Check Caravan earth bonding for continuity

[Daren225]

Hi to everyone,
Could anyone advise me on how to check earth bonding for continuity on the touring caravan.
Many thanks in advance

 

[ProfJohnL]

Are dealing with a touring or a static caravan/holiday home?

 

[Buckman]

Are dealing with a touring or a static caravan/holiday home?

In the first post they stated it was a touring caravan, but not exactly sure of their question and if there is a fault somewhere with the connections inside the caravan or the connection to the vehicle?

 

[Dustydog]

Over the years there have been great changes on EHU and caravans on 230v wiring. We need to know the make model and age of Daren’s caravan

 

[Jcloughie]

I am not an electrician, but the only opportunity to bond a touring caravan is to the chassis. Though, I do not remember ever remember seeing a connection on mine. I have though heard of some who adding an earthing rod to permanently sited vans.

Other than that, surely just a matter of checking continuity.

The earth's integrity will, I feel sure, be checked as part of a service.

John

EDIT. after a little research I find that earthing rods are NOT a good plan when RCD’s are used.

 

[Dustydog]

I am not an electrician, but the only opportunity to bond a touring caravan is to the chassis. Though, I do not remember ever remember seeing a connection on mine. I have though heard of some who adding an earthing rod to permanently sited vans.

Other than that, surely just a matter of checking continuity.

The earth's integrity will, I feel sure, be checked as part of a service.

John

EDIT. after a little research I find that earthing rods are NOT a good plan when RCD’s are used.

John , spot on .
I think the jury is still out and like you I am no qualified spark.

A chap on another caravan forum, no names , posted this a while back. One or two on here will fully comprehend what he says.BTW he is a fully qualified spark.

”
Many people plug in their caravans without thought for this, but if you are providing a supply specifically for a caravan then yes, it shouldn't be connected to a PME earthing setup.

Regarding why:
On a TNCS earthed supply there can be a difference in potential between the combined installation Neutral and Earth and real earth due the return neutral current.
Inside a house this is relatively safe.
Outside there are two particular scenarios to consider:
1 - standing on real earth and touching anything earthed can give a tingle. Not dangerous, but un-nerving!
2 - very rare scenario, but if the supply Neutral breaks, then worst case the turn Neutral current goes to the cutout, is linked to earth, and is then looking for a return path through everything that is earthed. The degree to which it will find one depends on each unique situation, e.g. whether there's a metal bonded water pipe. But standing outside on real earth and touching anything earthed is worst-case putting 230v between your hand and your feet with you in the middle as you could be the return path.

So on caravan sites, and supplies to caravans, the installation earth is not connected to the caravan earth, to avoid these scenario's happening.”

I hope this makes sense. DD

 

[ProfJohnL]

I'm sorry I missed the OP's reference to the Touring caravan...

The role of the caravans chassis in the electrical system is often misunderstood. It is often said to be earthed, and it may well be connected to earth terminal in the consumer unit, but it is not to be relied on to act as the safety circuit by being the only path for fault current to pass.

Every mains appliance that needs to be earthed (class 1) must have a direct wired CPC (Circuit Protection Conductor) back to the consumer unit.

The IEEE wiring regs set out the gauge of the CPC (Green/Yellow) conductor and the maximum resistance it should exhibit under load.

The IEEE also set out how the circuit must be checked, and the calibrated equipment needed to perform it.

The CPC is an essential part of the protection circuit, and if its not correctly installed or damaged, the RCD may not protect users if a fault occurs.

I strongly suggest that this is not a DIY job, and should be carried out by a qualified and approved electrician.

 

[Daren225]

Just to remind for everyone my question was HOW TO PERFORM EARTH BONDING CONTINUITY CHECK ON TOURING CARAVAN.
That’s it
Thanks again

 

[Dustydog]

Just to remind for everyone my question was HOW TO PERFORM EARTH BONDING CONTINUITY CHECK ON TOURING CARAVAN.
That’s it
Thanks again

I think we all got it first time. Daren , capital letters on this Forum is seen as shouting! You are asking something very complex, subject to make model and year of your caravan, what extra wiring has been added . Already some Forumites have answered you, but clearly not to your satisfaction.
People are on the case. Where do you think the earth bonding continuity starts? I don’t know .

 

[Hutch]

Just to remind for everyone my question was HOW TO PERFORM EARTH BONDING CONTINUITY CHECK ON TOURING CARAVAN.
That’s it
Thanks again

Hi Darren, your question is not just a straight forward one, and fortunately you received comprehensive replays.
Forum members are not sure if you are asking about 12 volt car // caravan light systems or 240 volt systems.
Maybe stating, why you want to check the earthing may help to answer your question, ie I have replaced the fridge/ cooker / microwave. Or I have replaced a rear light unit and the lights are not working
. And want to check before getting a full service. To make sure everything is correct.

 

[ProfJohnL]

Just to remind for everyone my question was HOW TO PERFORM EARTH BONDING CONTINUITY CHECK ON TOURING CARAVAN.
That’s it
Thanks again

If you were electrically qualified to carry out mains wiring tests, you would know how to do it, so the fact you have asked implies you don't know and therefore are not qualified.

I actually told what was required in Parra 3 of my earlier reply.

Essentially it is a series of resistive tests to ensure all the CPC points in the circuit have the capacity to carry the full circuit current, and its resistance is low enough to make it the preferred route for current to take rather than through a human body.

