# Internal 12v electric fault



## barryd (May 9, 2008)

Yes it's that time of year again. Away for Christmas and we have a problem already.

The 12v internal electrics in the van is tripping when on hook-up. There is a Power Management System in our wardrobe and on it are three MCB's (Miniature Circuit Breakers) and also a charger switch which I think is linked to a Motorhome type charger installed underneath the wardrobe and fitted by Leisuretech a few years ago.

I have attached a photo and you will see that the charger red switch on the top is not lit up and that the third MCB is now off. If you put it on the whole system trips. The other two MCB's seem to control the 240v supply so that's working fine. All the 12v stuff in the van is working but obviously it's not charging so would go dead in a few days. I have got around this (thanks to the Gnome helpline) by plugging in a standard 12v battery charger and connecting it onto the battery and plugging it into the 240v system.

Battery is charging right now so I guess I'll just plug it in when I'm in the van, leave it off for a day or two then plug it in again etc.

But why has this happened and can I rectify it on site? We are here for three weeks. Everything was working fine for the four and a half months we were away but last week I had some welding done on the van. Maybe this could have caused a short somewhere if it was electrical welding as I am guessing they won't have thought to disconnect the leisure battery.

Any thoughts for this year's Christmas motorhome problem? 

Thanks


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## listerdiesel (Aug 3, 2012)

Welding can introduce spikes and excessive ripple currents through associated wiring, and it looks as though your charger has gone t*ts up.

Use the external one for now, give me a shout when you get back and we can talk you through what to look for.

Assuming nobody else pops up with a solution.

Peter


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## rayc (Jun 3, 2008)

Could you check what happens if you remove the lead that goes from the unit to the battery? Does it still trip?


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## barryd (May 9, 2008)

Thanks guys. I cant remember if I took the lead out of the battery charger but I did try it with the battery charger turned off and it still tripped. I was trying to trace where the lead goes into the PMS but couldnt figure it out. Looks like there are two leads coming out of the charger. Like an electroblock lead (if that is the right word) and there are several leads going in the bottom of the PMS so presumably one of them is for the charger. Ill try disconnecting it later and see what happens. Ill try and get a photo of the charger as I guess I could just replace it if its that that is the problem but it makes sense that it could be.

From memory I think it was quite expensive. That probably included Leisuretech fitting it of course but surely I could just do it myself if I get a like for like.


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## peribro (Sep 6, 2009)

Alternatively could there be something faulty with the power supply that is causing the MCB to trip? Since presumably the alternative battery charger you are using is not protected by a MCB you will have no way of knowing for sure unless you connect the van's battery charger to an alternative supply - maybe somewhere else on the site if possible?


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## barryd (May 9, 2008)

Hmm. Thanks. We are on a farm and the supply is coming from the farm house. They have an outside hookup point but when it wasnt working yesterday before I discovered it was tripping we stuck the end of the lead through the window and into the farmhouse kitchen to a socket on the wall which was definitely working and the same. This morning we have put it back in the one outside so thats two supplies its been plugged into and it trips on both. Ok so they are coming from the same house but I also put my tester in which showed all three red lights for live, earthed and standard polarity. There is no other sockets to try unfortunately.

The charger below the wardrobe is a volta intelligent 3-stage 18 amp leisure battery charger and a photo is below. Can get one on ebay between £100-£150. http://www.ebay.co.uk/itm/Volta-Int...hash=item4642a685df:m:m_TtaHJ-mRC-S9PXwWcrXXQ but I am reluctant to shell out that sort of money if it turns out its something else. According to the Volta bumf it should be well protected anyway. I just hope its not something in the internals of the PMS though as I bet thats expensive even if you can get hold of one.


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## Mrplodd (Mar 4, 2008)

Barry

Surely the MCB's are ONLY on the 230 volt system and not the 12V ?? Therefore you have a mains issue NOT 12 volt issue.

I would try disconnecting all of the 230V items from their supply (remove plug/switch off etc) and then reinstall each in turn, when the MCB trips you have found the suspect unit. Could be any of the 230 v systems fed off that MCB (or is it the main MCB as in the one that turns everything off.)

