Electricl supply nightmare

[Jericho]

Hi everyone. I have a catering van that is located about 25 metres from an electricity supply. Until now I have been using a standard 2.5mm orange hook up cable and a 63A rcd fitted with a 16amp fuse in the trailer. My max load has been around 4000watts peak and around 3000watts or less when the equipment goes into 'keep warm mode'. I want to add a 3000w fryer, replacing a pie warmer but this will take the loading upto around 6000w. I believe the supply i'm using from an industrial unit is 32amp. I have to also now move the trailer to a distance of around 50metres from the supply.

I'm guessing i'll have to replace the consumer unit (or upgrade the 16a fuse) regardless. But will I need to upgrade the hook up cable? I could buy a 50m run of armoured cable and bury it (my van is in a field) but just dont know if I can create a run that long?

 

[ban-all-sheds]

• //www.diynot.com/wiki/electrics:mcbtocable
  
  
• http://www.tlc-direct.co.uk/Book/4.3.1.htm
  
  
• http://www.tlc-direct.co.uk/Book/4.3.11.htm
  
  
• http://www.tlc-direct.co.uk/Book/5.3.1.htm
  
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/cableselection_web.pdf
  
  
• http://www.tlc-direct.co.uk/Technical/Charts/VoltageDrop.html
  
  
• http://www.tlc-direct.co.uk/Book/7.13.1.htm
  
  
• //www.diynot.com/wiki/electrics:swa-gland
  
  
• http://www.tlc-direct.co.uk/Book/8.1.1.htm
  
  
• //www.diynot.com/wiki/electrics:part-p
  

Please note - the above is not an attempt to blind you with science or anything - if you want to DIY this then you really do have to know and understand it all, because unlike decorating, gardening etc, with electrical work you simply cannot work to lower standards than a qualified electrician, especially with outside supplies, mobile units etc.

 

[plugwash]

The first thing you need to do is determine the characteristics of your supply. What is the Zs? what is the protective device (type and rating)? is your supply from the origin of the installation or is some of the volt-drop budget used up by distibution circuits? are the earthing arrangements appropriate and so on.

Once you know the answers to those questions you can work out what size cable you need.

Whatever the supply characterisitics you will need a larger cable than you have now but exactly how much larger depends crucially on the answers to the above questions.

If you are running underground you MUST use a cable with a built in earthed metal layer. Usually that would mean SWA though other cable types can be used.