wildwest
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I'm in a trench being attacked by flies that want my blood.
The cable is a 4mm csa 3 core SWA, new colours.
The cable is burried 1.5m in made up ground behind a wall built of sleepers .
There is yellow tape 0.1m above the cable.
The Run is about 70M
The supply was switched off, so dispite having a detector and knowing there was a cable there some where in there, the digging team didn't have a chance.
The property is locked, the location is remote.
The digging team are laying a pipe and back filling as they go.
They have stalled.
So here I am with submarine kits to patch it up so they can carry on.
I check the ends with a test meter, volts against the ground I'm in first.
All dead.
Then resistances,
on the sink end 31.3ohm between Brown and Black, 0.67ohm between Grey and armour. 1.17Mohm between Brown and Grey.
On the source end
>50Mohm between Brown and all others,
0.09ohm between Grey and armour, 0.08ohm between grey and black.
From these readings I take the following guesses.
The supply system is TNCS and is live.
If there is an RCD it did not trip but may still trip if I short the black and grey.
Only the supply circuit breaker or fuse is out.
The load is about 7A single phase
The spark who connected the system used the grey coloured cable as a cpc in parrallel with the armour.
So whilst I 'm waiting for the resin to cure and hoping not to have to come back when they key holder is found, I'm thinking..
In the good old days when we used red blue and yellow it was obvious which conductor to use for single phase cpc and which for the phase and neutral. These days it is not so.
And the question is, which colour do you choose for a cpc on a single phase system wire in three core brown black grey?
The cable is a 4mm csa 3 core SWA, new colours.
The cable is burried 1.5m in made up ground behind a wall built of sleepers .
There is yellow tape 0.1m above the cable.
The Run is about 70M
The supply was switched off, so dispite having a detector and knowing there was a cable there some where in there, the digging team didn't have a chance.
The property is locked, the location is remote.
The digging team are laying a pipe and back filling as they go.
They have stalled.
So here I am with submarine kits to patch it up so they can carry on.
I check the ends with a test meter, volts against the ground I'm in first.
All dead.
Then resistances,
on the sink end 31.3ohm between Brown and Black, 0.67ohm between Grey and armour. 1.17Mohm between Brown and Grey.
On the source end
>50Mohm between Brown and all others,
0.09ohm between Grey and armour, 0.08ohm between grey and black.
From these readings I take the following guesses.
The supply system is TNCS and is live.
If there is an RCD it did not trip but may still trip if I short the black and grey.
Only the supply circuit breaker or fuse is out.
The load is about 7A single phase
The spark who connected the system used the grey coloured cable as a cpc in parrallel with the armour.
So whilst I 'm waiting for the resin to cure and hoping not to have to come back when they key holder is found, I'm thinking..
In the good old days when we used red blue and yellow it was obvious which conductor to use for single phase cpc and which for the phase and neutral. These days it is not so.
And the question is, which colour do you choose for a cpc on a single phase system wire in three core brown black grey?
![[ElectriciansForums.net] down a hole fixing a cable](https://electricians.s3.eu-west-1.amazonaws.com/data/attachments/33/33894-0245390a45e8beb8f987ebb6d3ff362a.jpg "[ElectriciansForums.net] down a hole fixing a cable")
