eaton rcd

[Tridentsystems]

Anyone find eaton rcds won't trip when tested at cu with loads disconnected ?

 

[Flanders]

Yes every time connect a short peace of cable to the live connection on the RCBO and then test at the end of it and it will work or you will have yo test it at the socket

 

[Tridentsystems]

Pain in the ---. Anyone got a technical explanation for it ?

 

[telectrix]

some rcd's need a few feet of cable attached for testing.

 

[Flanders]

This has been coverd before
http://www.electriciansforums.net/electrical-forum-general-electrical-forum/35461-mem-rcbo-pods-not-tripping-whilst-under-test-new-one-me.html

 

[telectrix]

Pain in the ---. Anyone got a technical explanation for it ?

yep. fairy dust.

 

[HandySparks]

As I understand it, some RCBOs have the current sensing coil around the hole that you push the output cables through before they reach the actual terminals. If you test at the terminal screw heads, you bypass this. I've been testing an MEM board today, and has exactly this problem. I don't think that you need a specific length of cable attached, just that it passes by the correct route into the RCBO terminals.

 

[Engineer54]

The manufacturer suggests around 10cm tails for testing purposes...

 

[telectrix]

bugger, had to get the tape measure out to convert that 10cm to english. about 4", if i read it correct.

 

[Engineer54]

bugger, had to get the tape measure out to convert that 10cm to english. about 4", if i read it correct.

Yep, that'll be about right!! lol!!

 

[HandySparks]

The manufacturer suggests around 10cm tails for testing purposes...

I suspect that is just a suggestion for a convenient length. The line connection on the MEM RCBOs is buried about 50mm inside, so you'd not want much shorter anyway. After all, you're going to be clipping your test leads of unspecified length to them, so I doubt it's critical.

 

[Engineer54]

I suspect that is just a suggestion for a convenient length. The line connection on the MEM RCBOs is buried about 50mm inside, so you'd not want much shorter anyway. After all, you're going to be clipping your test leads of unspecified length to them, so I doubt it's critical.

No idea to be honest and never really had cause to think about it!! Only really work with the up-market stuff. Not that, that necessarily means they are anymore reliable as RCD/RCBO's, than the run of the mill stuff out there...

 

[Marvo]

bugger, had to get the tape measure out to convert that 10cm to english......

Just under a quarter of a cubit Tel.

 

[telectrix]

and there's 4 cubits to the perch.