.

 

[peterc10]

Maybe it will change for new models now we are out of the EU and UK manufactures are not tied the the EU directive that require the nonsense.

Paul

I really do think that is an excuse used by the NCC rather than a reason. The EU EMC regs are the same in the rest of Europe and yet they allow German converters to keep on the electrics. The suggestion that these laws are being ignored is fanciful to say the least. And in reality the lights, water-pump, hob/oven/fridge gas-igniters you refer to are nearly all made and supplied by the same few major suppliers whether the motorhome is being converted in the UK or the EU. And those all have the correct EMC approvals, as they are required to have in order to sell them, thus ensuring that "electrical and electronic equipment does not generate, or is not affected by, electromagnetic disturbance".

This is not down to EU or UK laws. It is down to a whim of the NCC from a time when their members used to make only caravans and long before the 2014 regulations your refer to came out . There is and never have been nothing legally stopping UK converters doing the same as the rest of Europe, other than inertia.

 

[wheelie67]

wave a magnet by the sensor and see if the lights turn off.

Thats a great idea.

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[wheelie67]

If you can’t find the relay that cuts off the power would it be easier to add a second relay that bypasses it and neutralises the effect? A normally open relay powered by a D+ signal could provide the bypass when the engine is running and leave everything as normal when the engine is off.

I can understand an isolation circuit in a caravan in case unwanted circuits are left on but it seems the manufacturers and NCC have not noticed that motorhomes need different services. Sadly I think our UK motorhome manufacturers have a problem keeping up with developments, which is perhaps why some of them are being picked off by oversees competitors.

Yes, that's an option to think about.

 

[wheelie67]

The Hall Current Sensor is a device that measures current (amps). Typically it's used to monitor the charge going into and out of the leisure battery, and using a microcomputer to calculate the % state of charge of the battery. It won't be related to the relay that turns off the habitation circuits. It's an alternative technology to the 'current shunt resistor' method that is more popular.

Disabling the D+ signal from the alternator isn't a good idea, because it's used for several functions, including the fridge while the engine is running, and the split charge relay that charges the leisure battery when the engine is running. If we knew which electrics box it was, someone might know which relay is the habitation relay, and how to disable it.

Thanks, I've learnt something new.

 

[wheelie67]

No, Bailey just re-badge them. They are made by BCA and Elddis use the same units.

View attachment 461749

This is the CBE SRX 250 relay unit that switches the hab 12v electrics when the engine is running on our Elddis and it's located at the bottom of the drivers side "B" post and is triggered by the alternator D+ energising.


View attachment 461754

Very very helpful thank you.

 

[wheelie67]

Hi Wheelie67.
You do not say why you want to turn off the Hab electrics when the engine is running.
Is it to put more charge into the engine battery. If this is the case & you do succeed in being able to do this, notwithstanding the fridge & other essential circuits, you may be disappointed.
The alternator is designed to charge the engine battery quickly, initially at a high current rate. After a very short time the engine battery voltage will start to rise & the current output from the alternator will ramp back automatically in proportion to the higher voltage. So perversely the additional domestic load may cause the alternator to provide a longer period of high charging current by holding the voltage down. I found a lot of helpful technical guidance on the Sterling web site who sell among many products a interposing device to fool the alternator into thinking the engine battery is still flat thus improving the charging of the batteries. This was a product for boats, so I do not necessarily recommend it for modern motorhomes.

It's partly because if someone says you can't have that, then I want it, partly because at the moment when pottering about in it in the yard, I want to run the engine for the heating, but still be able to tinker in the rear , and partly when we do get out, be able to leave things charging in the back.

 

[Pausim]

Why would you think the electrical equipment in a caravan would produce EMC any differentially to that in a motorhome.

I didn’t say that.

I said that there is electronic equipment available which has the right accreditation to be left live i.e. turned on whilst driving. Obviously that would apply to caravans and motorhomes. The problem lies with the NCC which is a trade body not a Government agency and appears to be woefully out of touch with what motorhome users expect.

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[Two on Tour]

Unless Bailey have put in another provision for running the fridge on 12V then the BCA power distribution unit will initiate that by a relay in the unit when the alternator runs.

I have a schematic of the BCA power distribution unit if you want to trace any circuits.

 

[wheelie67]

Unless Bailey have put in another provision for running the fridge on 12V then the BCA power distribution unit will initiate that by a relay in the unit when the alternator runs.

I have a schematic of the BCA power distribution unit if you want to trace any circuits.

Cor, yes please. ady67@hotmail.co.uk Thanks.

