Caravan wiring installation

All the static caravan setups I've seen the cable between the caravan and the pitch has been supplied by the installer on-site rather than being part of the caravan as supplied - you often see all sorts of bits of orange or blue arctic flex pressed into service. Normally the braid of an SY cable is terminated into a special brass device (a gland) to make it available for earthing as well as anchoring the cable (or sometimes the braid itself is "pig tailed" into a terminal). Leaving the braid unearthed is certainly poor practice, but if the situation is such that ordinary flex would have been acceptable, the actual risks are typically minimal. The apparent voltage between the SY braid and Earth might well be due to no more than capacitive coupling between it and the live conductors - which can show up as a significant voltage on modern high impedance (digital) voltmeters but there's next to no current behind it -the voltage would collapse to next to nothing if anyone touched it, so if that is the case (and there's no underlying damage to the SY flex) the risks are again very low to negligible.

As for the fan, I think your electrician may be mistaken. 230V fans are permitted in even in zone 1 (provided the manufacturer says they're suitable) and zone 2 is even less restrictive. Most purpose designed bathroom fans will have a sufficient IP rating (IPX4). It might be worth looking up the instructions for the particular make/model of fan you have.

   - Andy.

Hi, thanks for the info and assuring us that it isn’t a danger.  However we need to get remedial work done before anyone will issue a certificate of compliance.  I just don’t think this cable set up should have passed final inspection at Willerby.  

I am inclined to agree concerning the cable - it was never correct.

Ventilation equipment is permitted in Zone 1, i.e. directly above a bath or shower basin. Please feel free to quote BS 7671, article 701.55 (viii).

I guess someone needs to check if it is an IP rated fan, or a normal extractor fan for kitchens, etc.

It would be a strange fan if it cannot cope with moist air.

Barbara W said:

I just don’t think this cable set up should have passed final inspection at Willerby.  

Unless the SY flex wasn't present at the factory? The connection between the caravan and site will vary depending on a lot of factors - a short length of 2.5mm² would be fine for a 16A supply from a above ground hookup point that happened to be close to the caravan's intake position. Other sites can provide 32A (or higher) for statics (more common where the caravan is lived in full time) in which case a much more substantial cable (4mm² or 6mm²) would be needed. For those sites where connection is direct from underground, an armoured cable would be required rather than flex. Thus normally the cable is provided by the electrician connecting up the caravan on site. Another clue would be the method of terminations - if it's been done the same, incorrect, way at both ends even down to the same colour of tape used, that would again suggest that both ends were connected by the same person - as the site end must have been done by the on-site installation electrician, chances are they did the caravan end too.

   - Andy.

Andy makes a good point.

So how expensive, and how much trouble would it be to get the cable replaced?

(I have to admit that I find it almost impossible to accept less than skilful workmanship, but sometimes there is no choice.)

I'd seek clarification for the fan at least - most mains voltage bathroom fans are perfectly fine in Zone 2, and it may be the inspector is not used to what is in effect a caravan and or has looked up the wrong model of fan..
Un-glanded cable sounds rough and while not dangerous unless it gets pulled out, needs improvement - though as above that sounds quite likely to be an installation matter when it was planted on the pitch.
No one has mentioned earthing - I assume there is an earth electrode (spike into the ground) near your 'van and that has been tested ?


Mike.

I'd seek clarification for the fan at least - most mains voltage bathroom fans are perfectly fine in Zone 2, and it may be the inspector is not used to what is in effect a caravan and or has looked up the wrong model of fan..
Un-glanded cable sounds rough and while not dangerous unless it gets pulled out, needs improvement - though as above that sounds quite likely to be an installation matter when it was planted on the pitch.
No one has mentioned earthing - I assume there is an earth electrode (spike into the ground) near your 'van and that has been tested ?


Mike.