Singles and Data in the same Dado trunking compartment

The risk of mains giving someone on a phone or using data network a shock is pretty much nil, unless the trunking also includes choc block or wagos or other un boxed mains joints., or perhaps there is a mouse problem.

However there is a very real risk of interference with data/ comms wiring that runs very close to mains cable, and that may give effects that are hard to trace. Back in the last century phones that had background hum and crackles whenever some specific piece of machinery was in operation stood some chance of being understood and traced. These effects are replaced by data links that magically crash or stop loading but only at certain times and such things can be very hard to debug. especially when interferer and victim may be hundreds of metres apart.

How short is the so called  'short' distance - a few 10s of cm will be negligible, the full length of a wall probably not. In general, I share your unease - its probably OK, but its not good practice, and we are told not to,  for a reason.

Also, if they are breaking that guidance, what else is happening where you cannot see ? Fire stopping, grouping factors and many other details usually don't matter but should not be omitted willy nilly. 

Mike.

The risk of mains giving someone on a phone or using data network a shock is pretty much nil, unless the trunking also includes choc block or wagos or other un boxed mains joints., or perhaps there is a mouse problem.

However there is a very real risk of interference with data/ comms wiring that runs very close to mains cable, and that may give effects that are hard to trace. Back in the last century phones that had background hum and crackles whenever some specific piece of machinery was in operation stood some chance of being understood and traced. These effects are replaced by data links that magically crash or stop loading but only at certain times and such things can be very hard to debug. especially when interferer and victim may be hundreds of metres apart.

How short is the so called  'short' distance - a few 10s of cm will be negligible, the full length of a wall probably not. In general, I share your unease - its probably OK, but its not good practice, and we are told not to,  for a reason.

Also, if they are breaking that guidance, what else is happening where you cannot see ? Fire stopping, grouping factors and many other details usually don't matter but should not be omitted willy nilly. 

Mike.

mapj1 said:

The risk of mains giving someone on a phone or using data network a shock is pretty much nil, unless the trunking also includes choc block or wagos or other un boxed mains joints., or perhaps there is a mouse problem.

Although from a BS 7671 point of view we "don't trust" basic insulation alone for shock protection (and perhaps with some reason - overheating conductors aren't unknown to creep through insulation on sharp bends for instance) - exposed basic insulation is a C2 and although this is within trunking unless the data cables are OK to be exposed directly to sustained mains voltage (and mains surges) we really should consider that the data cable could be energised by a fault ... and an exposed RJ45 somewhere then makes that touchable.

Had the singles been sheathed though, BS 7671 would have been a lot happier from a shock perspective.

  - Andy.