 

[Two on Tour]

On it's way.

Delete your email address a bit smart-ish if I were you, not a good thing to advertise on a public forum.

 

[DiggerDogs]

The 12v on my Rollerteam 707 works when the engine runs. I know that as my battery is almost dead and it lifted the electric bed when the engine was going.

 

[Pausim]

The 12v on my Rollerteam 707 works when the engine runs. I know that as my battery is almost dead and it lifted the electric bed when the engine was going.

As part of the Italian Trigano Group, Rollerteam probably don’t feel the need to do silly things with the electrics.

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[Jonno1103]

As part of the Italian Trigano Group, Rollerteam probably don’t feel the need to do silly things with the electrics.

The Rollerteam & Chausson panel vans are the same and they're built by Auto Trail in Grimsby. Same goes for Swifts left leggers destined for Scandinavia but end up at Brownhills... the Norden's & Toscana's.

This suggests to me that it's purely a Brit thing? Are we the only country bothered about reverse polarity too?

 

[Pausim]

This suggests to me that it's purely a Brit thing? Are we the only country bothered about reverse polarity too?

Probably. I am no expert but I think most European countries use double pole switching whereas a lot of UK installations have single pole switches. For example our switched wall sockets have a single pole switch which means we only turn off the brown positive wire, if the polarity is reversed the blue negative wire becomes live. As I understand it most EU countries only allow switches that turn off both wires. They probably don’t bother putting switches on individual sockets and know that you are only safe if you have pulled the plug out.

 

[Coolcats]

Fridge/freezers run on 12v while the engine is running on UK van and yes, it's a total nonsense having the hab electrics switch off on UK vans.
It's not a case of the European van being allows to have the hab electrics on, more a case of not putting into practice the EU directives issued which as usual the Brits had been follow to the letter.

Just read the directive and I cannot find anywhere in the document it says the 12v system has to be switched off unless I have missed it, has anyone else read it and found the section that says the system needs to be switched off? (Could be another straight banana story).

 

[peterc10]

This suggests to me that it's purely a Brit thing?

It is a Brit thing. It is a requirement of the NCC (National Caravan Council) who are the trade body that all British converters are members of. There is no specific requirement in law for it anywhere in the UK or Europe. It is just their (well out of date) way to deal with getting over any stray electrical emissions.

 

[pete4x4]

Afternoon Guys,

So I'm trying to find the supposed relay that turns the habitation electrics off when the engine is running on our 2018 Bailey.

I've searched and searched but Google can't give me a definitive answer of where this relay is, or a wiring diagram, but I believe that the green alternator wire is the signal wire.

Today I've taken the 12v / 240v electric box under the seat apart, and inside, hidden in the wiring is a little black box with 'HALL CURRENT SENSOR' written on it.

Could this be the mischievious little monkey that I'm after, (although obvs it's not a relay) that senses a current and shuts the electrics down?

I've never come across one of these before in 30 years of building custom cars so not totally sure what it does.

Cheers Ears.

The BCA unit takes the D+ signal onto a PCB that also has the fuses mounted on it, there are a number of relays on that pcb that enable or disable the various circuits, there is not one individual relay that disconnects everything.
The lights have its own relay as does the 12v sockets, the fridge and battery charging each have their own so its a bit of a nightmare to do.
I have a B2B charger so I use the D+ line to switch a relay to disconnect the battery from the split charge circuit when travelling. ( this was done to prevent the B2B also powering the fridge)
I have a switch in the D+ line so I can keep everything on when I'm parked up and the batteries need charging off the engine. The fridge is not fed from 12v in this instance but would be on gas anyway and the batteries being charged via the B2B.

It was too messy to isolate the part of the pcb circuitry that turns off the hab side, although it could be done but you would have to cut tracks on the pcb and solder wires to them to an external switch.

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[pwilmo]

Hi one and all
Maybe the electrics are different now but I solved the hab shut off by disconnecting wires on a relay in the engine fuse box.
There is a relay on Ducato 2005/ 2006 that activates on engine ignition and switches off power to hab electrics but keeps 12v to fridge.
I have long ago posted this solution with pictures identifying which wires and relay to disconnect but being older vehicles maybe the wiring will be different.
Job done, granchildren loved watching 12v TV on the move and being able to flush/use toilet on the move.
Yeah Blah di da .. should you be out of seat belts, moving about whilst driving .. What happens on travel tour buses, trains, aeroplanes when you go to the loo, Elf &Safety Cor Blimey!!