Schneider breaker didn't turn off.

[giddyup]

Had a new Schneider fuse box installed a few years ago as protection against any shorts or accidental electrical contacts, but yesterday managed to cut the power cord while using an electrical hedge trimmer. It didn't sever the cord completely but sparks flew and the bare wires were exposed. When I inspected the fuse box I was surprised to see no fuses had flipped off. This concerns me a bit as I don't see the breaker box giving us full protection. Am I right?

[Crossy]

Please post a photo of the board you have.

 

It does sound like you don't have any earth-leakage protection, but we will be able to tell more with an image.

 

[giddyup]

6 minutes ago, Crossy said:

Please post a photo of the board you have.

 

It does sound like you don't have any earth-leakage protection, but we will be able to tell more with an image.

 

 

[Crossy]

Yeah, that main breaker probably should have tripped. Press the Test button.

 

Did anyone actually get a shock or the cut end touch the ground? It's possible that just a bit of sparking didn't cause enough current flow to do much.

 

[MJCM]

1 minute ago, Crossy said:

Yeah, that main breaker probably should have tripped. Press the Test button.

We do that regularly on all our individual ones. 
 

[giddyup]

Just now, Crossy said:

Yeah, that main breaker probably should have tripped. Press the Test button.

 

Did anyone actually get a shock or the cut end touch the ground? It's possible that just a bit of sparking didn't cause enough current flow to do much.

 

No shock, and the cord wasn't actually severed, but the cut wires were bared.

[Crossy]

Just now, giddyup said:

No shock, and the cord wasn't actually severed, but the cut wires were bared.

 

Just bare wires won't trip anything, current actually has to go where it's not wanted.

[giddyup]

4 minutes ago, Crossy said:

 

Just bare wires won't trip anything, current actually has to go where it's not wanted.

Well, sparks flew from the blade of the hedge trimmer, so obviously the current came in contact with the trimmer. I just tried the Test button and it flipped of the main breaker.

Edited October 1, 2022 by giddyup

[Crossy]

Just now, giddyup said:

Well, sparks flew from the blade of the hedge trimmer, so obviously the current came in contact with the trimmer.

 

Very possibly, going on its way to the other pole via the blade, to the MCB that would look like just a regular load and not a big enough one to trip it.

 

If it didn't go to ground there was nothing for the RCBO to detect.

 

If the beast tripped on the test button all is well.

 

[giddyup]

4 minutes ago, Crossy said:

 

Very possibly, going on its way to the other pole via the blade, to the MCB that would look like just a regular load and not a big enough one to trip it.

 

If it didn't go to ground there was nothing for the RCBO to detect.

 

If the beast tripped on the test button all is well.

 

Thanks. That makes me rest easier. I will be buying a cordless hedge trimmer with a battery pack, it's the second time in 10 years I've cut the cord.

[Crossy]

1 minute ago, giddyup said:

Thanks. That makes me rest easier. I will be buying a cordless hedge trimmer with a battery pack, it's the second time in 10 years I've cut the cord.

 

Yeah, the hedge trimmer is the only corded garden appliance we have, everything else is either cordless or petrol.

 

SiL used to cut the cord on a regular basis until I showed him how to feed it over his shoulder without strangling himself ????  

[lopburi3]

2 hours ago, giddyup said:

Well, sparks flew from the blade of the hedge trimmer, so obviously the current came in contact with the trimmer. I just tried the Test button and it flipped of the main breaker.

Sparks could have been metal on metal - just as you would have sparks if you hit a wire fence.

[giddyup]

2 minutes ago, lopburi3 said:

Sparks could have been metal on metal - just as you would have sparks if you hit a wire fence.

Really? A bare wire could cause a shower of sparks just by coming into contact with the blade? It's a thin wire not an angle grinder.

[4MyEgo]

2 hours ago, giddyup said:

Thanks. That makes me rest easier. I will be buying a cordless hedge trimmer with a battery pack, it's the second time in 10 years I've cut the cord.

I cut through a cord about a couple of years back and didn't even realise it, wife came outside where I was and said we have a black out.

 

I went inside and noticed the big switch down, I pushed it back up and the power kept tripping off, I think, I can't really remember to be honest, but sounds right, so when I went back outside to continue cutting after I told the wife to ring the builder who built the place, only lives up the road and is always available for us.

 

When I went to continue cutting the vines, I saw this strange looking vine that I cut through, which was part of what I thought was the other vines, but the vines had grown around this strange looking discoloured white external wire which looked like a vine, which was for the outside gate lights.

 

The wire was put in one of those plastic strips and ran along the wall under the ledge, out of sight, but the part that went from the fence to the street power pole (1.5 metres) is what I cut on our side of the fence, which made me wonder why on earth he would have done it that way, possibly a short cut which could have cost me my life I think, anyway, we called him to come and sort it, he did, and wrapped the live cut part from the wire that I cut to the other power pole wires running to our place, I said why doesn't he just remove it, wife translated for me, he smiled and said my pen rye, no need, yeh right, next guys problem right. 

 

This reminds me when I purchased the box and all the circuit breakers and the big tripper, we discussed it with him and he said, no need, same with the smoke detectors, haha, guess I like listening to myself, because the decisions I make are for a reason, suffice to say, I don't have that care free Thai attitude, I like to get what I want because I know better sometimes, ok, all the times, same with the sisalation and ceiling batts, it would be an oven in here if I listened to him, go figure.

 

[Muhendis]

3 hours ago, Crossy said:

 

Very possibly, going on its way to the other pole via the blade, to the MCB that would look like just a regular load and not a big enough one to trip it.

 

If it didn't go to ground there was nothing for the RCBO to detect.

 

If the beast tripped on the test button all is well.

 

Good answer, 

So the next project will be to ensure all such bare metal gadgets have an earth terminal connected to earth at the mains plug.

[Crossy]

32 minutes ago, Muhendis said:

Good answer, 

So the next project will be to ensure all such bare metal gadgets have an earth terminal connected to earth at the mains plug.

 

Making them Class-2 (double-insulated) is normal and is fine for normal use, that great lump of metal sticking out the front is protected from becoming live my at least two sets of insulation. Most power tools are now Class-2 no earth required.

 

Cutting the wire is not normal use hence the recommendation to use an RCD which will (probably) protect you from a fatal shock if you do touch a live wire in the cut ends (or will kill the juice first if the end actually touches the ground).

 

[degrub]

A plastic grab handle and plastic enclosure around the motor and electrical also helps reduce the chance of the cut wire current using your body as a path to earth as most plastics do not have enough, if any,  carbon black in them to become conductors. Same for wearing shoes with thick rubber soles.  However, not perfect or reliable, as moisture from sweat and vegetation can create a conductive path over the surface. 

[Muhendis]

2 hours ago, Crossy said:

 

Making them Class-2 (double-insulated) is normal and is fine for normal use, that great lump of metal sticking out the front is protected from becoming live my at least two sets of insulation. Most power tools are now Class-2 no earth required.

 

Cutting the wire is not normal use hence the recommendation to use an RCD which will (probably) protect you from a fatal shock if you do touch a live wire in the cut ends (or will kill the juice first if the end actually touches the ground).

 

That lump of metal sticking out the front may be insulated from the motor and the electrical bits inside the machine but the second it cuts into the mains lead it is likely to become live. That is why my Bosch hedge trimmer in the UK had an earth and that is why the ELCBO in the consumer unit instantly tripped when I cut the supply cord (Yup. Me too). The blade would have connected the earth wire to one of the current conductors and hey presto. No dangerous bare leads lying around waiting for me to pick up.