No power but RCBO has power.

[Bradmarsh]

HI guys,

I have an odd problem. I haven RCBO that did trip, I have found the reason and corrected it. However, when turning the RCBO it stays on, it has power yet it does not seem to provide power to my light. this is for a lighting circuit only, so there are no power points to remove things from. The RCBO is not tripping as mentioned and has power.

Any ideas what I need to do here to get this working?

 

[littlespark]

Rcbo’s can go faulty... especially if they have been continuously tripped on a fault and reset.... and then “held on” to try to clear a fault.

how have you tested that it has power? Is there voltage on the outgoing terminals?

the proper test equipment can test how fast it operates, and at what amount of mA it trips.

I see you’re in Sydney, and the time this was posted, so my advice is from a UK point of view.

Also check the basics.... is the lamp working? Is there another mcb in circuit that has also tripped?

 

[Dustydazzler]

As above an rcd , mcb or rcbo that has been tripping and reset under fault can break down. It’s quite rare but I have come across it. Sometimes the switch feels a bit more floppy than normal

are you using a normal voltage meter to probe the outgoing terminals , are you definitely getting 230/240v

 

[brianmoooore]

The most common reason I've come across for RCDs/RCBOs not resetting is that their test schedule has been ignored, and this is the first time they've ever been 'off' since they were installed.
Hair trigger mechanism sticks, and they won't reset.
Cure is to turn the power off and then vigorously 'exercise' the breaker to free up the mechanism. Sometimes the device has to be removed and slapped down flat on a hard surface a few times before it cooperates.

 

[Dustydazzler]

The most common reason I've come across for RCDs/RCBOs not resetting is that their test schedule has been ignored, and this is the first time they've ever been 'off' since they were installed.
Hair trigger mechanism sticks, and they won't reset.
Cure is to turn the power off and then vigorously 'exercise' the breaker to free up the mechanism. Sometimes the device has to be removed and slapped down flat on a hard surface a few times before it cooperates.

Joking aside when I was doing my on site training I once saw an old skool sparky take out a stuck RCD and smack it on the ground 6 or 7 times and he got it working again...
Reminded me of the old TV repair man who would slap the side of the telly 3 times and the picture would come back on ?

 

[DPG]

Joking aside when I was doing my on site training I once saw an old skool sparky take out a stuck RCD and smack it on the ground 6 or 7 times and he got it working again...
Reminded me of the old TV repair man who would slap the side of the telly 3 times and the picture would come back on ?

A good fix for old electronic items was to drop them on to the workbench from a few inches. Sorted out any contact issues between ICs and their sockets. When IC sockets were used that is.

 

[Bradmarsh]

As above an rcd , mcb or rcbo that has been tripping and reset under fault can break down. It’s quite rare but I have come across it. Sometimes the switch feels a bit more floppy than normal

are you using a normal voltage meter to probe the outgoing terminals , are you definitely getting 230/240v

Yes using a normal votage meter. Its getting reliably 235-238v each time. When I flip the RCBO to off, there is no voltage as expected, and then on and volla we have the expected voltage.

 

[brianmoooore]

Meter has two wires. 235-238V between what?

 

[timhoward]

it has power yet it does not seem to provide power to my light.

What sort of light fitting are we talking?
How many lighting points are on this circuit?
Do any of them work?

 

[Bradmarsh]

So the problem I found this morning. I traced the wires back from the switch board, and there was a break in the wire with some melting around the connection. I was able to cut and join it back and hey presto I have power again. Glad the break was not further in the wiring, that would have been a painful job!

 

[telectrix]

ta for the update.

 

[telectrix]

slapped down flat on a hard surface a few times before it cooperates.

we all have the occasional marital problems.