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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
    Do you mean L&N reversed Zoom? Otherwise, it never worked or would trip the VOELCB. I don't think the trip current can be anything like 500mA, because that would be useless on a slightly high Ze electrode of say 125 Ohms, giving no volts for the trip, or at least far less current. I seem to remember the coil resistance was several K Ohms, so the current might not be too far from 30mA. Anyway changing to a 30mA RCD is very cheap and easy, everything is in place for the wiring
  • 0
    Maybe being a belt and braces man Zoomup‍ might be inclined to fit a RCD downstream of the VOELCB?
  • 0
    A class one appliance used outdoors would give the user a 49 volt shock. Much less dangerous than line voltage, but still twice the limit of SELV.

    Eh? I thought ELV was under 50V a.c. (or 120V d.c.)?

      - Andy.
  • 0
    With a VOELCB if the earthing is good you can get a surprisingly long way with a very badly wired plug indeed.

    Silliest I have seen was green to neutral , red to earth and black to live. Worked OK apparently, until it really was plugged into an new fangled RVD, then it knocked the power off to a whole camsite.

    Mike.
  • 0
    davezawadi (David Stone):

    Do you mean L&N reversed Zoom? Otherwise, it never worked or would trip the VOELCB. I don't think the trip current can be anything like 500mA, because that would be useless on a slightly high Ze electrode of say 125 Ohms, giving no volts for the trip, or at least far less current. I seem to remember the coil resistance was several K Ohms, so the current might not be too far from 30mA. Anyway changing to a 30mA RCD is very cheap and easy, everything is in place for the wiring


    David I need to clarify things as many are confused or making assumptions, although Andy is perfectly correct in what he said. The old electric drill is Class 2 plastic cased. The condition of the old installation may be very bad. The one next door of similar age was just hanging on by a thread, and when I moved the earthing lead (conductor) for inspection it just came away from the rod.


    The drill was being used outside and that posed addition dangers to my mind or damp grass, possible flex damage etc.


    The drill plug was showing inner worn cores outside its 13 Amp. plug. I rewired the plug for the owner and noticed that the two live conductors were reversed at the plug terminals. (I know that this makes no difference for a Class 2 appliance regarding safety).


    The whole situation shouted "DISASTER WAITING TO HAPPEN"


    Also, the lack of proper earthing/protection means that I can not add the new socket requested by drill man's wife.


    z.


  • 0
    Sparkingchip:

    Maybe being a belt and braces man Zoomup‍ might be inclined to fit a RCD downstream of the VOELCB?


    Quite blinkin' right Andy. Get it right though. A BIG belt and braces are required these days. How I get into lofts still amazes me.


    Anyway Andy, when you are this way, I will get you to try to persuade the owner with tight purse strings to get a new R.C.D. and rod installed. You seem to be a persuasive charmer? they tell me.


    I did advise the owner of the antique drill about needing an upgrade.


    Z.


  • 0
    AdrianWint:

    So, using such a device but connected between a 'PME neutral/earth' & "true earth" would give a mechanism that would disconnect if they moved more than about 50V apart.


    The VOELCB having the distinct advantage that it already has a set of high current contacts! 


    Maybe they arent so useless after all!

     


    50 Volts maximum. Normally between 20 to about 40 Volts ensures reliable tripping off. But J.W. in his (previously referenced) video about V.O.E.L.C.B.s, shows his example  tripping off  at about 11 Volts.


    Z.


    Z.


  • 0
    Silliest I have seen was green to neutral , red to earth and black to live.

    I might have guessed an old Tutonic influence there?

       - Andy.
  • 0
    AJJewsbury:
    Silliest I have seen was green to neutral , red to earth and black to live.

    I might have guessed an old Tutonic influence there?

       - Andy.


    But the appliance still worked, and it proved a good effective earth path.


    Z.


  • 0
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