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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
  • I don't think that BS 7671 is intended to protect people from deliberate acts of complete stupidity.


    When I take a shower at home, there is a fan just above my right ear i.e. in zone 1, where it is permitted. I could lift off the shower head and wash it out if I really wanted to! (How do you make a fan IPx-anything?)


    I had never given much thought to those beads which Mike mentioned - I had assumed that they are to facilitate replacement of the cord. Every day is a learning day in here!


    A pull-cord switch might well be not only above but also to the side of the zones; however, it doesn't take much to pull the end sideways into them.


    Incidentally, please do not fall into the trap of thinking that switches have to be outside a bathroom. Unless the bathroom is very small (and many modern ones are) there is plenty of room to install them by the door in the usual place.
Reply
  • I don't think that BS 7671 is intended to protect people from deliberate acts of complete stupidity.


    When I take a shower at home, there is a fan just above my right ear i.e. in zone 1, where it is permitted. I could lift off the shower head and wash it out if I really wanted to! (How do you make a fan IPx-anything?)


    I had never given much thought to those beads which Mike mentioned - I had assumed that they are to facilitate replacement of the cord. Every day is a learning day in here!


    A pull-cord switch might well be not only above but also to the side of the zones; however, it doesn't take much to pull the end sideways into them.


    Incidentally, please do not fall into the trap of thinking that switches have to be outside a bathroom. Unless the bathroom is very small (and many modern ones are) there is plenty of room to install them by the door in the usual place.
Children
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