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SW1970
Hi Folks, gas service engineer reported incorrect bonding to gas so customer calls me in to fix. Fixed that no worries. Explain earthing & bonding to customer; they say they've got sinks in every bedroom and ask me to have a look.
Scenario is CU is mechanically poor and needs replacing (strangely it's a metal MK sentry but front cover is flexing and can get finger in around the side). Looks like done to a good standard at 16th. No RCD protection on lighting circuits. I'm going to propose a CU upgrade but for the purposes of my proposal I want to build on wider bonding issue as follows but a few questions arise:
1. In one bedroom, there's no pendant lamp, only wall lighting, and a sink with copper all the way to the taps. If the light switch and the wall lighting are located such that there's no way a user could touch the taps and an exposed conductive part at the same time then I think that these items are not "simultaneously accessible" per reg 415.2.1 (Not worried about items plugged into sockets because they are RCD protected). Does that sound about right?
2. In another bedroom, inside the bottom of the sink unit and usually covered in toiletries etc, about 10cm of copper water pipe is visible and then PVC up to taps. Should these copper pipes have supplementary bonding or is the simultaneously accessible rule as per Q1 considered before anything else?
3. In another bedroom, it's copper water pipe all the way up to the taps and the (non SELV) light fitting is directly above the sink. Using wander lead I measured R2 at the copper pipe where it meets the tap and recorded 0.03ohm back to the MET. This copper may already have supplementary bonding but I can't locate it. Is there a threshold below which an extraneous conductive part is considered to adequately bonded? Maybe 0.05ohm? If yes, but the bonding cannot actually been seen (perhaps under a floorboard), is that considered satisfactory or must it be inspectable?
Thanks loads! SW
Scenario is CU is mechanically poor and needs replacing (strangely it's a metal MK sentry but front cover is flexing and can get finger in around the side). Looks like done to a good standard at 16th. No RCD protection on lighting circuits. I'm going to propose a CU upgrade but for the purposes of my proposal I want to build on wider bonding issue as follows but a few questions arise:
1. In one bedroom, there's no pendant lamp, only wall lighting, and a sink with copper all the way to the taps. If the light switch and the wall lighting are located such that there's no way a user could touch the taps and an exposed conductive part at the same time then I think that these items are not "simultaneously accessible" per reg 415.2.1 (Not worried about items plugged into sockets because they are RCD protected). Does that sound about right?
2. In another bedroom, inside the bottom of the sink unit and usually covered in toiletries etc, about 10cm of copper water pipe is visible and then PVC up to taps. Should these copper pipes have supplementary bonding or is the simultaneously accessible rule as per Q1 considered before anything else?
3. In another bedroom, it's copper water pipe all the way up to the taps and the (non SELV) light fitting is directly above the sink. Using wander lead I measured R2 at the copper pipe where it meets the tap and recorded 0.03ohm back to the MET. This copper may already have supplementary bonding but I can't locate it. Is there a threshold below which an extraneous conductive part is considered to adequately bonded? Maybe 0.05ohm? If yes, but the bonding cannot actually been seen (perhaps under a floorboard), is that considered satisfactory or must it be inspectable?
Thanks loads! SW
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