supplementary bonding resistance

[havoone]

reg 415.2.2, say i have a 20A breaker. is this then 50V/20= 2.5 ohms. and am i right in saying that the actual test of the supplementary bonding conductor is done with a low reading ohmeter and should not exceed 2.5 ohms ? thank you.

 

[WayneL]

reg 415.2.2, say i have a 20A breaker. is this then 50V/20= 2.5 ohms. and am i right in saying that the actual test of the supplementary bonding conductor is done with a low reading ohmeter and should not exceed 2.5 ohms ? thank you.

It's not, mate.

If its a type B 60898 then....

It's 50v/100A = 0.5 ohms.......this is the resistance between two simultaneously accessible, exposed/extraneous conductive parts, and would be tested with a low resistance ohm meter.

You don't use the rating of the breaker, you use the current that is required to trip the breaker in 5 sec or less.....which is 100A

Is there a reason you're considering this method of additional protection?

 

[havoone]

not considering it. its a question in a 2382 paper, its a type c breaker in the question.but see my mistake now. i now have to look at time current tables in App 3 and its 200A for a type c. so 50V/200=.25 ohms. and the measured resistance should be equal to or less than this. thanks waynel

 

[Tester Steve]

not considering it. its a question in a 2382 paper, its a type c breaker in the question. does this make a difference then

Yes, the tripping current is 200A, so it's now 50/200 = 0.25 ohms.

Steve.