Minimum separation distance between LV power (230V-400V) and unscreened UTP

Question

From a containment perspective, what is the minimum separation distance between LV power (230V-400V) and unscreened UTP cable in the UK?

gkenyon · Answer

MS01 said: From a containment perspective, what is the minimum separation distance between LV power (230V-400V) and unscreened UTP cable in the UK? 
 For copper data cabling indoors, the minimum separation for safety is 50 mm, but in some circumstances, 150 mm is required (see Clause 5.4.4.2 of BS 6701). The requirement applies even if one or both cables are in metallic containment, and/or separated by metallic screen, and apply regardless of whether BS 7671 requirements for zero separation of different voltage bands. 
 There are also separation requirements for EMC, in BS EN 50174-2 for indoor cables (required by Clause 5.4.4.1 of BS 6701). This aligns with the guidance in Section 444 of BS 7671 (see A444.4). Outdoors, an outdoor grade cable is to be used, and again an assessment of EMC, surge protection (if required) as well as insulation for different voltage bands. The requirements are in BS EN 50174-3. You might need to consider Table A444.2 of BS 7671 outdoors, depending on what power cables you are close to. 
 For both indoor and outdoor cases, the worst-case minimum should be used when safety and EMC are taken into account - for example, if safety says 50 mm and EMC says zero segregation, then use 50 mm - or of EMC says 150 mm and safety 50 mm, use 150 mm. 
 Some guidance on the above, and the wording of the relevant Clauses in BS 6701, can be found in: 
 
 Annex I, Section I2 and I3 (pages 181-183) of the IET Code of Practice for Electrical Energy Storage System , 3rd Edition; and 
 Section 5.13.2 (pages 54-57) of the IET Code of Practice for Electric Vehicle Charging Equipment Installation , 5th Edition.

gkenyon · Answer

Heera said: I have screened network fibre cable, and LV power being FP500 which is SWA feeding FAP, and FP200 enhanced looping the fire detection devices etc. 
 These are questions for BS 5839-1, not just BS 7671, and also perhaps the relevant devolved national HTMs.The following are specifically relevant: 
 
 If the fibre cable is not associated with the fire alarm system critical path, then it should be in separate containment - see 26.2 k) of BS 5839-1:2017. 
 With respect to LV and loop cables of the FAS, sharing the same containment, see 26.2 l) and n) of BS 5839-1:2017, and this will depend on the FAS manufacturer's EMC advice as well as the choice of cables.

Minimum separation distance between LV power (230V-400V) and unscreened UTP

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