Blown Fuse Replacement??

[coffee]

Myth Busters on SBS had fun dropping electrical appliance's into a bathtub a few weeks back.

Geoff

 

[Lplate]

Sorry Lplate but this is totally incorrect. Mis-information is one of the biggest dangers besetting the electrical industry. The way earth leakage devices work is that both the active and neutral conductors pass through a toroidal core. Any imbalance caused by current leaking to earth via, lets say "water in a vanity or bath" will cause an imbalance in the core, tripping the RCD. [snip]
JIM

Jim
Thanks for that, I was going on the advice of the sparky who installed the device in my new house recently. Maybe he was the assistant, not the expert.

So I assume I can stop nagging the family about having double insulated electrical gear incl electrical toothbrushes on the vanities? They will be relieved.

I understand now that the current through the active must equal that through the neutral or the device will trip. But that leaves the possibility of current passing through the person and back via the neutral wire and in this case the device would not trip. How could this happen?
LPlate

 

[Cosmo]

RCD’S don’t offer protection in all circumstances. For eg if you grabbed neutral in a light socket and then touched active you would get a nasty shock.

On the other hand, if you were in contact with something earthed and touched active the RCD would trip before you’d feel anything.

 

[Cosmo]

So where is the current going? Are you assuming that there will be a current flow to ground in the order of the trip current of the RCD (20-30ma)? What would happen if you were up on an insulated ladder?

My brother is an eleco and he used to work on live ccts all the time…….he used to say don’t come near him because I could possibly provide the path to earth therefore zapping him.

Interesting topic……….

 

[Rixter]

So where is the current going? Are you assuming that there will be a current flow to ground in the order of the trip current of the RCD (20-30ma)? What would happen if you were up on an insulated ladder?

My brother is an eleco and he used to work on live ccts all the time…….he used to say don’t come near him because I could possibly provide the path to earth therefore zapping him.

Interesting topic……….

The current is going to earth via yourself as the conductor. If you are not touching any earth point as would be the case if you were up an insulated ladder then the RCD would not trip out. (providing it was just the neutral conductor you had hold of)

 

[GreatPig]

Jim,

if you grabbed neutral in a light socket, the imbalance of current going through you would trip the RCD well before you got hold of the active.

Why would there be any current flowing between neutral and earth?

GP

 

[Jimmyjamjars]

Sorry,
I got my words twisted the wrong way, I thought the question being asked was what if you grabbed both active and neutral, I meant to say that if you grabbed the ACTIVE, it would trip before you grabbed hold of the neutral. Its been a looooong day.
JIM

 

[Jimmyjamjars]

The point I'm really trying to make is don't question the ifs and buts, just get one installed in your IP's, they are cheap.
JIM

 

[pulse]

Buy the plug in circuit breakers - $16 or so from Bunnings, Cheap, easy and no sparky needed. Alternative is to get a sparky to wire an RCD (or ELCB) and mini circuit breakers for the circuits at the same time. These are cheaper from about $5 each for the parts.

Cheers
Pulse

 

[Rixter]

Buy the plug in circuit breakers - $16 or so from Bunnings, Cheap, easy and no sparky needed. Alternative is to get a sparky to wire an RCD (or ELCB) and mini circuit breakers for the circuits at the same time. These are cheaper from about $5 each for the parts.

Cheers
Pulse

A circuit breaker has no where near the safety effectiveness for tripping out. Its purely there to protect the circuit WIRING for overload. You can still be hanging off the circuit with current being conducted to earth via your body and NOT trip out the circiut breaker.

 

[Jimmyjamjars]

I won't comment any further on this topic for the fear that what people read on the forum may be interpreted as advice. I do not want anyone to think that as long as they do this or that or dis-connect something, that it is OK to commence work on an electrical installation. Please, do not attempt electrical wiring on your PPOR or IP, contact a licensed electrician. They are licensed for a reason. Its a tax deduction for your IP, and peace of mind.
JIM

 

[agent 86]

I won't comment any further on this topic for the fear that what people read on the forum may be interpreted as advice.

JIM,

Good advise

I've been following this thread as i've had a couple of different sparkys install circuit breakers and they confused me in their (different imo) explanations.
Reading this thread has confused me even more!
Maybe its just me!

Looks like I'll remain "electrically challenged".

A86

 

[Les]

G'day A86,

Looks like I'll remain "electrically challenged".

Sounds like a safer way to be.... Stay that way. Too much confidence has been known to lead to a downfall in unusual situations.

And, Jimmy, I hear you - thanks for your input - it's all good sense,

Regards,