# Masterclass in using multimeter



## jiwawa (Jun 22, 2007)

We were using our daughter's electricity to the van - our normal lead with an additional adapter lead with 13A plug on one end and the normal caravan site adapter on the other. 

Unfortunately rain got into the dual plug combo below the 13A plug and tripped the supply. I opened up the plug and set it in the hotpress for a couple of days. 

Just tried it again and it's tripped the supply again. 

I have a digital multimeter, and the instructions for how to test what. 

The trouble is, I don't know WHAT it is I should be testing, or where. 

Can someone enlighten me, bearing in mind I'm a technophobe when it comes to electrics? 

Or should I just take all the plugs apart and clean them up? In the one I separated, the screws holding the 2 halves together were a bit rusty but I didn't notice anything else. 

Many thanks.


----------



## erneboy (Feb 8, 2007)

Test continuity. First check using both ends of the lead that the live at one end is reaching the other end and do the same for neutral and earth. Then test whether there is continuity between live and earth and neutral and earth.

The meter should show 1 when continuity is not present and other than 1 when it is. So for the first three tests you want to see something other that 1 and for the last tests you don't want continuity so should still see 1 if all is OK. If you see other than 1 doing the second set of tests there is a problem. Disassemble the lead and do the tests again, then you will know whether the fault is in the wires or in one of the ends, Alan.

Edit: The continuity symbol is an arrow pointing to the right touching a plus sign. Switch the meter to that.

Obviously the lead must be disconnected when doing all of this.

Other edit: Does the trip stay up with the lead connected but not plugged in to the van? If so it's probably not the lead.


----------



## trek (May 1, 2005)

From your description I would assume that water has got into either or both of the couplings that joined the two cables together. 

So I would take both apart and dry them out

Using a multi meter you would need to set it to ohms scale. To measure resistance. And use the leads in the appropriate sockets on the meter. Com and resistance/voltage (not the amp one)

Then check between the different conductors they shoul be open circuit, but with the water fault then a resistance reading will be seen

Check all combo,s. 
Live to neutral
Live to earth
Earth to neutral







unplug it from house supply first


----------



## jiwawa (Jun 22, 2007)

Thanks Alan. I'm going to try your advice re continuity - except the instructions don't mention continuity! 

I've the dial set to the continuity symbol, but where do I put the leads? Red/black and 10A, A, COM, and V/Ohms (I think,) are the options. 

Sorry to be so dumb! 

Trek, thanks, I'll check out your info after. 

Jean


----------



## erneboy (Feb 8, 2007)

Com and Volts/Ohms Jean.

I should declare that I am no electrical expert and I'm sure the advice given above is better than mine. Still those I outlined would be my first checks to see if there is a disconnection or a short, Alan.


----------



## jiwawa (Jun 22, 2007)

I've just tried the bit about turning on the supply when the other end is disconnected from the van, and it didn't trip. 

Does that mean the problem is IN the van? Or should I continue to investigate the leads?


----------



## erneboy (Feb 8, 2007)

Less likely to be the lead. You could trip the trip in the van then plug the lead in and see what happens. If that sets the house trip off there may be a fault in the inlet to the van, or at least between it and the trip in the van, Alan.


----------



## Evs54 (Mar 11, 2013)

JWW said:


> We were using our daughter's electricity to the van - our normal lead with an additional adapter lead with 13A plug on one end and the normal caravan site adapter on the other.
> 
> Unfortunately rain got into the dual plug combo below the 13A plug and tripped the supply. I opened up the plug and set it in the hotpress for a couple of days.
> 
> ...


A Multimeter is of little use in the event of an Earth fault , you need a Megger but be very carefull how you use it .


----------



## erneboy (Feb 8, 2007)

Way above my head now Jean. Time I was out of it and probably shouldn't have ventured my amateurish advice in the first place.


----------



## jiwawa (Jun 22, 2007)

No, Alan, I'm glad of your help. 

I'm a bit slow here as I'm working round making and eating tea! 

Re the Megger - no idea, but I'll Google. But if I have to be very careful with it, I probably won't go there! Thanks for the info.


----------



## Bigusdickus (Nov 6, 2012)

As a sparky, in a previous incarnation, put all the testing stuff on the shelf, you don't need it as you have conductivity because it's everywhere and blowing your circuit breakers, throw the connector away and buy a new one with weatherproof ends if you intend to use this facilty often. On your hook-up lead, if it got wet, cut off about 18", throw this away and fit a new (weatheproof?) plug. In my experience once something has been waterlogged you will always get problems with it because circuit breakers are so sensitive. You can buy these in Toolstation type places.
Bd..


----------



## jiwawa (Jun 22, 2007)

Well, here's what I've found. 

There's continuity everywhere there should be, on the main cable and on the 13A extension. There's also no continuity anywhere there shouldn't be, so it all should work. 

However I think BD has probably hit the nail on the head as the supply end socket of the main cable has like salty deposits on screws, tho the wired themselves seem fine. Some of the screws are rusted in and I can't now secure the neutral wire. 

So, I shall try cutting that end off and fitting a new plug. All our plugs (apart from the 13A of course) are the so-called waterproof ones but there is some degradation of the rubberised seal where the cable enters. We'd some terrific winds before we had this problem so I guess a moving cable + heavy rain = water ingress. 

Also, daughter's house is new and the electrics are probably hyper-sensitive. 

Thanks to all who contributed - I knew I could depend on MHF to give me advice. And confidence! 

If there's something else I should be doing, let me know. 

I won't get this sorted for a while but will try to remember to come back n let you know if it works!


----------



## jiwawa (Jun 22, 2007)

I see plugs and sockets here 
http://www.towsure.com/product/Caravan_Site_Mains_Electric_Hookup_Plug

They're considerably cheaper than the ones I bought a few years ago. Will they be waterproof, do you think? Or are all of this design waterproof?


----------



## rowley (May 14, 2005)

In my understanding IP44 is not waterproof but splashproof. However that is the type of plug that is generally used.


----------



## ThursdaysChild (Aug 2, 2008)

Assuming you are using " normal " blue Euro male and female plugs, 
THEY ARE NOT WATERPROOF !!
If you are going to leave them exposed to the elements, you must expect trouble eventually.
But why leave them exposed ? If you are running a cable from a 3-pin socket in your daughter's house, just make sure the joint is inside the house.
Wrap flexible insulating tape or gaffer tape around the ends where the cables enter the plugs - at least two layers - making sure that you leave no open gaps.
Then more tape around the middle where the plugs join together.
Then fold the join and put it in a plastic shopping bag. Gather the neck of the bag and seal that with tape.
If you have enough cable you can hang the bagged joint off the ground under the 'van.

Ve haff vays........


----------



## jiwawa (Jun 22, 2007)

Thanks folks. I've discovered Donaghey's in Letterkenny have them at about €3.50 each so we'll pick up on the way through. 

Daughter's 13A socket is a supposedly showerproof housing outside. 

I'll follow the advice on taping and wrapping the joined sockets. Thanks.


----------

