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

 

[davesparks]

I don't know off the top of my head, I would have to check bs7671 after finding out the type of supply etc.

Have you tried looking in bs7671 yourself?

What sort of caravan is it for a start, static or mobile?

It's unusual for an individual caravan to need an earth rod

 

[Adrian Sadler]

I should have made the post clearer.

Its a facilities caravan for an asbestos firm. First room is dirty. Then shower. Then clean. They are built on caravan chassis basis.

They either run off a usual caravan lead with a 13a plug on the end - or an on board gas powered generator. When genny used a rod gets used.

I rang my tech helpline who gave me the run round and never helped at all....

 

[Adrian Sadler]

If it has to he half the size of the supply conductor - a 2.5mm gas bond just seems unreal.

I know with the rod it seems to depend on if its protected etc etc but does that apply to caravans too? Im stumped but ill get the book out later and see....

 

[davesparks]

You can't use half the size of the earthing conductor because you don't know the size of that earthing conductor if all you are doing is plugging in to a socket.

What size is the generator? Does it actually need an earth rod?

 

[Adrian Sadler]

This is what i dont get. How can o assess the correct size?
Genny is a small 2.7. 16a max. Tiny thing they actually use in go carts lol. Im sure it would need a rod as its essentially a TT. Genny isnt no big thing with neutral n earth linked

 

[davesparks]

It is not a TT, how on earth could a generator be a TT supply? It will either be a TNS or a seperated supply.

If there is no N-E link then what would be the point of installing a rod?

 

[Adrian Sadler]

Well now im learning

Ive never dealt with genny supplies before but since the manufacturer (of the caravan) states when using the genny the rod must be used I dont know if im meant to ignore them :-/

Keep it coming as im learning something new here

 

[davesparks]

Then I strongly recommend you employ someone who does know what they are doing.

What exactly are you doing to this caravan?

 

[Adrian Sadler]

They have asked me to 'check the electrics' but ibknow nothing about generator sets...

 

[Adrian Sadler]

http://http://www.stephill-generators.co.uk/technical-handbooks?information_category=2&category=alternator_handbooks&status=Current

Its the nsm k80 genny. Wiring diagram is there. Dont know if that's any use.

 

[davesparks]

They have asked me to 'check the electrics' but ibknow nothing about generator sets...

Then the best thing you can do is politely decline the job. You can't expect to be able to 'check the electrics' if you don't know anything about the equipment.

You are possibly straying out of the territory of bs7671 here.

 

[DuaneMHunt1976]

so your testing the wiring inside the caravan

I would guess test like you do a House. Dead Tests
Not a normal thing i look at but Section 721 of the Wiring Regs Electrical Installations in a Caravans and Motor Caravans p269
just trying to read it

 

[davesparks]

http://http://www.stephill-generators.co.uk/technical-handbooks?information_category=2&category=alternator_handbooks&status=Current

Its the nsm k80 genny. Wiring diagram is there. Dont know if that's any use.

I can't find a generator with that part number, only the alternator in your link?

 

[Adrian Sadler]

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....