Discuss The old one still learning in the Looking for Domestic Electricians? area at ElectriciansForums.net

Gary latto

Regular EF Member
Messages
49
Location
Leed
Hi guys me again still learning at 54.
Just doing some testing at home to get my head around things
Testing end to end of rfc and getting different readings on end to end of phase and end to end of neutrals.
Am I correct to be thinking a bad connection on an outlet somewhere as rfc wired in 2.5 t&e pvc so both phase and neutral both same csa ?
Tia
 

Pete999

Forum Mentor
Messages
21,801
Location
Northampton
What sort of a difference are you getting? could be a week croc clip connection.
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
is it a long circuit - is it just sockets or what?
did you wire in all the accessories? is the cable pinched or snagged anywhere?
 

Barnaby Stedman

Regular EF Member
Messages
183
Location
England
ok - well it's difficult to diagnose without taking each socket off until you find a loose connection. that's probably the next step to be honest im afraid.
I presume you have tested more than once to check?
 
OP
G

Gary latto

Regular EF Member
Messages
49
Location
Leed
So am I correct to be thinking will be a bad connection ?
So nothing else can make it have a difference between the two other than bad connection or damaged cable ?
 
OP
G

Gary latto

Regular EF Member
Messages
49
Location
Leed
Cheers barnaby appreciate the advice
I'll be checking all connections etc just wanted to confirm what I should be looking for cheers gary
 

mjroe

EF Member
Messages
12
Location
Devon
With an r2 of 0.84 that would imply that the neutral reading you got was correct (0.84 / 1.66 = 0.5). So I'd be looking at a fault in the line conductor, most likely a loose connection in one of the accessories.
 
OP
G

Gary latto

Regular EF Member
Messages
49
Location
Leed
Hi mj thanks for reply .
Where does the 1.66 come from ?
Sorry if obvious and I'm just not getting it
 
OP
G

Gary latto

Regular EF Member
Messages
49
Location
Leed
Think the penny just dropped is it the 0.5 difference allowed between readings of end to end between phase and neutral end to end ?
 
OP
G

Gary latto

Regular EF Member
Messages
49
Location
Leed
Hi telectrix I understand the cpc would be 1.67x greater due to only 1.5 , so yes like you say 0.5 x1.67 =0.83 .
But totally confused with regards the 1.66 calculation
So like you say the phase and cpc seem fine so neutral problem am I still looking at a bad connection do you think ?
 

mjroe

EF Member
Messages
12
Location
Devon
Ignore me, listen to Tel, I mis read your line and neutral end to end readings. The r1 seems to be right, as Tel said it's the rN that needs investigating, again a loose connection could quite easily be the cause.

The 1.66 (or 1.67 if you want to round up the recurring figure) comes from the difference in the cross sectional area of the live conductors and cpc. 2.5 (mm2) / 1.5 (mm2) = 1.666666666 (recurring).

So r2 should be 1.66 x greater than r1 (and rN).

Hope that makes sense.
 

telectrix

Scouser and Proud.
Respected Member
Messages
60,287
Location
cheshire/staffordshire
yep.might just be a terminal screw a bit loose in a socket. any why the confusion with 1.66? it's the ratio of 1.5/2.5.
 

telectrix

Scouser and Proud.
Respected Member
Messages
60,287
Location
cheshire/staffordshire
Ignore me, listen to Tel, I mis read your line and neutral end to end readings. The r1 seems to be right, as Tel said it's the rN that needs investigating, again a loose connection could quite easily be the cause.

The 1.66 (or 1.67 if you want to round up the recurring figure) comes from the difference in the cross sectional area of the live conductors and cpc. 2.5 (mm2) / 1.5 (mm2) = 1.666666666 (recurring).

So r2 should be 1.66 x greater than r1 (and rN).

Hope that makes sense.
you are excused due to the fact that you are in Devon. too much time smuggling booze and hanging pirates.
 

telectrix

Scouser and Proud.
Respected Member
Messages
60,287
Location
cheshire/staffordshire
my favorite tipple at my old local was Addlestones cloudy cider on draft. 7%. only 2 of us drank it, but we got through 2 x 10 gallons a week between us. sadly my mate has moved to a better world, having been crushed between a 50ft. canal barge and a lock when pi$$ed.
 
OP
G

Gary latto

Regular EF Member
Messages
49
Location
Leed
Confused with the 1.66 cause I learnt the 1.67 factor
Guys many thanks for your replies/answers all makes sense now thanks yet again much appreciated to all
 

telectrix

Scouser and Proud.
Respected Member
Messages
60,287
Location
cheshire/staffordshire
yeah, it's that tricky maths again. 1.6666666666 rounded up to 1 67. was much easier when we had roman numerals. XVIIIIIIIIIIIIIVIII.
 

static zap

Regular EF Member
Messages
1,822
Location
west midlands
yeah, it's that tricky maths again. 1.6666666666 rounded up to 1 67. was much easier when we had roman numerals. XVIIIIIIIIIIIIIVIII.
I always preferred vulgar fractions 2.5/1.5===5/3

(then reminding your common sense 0.99999999 .. =1)
so a third is 0.333333333 ..
 

telectrix

Scouser and Proud.
Respected Member
Messages
60,287
Location
cheshire/staffordshire
I always preferred vulgar fractions 2.5/1.5===5/3

(then reminding your common sense 0.99999999 .. =1)
so a third is 0.333333333 ..
Spock strikes with logic yet again. but McCoy would argue that 0.3333333 is not a turd. it's life Jim, but not as we know it. (enter the Borg).
 

Electrician Talk

Top