240V Electric Sockets

[arcodan]

Hi,

 

I am a relative newcomer to caravanning but have a basic understanding of electrics and have a decent voltmeter for testing.

I have an Ace Jubilee Statesman Caravan which the previous owner installed 2 extra plug sockets which now don't seem to be working.

I have traced all the cables and isolated the electric socket nearest to the Control panel.

How can I test that power is getting to this socket ?

 

Many Thanks for any reply and Happy Christmas

[gumdrop]

Do you have an EHU to supply 240v, are the trips in, all the fuses ok.

[Ern]

Sorry to be blunt but, as you know so little about electrics I think you should ask a local electrician to have a look. You don't know whether it has been done very badly, so you could get a bit of a shock!!.

[WispMan]

I agree. You have two sockets put in by a third party and one does'nt work. Don't investigate yourself as it can be dangerous. Not worth it. Get it checked out by a qualified person.

 

Oh - and welcome to Caravan Talk.

[ericmark]

Plug a standard lamp in a socket at home see if working it it is plug it in the caravan socket and if it works you are getting power. I am sure your not asking something that simple so if you want to check a socket is working safely then the Martindale EZ150 Non-Trip Earth Loop Impedance Tester is about £35 and will do most tests required to ensure a socket is safely installed.

 

However in a caravan which will likely have a TT supply and two RCD's in series not really sure if that is really required? and a Martindale CP501 Socket Tester at around £10 is likely good enough.

 

Main thing with caravans is to test the lives are the right way around with line being overload protected and neutral not.

 

To test a supply to find where the break is one normally assumes it will not be in the cable but where the cable is connected. However I have even seen so called electricians wire a caravan with twin and earth solid core cable unlike the house caravans flex and so the cable also needs to be able to flex and we have a special name for that type of cable it's called flex. Yes it seems obvious but you would not believe how many people do not use flex when wiring a caravan.

 

Testing without mains power first thing is to test line to neutral with some sort of tester be it a buzzer, light or meter to "Bell" it out. In fact a old style door bell with batteries will do it fine. To start with on a known good socket bell should not ring then short the two pins on the blue plug and it should ring. Now go to suspect socket and try that one. Thing here is you can try all connections with bell attached and as soon as you find the problem the bell will show you.

 

The problem is where items like battery charger cause a DC short but flicking off battery charger MCB should get around that problem.

 

I think there is something missed out with question as "basic understanding of electrics" and "How can I test that power is getting to this socket" don't seem to go together.

[AndyPoole]

I would agree with the others that you probably dont have enough knowledge of electrics if you are asking such a basic question.

 

Please dont rely on using a lamp to test the socket works you need to go and buy a Martindale CP501 or equivalent as the minium tester for sockets

[ericmark]

I would agree with the others that you probably dont have enough knowledge of electrics if you are asking such a basic question.

 

Please dont rely on using a lamp to test the socket works you need to go and buy a Martindale CP501 or equivalent as the minium tester for sockets

I would agree. Remember there is a difference between working and working safely a lamp will show it works but not if working safely.

 

The standard test set used by electricians costs around £750 and £75 to hire and clearly a plug in tester will not do the same job. It is near impossible for a DIY man to do electrical work on low voltage (230vac is classed as low voltage) and comply with the regulations. So there has to be some trade off between cost and safety personally I do have a full test set so have never used the simple plug in testers but I would say the Martindale EZ150 is reasonable trade off between cost and safety for the DIY guy doing repeated work on low voltage. See http://martindale-electric. co. uk/martindale-ez150-eze-check-xtra-earth-loop-impedance-indicator-p-285. html Note I would expect to see the left or centre red lamp flashing with a caravan as it is on a TT system. With a house without a RCD then left green lamp should flash. With RCD then it could be like a caravan with a TT supply.

 

What the loop test does is test the earth is sound. Above 200 ohms the earth is likely to fail and although the Martindale CP501 does show if earth completely missing the earth connection due to the caravan legs being pressed into the ground could be enough to show earth as good.

 

Because caravans have a TT supply (uses an earth electrode forced into ground) it is easy for this to be damaged and if you are going out to buy a tester for the extra £20 does not seem to make sense to buy the cheap one.

[dreadly]

I would agree. Remember there is a difference between working and working safely a lamp will show it works but not if working safely.

 

The standard test set used by electricians costs around £750 and £75 to hire and clearly a plug in tester will not do the same job. It is near impossible for a DIY man to do electrical work on low voltage (230vac is classed as low voltage) and comply with the regulations. So there has to be some trade off between cost and safety personally I do have a full test set so have never used the simple plug in testers but I would say the Martindale EZ150 is reasonable trade off between cost and safety for the DIY guy doing repeated work on low voltage. See http://martindale-electric. co. uk/martindale-ez150-eze-check-xtra-earth-loop-impedance-indicator-p-285. html Note I would expect to see the left or centre red lamp flashing with a caravan as it is on a TT system. With a house without a RCD then left green lamp should flash. With RCD then it could be like a caravan with a TT supply.

 

What the loop test does is test the earth is sound. Above 200 ohms the earth is likely to fail and although the Martindale CP501 does show if earth completely missing the earth connection due to the caravan legs being pressed into the ground could be enough to show earth as good.

 

Because caravans have a TT supply (uses an earth electrode forced into ground) it is easy for this to be damaged and if you are going out to buy a tester for the extra £20 does not seem to make sense to buy the cheap one.

That EZ150 looks like a nice handy bit of kit for less than 50quid. .. May have to treat myself soon

[arcodan]

Hi thankyou to everyone for their advice .
the situation is this . I have 2 sockets high up which work fine one in kitchen area and one for tv etc. I have 2 sockets that have been installed lower down presumably to provide more flexibility. Neither of these sockets work. The way they are wired is that a cable comes from the control unit down to the first socket and that in turn is joined to the other socket. I have tried a lamp and portable fire in both sockets so know they dont work. I disconnected the second socket from the first to see if that was causing the problem but the first socket still does not work . I have checked the fuses that I can find and they seem ok. Obviously I can link up an extension lead to the upper sockets but that sort of defeats the object of having extra sockets.
I may well have to get an electrician to look at it but was trying to save some money.
I can post pictures if that would help explain. Thanks again for any advice.

[WispMan]

If you don't understand fully some of the above posts about circuit testers, then do use an electrician. You have a high risk of electrocution unless you truly understand what you are doing.

 

Some of our members are very knowledgable, but without their experience, you are putting yourself and tbe caravan at risk.

[Gordon]

Hi thankyou to everyone for their advice .

Please read my PM to you.

Gordon.