Home |
Search |
Today's Posts |
|
UK diy (uk.d-i-y) For the discussion of all topics related to diy (do-it-yourself) in the UK. All levels of experience and proficency are welcome to join in to ask questions or offer solutions. |
Reply |
|
|
LinkBack | Thread Tools | Display Modes |
#41
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On Thu, 30 May 2019 18:22:17 +0100, John Rumm wrote:
On 30/05/2019 08:19, PeterC wrote: On Wed, 29 May 2019 21:27:25 +0100, ARW wrote: On 29/05/2019 11:41, Tricky Dicky wrote: The wall where the garage supply cable will be buried in the wall is an exterior cavity wall with the internal wall being cinder type breeze blocks so quite easy to chase out to a depth of 50mm. Elsewhere the cable will run either through trunking or on the surface. I am a little concerned about carving halfway through the blocks for a 2m vertical run and I am not sure if they are already the hollow type, the ones I have had to sink boxes into elsewhere appear solid but you never know? It's 50mm from final finished surface not 50 mm into the blocks. Just to clarify: if the cable(s) are protected by a 30mA, 30ms RCD or RCBO do they have to be a) protected The RCD protection alone is adequate. Its only when RCD protection is not available, that other remedies may become required. b)as far in a 50mm? For a non RCD cable, then its needs: Surface wired (bare or in trunking), or To be buried = 50mm from the surface, or Mechanically protected by earthed metal - be it capping, conduit, armour etc, or A deviation from the regs based on the specific circumstances. It seems that surface-mounted mini-trunking would be OK; what if that were flush with or just below the surface? If its visible and obviously a cable, then its fine. Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! -- Peter. The gods will stay away whilst religions hold sway |
#42
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
Just an update. The RCBO plan has been shelved having missed the offer so it is back to RCDs and MCBs. The garage CU will now be a RCD protected unit with MCBs the supply cable will come from an non RCD protected MCB in the main CU this arrangement should mean faults in the garage circuits should not affect the house circuits which was my main concern when considering RCBOs. The garage supply cable will either run down 50mm below the surface for 2m or run on the surface behind a kitchen unit. I got an MK CU with RCD and fully populated for £73, a couple of MCBs need swapping but I can do that when the main CU is replaced as the existing one is an MK.
Thanks for all the help and advice particularly Adam. Richard |
#43
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 31/05/2019 08:52, PeterC wrote:
On Thu, 30 May 2019 18:22:17 +0100, John Rumm wrote: Just to clarify: if the cable(s) are protected by a 30mA, 30ms RCD or RCBO do they have to be a) protected The RCD protection alone is adequate. Its only when RCD protection is not available, that other remedies may become required. b)as far in a 50mm? For a non RCD cable, then its needs: Surface wired (bare or in trunking), or To be buried = 50mm from the surface, or Mechanically protected by earthed metal - be it capping, conduit, armour etc, or A deviation from the regs based on the specific circumstances. It seems that surface-mounted mini-trunking would be OK; what if that were flush with or just below the surface? If its visible and obviously a cable, then its fine. Next door had the same problem. He used just steel capping and RCD so that If you have the RCD, then no additional protection is required - although for cables that are being installed before plastering, capping is normally a good idea to protect them from damage during plastering. it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! Cables tend to not be magnetic unless armoured. The requirements these days specify RCD protection for all sockets - regardless of how the cables are run. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#44
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 30/05/2019 18:30, wrote:
I have a house consumer unit in the hallway. A cable runs in a straight line from the middle of the back of the consumer unit straight through a double skin wall, then a ceiling - floor void and then a second double skin wall and then it is surface clipped around the garage wall to a secondary consumer unit which will be filled with RCBOs. So from my understanding of this thread I can fit a 45a MCB in the main consumer unit and connect the secondary consumer unit to that? Pretty much. The cable is currently 6mm2 T&E and is more than 50mm from the floorboards and plasterboard...... Depending on the installation method, that's borderline for a 45A MCB. Have a look at the table: http://wiki.diyfaq.org.uk/index.php/Cables#Cable_Sizes The max current for 6mm^2 will only be large enough if installed method C (i.e. clipped direct to a surface, or embedded in masonry). Your described installation method more closely matches number 47 (BS7671 18th ed, blue book) for the section through the ceiling. That is described as "Single-core or Multicore cable - in a ceiling void, or in a suspended floor.", and the reference method listed is B. So that reduces the capacity of the 6mm^2 to 38A. While that *might* still be acceptable - depending on what load is going in the final CU[1]. However in applications like this, it would be much much better to have overload protection for the submain as well, since its impossible to predict what might change in the future and you don't really want to rely on a future installer understanding the restrictions imposed by a sub optimal submain. So smaller head end MCB, or bigger cable... [1] (if the load is less that that so overload of the submain is not possible, then you can argue that the head end MCB only needs to provide fault protection for the submain) -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#45
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 31/05/2019 08:52, PeterC wrote:
Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. |
#46
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On Fri, 31 May 2019 11:11:43 +0100, John Rumm wrote:
