H07RN‑F - Plantroom Installation

Question

Is H07RN‑F permitted under BS 7671 to be used in a plant room as a fixed installation, specifically for final connections between a DB and plant (e.g. pumps, fans)? Are there any regulations that would prevent its use compared with SWA, or is it acceptable where suitable for the environment?

Chris Pearson · Accepted Answer

Yes. 
 521.9.1 permits the use of "heavy duty" flexible cable. 
 H07RN‑F is heavy duty cable: BS EN 50525-2-21 section 4.3.

mapj1 · Answer

Yes - it is all perfectly fine, as long as suitably terminated (for some terminals expecting solid core such as on contactors or similar that may require the addition of bootlace ferrules or maybe pin or fork lug crimps to avoid a 'stray strand' issue.) and installed sensibly with good cable grip ( think compression glands mainly) - and, like any cable really, not in a place where it will be snagged or run over. Mike.

gkenyon · Answer

mapj1 said: sensibly with good cable grip ( think compression glands mainly) 
 If the cable is to be secured to a containment system, or using cable clips, or is generally out of reach can unlikely to be accidentally pulled out, this is OK. 
 Where the cable is not supported to the plant, a cable-grip is needed to prevent accidental pulling out. A standard stuffing gland is insufficient to prevent accidental pulling out. In a similar way, a cooker connecting point has a cable grip (and often flat 2c+cpc is often used for the cooker itself).

Chris Pearson · Answer

gkenyon said: In a similar way, a cooker connecting point has a cable grip (and often flat 2c+cpc is often used for the cooker itself). 
 Hm, I suppose that cookers do not usually vibrate (by contrast to motors in the OP), so the exception in 521.9.3 can be applied. 
 In any event, how often do people clean behind a cooker?

gkenyon · Answer

Chris Pearson said: Hm, I suppose that cookers do not usually vibrate (by contrast to motors in the OP), so the exception in 521.9.3 can be applied. 
 Yes, agreed ... but that doesn't change the need for a cable grip or clamp ? I was trying to illustrate the fact that the cable grip/clamp is needed because the cable isn't fixed, not how often the cable is moved.

H07RN‑F - Plantroom Installation

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