maximum size of RCD

[xAlex]

Guys, Admittedly a college question but i'm really pushed tonight..If anyone can respond (with the answer) by 9:30pm i would really appriciate. I swear I will look it up subsequently and fully understand the topic.
Cheers...

Q
An earth electrode has a resistance of 120Ω. What is the maximum size of RCD permitted to keep the touch voltage below 25V?

 

[ban-all-sheds]

Surely they've covered Ohm's Law by now?

 

[xAlex]

Awww, you like to see a bloke struggle. But thanks for the tip. ... I reckon this anyway...

I Delta N

• xAlex
• 9 Apr 2008
• 1

 

[ban-all-sheds]

There you are - you knew the answer all along.

And like you've always been told, the good thing about showing your working is that it shows you understand it, and that saying 25/120 = 0.21mA was just a minor slip...

 

[xAlex]

A-hem, ..of course!