On 31/05/2019 08:52, PeterC wrote: On Thu, 30 May 2019 18:22:17 +0100, John Rumm wrote: Just to clarify: if the cable(s) are protected by a 30mA, 30ms RCD or RCBO do they have to be a) protected The RCD protection alone is adequate. Its only when RCD protection is not available, that other remedies may become required. b)as far in a 50mm? For a non RCD cable, then its needs: Surface wired (bare or in trunking), or To be buried = 50mm from the surface, or Mechanically protected by earthed metal - be it capping, conduit, armour etc, or A deviation from the regs based on the specific circumstances. It seems that surface-mounted mini-trunking would be OK; what if that were flush with or just below the surface? If its visible and obviously a cable, then its fine. Next door had the same problem. He used just steel capping and RCD so that If you have the RCD, then no additional protection is required - although for cables that are being installed before plastering, capping is normally a good idea to protect them from damage during plastering. Good, thank you. it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! Cables tend to not be magnetic unless armoured. Agreed - but the steel capping might be :-) The requirements these days specify RCD protection for all sockets - regardless of how the cables are run. At least tht's OK then. -- Peter. The gods will stay away whilst religions hold sway |
#47
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
|
#48
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 31/05/2019 15:42, dennis@home wrote:
On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#49
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote:
On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. -- Peter. The gods will stay away whilst religions hold sway |
#50
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 01/06/2019 03:24, John Rumm wrote:
On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: While the picture is clear, I find the regulation anything but when it comes to zones defined by sockets, switches etc. 522.6.202 has - so far as relevant - "Where the cable is connected to a point, accessory or switchgear on any surface of the wall or partition, the cable may be installed in a zone either horizontally or vertically, to the point, accessory or switchgear. Where the location of the accessory, point or switchgear can be determined from the reverse side, a zone formed on one side of a wall of 100 mm thickness or less or partition of 100 mm thickness or less extends to the reverse side" On a plain reading that seems to mean one can't use the zone defined by a socket, switch etc to run a cable that's /not/ connected to a socket etc in the zone but is just "passing through" on the way to another room, a garage or wherever. -- Robin reply-to address is (intended to be) valid |
#51
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 01/06/2019 08:17, PeterC wrote:
On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. |
#53
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote:
On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. -- Peter. The gods will stay away whilst religions hold sway |
#54
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 01/06/2019 13:23, PeterC wrote:
On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote: On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. The wiki article gives the definition of the 3 safe zones. The cables only need to be in one of them. They may if needed use 2 or all 3 of them. -- Adam |
#55
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 01/06/2019 13:23, PeterC wrote:
On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote: On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. They don't need to be... A safe (or in this context a better word might be "expected") zone is one of three separate and distinct areas: 1) Horizontally or vertically intersecting with the location of a visible electrical accessory. Hence the position of the zone is not a fixed place, but is defined by where the accessory actually is. So if you see a socket you know not to drill directly above, below, or to either side of it. That socket might be 2m from the nearest corner - but it still defines a zone around it. 2) At the intersection of two vertical walls - this applies even if there is no visible accessory. So don't go drilling in the corner beside a chimney breast even if you can't see a switch or socket. 3) At the intersection between wall and ceiling. Basically, if installing cables, they need to be in a least one of these zones. They can be in more than one, but there is no benefit or requirement for this. Hence avoid running cables at odd angles, or changing direction of them mid run. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#56
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 01/06/2019 11:12, Terry Casey wrote:
In article , says... On a plain reading that seems to mean one can't use the zone defined by a socket, switch etc to run a cable that's /not/ connected to a socket etc in the zone but is just "passing through" on the way to another room, a garage or wherever. Surely not. The whole point of the safe zones is to indicate where it is safe to run the "just passing through" cable because these zones coul;d equally be designated danger zomnes when it comes to drilling holes, etc. Iy you took a different route for the cable avoiding these zones there is nothing to indicate where the cable runs, making it particularly vulnerable. My point was that IMO the regulation doesn't actually say what it is generally taken to. I'm happy to be guided to how to be read it so the zones created by an accessory etc on the wall apply to a cable that is not connected to it. The only way I can see is to read "the" as "any" so it becomes: "Where /any/ cable is connected to a point, accessory or switchgear on any surface of the wall or partition, /any/ cable may be installed in a zone either horizontally or vertically, to the point, accessory or switchgear." But if so, WTF don't they say that in the first place? Reading "the" to include "any" is not normal. (And still means fitting an accessory with nothing connected to it does not create safe zones.) .. -- Robin reply-to address is (intended to be) valid |
#57
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 01/06/2019 13:23, PeterC wrote:
On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote: On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. I am a very strong advocate of DIY by competent DIYers but sometimes we all need to recognise when it is best to "get someone in", perhaps this is a case when that would be wise. Please don't flame me for making the suggestion. |
#58
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On Saturday, 1 June 2019 17:14:10 UTC+1, wrote:
I am a very strong advocate of DIY by competent DIYers but sometimes we all need to recognise when it is best to "get someone in", Yes. But that only happens on occasion perhaps this is a case when that would be wise. Please don't flame me for making the suggestion. I'm firing up the barbie. Seriously, installing cable in walls is not difficult. NT |
#59
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
One of the worst areas I see in the home where cables are not in the sage zones is on the kitchen and more specifically for the cooker.
