12v electrical proplem

[Shaun_374468544]

Right, I dont quite know how to explain this, but i'll do my best.. Ive just fitted another mains charger to charge the battery.. Connected everything up, + from battery to pin 1, + to caravan switch panel to pin 2, - from battery to pin 3, now not connected the - to switch panel yet, but it works, I know it shouldnt, but it would appear the - return to the battery from the control panel is somehow running through the earth on the mains circuit.... Any ideas? been racking my brain for hours and cant figure it out...

Thanks

Shaun

 

[oldievanner]

As the "earth" connection from the 230v is connected to the caravan chassis, it would appear that the -ve from the 12v system is also some how connected to it as well.I would get this looked at swiftly as this is not very safe!!

 

[rayc]

quote: "As the "earth" connection from the 230v is connected to the caravan chassis, it would appear that the -ve from the 12v system is also some how connected to it as well.I would get this looked at swiftly as this is not very safe!!"

My motorhome,{and all others}, has the mains earth, the habitation battery negative and the vehicle battery negative connected to the vehicle chassis. How is this unsafe?

 

[ProfJohnL]

It is not permitted to use the chassis of a caravan(or motor home) as part of the Continuous Protective Conductor for mains appliances.

In other words The chassis should be earthed, but none of it should be relied on to complete a CPC circuit between appliances or the supply. the same applies to gas and metallic water pipes.

It is also seen as poor practice in the construction of caravans to use the chassis as a negative return for 12V appliances or road lights

 

[rayc]

It is not permitted to use the chassis of a caravan(or motor home) as part of the Continuous Protective Conductor for mains appliances.

In other words The chassis should be earthed, but none of it should be relied on to complete a CPC circuit between appliances or the supply. the same applies to gas and metallic water pipes.

It is also seen as poor practice in the construction of caravans to use the chassis as a negative return for 12V appliances or road lights

None of this distracts from the fact that on MH's the chassis is bonded to the mains earth, the vehicle battery negative and the habitation battery negative.