Problem with mains circuit breaker

[Tim2]

I have a problem with the mains circuit breaker in the caravan. This is the breaker on the socket circuit. It has recently begun repeately tripping off even when there are no large appliances being used. At a recent service my dealer could only offer the solution of changing the unit at a cost of £50 + labour. Is there anything else that I could try first. Thnaks

Tim

 

[ProfJohnL]

Hello Tim,

When you brefer to the main circuit breaker, I take it that you men the one with the test button near it?

If my assumption is correct, the device is an RCB (Residual Current Breaker some times also known as an RCCD).

These devices are no over current devices, but are designed to detect very small earth leakage currents, so the size of the appliance has nothing to do with its operation.

Before assuming the RCB is faulty, it may be doing just what it is designed to do i.e. protecting you from a faulty appliance.

As a simple test, just turn off or isolate every piece of electrical equiepment in the caravan, Then one at a time turn them on, and see if one partiular item consistsntly causes the trip to operate.

Unless you are electrically trained, and with respect if you were, you would not need to have asked this question, I reccomend that you have the caravan checked over by a competenmt electrician to find out if it is a faulty appliance, or a faulty or over sensitive RCB.

What price safety?

 

[RogerL]

Tim, the info given by John is misleadlingly incomplete.

The mains electrical system in modern caravans has TWO types of electronic circuit breaker. The first, immediately after the mains input, is a Residual Current Circuit Breaker (RCCB). There are also one or more Miniature Circuit Breakers (MCB) acting like a fuse.

Electronic breakers have no replaceable or adjustable parts, not even by an electrician, so replacement of the MCB or RCCD is the only option if it's faulty.

MCBs are designed to act like a fuse to protect against excessive currents being drawn so you need check that each mains device is functioning properly. Check each item / socket one at a time to see if you can identify a faulty device before simply replacing MCBs.

 

[GStockton]

What is a RCBO then

 

[rayc]

A RCBO is a combination of a MCB and a RCD. This enables both over current and earth fault current protection in a single unit.

 

[GStockton]

Ray C I know I was just testing the others.

next question is what are the max readings in millisecs for testing a bs 61009 rcd 30 ma with a rcd tester ?

this a is how to spot the electricians

 

[Damian]

Who needs to spot the electricians?

Surely, if one is not competent to do electrical repairs, entrust the problem to a qualified person, simple really

 

[ProfJohnL]

Tim, the info given by John is misleadlingly incomplete.

The mains electrical system in modern caravans has TWO types of electronic circuit breaker. The first, immediately after the mains input, is a Residual Current Circuit Breaker (RCCB). There are also one or more Miniature Circuit Breakers (MCB) acting like a fuse.

Electronic breakers have no replaceable or adjustable parts, not even by an electrician, so replacement of the MCB or RCCD is the only option if it's faulty.

MCBs are designed to act like a fuse to protect against excessive currents being drawn so you need check that each mains device is functioning properly. Check each item / socket one at a time to see if you can identify a faulty device before simply replacing MCBs.

Point agreed!

 

[Rayc1]

Well of course a little knowledge is dangerous but that shouldn't stop people understanding how things work. It is perhaps neccessary when you read Tim's original post of a quoted

 

[Rayc1]

Well of course a little knowledge is dangerous but that shouldn't stop people understanding how things work. It is perhaps neccessary when you read Tim's original post of a quoted

 

[GStockton]

Damien, I fully agree with you. I was trying to sort out the people who know what they are taking about from those who think they know what they are talking about.

The answer to my question is a 30ma rcd should trip at its rated current within 200 milli secs and when tested with a fault current of 5 times its rating within 40 ms.This can only be tested with the correct tester in calibration of course

I am a niceic registered electrical engineer with 36 years in the trade and really wish people would not mess with 240volt electrics unless fully competent.

How many people take any notice of the periodic test notice affixed adjacent to the main switchin a caravan which says this installation should be inspected and tested every 3 years?

 

[Guest]

Gentlemen, please! The point of the forum is for anyone to submit input. It is up to the recipient to decide if he/she wishes to follow it. Sometimes experts do get it wrong as well. Have a little patience and tolerance please.

 

[Damian]

To answer a couple of points raised, firstly, Ray c , your reply is exactly why unqualified people should NOT attempt to repair services on which they are not fully competent, be it Gas, Electric or any other service.

A little knowledge IS dangerous, and if you get it wrong, will kill you.

To pay for a qualified person to fix the problem is just that, FIX the problem, no fix, no pay.

G Stockton, I take what you say, and agree, people should not mess with 240 volts, unless theyare fully competent to do so, and the same applies to gas installations.

