G
GMjohn
The situation - Cables were laid in a customers garden ready for lighting and power installation a few years ago by some other electrician but never finished. We've been called in to finish the job. As a trainee, I've been told by my boss to try and figure it out before work commences, but I have some confusion.
Looking at the lighting cable that's been installed, it looks like sy cable - transparent flexible cable with steel wire braiding. It wasn't connected into the ip junction boxes correctly as they all had water in them. All the cables have water damage to an extent - mould getting inside the ends to various degrees under the sheath and some discolouration/rust on the braiding in places. The cable still tests ok.
Looking at the way the cable was terminated at various boxes, an internal conductor was used for the cpc, and the steel braiding was not earthed. The braiding just had tape around it where the sheath was stripped back inside the junction boxes.
Not sure about the exact cable run. It's a very, very large garden with a stream and bridges, and the cable is buried in places but most of the buried cable seems to be under flagging, concrete or stones around the border.
Quite a few questions and concerns about this. Don't really feel that comfortable with the job, but that may change as I gain more knowledge about it. We're supposed to make the best of the situation, but at the moment I'm not sure it could be done safely and to regs given the stated situation.
Some questions -
1- Is this sy cable ok for use on garden lighting under these conditions instead of swa?
2 - Even though an internal conductor is used for the cpc, does the steel wire braiding also need to be earthed in addition to this, or was the other guy right to just tape it and have no earthing of the braid?
I know swa needs earthing even if an internal conductor is used as the cpc, though I'm not sure why this is the case. Is it purely for shock protection in the event of damage, or does it have anything to do with induced voltages? And does this also apply to the braided armour on this sy cable?
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I'm also not even sure the guy installed the correct size swa power cable for the length of the ring if it's to be on a 16a breaker like I'd want it to be. At least not according to my quick voltage drop calculation. But he did install swa on that circuit and seems to be terminated and earthed correctly, assuming he used weatherproof glands. Anyway, that's a different post for later.
Any help would be appreciated.
Looking at the lighting cable that's been installed, it looks like sy cable - transparent flexible cable with steel wire braiding. It wasn't connected into the ip junction boxes correctly as they all had water in them. All the cables have water damage to an extent - mould getting inside the ends to various degrees under the sheath and some discolouration/rust on the braiding in places. The cable still tests ok.
Looking at the way the cable was terminated at various boxes, an internal conductor was used for the cpc, and the steel braiding was not earthed. The braiding just had tape around it where the sheath was stripped back inside the junction boxes.
Not sure about the exact cable run. It's a very, very large garden with a stream and bridges, and the cable is buried in places but most of the buried cable seems to be under flagging, concrete or stones around the border.
Quite a few questions and concerns about this. Don't really feel that comfortable with the job, but that may change as I gain more knowledge about it. We're supposed to make the best of the situation, but at the moment I'm not sure it could be done safely and to regs given the stated situation.
Some questions -
1- Is this sy cable ok for use on garden lighting under these conditions instead of swa?
2 - Even though an internal conductor is used for the cpc, does the steel wire braiding also need to be earthed in addition to this, or was the other guy right to just tape it and have no earthing of the braid?
I know swa needs earthing even if an internal conductor is used as the cpc, though I'm not sure why this is the case. Is it purely for shock protection in the event of damage, or does it have anything to do with induced voltages? And does this also apply to the braided armour on this sy cable?
-
I'm also not even sure the guy installed the correct size swa power cable for the length of the ring if it's to be on a 16a breaker like I'd want it to be. At least not according to my quick voltage drop calculation. But he did install swa on that circuit and seems to be terminated and earthed correctly, assuming he used weatherproof glands. Anyway, that's a different post for later.
Any help would be appreciated.