It's not something you can do without the proper test equipment to ensure the safety of you or your family or any other person

 

[Daren225]

Hi Darren, your question is not just a straight forward one, and fortunately you received comprehensive replays.
Forum members are not sure if you are asking about 12 volt car // caravan light systems or 240 volt systems.
Maybe stating, why you want to check the earthing may help to answer your question, ie I have replaced the fridge/ cooker / microwave. Or I have replaced a rear light unit and the lights are not working
. And want to check before getting a full service. To make sure everything is correct.

Hi,
Thanks for your reply.
My caravan recently had full service performed by qualified AWS engineer.
One of the box on the job sheet asking for earth bonding continuity check (check earth bonding for continuity PASS/FAIL)
I’m simply want to know how did the engineer perform this test ?
Thank you

 

[Dustydog]

Darren,
some of our replies may seem less than helpful. I am not a qualified spark and whilst I know a lot we do have to be careful what we say for fear of misleading people with erroneous advice.
This older thread may be of interest to you and help find the source of the problem. If you check all the plugs , sockets any copper pipes that may have bonding tags, for security and no corrosion you should find the problem. I’m surprised your AWS didn’t offer to resolve it for you.

https://forums.practicalcaravan.com/threads/earth-bonding.57091/reply?quote=466579

 

[otherclive]

I don't think Darren has said that he has a problem, he just wants to know how a test is performed but he has not said if the AWS engineer actually ticked the service record Pass/Fail, or left it blank. Back in 2009 (ish) there was much discussion wrt electrical safety and the potential introduction of mandatory testing. Some sites were even refusing customers if they could not show a certificate. That all died down, viz

New Caravan Electrical Test - This could effect you !!!!!

Hi, I have heard in the new year some sites will require caravans to prove/produce an electrical safety certificate. Could someone in the know please tell me what the proposed electrical test involves. How long does it take and what is the likely cost that we are expected to pay for the...

forums.practicalcaravan.com

 

[Daren225]

Darren,
some of our replies may seem less than helpful. I am not a qualified spark and whilst I know a lot we do have to be careful what we say for fear of misleading people with erroneous advice.
This older thread may be of interest to you and help find the source of the problem. If you check all the plugs , sockets any copper pipes that may have bonding tags, for security and no corrosion you should find the problem. I’m surprised your AWS didn’t offer to resolve it for you.

https://forums.practicalcaravan.com/threads/earth-bonding.57091/reply?quote=466579

Hi mate,
Thanks for your reply but again I just simply want to know how the test is performed

 

[Buckman]

Hi mate,
Thanks for your reply but again I just simply want to know how the test is performed

Maybe the best person to ask is the AWS technician that serviced the caravan?

 

[Dustydog]

Ok. Start with the EHU cable. Use your multimeter , set on ohms , on the earth pins. Plug the cable into the caravan socket but not the mains. Multimeter on the earth pin and then probe the metal parts of the caravan. That’s the broad idea but probably no where as sophisticated as the AWS.
Did yours pass or fail?

 

[Buckman]

Ok. Start with the EHU cable. Use your multimeter , set on ohms , on the earth pins. Plug the cable into the caravan socket but not the mains. Multimeter on the earth pin and then probe the metal parts of the caravan. That’s the broad idea but probably no where as sophisticated as the AWS.
Did yours pass or fail?

Makes you wonder about reversed polarity found on some sites in France as caravans are not earthed. Perhaps the OP is wondering why they have paid for something that isn't possible? After all we got charged £5 for the service department to test the CO2 detector. 😂😂 😂

 

[Jcloughie]

My guess, and I emphasise guess, is that the continuity of the earth is checked at all outlets from the mains inlet. IF, the chassis is grounded, this would be part of the check, (but I don’t know that it is).

The hook up cable also forms part of the check, but only if it is accessable. The service engineer cannot check it if it is not with the van.

John

 

[Daren225]

Darren,
some of our replies may seem less than helpful. I am not a qualified spark and whilst I know a lot we do have to be careful what we say for fear of misleading people with erroneous advice.
This older thread may be of interest to you and help find the source of the problem. If you check all the plugs , sockets any copper pipes that may have bonding tags, for security and no corrosion you should find the problem. I’m surprised your AWS didn’t offer to resolve it for you.

https://forums.practicalcaravan.com/threads/earth-bonding.57091/reply?quote=466579

Maybe the best person to ask is the AWS technician that serviced the caravan

Ok. Start with the EHU cable. Use your multimeter , set on ohms , on the earth pins. Plug the cable into the caravan socket but not the mains. Multimeter on the earth pin and then probe the metal parts of the caravan. That’s the broad idea but probably no where as sophisticated as the AWS.
Did yours pass or fail?

This all I actually wanted to know.
Many many thanks mate👍👍👍

 

[ProfJohnL]

Hello Daren,

I'm sorry that you had not received the information you were looking for. Please understand that forum contributors only have what you tell us to go on. We are not mind readers and therefore cannot always meet covert reasons.

If you had told us what you were looking for and importantly why? our responses may have been more focused.

However as Dusty says the simple multimeter cannot do the whole job to the required standard. You should also be aware, that not all metal parts in a caravan will necessarily need to be "earthed" so the results you get that may produce a concern which unless you know the status of the metal part may be unfounded.

You must have some reason for querying the job, Why not ask the company that carried out the work?