Testing Ring Continuity short Question

[LukeScotty]

just a quick question I want to clear up, basically when testing a ring circuit, why is it that the ohm values slightly increase per reading, and highest at the centre point?

and by how much does the resistance increase when a cable is connected, say with a terminal block. apposed to say a complete round circuit with no connects, if it as possible to make such a cable, (like the letter O, a complete band , hope u get my drift)

cheers

 

[markthespark]

The reason the ohm value increases is because the cable length is longer which increases the resistance of the cable. And for your second question i havent got a clue.

 

[LukeScotty]

the ohm value shouldnt increase at all, should it? If the readings taken at the interconnection then shouldn't it be the same at every other point? so confusing

 

[markthespark]

Hmmm yeah i get what you mean mate, but i dont know haha im no expert im just a guesser ha.

 

[TonyM58]

Luke,

if the readings are increasing, then you are doing it wrong

step one - end to ends of the phase (r1) neutral (rn) and cpc (r2)

if using 2.5/1.5 twin and earth then r2 is 1.66 times higher value than r1 and rn (because 2.5/1.5 = 1.66)

step 2 cross connect phase and neutral - incoming phase to outgoing neutral and outgoing phase to incoming neutral

measure between phase and neutral at each socket. value should be the same (+-0.05 ohms) with the value being r1+rn divided by 4. If you your valew is increasing then you have connected incoming to incoming, and outgoing to outgoing

step 3 - do same with phase and CPC, value will be r1 + r2 divided by 4, and will be your R1+R2 value for the circuit.

Both step 2 and step 3 readings will increase slightly on spurs.

any junctions boxes or connections that yopu add to the circuit will potentiall add resistance

sorry if i am egg sucking, but i appreciate that some people may be reading this and learning something!!!

 

[Girlyspark]

If they are going up and down around the ring, it normally means you've got the wrong legs crossed! (Most uncomfortable! )

 

[LukeScotty]

cheers guys

 

[Gary latto]

If different readings on r1 and rn what normally causes it bad connection some where ??

 

[Andy78]

Nearly 12 years. Thread resurrection record ?

 

[ipf]

Nearly 12 years. Thread resurrection record ?

Congratulations in order?

#6 sounds a bit raunchy, though....