I hate to surmise, but expect most peoples understanding of the periodic test is to press the trip button every 3 years to see if it still works, not at what voltage and time.

 

[Rayc1]

Damien, I understand that as a qualified electrician you have a duty of care to warn persons of the dangers of meddling with electricity. I have though re read the replies given to Tim by myself, JohnL and RogerL and non of us has advised him to attempt to repair it himself, in fact we all have said in some way or another not to.

That does not mean he should not have an understanding of what the problem may be. His query was regarding a MCB that was tripping, somehow the technicalities of a RCD have been brought into the discussion.

I do not believe that if you took your vehicle to a garage for repair and were told the brakes were shot, and that you needed new discs and pads that you wouldn't try to have an understanding of the problem, even though you had not been on the manufacturers training course or were bnot a time served mechanic. Or if you went to the doctor and he said you had high blood presssure and would have to take tablet X for the rest of your life that you wouldn't try to find out a bit about it.

We may as well just have a notice on the Technical section of the forum saying "Any technical queries take it to an expert" and not allow any posts.

 

[Damian]

Ray, I take you point, and actually agree with you, we should understand how the various things in our vans and cars work.

I dont know why the technicalities about RCD's came into the topic, but it did.

What I do, with both car and van, if there is a problem, is get the fault diagnosed by a trained person first, then decide if the repair is within my capabilities.

If it is within my capabilities, then I will do it, if not I leave it to the repairer of my choice, which may or may not be the main agent of the vehicle.

I am all for people making the most of their abilities, but in a safe way, after all, it is the lives of yourself and your loved ones we are talking here.

 

[ProfJohnL]

Hello Mr Stockton.

I am disappointed at the inference in your responses that I may not be sufficiently qualified to answer. Like you I have many years experience, not just in electrical supply systems, but also in electronics, and LPG.

Having seen the mess that can ensue from incorrectly installed equipment, I am ever conscious of the need for invasive service or repairs only to be carried out by competent persons.

If a person posts a question on these forums that by inference suggests they do not understand the basic process related to their problem, then I assume they are not competent, (which may be incorrect in some cases) and thus should for safety refer it to a competent person to diagnose and repair.

In such a situation where basic electrical processes are not fully understood, it would in my opinion be of no benefit to start to quote details or specifications especially as it is unlikely that the questioner would fully understand the terminology, or have the necessary equipment to proof test the verify or validate the equipment. These are matters that the competent person would deal with.

It seems to have escaped yours and Damian's notice that the mains supply in the UK is now nominally 230V ac - thanks to our wonderful EU.

 

[GStockton]

John L I think you misread my post In fact your first reply to Tims post is spot on and not in any way misleading.I appologise if you thought I was refering to you,in fact I mention No names at all.

it is just my opinion that some people on the forum somtimes give out misleading information.

lets not fall out about the 230-240 volt deceleared nominal voltage after all it is 230+or- 5%

 

[ProfJohnL]

John L I think you misread my post In fact your first reply to Tims post is spot on and not in any way misleading.I appologise if you thought I was refering to you,in fact I mention No names at all.

it is just my opinion that some people on the forum somtimes give out misleading information.

lets not fall out about the 230-240 volt deceleared nominal voltage after all it is 230+or- 5%

Hello G,

Thank you for clarifying. You are quite correct when you say that some responses are not adequate, and of course the questioner has no way of knowing (Apart from experience)if the respondants are making sence or not.

The antics of one or more people have damaged the standing and standard of this forum, but I hope that most people can see through the fog that they try to produce.

We will not fall out over 5% (unless Gordon Brown trues to take even more)! In practice I have seen sustained supply voltages upto 264V off one leg of an Npower 11K to 415 3 phase factory supply transformer.

Regards

 

[Tim2]

Thanks for all the advice lads.

I had not ever intended trying to sort the job myself. I was just a little surprised by the caravan mechanic's only suggestion being to change the RCD as even I realised that would not solve the problem if it was "tripping" because of another fault elsewhere.

I have subsequently tested the 4 13-amp sockets with a rapitest socket tester- the type that checks whether the sockets are wired correctly - all came up as okay. I have subsequently run the van with all other electrical appliances,ie, heater, water heater, on without the RCD tripping and so it may just be that it has become over-sensitive with age.

Comments on the price of a replacement unit were, also, very illuminating.

Thanks again

Tim

 

[GStockton]

Hello G,

Thank you for clarifying. You are quite correct when you say that some responses are not adequate, and of course the questioner has no way of knowing (Apart from experience)if the respondants are making sence or not.

