ring final question

[ezekiel]

got a exam question that i cant figure the answer to:

why phase to neutral readings at each socket would increase towards the mid point of the ring then decrease again ?

i first thought maybe as the ring was being fed from both sides, or maybe because of interconnections

 

[Spark123]

You mean when you have your cross connection in as part of the continuity of ring conductor tests?
It is because you have not connected the cross connection correctly i.e. you haven't got Leg 1 L to Leg 2 N, Leg 2 N to Leg 1 L.
Would happen if you connected Leg 1 L to Leg 1N, Leg 2 L to Leg 2 N.

 

[Hann]

got a exam question that i cant figure the answer to:

why phase to neutral readings at each socket would increase towards the mid point of the ring then decrease again ?

i first thought maybe as the ring was being fed from both sides, or maybe because of interconnections

You would get this scenario (during ring continuity testing with opposite phase and neutral connected) if a bridge (interconnection) exists.
The readings increase beyond the interconnection to the ring's midpoint, then decrease back towards the interconnection.
Normally the readings should be very similar and approximately (r1+rn)/4 where r1 and rn are the end-to-end resistances of the phase and neutral conductors.

Hope this helps.

 

[ban-all-sheds]

You would also get it if you messed up the cross-connections at the CU, so maybe the question is designed to find out if you know that....

 

[Hann]

You would also get it if you messed up the cross-connections at the CU, so maybe the question is designed to find out if you know that....

duly chastened