Nuisance tripping

[muttlydog]

Ok so i recently moved onto a static caravan park of about 10 static caravans.

The caravan park is suffering from nuisance tripping at least 10 times a day the main rccb breaker for the site trips, all the caravans as well as having a rcd board in each there is another one on the outside the caravan that we plug into. Speaking to the other owners no one on site has problems with there boxes tripping itsa just the 1 main rccb breaker that trips all the time. I noticed that on a few of the statics there is an earth wire coming of them connected to nothing im assuming they should be connected to some kind of earth spike. With my multi meter im reading around 2-3v accross neutral and earth is this normal or could this be the cause of the tripping?

 

[sparkyspike]

Hi

Are you saying that each caravan is protected by three RCDs? What is the rating (mA) of the main RCD that supplies the whole site (the one that is tripping)?

 

[muttlydog]

its a HAGER CD280U 80A 30mA

 

[Steve]

bad design. The main RCD should somehow be eliminated and replaced with a mainswitch.

 

[sparkyspike]

You will probably need an electrician to establish what is causing the problem. Do you know what sort of supply it is? Is it TN-S? The redundant earth cables could be a red herring - from a previous installation maybe. Stakes are used for TT (or TNC-S) installations. They may not be required on your site.

It's possible that that 30mA supply RCD is too sensitive for accumulative earth leakage. It is also possible that you have one or more earth leakage faults which an electrician should be able to detect.

One possible remedy would be to change the main RCD (to a 100mA or to a normal isolator) but this depends entirely on the supply type (TN-S or TT), the cable type and the function of the RCDs at each plot.

 

[muttlydog]

that would be ideal but i dont think the landlord would go for that plus there unwilling to pay anyone to sort it out....

 

[sparkyspike]

Well, that's the end of that then.

 

[muttlydog]

no idea of the supply tbh got a pic though of said rcd bit appears to be onlly 2 pole

 

[flameport]

its a HAGER CD280U 80A 30mA

For the whole site of 10+ caravans?

If the landlord is unwilling to pay for essential repairs, then presumably you and the other residents won't be paying them any rent from now on?

The landlord has a duty to ensure the installation is safe and works as intended. Power going off 10 times a day is clearly not acceptable to anyone.
If the main RCD really is a 30mA one, it suggests the installation was poorly designed at best, or is a complete lash up at worst.

Sorting it out properly isn't a DIY job either.

 

[muttlydog]

im after suggestions that us as site users can do to help stop it i read somewhere that surge protection bars (the type you plug your computer in) can cause nuisance tripping

 

[muttlydog]

*sigh* I new you guys would say this kinda hard to grief up the landlord when the rent is soo cheap i guess if you pay peanuts...I suspect it was a bit of a lash up

 

[sparkyspike]

That's unlikely to be the problem. You need to change the 30mA RCD (if that is ok with the installation method) BUT AN ELECTRICIAN NEEDS TO DO IT because you need to understand supply types and installation methods.

THEN you can look at accumulative leakage problems.

 

[muttlydog]

cool beans Im just looking to get my arsnal together before i approach the landlord as its likely were going to get the blame for the problem. Even though i consider myself fairly okay with sparks i wouldn't do it my self

 

[flameport]

There is nothing you or any of the other residents can do.

Surge protectors can have a small amount of leakage to earth.
So can washing machines, dishwashers, kettles, computers, irons, ovens, toasters and dozens of other commonly used appliances.

The problem here is that with a 30mA RCD should only be used to supply one property, or part of it. In that case, you would need many 'leaky' appliances to cause any tripping - say 10 of them at 2 or 3mA each.

However use it to supply 10+ units, and you only need 2 or 3mA per unit to cause the tripping. That could be as little as one appliance per unit - and the appliance could be in perfect working order.
Alternatively there could be one or several faults on the cables, appliances or other switchgear.

 

[muttlydog]

so basically i need to pester the landlord to get a spaky in to upgrade the rcd and check it all out.