Andy


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## trek (May 1, 2005)

There is a power switch on your volta 230 to 12v charger Turn it off then turn the tripping mcb off then back on and connect up the 230 hook up again 

If it still trips with the volta turned off i suspect its something else conncted to the same mcb , if it doesnt trip then switch the volta back on and wait for it to trip the mcb



Is the mains lead going into e back of the volta psu a kettle lead ? Can it be pulled out or is it hard wired in?


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## rayc (Jun 3, 2008)

The way I read it was that the MCB that is tripping is only feeds the charger. The 12v switch on top of the mains unit is really a charger on switch. It should be possible to remove the mains input from the charger and confirm the MCB does not trip under those circumstances. [ all safety precautions taken of course].
Perhaps Barry could confirm what the 12v switch does and whether it is a PMS1 or PMS4 unit?
Hopefully it will not be the PMS but they are relatively common and cheap on the used market
http://www.ebay.co.uk/itm/PMS1-Cara...eae9689&pid=100011&rk=2&rkt=3&sd=301683526143


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## trek (May 1, 2005)

Have you got two battery chargers ? 


Is there one built into the box with the mcb's and the 12v switch ? As you also have this volta psu which could have been added later ?


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## rayc (Jun 3, 2008)

trek said:


> Have you got two battery chargers ?
> 
> Is there one built into the box with the mcb's and the 12v switch ? As you also have this volta psu which could have been added later ?


This range of PMS manufactured by Plug In systems were very commonplace years ago in caravans and motorhomes. I suspect that the charger section went duff and a the stand alone one fitted by Leisuretech.

The three MCB's were normally allocated 
MCB1(10A) - SOCKETS
MCB2(6A) - LIGHTING
MCB3(6A) - FRIDGE / CHARGER

Of course there may have been additions over the years such as mains water heater etc but it is possible that the fridge is tripping the MCB and not the charger?


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## delawaredandy (Oct 12, 2012)

:spam1: God help us

M


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## barryd (May 9, 2008)

rayc said:


> This range of PMS manufactured by Plug In systems were very commonplace years ago in caravans and motorhomes. I suspect that the charger section went duff and a the stand alone one fitted by Leisuretech.
> 
> The three MCB's were normally allocated
> MCB1(10A) - SOCKETS
> ...


Ah ha! This makes sense. Just commented that stuff isnt that cold in the fridge and the freezer is hardly working at all. Its not on is it!

Just put it on gas so tomorrow Ill unplug, leave the fridge on gas and the charger off and then switch on the fridge first and see if its that. then the charger.

The external charger was indeed fitted when the original one went duff.

Its really hard to see what leads go where but ill get on it tomorrow morning.

Great stuff guys thanks


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## Geriatricbackpacker (Aug 21, 2012)

On the plus side I see from your photo that you have taken shoes and left your sandals at home.


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## tugboat (Sep 14, 2013)

Geriatricbackpacker said:


> On the plus side I see from your photo that you have taken shoes and left your sandals at home.


Yeah, what's wiv the buckles? You putting on Pirates of Penzance for the donkeys?


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## barryd (May 9, 2008)

Thought I had sussed it but its as clear as mud now. Switched the fridge and power supply for the 12v off and turned back on the third trip switch. All good so far. Didnt trip. Turned on the 12v battery supply, charger came on and immediately started charging. So then turned on the fridge onto EHU. Still didnt trip. So it looked like all was working. Two minutes later everything went off. The third tip switch went off but so did everything else. 

Now Im panicking a bit as we had lost all EHU power despite the other two trip switches still in the upright position. After much flapping of arms and choice words it turns out it had actually tripped the supply in the house where its plugged in outside so that was reset and it came back on. So Im back to where I was yesterday. Ive left the third switch off, put the fridge on gas and Im just using the supplied battery charger to keep the battery topped up.

Im just going to leave it at that as I dont want to end up with no power at all and dont want to keep bothering the farmer. 

The Fridge was the last thing switched on but Im now wondering if I have overloaded the house supply and maybe there is nothing wrong internally. Always been ok before here though.

Odd.


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## rayc (Jun 3, 2008)

barryd said:


> Thought I had sussed it but its as clear as mud now. Switched the fridge and power supply for the 12v off and turned back on the third trip switch. All good so far. Didnt trip. Turned on the 12v battery supply, charger came on and immediately started charging. So then turned on the fridge onto EHU. Still didnt trip. So it looked like all was working. Two minutes later everything went off. The third tip switch went off but so did everything else.
> 
> Odd.


