Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Not Answered
  • Locked Locked
  • Replies 57 replies
  • Subscribers 32 subscribers
  • Views 6923 views
  • Users 0 members are here
Options
You may also be interested in
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

V.O.E.L.C.B.

Zoomup
It dawned on me fully today while working in an old holiday chalet circa 1940s.


The man in the next chalet was trying to use his old Black and Decker 1970s car boot sourced electric drill outside on the grass. He was making a wooden clothes hanger with wood and pegs. A jolly good job too.


I had had a quick look inside his chalet as he needs some new sockets. The  fuse box is an old cream coloured Wylex 6 way unit with fuse wire carriers. There is an old Crabtree V.O.E.L.C.B. installed before the fuse box.


As he worked in the garden drilling wood, it dawned on me that he had zero shock protection as he would if he had a R.C.C.B. installed.


It's strange how a picture speaks a thousand words.


Z.


  • 0
    I read the T C Gilbert article can't say I completley understood it I don't think the idea of earthing a small farm motor with a stake just like he describes is allowed now is it?

    I guess it's rather like having a local TT island - as long as there are no other exposed-conductive-parts or extraneous-conductive-parts within reach, and (the equivalent of) an upstream RCD - it would just about pass today.


     
    Historical vat appears more varied than I remember - not quite 12.5% in the late 1970s.

    I recall 8% for 'essential' items and 12.5% for 'luxury' items. The categorization did seem rather arbitrary at time though.


       - Andy.
  • 0
    Sparkingchip:

    Have a look at Table 5 on page 12 in This article listing the causes of broken neutrals in the distribution network ?


     


  • 0
    Zoomup:

    The excellent quality Crabtree E-60 model V.O.E.L.C.B. has a lighting protection spark gap (discharge gap) installed internally in parallel with the trip coil.


    In the mid to late 70s, a Crabtree 100 Amp E-60 model, without overload protection,  cost approximately £8.40 plus VAT. VAT tax was half the rate it is today at 12.5 per cent.




    Thanks - actually not quite so expensive as I'd have guessed.  Using BofE's inflation calculator on £8.40, and adding today's 20% VAT, it's around £75 total.  (Historical vat appears more varied than I remember - not quite 12.5% in the late 1970s.)  Some modern RCDs from the fancier names could be that much, even without special features of what waveforms they handle. 


    I didn't remember the spark-gap, but I remember contacts for disconnecting the installation (F) terminal while pushing the test button.

     


  • 0
    Have a look at Table 5 on page 12 in This article listing the causes of broken neutrals in the distribution network ?
  • 0
    I read the T C Gilbert article can't say I completley understood it  I don't think the idea of earthing a small farm motor with a stake just like he describes is allowed now is it?
  • 0
    Sparkingchip:
    T C Gilbert


    Thanks Sparkingchip. The article is most interesting and ahead of its time.


    Z.


  • 0
    (there was worry about damage from e.g. nearby lightning, though one comment mentions no recorded trouble). 


    The excellent quality Crabtree E-60 model V.O.E.L.C.B. has a lighting protection spark gap (discharge gap) installed internally in parallel with the trip coil.


    In the mid to late 70s, a Crabtree 100 Amp E-60 model, without overload protection,  cost approximately £8.40 plus VAT. VAT tax was half the rate it is today at 12.5 per cent.


    Z.


     


  • 0
    Sparkingchip:

    Whilst I was measuring the resistance of the VOELCB coil I didn’t take into account it will be a resistance in series with the earth electrode. ?


    500 Ohm Impedance in series with the earth rod. (A.C. supply). 


    Z.


  • 0
    T C Gilbert
  • 0
    Don't trust the tester to push out 200 mA.  Measure it with another meter in series [as well as the VOELCB coil].  Or connect the coil to a car battery.   The tester should test with e.g. 200 mA to a near-zero resistance, such as a conductor through an RCD.  But if the VOELCB's coil really is tens or more of ohms of resistance, your tester is unlikely to produce the required voltage to get 200 mA [or 35 mA] - it probably only runs off a few AA batteries.


    (You see ... I really don't want to give up my faith in the reliability of the old stuff, until forced.)

Community Rules & Guidelines