Caravan bonding

[Adrian Sadler]

Hiya

Anyone know whats the minimum size for cable is for...

A. Cu to rod
B. Gas/water/chassis bonding

also if metal framework of the door need extratous bonding?

Cheers

 

[Adrian Sadler]

The alternator manual has the wiring diagram inside. Its a portable genny with a floating earth it seems

 

[DuaneMHunt1976]

Well i couldnt find it in the Wiring Regs .. but TLC

"All metal parts of the caravan, with the exception of metal sheets forming part of the structure, must be bonded together and to a circuit protective conductor, which must not be smaller than 4 mm² except where it forms part of a sheathed cable or is enclosed in conduit."

https://www.tlc-direct.co.uk/Book/7.9.2.htm

I think what you are after is how to test a Caravans Wiring, so basically a Full Periodic Inspection that should be done every 3yr and the RCD tested every time you use it.

 

[davesparks]

The alternator manual has the wiring diagram inside. Its a portable genny with a floating earth it seems

So what would be the point of any earth rod?

 

[davesparks]

Well i couldnt find it in the Wiring Regs .. but TLC

"All metal parts of the caravan, with the exception of metal sheets forming part of the structure, must be bonded together and to a circuit protective conductor, which must not be smaller than 4 mm² except where it forms part of a sheathed cable or is enclosed in conduit."

https://www.tlc-direct.co.uk/Book/7.9.2.htm

I think what you are after is how to test a Caravans Wiring, so basically a Full Periodic Inspection that should be done every 3yr and the RCD tested every time you use it.

That quote sounds a lot like 16th edition language

 

[davesparks]

Rather than gonto the pub im gonna swat up on the regs and see whats what. If i dont understand ill give it a swerve. I do understand whats your saying about declining but it would be nice to understand whats going on and educate myself.

Ive spent years as an electrician but yer always learning....

What earthing/bonding is currently installed?
How old is the van?
Are there any records available for electrical testing?

 

[Adrian Sadler]

Most have 6mm bonds. A few have 4mm bonds. Vans range from 6 months old to 10 years

 

[Adrian Sadler]

If the gas bottles or water is outside the van im sure you would have to bond everything together to make things equal as i suppose you could introduce an imbalance if it wasnt. I know what im tryin to say but cant phrase it well :-(

 

[Adrian Sadler]

Right. After a bit of digging the genny has a floating earth.

In the manual it says it must be earthed (guessing via a rod)
all the cpc's that go back to the board and then staked.

From what ibhave read on other forums and genny sites - the 'best' way for a genny feeding a van is to link Earth to neutral in the genny or make a specific lead and stake it.

Any of this make sense to anyone? Would this then create a tn system? Head explode brewing.

In the regs book there are pictures showing the setup thats currently in place where its fed from a genny and all earth point for sockets/lights etc all bonded together

 

[GEOFF S]

Get an onsite guide, its all in there i believe.

Cheers

 

[shanky887614]

Right. After a bit of digging the genny has a floating earth.

In the manual it says it must be earthed (guessing via a rod)
all the cpc's that go back to the board and then staked.

From what ibhave read on other forums and genny sites - the 'best' way for a genny feeding a van is to link Earth to neutral in the genny or make a specific lead and stake it.

Any of this make sense to anyone? Would this then create a tn system? Head explode brewing.

In the regs book there are pictures showing the setup thats currently in place where its fed from a genny and all earth point for sockets/lights etc all bonded together

there is usually an earth terminal on the genny, just take a cable from there to the supply.

correct me if im wrong but what is the point in a rod?

so you have a rod at the genny and another at the caravan right next to it?

 

[davesparks]

Right. After a bit of digging the genny has a floating earth.

In the manual it says it must be earthed (guessing via a rod)
all the cpc's that go back to the board and then staked.

From what ibhave read on other forums and genny sites - the 'best' way for a genny feeding a van is to link Earth to neutral in the genny or make a specific lead and stake it.

Any of this make sense to anyone? Would this then create a tn system? Head explode brewing.

In the regs book there are pictures showing the setup thats currently in place where its fed from a genny and all earth point for sockets/lights etc all bonded together

Does this thing sit in metal legs or is it only supported on rubber tyres?

If you are carrying out periodic inspections on these then you need to be checking against the specification they were built to, not just randomly applying the regs you happen to know.

Yes you can turn one of the line conductors into a neutral by referencing it to earth, but if the installation has been designed to operate without an earth reference what danger will you create by adding the link?

 

[Adrian Sadler]

At the mo we have the chassis of the genny bonded to the internal consumer uni and framework and gas etc. The usual 16a blue plug from genny to hookup socket on the van. Also spec says in the van that a rod must be used.

If its a floating earth on the genny does this seem right? It seems the genny manual says genny must be earthed. Im just tryin to get my head round the earth path. If you stake the genny and stake from the cu to earth rod too - the fault would go down the cpc ofba 13a socket - to the board whichbin turn goes to thebearth rod. The genny frame is staked to the ground but unless n and e are linked in the genny there isnt a full circuit. Which it isnt.

 

[davesparks]

there is usually an earth terminal on the genny, just take a cable from there to the supply.

correct me if im wrong but what is the point in a rod?

so you have a rod at the genny and another at the caravan right next to it?

What supply?

The point of a rod (combined with a N-E link) with a generator is normally to make one of the lines be a neutral and reference this to the mass of earth. The same way that earthing the star point of a transformer does.

No they have one rod which they install when running from the generator and hopefully don't install when they are running from a mains supply.

 

[shanky887614]

What supply?

The point of a rod (combined with a N-E link) with a generator is normally to make one of the lines be a neutral and reference this to the mass of earth. The same way that earthing the star point of a transformer does.

No they have one rod which they install when running from the generator and hopefully don't install when they are running from a mains supply.

supply of caravan i mean, yes earth the genny but i would take the earth direct to the genny rather than another rod

 

[Adrian Sadler]

I think Dave may be right. I think i need to speak to the manufacturer.

But on the same token - whats to stop anyone just hooking a caravan to a genny sitting on the floor. It essentially wouldnt have an earth if it was a floating earth genny. Im trying to ascertain how/if this is even safe. Ya dont see non electric caravan pitches with rods on their gennys