If standard the third MCB is only 5A. If you try it again then do either the charger or fridge alone for a longish period of time. The fridge 240v element could for example be failing as it gets hotter, causing more current flow as its resistance goes down. It appears to be an over current problem as the MCB is tripping and not the RCD.

Either way your thought on leaving it and trying it elsewhere on a different EHU is sensible but if it has the same result then in my opinion the third MCB circuits need testing by a competent person who can split the third MCB circuits and test them individually with a high current tester.


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## erneboy (Feb 8, 2007)

Write that down Baz, "A Competent Person". Just so you don't forget.


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## zoro (May 1, 2005)

Sometime MCB's get tired and need replacing just one on many things that maybe wrong of course.

http://diy.stackexchange.com/questions/15286/is-there-a-lifetime-failure-count-for-a-breaker

Steve


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## trek (May 1, 2005)

But it sounds as though the farm house tripped out on its RCD - mmh!

Pity Barryd's camper RCD didnt trip , could be worth pressing the test button on that to check it 


I would hope its the fridge , and more than likey to be the element - and probably the cheapest item to replace excluding the removal and refitting of the fridge to change it , is Barryd up for this ?


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## barryd (May 9, 2008)

Thanks folks. Interesting Trek that you say you hope its the fridge. I was worried that would be the most expensive to replace. Charger I think was about £100. I think the charger is fine now though as it was working ok in the test until it tripped.

I had the solar and MPPT controller disconnected as a precaution but ive reconnected it as the Kontikis standard battery indicator was way over to the right, much more than normal and the MPPT controller when connected eventually sounded an overcharge alarm, it was showing 14.7 volts, F1 error and blue light which indicates over charge so I have switched off the charger. Ill let it run down a bit but I guess Ill need to keep an eye on this temporary battery charger as it seems it may just carry on and fry the battery. Im surprised as its only been on a few hours this morning but I guess most stuff is running on the 240v circuit. Showing 13.1 now.

As said, we have a working solution for now so Ill just carry on like we are and hope it stays like this.

Thanks again for all the help.


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## Mrplodd (Mar 4, 2008)

Once, just once, Barry will get away WITHOUT having a problem of some description. 

To quote Mrs Brown "You know what you are don't you Barry? 

A feckin' jinx" 

Andy


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## trek (May 1, 2005)

Personally i think Barryd just makes up these crisis - perhaps he needs some one other than Mrs B to talk too while he is away

- i must say if he does then they are very imaginative and shows his real knowledge of motorhomes , maybe he is just testing us in some perverse way


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## tugboat (Sep 14, 2013)

You give Barry too much credit.

If you'd ever met him, you'd know he really is a complete disaster.


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## barryd (May 9, 2008)

Im on Commission from VS to get the post count up. Truth be known I dont even have a Motorhome and live in Toronto!  Rumbled!


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## Pudsey_Bear (Sep 25, 2008)

trek said:


> Personally i think Barryd just makes up these crisis - perhaps he needs some one other than Mrs B to talk too while he is away


Mrs D won't like that.


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## barryd (May 9, 2008)

Everything seems to be kind of working at the moment. The borrowed charger is plugged into a 240v socket and is charging the leisure battery but at times it seems to be putting too much charge in. The MPPT controller the other day registered 14.9 volts and the overcharge alarm came on. I just keep switching it on for 2-3 hours and when it creeps up to about 14.2 Volts I turn it off. I am not leaving it on when the van is unattended. Am I best letting it run down to about 12.1 then leave it on for several hours or best just trying to keep it topped up?


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## erneboy (Feb 8, 2007)

I wouldn't let it get as low as 12.1 Baz. I'll send you a useful guide to voltage against state of charge, can't seem to post it here unless I put it in the cloud first.


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## barryd (May 9, 2008)

Thanks Alan, got that. I dont normally let it go that far down and there is no need to at the moment but as I have posted I think before I Reckon that battery is either duff or just not very good as it quickly goes down to about 12.1 after a day or so off hookup.


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## HermanHymer (Dec 5, 2008)

You know why Barry loves y'all don't you??? 

