14' Series Advice for new 14.44-4 owner

[Boots in Action]

Thanks. Yes, I've tried this using earth from another 20m extension lead - 1.5ohm resistance from chassis to house earth.
15A earth pin on van inlet plug to van chassis is 0.1ohm.
Same with any GPO earth in van to van chassis.
Removed and tested extension lead, all continuity and resistances check out ok.
No RCD's tripping

@Dirtynidge , there is something wrong alright. The 240 volt AC circuits should be entirely isolated from the 12 volt DC circuits. The only "common" area is the Setec where 240 volt AC is changed to 12 volt DC to charge battery and provide 12 volts source for 12 volt appliances. And that is where AC current could be getting into the 12 volt lines. Try disconnecting the Setec at its 240 v power point and check trailer connections then for 12 volt power without any AC current superimposed on the lines.

 

[mikerezny]

It is not uncommon for wiring around 240V cabling to pickup some voltage from induction. In AV, one quickly learns to run microphone cable well away from lighting cable unless one particularly wants a 50Hz or 100 Hz hum in the speakers throughout the performance.

Yes, you may well be able to pick up some AC induced into the 12V cables. Especially if you are using a digital multimeter or a very high impedance analog multimeter.
So it could be induction OR it could be leakage from a 240V device such as the Setec.
Now, if it was leakage, the RCD unit would pick it up and trip the circuit. You need to check that this is indeed functioning correctly.
First test, go to the RCD unit and press the test button. It should trip the breaker. Reset the breaker and test it a few times.
If it trips every time, there is a strong possibility that it is not leakage from a 240V appliance.

As a reminder, this should be checked EVERY time the van is connected to 240V to ensure the occupants are protected.

But to make absolutely sure, unplug all appliances from the sockets except the Setec : stove, fridge, H/W etc to see if it is any of those appliances.
Check for the AC voltage each time.
Finally, unplug the 240V lead for the Setec and check again.
If you have had AC still on the 2V wiring after all this, it is most likely induction from the 240V cabling into the 12V cabling.

As I said in a previous post, measure the resistance from the earth pin on the 12V trailer plug, pin 3 to the van drawbar and post your results.
It should be close to a short circuit. If it is not, the van -VE is not grounded to the chassis. If that is the case run a wire from the -ve of your battery to the chassis and the voltage may well disappear.

Another question. Are you making these measurements with the van disconnected from the vehicle?
If so, you will probably find that the voltage disappears when you hitch the van up and connect the 12-pin plug. In that case, the car earth will then ground the van and the problem may disappear.
Again, if this is the case, your van -ve is not connected to the van chassis except through the car.

If you are in ANY doubt how to follow and understand the above instruction, go and get it looked at professionally. Faulty 240V wiring inside a metal van can be dangerous and can easily kill someone.

take care
Mike

 

[Dirtynidge]

It is not uncommon for wiring around 240V cabling to pickup some voltage from induction. In AV, one quickly learns to run microphone cable well away from lighting cable unless one particularly wants a 50Hz or 100 Hz hum in the speakers throughout the performance.

Yes, you may well be able to pick up some AC induced into the 12V cables. Especially if you are using a digital multimeter or a very high impedance analog multimeter.
So it could be induction OR it could be leakage from a 240V device such as the Setec.
Now, if it was leakage, the RCD unit would pick it up and trip the circuit. You need to check that this is indeed functioning correctly.
First test, go to the RCD unit and press the test button. It should trip the breaker. Reset the breaker and test it a few times.
If it trips every time, there is a strong possibility that it is not leakage from a 240V appliance.

As a reminder, this should be checked EVERY time the van is connected to 240V to ensure the occupants are protected.

But to make absolutely sure, unplug all appliances from the sockets except the Setec : stove, fridge, H/W etc to see if it is any of those appliances.
Check for the AC voltage each time.
Finally, unplug the 240V lead for the Setec and check again.
If you have had AC still on the 2V wiring after all this, it is most likely induction from the 240V cabling into the 12V cabling.

As I said in a previous post, measure the resistance from the earth pin on the 12V trailer plug, pin 3 to the van drawbar and post your results.
It should be close to a short circuit. If it is not, the van -VE is not grounded to the chassis. If that is the case run a wire from the -ve of your battery to the chassis and the voltage may well disappear.

