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Location of Pull cord for shower isolator outside zones but could still be touched.

Former Community Member
Former Community Member
Hi 


Sorry if this is a bit of a basic question, I am still in training as an electrician and trying to make sure I understand how rules are applied in practice.


I have been thinking about where shower isolator pull cord switches can be installed following section 701 in BS7671 and having looked at a few other books I am a bit confused as my interpretation of the rules doesn't match what I would consider as common sense.


From my understanding a pull cord switch can be mounted above zone 1 with the insulated cord dropping in to zone 1 and as the switch is outside the zones it doesn't need anything beyond standard IP2x protection based on 701.512.3.

Zone 1 extends to 225 above the fixed floor height or where the shower head is fixed at a height greater than 225 then zone 1 extends to the height of the shower head. There doesn't appear to be any mention of extending the zones if the shower head is not fixed and in theory could be directed at the ceiling.


The bit that doesn't make sense to me is that there are lots of precautions to keep water and electricity separated and to prevent people coming in to contact with electricity when wet. If my interpretation is correct a pull cord switch can be mounted above the shower basin at 225cm, which I as an average height person can touch quite easily, especially as the height appears to defined from the floor and not the shower basin (fig 701.2(C)). Also if the shower head is not fixed it can be pointed directly at the switch. There doesn't appear to be any requirement to protect the switch against water ingress.


I know it's unlikely but I could spray the switch with water and then put my hand on it whilst holding a shower head that could presumably be connected to earth by the flexible pipe.


I know everything in a modern installation should be protected by bonding and RCD's but to me this feels fairly risky.


Is there something I am missing?


Thanks


Alan 

Parents
  • The more general thing to realise is that the regs are a starting point, not the be-all and end-all. It is quite possible to design something foolish that meets the letter of the regs, and from time to time you will find things that are not regs compliant, but none the less, in that case, are the sensible thing to do.

    In reality some gumption on the part of the designer is assumed - and maybe from time to time it you will see an installation where that ability  has been left switched off.


    You are quite right, in practice  you would site the switch somewhere out of the firing line, and that may need to be be further away in a facility expected to be used by boisterous youngsters like a hostel or a school, than perhaps for some old folks home (but maybe not, depending on level of care needs and mental faculties expected )  Indeed the switch outside is problematic with kids who think it is great fun to turn off while their friend (soon to be enemy) is in it and another approach altogether may be better, as well as fixed shower heads....

    Mike.
Reply
  • The more general thing to realise is that the regs are a starting point, not the be-all and end-all. It is quite possible to design something foolish that meets the letter of the regs, and from time to time you will find things that are not regs compliant, but none the less, in that case, are the sensible thing to do.

    In reality some gumption on the part of the designer is assumed - and maybe from time to time it you will see an installation where that ability  has been left switched off.


    You are quite right, in practice  you would site the switch somewhere out of the firing line, and that may need to be be further away in a facility expected to be used by boisterous youngsters like a hostel or a school, than perhaps for some old folks home (but maybe not, depending on level of care needs and mental faculties expected )  Indeed the switch outside is problematic with kids who think it is great fun to turn off while their friend (soon to be enemy) is in it and another approach altogether may be better, as well as fixed shower heads....

    Mike.
Children
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