Answer: He'd be screwed without MHF! (Me too!)


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## erneboy (Feb 8, 2007)

Well as it's mid winter and you're probably watching telly and using lights and maybe heating with fans etc. it may be going down that far if not getting a charge for 24 hours. Especially as it sounds as though you may have a single leisure battery. It's quite easy to calculate your usage you know, then you will know whether the battery is performing as it should.

Is it just one battery, if so what capacity? In amp hours that is, not how much liquid is in it.


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## barryd (May 9, 2008)

Thanks. Its an Alphaline DC31 125AH and the thread about the original one failing and us getting it at the Battery Megastore in Caen is here. http://forums.motorhomefacts.com/182-electrical/122915-leisure-battery-woes-3.html

There is hardly anything running off the 12v circuit. TV is plugged into the mains but the lights, water pump and Satellite receiver are running off it. I might be inventing problems that are not there and its not a worry as I can just flip the charger plug and charge it for a while but I noticed even in the summer after a full charge on solar by morning it was showing much lower volts than the old one did before it broke last year. I think the old one was a Banner but I Cannot remember but literally it would start at 12.7 and only go down .1 amps per day in general usage, this one just doesnt seem as good.

Its sealed and requires no maintenance. If you read the thread it wasnt the one I wanted but I was kind of pushed into getting it but they supposedly are good batteries.

As said its not really an issue. Im just not that impressed with it. Maybe its worn out in a year of usage but the last one lasted 7 years.

Alan, I sent you an email by the way.


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## erneboy (Feb 8, 2007)

Ta Baz. I've replied.

Wait till you get home and do a proper drop test on the battery. Then you'll know.


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## Pudsey_Bear (Sep 25, 2008)

I'm surprised lord Jim hasn't responded to you Barfy, no sign on him for a month or so.


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## nicholsong (May 26, 2009)

erneboy said:


> Ta Baz. I've replied.
> 
> Wait till you get home and do a proper drop test on the battery. Then you'll know.


Last two times I have asked for a 'Drop-test' I have been told they are now not allowed to do them for 'elf aand safety' reasons.

Is this true or is it a training problem?

Come in Peter 'listerdiesel' please - you are are our battery expert.

Geoff


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## erneboy (Feb 8, 2007)

Just do it yourself, it's simple enough.


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## barryd (May 9, 2008)

Kev_n_Liz said:


> I'm surprised lord Jim hasn't responded to you Barfy, no sign on him for a month or so.


The Gnome has left the building so to speak. He just quietly flounced off into the sunset without a goodbye speech. 

I might start a bring back 747 campaign over Christmas. Im sure thats what he is angling for. Guffaw! Nowt he can do as he cant reply so fill yer boots. 

Peter and Alan already gave me some useful advice regarding testing the battery, Ill do it when I get home.

Thanks everyone.


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## Pudsey_Bear (Sep 25, 2008)

barryd said:


> Nowt he can do as he cant reply so fill yer boots.


He looks to be still subscribed and looked in at 15:53 today so he could reply if he wanted to.

Come on Jim, speak up lad, your humour is missed.


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## nicholsong (May 26, 2009)

erneboy said:


> Just do it yourself, it's simple enough.


Alan

I do not have a drop-tester in my tool box. Do you? How much are they? Where do you buy them now?

Geoff


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## trek (May 1, 2005)

cheap Sealey drop tester in "new year Sale" for £20 + p+P (P+P free if you spend over £25 )

http://www.toolstop.co.uk/sealey-bt91-7-battery-drop-tester-6-12v-p15049

instructions :- http://www.sealey.co.uk/pdfs/instructions/BT91_7.V3.pdf?

And 3% via quidco


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## cabby (May 14, 2005)

Or you could just use a hydrometer first to see if anything shows up.


cabby


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## nicholsong (May 26, 2009)

cabby said:


> Or you could just use a hydrometer first to see if anything shows up.
> 
> cabby


Yeah

Got one on the boat but not in the MH

Geoff


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## Harrers (Dec 21, 2011)

cabby said:


> Or you could just use a hydrometer first to see if anything shows up.
> 
> cabby


More and more batteries are sealed "no maintenance" nowadays so you can't use a hydrometer.

