0.00 ohms r1+r2 on radial circuit?

[Plonker 3]

Quick quiz for you

A RFC has continuity values of r1=0.4 ohms, rn=0.4 ohms and r2=0.4 ohms

What is r1+r2?
What is R1+R2?

 

[Geoffsd]

Why does RFC stand for Ring FC and not Radial FC?

 

[telectrix]

Although technically its R1+R2 for your radial circuits. Whereas you record r1+r2 around your RFC with the highest value being classed as R1+R2. Is this a play on the capital 'R' telectrix?

no. with a rfc, you measure end/end of each conductor. these values are denoted by lower case r. when you cross connect on a RFC, or just connect L-E on a radial, you then measure R1+R2. ( denoted by upper case R ).

 

[Hobsoni]

Quick quiz for you

A RFC has continuity values of r1=0.4 ohms, rn=0.4 ohms and r2=0.4 ohms

What is r1+r2?
What is R1+R2?

Ok. Here it goes. I would take r1 (0.4) and r2 (0.4) add them together (0.8) and then divide by 4 (=0.2). This would be the reading I would expect for all outlets within the ring main. So I test and I test, and test some more jotting down all my values as r1+r2. As I test, I notice I have what I think is a spur as the value is greatest and is actually 0.36ohms. This value being the greatest of the circuit is recorded as my R1+R2 for the ring circuit. PS: with the values you gave, I'm guessing the cables used are singles. Did I Pass?

 

[Newbie90]

no. with a rfc, you measure end/end of each conductor. these values are denoted by lower case r. when you cross connect on a RFC, or just connect L-E on a radial, you then measure R1+R2. ( denoted by upper case R ).

I get it now haha :willy_nilly:

 

[Silly Sausage]

Why does RFC stand for Ring FC and not Radial FC?

Because higher beings than us say so!

 

[telectrix]

it also stands for Rugby Football Club, but i wouldn't like to attempt an IR test on a prop forward.

 

[telectrix]

Ok. Here it goes. I would take r1 (0.4) and r2 (0.4) add them together (0.8) and then divide by 4 (=0.2). This would be the reading I would expect for all outlets within the ring main. So I test and I test, and test some more jotting down all my values as r1+r2. As I test, I notice I have what I think is a spur as the value is greatest and is actually 0.36ohms. This value being the greatest of the circuit is recorded as my R1+R2 for the ring circuit. PS: with the values you gave, I'm guessing the cables used are singles. Did I Pass?

yes, but cable could also be SWA with the armour earthed but not used as cpc. the cpc core is the same size as the L and N.

 

[Silly Sausage]

it also stands for Rugby Football Club, but i wouldn't like to attempt an IR test on a prop forward.

Don't you fancy testing your wind up Megger on MDJ's goolies?

 

[Hobsoni]

it also stands for Rugby Football Club, but i wouldn't like to attempt an IR test on a prop forward.

Not necessarily a prop forward, but you might have some luck probing a hooker

 

[davesparks]

yes, but cable could also be SWA with the armour earthed but not used as cpc. the cpc core is the same size as the L and N.

Or flex, or hituff or ......,

 

[Hobsoni]

Hadn't given much thought to SWA cables in ring mains..............Theoretically yes you are right.

 

[Darkwood]

no. with a rfc, you measure end/end of each conductor. these values are denoted by lower case r. when you cross connect on a RFC, or just connect L-E on a radial, you then measure R1+R2. ( denoted by upper case R ).

Slight hypocrite to note the importance of a capital letter when needed ....lol telectrix

Although I cannot say anything either ... but I didn't bring the subject up :laugh3:

 

[telectrix]

Slight hypocrite to note the importance of a capital letter when needed ....lol telectrix

Although I cannot say anything either ... but I didn't bring the subject up :laugh3:

i blame it on my email addy which is all lower case.

 

[Matt85]

I had the same problem when I started using my fluke tester it turned out I had the null lock on.

 

[telectrix]

you don't get that problem with a megger. can't deride flukes, though as i've never used one.