dead short L-N but the fuse doesn't blow? | on ElectriciansForums

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ExArmy

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when doing an inspection i came accross a radial circuit serving 4 points, the IR between L-N @500V was 0.00 Mohms, on continuity between L-N I got 25 ohms. when I then energised the circuit and clamped the live, no current being drawn. I have yet to take any fronts off as it was just an inspection and i didn't want to start faultfinding, i'm almost certain i got the whole of the circuit and everything was unplugged and they were just plain 2G sockets with no neons, but this one has baffled me. surely if the reading was that low, then there would be about 10A being drawn?
 
You have a light plugged in, could be a lamp, neon on a FSU, (check emersion heater), shaver point if on lighting circuit

keep looking and you will find something!

I did come across a FSU the other day hidden behind a false wall, home owner extended a ring with a FSU.
 
shaver point! i don't know for sure, but this seems likely as the radial is for a hallway, utility and bedroom right next to the bathroom. it's there is no loft, just really high ceilings so it can't be that. i'm back there this week sometime i'll investigate further
 
Next-door neighbours illicit grow room? (Oh No not that subject again)!

As the others have said you’ve overlooked a load somewhere. Let the hunt begin.

Are you going to tell us what you find?
 
mmm trying to think of a load that gives a 25ohm dc resistance but could be much higher impedance on ac. It could be a big heater load like an immersion or it could be a small electro-magnetic load like a shaver point or motor of some type. Dont know what the dc resistance on a fluorescent light but suppose its around that amount.

Good Luck and lets have a pic of the offending item

*hite just spotted no current drawn ? (or very small for your meter) Shaver point for me
 
Last edited:
My bets on an immersion heater hidden in a cupboard.
An immersion heater in a tank of hot water is favourite:- 1) When you tested the insulation the hot water in the tank was below the set temperature and the thermostat was therefore ON presenting a load. 2) When the final circuit was re-energised, the hot water quickly rose above the set temperature switching OFF the thermostat and disconnecting the load before you had clipped the clamp meter on to monitor the load current.
 
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