Earlier in the thread barryd has confirmed "Its sealed and requires no maintenance."

Drop tester sounds a useful addition to the toolbox and thanks have been and are now given to trek for his link.


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## barryd (May 9, 2008)

So I cant test it then. Its charging quite well right now off the Solar Panel! Would you believe it in December?


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## barryd (May 9, 2008)

How do folks!

I know its been 3 months since I reported this problem but I have finally got around to testing the van at home.  Well Ive been busy you see and just getting the van out is a PIA (excuses etc).

Anyway Ive plugged it into the house today, flipped the third switch back up which was the problem one and put the fridge on the hookup setting which we think is what was tripping it. The Internal battery charger is working fine and I left the fridge on hookup for half an hour and nothings tripped. Plugged the telly in and played with that. Everything seems to be working. I only flicked the hot water tank on briefly as to make sure there was power as there is no water in it and it came on. The water tank was never in the equation though as it was a separate circuit to the one that was tripping. We thought it was either the fridge or the charger. 

It doesnt make any sense to me though because back at the farm at Christmas we tried the EHU plugged into the socket outside the house and one just inside the kitchen but probably on the same circuit. It still tripped and at one point tripped the house supply.

Im glad its working but I am always wary of stuff that miraculously fixes itself. Could it have been a fault at the house? Doesnt seem likely to me. Could it have been a dodgy earth thats somehow sorted itself on the way home with a bit of driving?

I suppose the only way to properly find out is to take the van off somewhere for a night or two. Anyone fancy a mini meet somewhere oop norf? 

Any opinions greatly appreciated.


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## Penquin (Oct 15, 2007)

Could it have been dampness in the ends of the EHU cable? Or in the socket into which you plugged it?

Tripping generally indicates a fault where the current has the opportunity to short circuit even a small amount (I think they used to be called Earth Leakage Circuit Breakers and picked up if any current was going to earth....) They also used to come in a variety of values in terms of the tripping current from 5 milliamps to 50 milliamps from memory - if a lightbulb blew in my m-i-l house the trip went - it was a 5ma one....... Apparently a blowing lightbulb can do that....

So it may not have needed much sogginess to cause the trip to operate....

Just a thought, but if the cables had been on the ground or it was VERY wet weather then dampness could have caused it and it might have dried out since.....

That's just my opinion and theory, probably way off, but it does show that I am still thinking and still awake....

Dave


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## barryd (May 9, 2008)

Penquin said:


> Could it have been dampness in the ends of the EHU cable? Or in the socket into which you plugged it?
> 
> Tripping generally indicates a fault where the current has the opportunity to short circuit even a small amount (I think they used to be called Earth Leakage Circuit Breakers and picked up if any current was going to earth....) They also used to come in a variety of values in terms of the tripping current from 5 milliamps to 50 milliamps from memory - if a lightbulb blew in my m-i-l house the trip went - it was a 5ma one....... Apparently a blowing lightbulb can do that....
> 
> ...


Its possible I suppose. Cable end was probably dragged across wet grass. I never understand this. The plug that goes into the van has a sprung hinged cap on it but the other end is bare which is often the one that gets slung on the ground. Hmm. It was only one of the three switches on the control board in the van that kept tripping though.


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## Penquin (Oct 15, 2007)

If it was only one switch, then the fault must be in that circuit not the mains lead (yet another idea goes out of the window, now if I had been a professional I could have charged £90 call out fee for that non-advice), what does that circuit do in detail?

You mentioned the fridge, the water heater and the charger, are these on separate circuits? What about the mains sockets?

Lots of questions - now you will regret ever asking or reading my post.... 

NB I am not going to charge any more for the second consultation, the fee is the same - nuffink......

Dave


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## barryd (May 9, 2008)

Thanks Dave. The circuit that was effected appeared to operate the Vans 12v charger and the Fridge. What I did in the end was leave it tripped and charge the battery of one off the 240v sockets with a battery charger and run the fridge off gas. 

I was now wondering if it was my hookup cable as its getting on a bit and I racked my brain as to when it was last used and it was in Brittany where it was laid across a road with a fair few vehicles running over it. I remember checking it and it seemed ok but I wondered if It could be that. Then why would it not trip all three switches or the main switch like you say?


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