IR testing MK dual RCD consumer unit.

[newbie111]

Hi all, when i was IR testing a MK dual RCD board LN-E i was getting 0.03 ohms with the rcd,s in the on position and when they were switched off the readings were greater than 200M ohms.
When circuits tested individualy all above 200 M ohms, could this be faulty rcds, installation installed less than 6 months ago and has been in service.
many thanks

 

[ezzzekiel]

mmmm shouldnt the rcd be disconnected so as not to interfere with test readings?

just a thought.

 

[sparkinlee]

Sounds like you've also got the Main Switch on as well as the RCDs, which will therefore be connecting the neutral bar back to the incoming neutral and so it should have a low resistance to earth.

 

[newbie111]

Hi ezzzekiel, thanks for reply. That would make sense, but have often seen the complete installation tested from the tails without RCD isolation.

 

[newbie111]

Thanks sparkinlee, that makes sense too but sure i had the main switch in the off position. will check again.

 

[ezzzekiel]

You will often see and do it yourself but as you have allready proved the rcds should not be in circuit

 

[newbie111]

Dave austin and Tony cable do it that way all the time...:yesnod::frown2:

 

[telectrix]

so did morcombe and wise

 

[newbie111]

haha, very true.