Another question. Are you making these measurements with the van disconnected from the vehicle?
If so, you will probably find that the voltage disappears when you hitch the van up and connect the 12-pin plug. In that case, the car earth will then ground the van and the problem may disappear.
Again, if this is the case, your van -ve is not connected to the van chassis except through the car.

If you are in ANY doubt how to follow and understand the above instruction, go and get it looked at professionally. Faulty 240V wiring inside a metal van can be dangerous and can easily kill someone.

take care
Mike

Thanks for the great advice. I've removed the 240v supply to van until the weekend when I'm going to get chance to look at it properly. Not taking any chances til then.

Yes, I am checking with trailer plug unplugged from car.

As per your advice, I did just check pin 3 on van trailer plug (earth) and measured no continuity to the van chassis, house battery -ve mustn't be earthed to van chassis.

Out of interest, as mentioned in the beginning of this thread, my Setec unit is unplugged from 240v as it's charger is 'fried' A 5A CTEK trickle charger is taking care of charging duties via the van's 240v circuit.

 

[mikerezny]

Thanks for the great advice. I've removed the 240v supply to van until the weekend when I'm going to get chance to look at it properly.
Yes, I am checking with trailer plug unplugged from car.
As per your advice, I did just check pin 3 on van trailer plug (earth) and measured no continuity to the van chassis, house battery -ve mustn't be earthed to van chassis.

Ok, then you are most probably picking up stray induced voltage from the 240V cabling into the 12V wiring. High impedance digital multimeter are sensitive enough to pick that up.
But you should still go through the entire procedure I outlined to see what results you get.

take care
Mike

 

[Boots in Action]

Ok, then you are most probably picking up stray induced voltage from the 240V cabling into the 12V wiring. High impedance digital multimeter are sensitive enough to pick that up.
But you should still go through the entire procedure I outlined to see what results you get.

take care
Mike

Hi Mike @mikerezny , my understanding of RCDs is that the AC line must be earthed for RCD to trip. If there is no proper earth for the AC line (at male entry point?) or elsewhere on the AC line, then certainly induction from high voltage AC power will probably be the cause of AC being picked up on close DC circuits especially if lines run parallel for some distance. Looking back over this thread, I cannot see or remember if @Dirtynidge has done a meter check from earth on 240v van input point to van chassis. It should prove if 240v line is earthed or not, even if it means checking every 240v outlet for earthing. That may cut down the time somewhat. Otherwise, he has to do all the other checks as suggested .

 

[Drover]

Did you change the 240v lead or do a continuity check on the lead, that is the lead on its own and each of the 3 terminals tested to make sure that they haven't broken................... I had similar problems once, checked lead and it was a broken earth in the lead, binned the lead and replaced with another and problem solved......if the earth in the lead is broken the RCD will do nothing.

 

[Dirtynidge]

Yep @Drover - I tested lead for insulation resistance and continuity, all sweet.

Thanks @Boots in Action - I maybe didnt mention it but Earth pin on van's 240v input has 0.1ohm to chassis.

Will do all the other checks as instructed over the wkend

 

[Drover]

On one van I was hunting a fault it was a screw in a cable, very difficult to find.... Unplugged everything then tested every powerpoint for continuity when turned on and off, of course no 240 connected, beauty of double pole points shows things up easily... Also on one was a slight water leak caused corrosion took hours to find.. isolting each section and testing, always started at the lead then the external socket, the RCDs called Gold something have had a known recall on them as well, common in many caravans.

 

[MDS69]

something fishy going on there. Can you measure from the van chassis to earth. Run another extension lead from a power outlet in your house and use the earth pin in that lead then measure to the chassis With the original power lead powering the van.

Thanks. Yes, I've tried this using earth from another 20m extension lead - 1.5ohm resistance from chassis to house earth.
15A earth pin on van inlet plug to van chassis is 0.1ohm.
Same with any GPO earth in van to van chassis.
Removed and tested extension lead, all continuity and resistances check out ok.
No RCD's tripping

sorry when I said measure from the chassis to another power lead earth pin I meant for voltage not resistance. While your at it check the polarity of the power point your original lead is plugged into.