Caravan Site - Overheating supply neutral connection on pitch RCDs

Hi,

Am presently staying at a farm caravan park in south of England and the owner has shown me a problem he is having with some individual pitch electrical devices. Apparently, over time a number of the Type C  16A RCD devices have been affect by the INCOMING supply neutral connection overheating. Seems unlikely to be loose connection on so many devices and device are not tripping. 
site is served by overhead 2 phase connection with single phase distribution to at least 3 sepeate areas built at different times. Pitches are served by buried SWA and marked up as “ring”. RCDs are British supplier and all other connections on the 30mA device are clean and unaffected. Are we looking at an harmonics problem or distribution system fault. All suggestions welcome (It won’t spoil my holiday) Thanks

Dave



Parents
  • Is the cable split-con , so the cable construction of the incoming phase and neutral are quite different ? (we assume SWA but maybe not. ) If so cooling will be uneven.

     Mike

  • Hi,

    walk around site again and all enclosure are same manufacturer with IP 65 enclosure and IP44 socket connections. Temperature rating from data sheet is -25 to +60C. 

    Re cable type the standard 3core,PVC/SWA/XLPE is very much what it looks like and a 16mm separate CPC to ground electrode at each position.

    Problem ha been ongoing for a couple of years minimum so still has me intrigued ?

    Keep try guys, must be a reason ? Why aren’t other sites having same issue ?

    cheers

    Dave

Reply
  • Hi,

    walk around site again and all enclosure are same manufacturer with IP 65 enclosure and IP44 socket connections. Temperature rating from data sheet is -25 to +60C. 

    Re cable type the standard 3core,PVC/SWA/XLPE is very much what it looks like and a 16mm separate CPC to ground electrode at each position.

    Problem ha been ongoing for a couple of years minimum so still has me intrigued ?

    Keep try guys, must be a reason ? Why aren’t other sites having same issue ?

    cheers

    Dave

Children
  • Why aren’t other sites having same issue ?

    Do we know that they aren't? On most sites I've been to the boxes seem to contain a mish mash of brands (some with even a mix of RCCB+MCBs and RCBOs so definitely look like they've gone through a fair bit of on-site revision). Seems to me that some of the box manufacturers don't always pick the most "reassuringly expensive" devices either (and their choice of components may vary over time anyway).

       - Andy.

  • I wonder how many

    Mechanical cycles
    Electrical endurance

    the RCD has had?