Anderson plug fuse in tvan keeps blowing when charging from car

[graemeb10]

Hi tvaners, i have a 2013 tvan murranji with dual 105 ah baterries. When i connect it to my car via anderson plug it initially starts charging and the victron dial tells me it is drawing around 36 amps. After about 5 minutes of this the 30amp maxifuse in the tvan battery box blows. I still get solar charging from onboard unit and can plug additional solar into the side anderson plug and it seems to work. I drive a 2015 colorado and had arb install the anderson plug with a redarc isolator to protect the crank battery. I am on the road at the moment in barcaldine qld and would like to sort this out.

Graeme

[Cruiser 105Tvan]

Good possibility that there's some wire rubbed through somewhere between the fuse on the Tvan and the Batteries.
Where are the Batteries in your Tvan., in the front or rear?
Have you checked the Batteries to see if they're OK?
The other Possibility is something getting cooked.
The wires from the solar controller, if original, will be separate and not use the larger cables.
Has the Tvan been used on corrugated roads a lot?
You could check the power lead in the A frame for damage, and then along where it is fixed to the trailer.
You sure the fuse is correctly rated for its job? 
My 2009 Tvan has a 30 Amp fuse for 2x105Ah AGM's.. Drawing 36 Amps. would stretch the friendship in mine a lot.

[graemeb10]

Thanks for the reply Robert. Batteries are in the back and all wires appear good from fuse to battery. Batteries hold charge well so they seem fine. The tvan has not done much off road but will do so soon i hope.

[Cruiser 105Tvan]

Greame,
One way to find the problem, not the most chosen of course.
you could always fit a 100A. fuse and take it for a drive and then check to see what was fried.
You would soon see what the problem was.
Just sayin, if this is the method of choice, you may need somebody close with an extinguisher.
Or someone sitting on the A frame ready to pull the leads and Anderson plug connector.
These are not the normal way to fix this either.
I would talk to an Auto sparkie for better help.

[Ray]

Wouldn't a 40 or 50 amp fuse be more appropriate? If I read the first post correctly it would be perfectly normal for the alternator to be supplying over 30 amps for a while if the batteries are low on charge so a bigger fuse will be needed. We have the 30 amp fuse and 1 old 100ah gel battery which never draws more than 20 amps so 30 amp fuse is fine for us.

Ray

[MYT150]

Graeme,

The wiring runs from the Anderson plug to the fuse and then to the battery. So the wiring form the fuse to the battery is probably fine, but the issue will be the wire from the anderson plug to the fuse, the idea is that the fuse should blow before there is any damage to the wiring in the van. I have blown the fuse when the anderson plug fell out and was lost, and the wires shorted out. So I would suspect that some where the wiring has rubbed through and is shorting out probably on the chassis.

The other option would be to try a 40 or 50 amp fuse and see if it still happens, I wouldn't go any bigger. On my 2016 model with dual batteries the fuse from the anderson plug is a 50amp fuse from memory.

[Cruiser 105Tvan]

As Aidan has mentioned it's probably in the pair of Battery wires inside the A Frame.
The wires could have been damaged when the front box was anchored to the trailer.
Disconnect the battery/s. If you Don't You will cause yourself grief.
Using a screwdriver, pull the big leads out of the grey anderson socket.
On the open end of the socket you can see a flat spring under the contacts.
Depress the spring and pull the cables out of the socket, one at a time.
This will allow you to pull the cables out of the A frame.
Tie a piece of builders line into the cables before you start so that you can pull the cables back when you have checked them.
Pull them out of the A frame from the body end, near the underside of the front box.
When you've done this you can check the cables for damage and repair or cover with another layer of flexible pipe similar to the original.
Tie the string onto the cables and pull them back inside the A frame to their original location.
Refit the cables into the Anderson socket as indicated on the socket.  Just by pushing the leads back into place.
If you still can't fix it, take it to an Auto Sparkie/Electrician.
The Battery terminals are insulated from the box they sit in aren't they?
They haven't bounced around and developed damage to the material insulating them from the box they sit in have they?
If there is polystyrene in there, pitch it, and replace it with closed cell foam matting like those fit together matting squares cut to fit.
Polystyrene doesn't last real well.

[weonatvan]

Before you go to all the hassle of removing the cable from the A frame for possibly no reason, I'd be doing a couple of quick checks first.
With the fuse removed place a multimeter set on continuity with the 'beeper' set (diode test setting) across the terminals in the Anderson plug first and then positive to earth/chassis. If all is good and no beep after wriggling the cable while testing then my guess is simply that you need to up the amperage of your fuse to say 40, max 50 and see how you go.
If your pushing 36 amps through a 30 amp fuse I would think it would pop after a short time anyway, whereas a short would blow the fuse immediately and my thoughts are that your panicking over nothing.

If there was a short in the main cables then the fuse would blow no matter whether your tug was connected or not.

But what would I know?


"You don't know what you don't know"

Cheers dave

[Eelezy]

On a similar note, if a 2014 Mark3 tvan has been fitted with only one battery from factory, will it already have the correct fuse in place for a second one?
Chris

[mal1958]

Hi,
Sorry if I sound a bit pedantic, thats the engineering side of me that likes to get the facts right.

In the original post I understand that you see that the batteries are being charged at 36 A.    Is that correct ?  (Not being discharged).

Assuming the above is correct, if the batteries are being charged at 36 A then the fuse is going to be underated and will blow.   

I assume that it is the "vehicle fuse" as per the diagram in the "Tvan3BatteryWiring.pdf" in the electrical section of this forum.

The next question is, Is that a fault or a design issue ?

For AGM batteries, the rule of thumb when charging is that they should be charged at no more than 20% of the capacity.     

So for 2 * 100 AH batteries (200 AH) this equates to 40 A maximum total charge.

It is my opinion that the 30A fuse is an incorrect value (ie design fault).   The correct value for the situation of 2 x 100 AH AGM batteries should be at least a 40 A fuse.   


Now if on the other hand you have a discharge of 36 A when plugging in your tow vehicle, then you have an issue where the TVan batteries are discharging into whatever you have in your tow vehicle.    That would require further investigation of what you have in the tow vehicle.





Cheers,
Mal

[wigan48]

Hi All

My van is fitted with twin  100amp batteries .connect to  redarc 40 amp charger with a 30 amp fuse in the t van,had no trouble in 3 years.
The wiring to the anderson plug from the vehicle battery should be protected with an appropiate  fuse usually ( 50 amp rated).this fuse would also protect the cables going from the anderson plug on the van to the live terminal on the 30 amp fuse inside the van (when plugged in to the tow vehicle
I would not increase the size of the fuse ,because if there is a short circuit to earth the wiring would catch fire before the fuse blows.You could easy check the cables as Mal said ,but i would pull out  the 30 Amp fuse first ,this way you would only be metering the cable only.Have you a copy off the TVan wiring diagram ! Iwould also check all the connections on both batteries and on the insulated studs  in the right hand battery compartment,.If the fuse blows straight away ou have a dead short some where,if it takes a little time to blow then i believe you have a bad connection which is getting hot ,ie increased resistance high current flow this will blow the fuse at a slower rate
Hope this makes sense.

Roy