Static Caravan 100ma OK ?

[scott1]

Just been to look at a single static caravan on a farm, they are looking for a EICR to be done.
Incoming supply is TNCS.
80amp DP protected 10mm 2core SWA running 100 meters or more to a outdoor box under caravan containing a 100ma rcd and 16amp mcb, where it has been TTd fine. From this runs a 6mm t+e, clipped direct, feeding a 30ma protected board in the caravan.

Have a couple of things I am unsure about

Is the TTd 6mm t+e submain clipped direct, under the caravan ok protected by a 100ma rcd?

The 100 meters or more 10mm SWA with the volt drop would only be able supply about 10amps to the caravan. Would a 10amp HRC fuse at the incomer and a 10amp 60898 at the caravan provide discrimination of a sort? If not think the caravan will only be able to have a 6amp supply!


Thanks

 

[davesparks]

TTD? What does the D stand for? Presumably you mean a separate TT earthing system has been set up.

There isn’t currently a requirement to provide 30mA RCD protection to a clipped direct cable.

A 10A mcb is highly unlikely to discriminate with a 10A fuse, or even a 6A mcb for that matter.
With the 16A mcb at the load end I can’t see the volt drop being much of an issue, and I should think that will discriminate with an 80A fuse.

Why are you worrying about planning remedial works before you’ve done the EICR? Surely you can’t know the outcome of the EICR or the customers wishes regards remedial work before it’s done?

 

[westward10]

These are the sort of questions you should not be asking if you are competent to undertake the task.

 

[Gareth Brookes]

Don't all tt earthing systems require rcd protection

 

[Ian1981]

Deleted post

 

[davesparks]

Don't all tt earthing systems require rcd protection

No, fault protection by RCD is only necessary if the Ra is too high to allow the ocpds to provide fault protection.

 

[mossep]

Caravan pitch supplies require a 30mA RCD.

 

[davesparks]

Caravan pitch supplies require a 30mA RCD.

Yes, but that is irrelevant to this thread as it is a static caravan, not a caravan pitch.

 

[telectrix]

debatable, Dave, as most statics are supplied from a RCD protected postand commando plug hook-ups, same as with tourer pitches. also metal skineed so PME not allowed.

 

[mossep]

Yes, but that is irrelevant to this thread as it is a static caravan, not a caravan pitch.

I think that’s debatable, if it looks like a caravan, has wheels and is metal framed then I class it as a caravan. Would you say that a PME connection is ok, I’d rather follow the regulations for caravan park installations than not.

 

[driverman]

All caravans--No PME allowed. Most sites are TT earthing.
All touring caravans must be 30ma RCD protected but can be TN-S earthing

 

[Toneyz]

Yes, but that is irrelevant to this thread as it is a static caravan, not a caravan pitch.

With respect Dave, be it a tourer or static the principle has got to be the same hasn't it?

 

[Deleted member 26818]

With respect Dave, be it a tourer or static the principle has got to be the same hasn't it?

No.
Touring caravans get moved from site to site, whereas static caravans never get moved.

 

[Deleted member 26818]

I think that’s debatable, if it looks like a caravan, has wheels and is metal framed then I class it as a caravan. Would you say that a PME connection is ok, I’d rather follow the regulations for caravan park installations than not.

Some caravans have wheels but cannot be towed on the highway.
They have the wheels just so they can comply with Regulations and be sited on caravan parks.
They are if anything, mobile homes.

 

[davesparks]

With respect Dave, be it a tourer or static the principle has got to be the same hasn't it?

No the principle is different.
Caravan pitches have RCD protection because it is a 16A socket outlet with no control over who plugs in to it and what they plug in.
Static caravans don’t move and have a fixed domestic electrical installation which is subject to the same regulations as any house so putting the whole thing onto a single 30mA RCD is non compliant