Testing Ring Circuit

[bathroomboy]

Fairly new at testing, got .53 on end to end R1 and .52 Rn, but getting 1.20 om cpc this does not add up is it to to parralel paths bonding etc. Cheers

 

[EasyFox]

csa of the cpc ?
poorly terminated cpc.
bonding ...........could be.

would be expecting in the region of 0.86ish if 2.5/1.5mm T/E

 

[PAUL M]

IF THE CPC IS 1.5MM IT SHOULD BE 1.66 TIMES YOUR r1 reading because the resistance will be higher on a smaller cable. which should give you a r2 ( cpc )reading of 0.87.as your reading is 1.20 it could be because its old cable and has a 1mm cpc or a loose connection,hope this helps you.

 

[bathroomboy]

Thanks Easy fox, .80 ish was what I was expecting, what can I check for? going to use this circuit for assesment, so it's got to be right. It's an existing ring and has a few spurs on it and is bonded to a water pipe in the kitchen.

Cable is 2.5 put in around 1980 I am assuming the cpc is 1.5 but as you say could be 1m/m I will check it out

Would a loose connection give me a higher resistance?

Would a loose connection give me a higher resistance?

 

[EasyFox]

what can I check for?

1mm cpc / poor terminations at accessories of the cpc / remove the bonding & retest.

and is bonded to a water pipe in the kitchen.

Kitchen bonding isnt a requirement now, so you could remove it if you so wish ( so long as its not the main equipotential bond)

Cable is 2.5 put in around 1980 I am assuming the cpc is 1.5 but as you say could be 1m/m I will check it out

Is it the old stranded stuff (3 strands for the cpc)? If so odds on its 1mm.
Off the top of my head I dodnt know what the multilier is for 1mm, Shakey may know if he's about.

Would a loose connection give me a higher resistance?

quote]

Yes it could.

 

[bathroomboy]

Cable was put in 1987 as part of extension kitchen and and garage ring.

Best check all connections on sockets etc. Cheers

It's not stranded.

 

[PC Electrics]

what can I check for?

also check for corrosion and damaged cable (esp garage)

 

[Shakey]

1mm cpc / poor terminations at accessories of the cpc / remove the bonding & retest.



Kitchen bonding isnt a requirement now, so you could remove it if you so wish ( so long as its not the main equipotential bond)



Is it the old stranded stuff (3 strands for the cpc)? If so odds on its 1mm.
Off the top of my head I dodnt know what the multilier is for 1mm, Shakey may know if he's about.

quote]

Yes it could.

Easyfox, hi mate , where you been?

for 2.5/1.5 multiplier comes from dividing 2.5 by 1.5 = 1.66

so for old 1mm

2.5/1 = 2.5 for multiplier

Thanks Easy fox, .80 ish was what I was expecting, what can I check for? going to use this circuit for assesment, so it's got to be right. It's an existing ring and has a few spurs on it and is bonded to a water pipe in the kitchen.

Cable is 2.5 put in around 1980 I am assuming the cpc is 1.5 but as you say could be 1m/m I will check it out

Would a loose connection give me a higher resistance?

Would a loose connection give me a higher resistance?

If the ring is disconnected at the CU to do the end to end checks (as it should be), even the kitchen bonding (which has NEVER been a requirement of the regs to my knowledge) should not produce a parralel path, and remember, any parralel path is going to automatically LOWER the resistance reading, not raise it!

 

[bathroomboy]

Thanks for the replies, tested other ring this morning and got similer results, appears the cpc is 1m/m, what is the calculation for checking this i.e 2.5 + 1.5 is multiplied by 1.67
so what will 2.5 + 1m/m be multiplied by. Cheers

 

[LukeScotty]

2.5mm/1mm = 2.5 for a multiplier (like shakey sed) :
so : .53 x 2.5 = 1.32ohms ?

wouldn't you be able to do a long lead test for this ??

 

[EasyFox]

Easyfox, hi mate , where you been?

for 2.5/1.5 multiplier comes from dividing 2.5 by 1.5 = 1.66

so for old 1mm

2.5/1 = 2.5 for multiplier

Hello Shakey.
Me I've been soooooooooooooo busy it's not funny, but what with all this talk of hard times ahead I've had the nose to the grindstone to see me through if/when the recession bites. So not been staying away for any particular reason mate

As for the multipliers................well dont I feel a dope, fancy not remembering how they are found oh well live & learn as they say

See you all later got some quotes to bash out now.

 

[bathroomboy]

All sorted now, Thanks again for the helpful replies. Cheers