Testing with two RCDs in series

[cambria]

A caravan supply has a 30mA non delayed RCD and the caravan has the same. Is there a cheat so that the one in the caravan can be the one forced to trip when performing the tests. It is not practical to simply bypass the one the supply.

 

[jmtisme]

Is a time delay suitable for it. On second thoughts wouldn't one of them have to be time delay to stop one tripping the other

 

[cambria]

Yes the one in the pitch supply should be delayed but most sites arent

 

[Guest123]

Caravan hook up's must have a 30mA RCD protecting the socket in them as per the regs.

You will find this situation nearly always on caravan sites, it's just the way they are put together.

Also, no such thing as a 30mA TD RCD.

 

[cambria]

Yes but im just looking for the simplest way of testing the caravan RCD i seem to remember there was some way of forcing one particular RCD to trip in these situations. The caravans are sometimes supplied from the local building just for testing and I dont want the building RVD tripping out

 

[m4tty]

There is a way but I can't remember it either mate. It's one side of meter on incomming live and other side on outgoing neutral or am I talking poo?

 

[xraytek]

What about a 1:1 isolating transformer between the caravan and the pitch supply?
If its only being used to test the RCD at the caravan (ie with lights & sockets mcb off) then it would not need a high VA rating.

The fault current from the RCD test will flow back to the transformer rather than back to the supply building.

 

[Graeme Harrold]

Plenty 2nd hand going on Fleabay for about £25 delivered..............

 

[trebor]

A caravan supply has a 30mA non delayed RCD and the caravan has the same. Is there a cheat so that the one in the caravan can be the one forced to trip when performing the tests. It is not practical to simply bypass the one the supply.

I have carried testing on several caravan sites, the answer depends on the control you have over the pich supply,the pitch socket supply RCD can be tested on the commando socket directly and the results recorded

Then test in the caravan, both trips will operate, if the result in ms is higher then record that result as the worse case, both trips have been proved operative, we always record the pitch supply result on a seperate line regardless of whether we are being requested both or the caravan only

 

[bobby101]

please consider this soloution but it will cost about 400 quid
buy the meterl easitest multifunction tester MI 3000 Easi PLUS it has rcd triplock function
only not sure how it will react to the situation.

 

[Sparky Ninja]

When I test caravans that are coming in I test the pitch RCD only.

I'll do a functional in the caravan, and attempt to test the RCD to verify it with the included cert reading, but if it does not trip and the pitch supply does then there is no problem.

 

[Graeme Harrold]

When I test caravans that are coming in I test the pitch RCD only.

I'll do a functional in the caravan, and attempt to test the RCD to verify it with the included cert reading, but if it does not trip and the pitch supply does then there is no problem.

This is all well and good should the caravan remain on that pitch. The cert I issue is for the caravan (valid for 3 years) and therefore the RCD must be tested hence the isolating transformer. Should the caravan be moved (as many do) on site how can you ensure the installation is still safe.

 

[Sparky Ninja]

This is all well and good should the caravan remain on that pitch. The cert I issue is for the caravan (valid for 3 years) and therefore the RCD must be tested hence the isolating transformer. Should the caravan be moved (as many do) on site how can you ensure the installation is still safe.

Which installation? The caravan or the pitches?

Both should always be independently tested periodically.

 

[xraytek]

Which installation? The caravan or the pitches?

Both should always be independently tested periodically.

The OP is with regards to the caravan not the park.
If you issue a PIR for a caravan then shouldnt the RCD readings be from the caravan RCD?
I can understand the fact that provided the park RCD operates correctly then the caravan is adequately protected, but wouldnt you have to record as a limitation on the caravan inspection report as the caravan RCD may not be displayed in the test results?