The antics of one or more people have damaged the standing and standard of this forum, but I hope that most people can see through the fog that they try to produce.

We will not fall out over 5% (unless Gordon Brown trues to take even more)! In practice I have seen sustained supply voltages upto 264V off one leg of an Npower 11K to 415 3 phase factory supply transformer.

Regards

John yes 260v is not unknown,I had to go recently to a job where several pc power supplys and laptop chargers had simply blown up,due to high voltage.Our local elecricity co, Central Networks of course denied it.Until I fitted a chart recoder for a 3 day period which provided a printed analisis of there supply going up to 270 v. the fault was traced to a loose neutral connection in there sub station just down the road!

 

[GStockton]

Tim glad you got it sorted pity this forum does not have a profile or personal message system because if you lived anywhere me (Nottingham) I would have nipped round and tested your rcd with the proper tester.

I will point out it my job testing electrics not many Rcd units do fail the test, they are very reliable with only one make being very sensative but this make I have never seen in a caravan regards Glenn.

 

[Tim2]

Tim glad you got it sorted pity this forum does not have a profile or personal message system because if you lived anywhere me (Nottingham) I would have nipped round and tested your rcd with the proper tester.

I will point out it my job testing electrics not many Rcd units do fail the test, they are very reliable with only one make being very sensative but this make I have never seen in a caravan regards Glenn.

Thanks Glenn

Very good of you to offer. Unfortunately I live on Merseyside so it's a bit far. Hopefully the RCD will be okay now and if I do have to get it replace in future at least I'll have a more realistic idea of the costs involved.

Thanks again All

Kind regards

Tim

 

[xtrailman]

Tim

Sorry I have only just read this post.

I have to say some people on this site seem more interested in demonstrating how clever they are, rather than helping with your problem.

Has it been sorted?

Caravan electric mains systems are well within the capabilities of a capable DIY person.

I was 10 years as a JIB approved ellectrcian.

& 25 years as a steel industry maintenance electrician.

Assuming you still have a problem.

The simplest solution would be to change the 10amp circuit breaker.

It could be a faulty breaker. These units have a mechanical aspect to there operation, which occasionally fails. The cost of a cb from an electrical supplier is quite reasonable around

 

[RogerL]

Caravan electrics need to be simple enough for unqualified people - after all most caravan dealers use unqualified staff to work on caravan electrics.

Qualified electrician isn't even a requirement for Approved Caravan Workshops, neither is qualified gas fitter! There are no minimum technical requirements for ACWs, just a code of practice for complaints!

There are, rightly, significant restrictions on unqualified people working on gas or mains electric installations in domestic properties, it's high time that these same restrictions are applied to caravan build and maintenance.

Perhaps the users of this forum who are qualified with gas or electricity should lobby their registration organisation to get this loop-hole closed.

 

[ProfJohnL]

Caravan electrics need to be simple enough for unqualified people - after all most caravan dealers use unqualified staff to work on caravan electrics.

Qualified electrician isn't even a requirement for Approved Caravan Workshops, neither is qualified gas fitter! There are no minimum technical requirements for ACWs, just a code of practice for complaints!

There are, rightly, significant restrictions on unqualified people working on gas or mains electric installations in domestic properties, it's high time that these same restrictions are applied to caravan build and maintenance.

Perhaps the users of this forum who are qualified with gas or electricity should lobby their registration organisation to get this loop-hole closed.

Hello Roger & Ray

What you say about there being no need for a caravan workshop or a DIY fitter to be qualified is true in relation to the requirements under the caravan build regulations.

But regardless of what the professional bodies may or may not have agreed in terms of who does the work, The standards of installation, and test still apply. All work is still subject to Health and safety regulations, which requires all work to be carried out by a competent person. If an incident occurs and HSE are involved, then failure to observe the ACOPS and HS standards is a criminal offence.

Another factor which is becoming increasing significant, is where an insurance claim is made, and it becomes apparent that relavant work on gas (and I assume electrics) has not been carried out to the required standards, then the insurance companies have been known to refuse or withdraw cover.

Effectively any substandard work means that who ever carries out the work is incompetent, and therefore a criminal offence has been committed. It is also an offence to allow an incompetent person to work on a system unless they are training under the guidance of a competent person who ultimately is responsible for the work.

Litigation and the cost of insurance cover is driving the industry towards the employment of qualified personnel to undertake gas and electrics in caravans.

Whilst many of these tasks may well be within the capabilities of DIYers, it is only prudent to suggest the work be carried out by a competent person. It is then up to the individual to make an informed decision whether to DIY or refer it to a professional.