Typically the cable going to the cooker isolation switch is in safe zones. There is typically a cooker cable junction box in the wall behind the cooker. Then there is a short run of cable from the cooker isolation switch to the cooker cable junction box and it's always diagonal! I have never seen a vertical and horizontal cable run between the isolation switch and junction box..... |
#60
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 01/06/2019 19:40, wrote:
One of the worst areas I see in the home where cables are not in the sage zones is on the kitchen and more specifically for the cooker. Typically the cable going to the cooker isolation switch is in safe zones. There is typically a cooker cable junction box in the wall behind the cooker. Then there is a short run of cable from the cooker isolation switch to the cooker cable junction box and it's always diagonal! I have never seen a vertical and horizontal cable run between the isolation switch and junction box..... If you have various accessories (switch, outlet plate etc) positioned diagonally to each other - there is always a rectilinear path between them that does not stray from their respective zones. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#61
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On Sat, 1 Jun 2019 15:31:40 +0100, John Rumm wrote:
On 01/06/2019 13:23, PeterC wrote: On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote: On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. They don't need to be... A safe (or in this context a better word might be "expected") zone is one of three separate and distinct areas: 1) Horizontally or vertically intersecting with the location of a visible electrical accessory. Hence the position of the zone is not a fixed place, but is defined by where the accessory actually is. So if you see a socket you know not to drill directly above, below, or to either side of it. That socket might be 2m from the nearest corner - but it still defines a zone around it. 2) At the intersection of two vertical walls - this applies even if there is no visible accessory. So don't go drilling in the corner beside a chimney breast even if you can't see a switch or socket. 3) At the intersection between wall and ceiling. Basically, if installing cables, they need to be in a least one of these zones. They can be in more than one, but there is no benefit or requirement for this. Hence avoid running cables at odd angles, or changing direction of them mid run. Thanks, this clarifies it. There's only one cable that's diagonal and that is clipped to the surface - and avoided a re-wire. -- Peter. The gods will stay away whilst religions hold sway |
#62
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On Sat, 1 Jun 2019 17:14:06 +0100, wrote:
On 01/06/2019 13:23, PeterC wrote: On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote: On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. I am a very strong advocate of DIY by competent DIYers but sometimes we all need to recognise when it is best to "get someone in", perhaps this is a case when that would be wise. Please don't flame me for making the suggestion. These were done by the original electricians. Next door had a shower pump taken from the lighting circuit that is on a 100mA RCD; that was done by a 'qualified' electrician (domestic and commercial). -- Peter. The gods will stay away whilst religions hold sway |
#63
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 02/06/2019 08:34, PeterC wrote:
On Sat, 1 Jun 2019 17:14:06 +0100, wrote: On 01/06/2019 13:23, PeterC wrote: On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote: On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. I am a very strong advocate of DIY by competent DIYers but sometimes we all need to recognise when it is best to "get someone in", perhaps this is a case when that would be wise. Please don't flame me for making the suggestion. These were done by the original electricians. Next door had a shower pump taken from the lighting circuit that is on a 100mA RCD; that was done by a 'qualified' electrician (domestic and commercial). Depending on the circumstances, that may be a sensible design decision. The use of the 100mA RCD might be because the earthing system is TT and hence all circuits needed to be RCD protected (even in days before this was common) to ensure disconnection in the event of an earth fault. If the pump is in a bathroom, there are quite possibly no other electrical circuits available near by, and the load from a pump is only likely to be a few hundred watts - so it will not stretch the supply. That's the same reason other small loads in bathrooms like extractor fans or shaver sockets are often fed from a lighting circuit. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#64
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On Sun, 2 Jun 2019 14:42:19 +0100, John Rumm wrote:
Next door had a shower pump taken from the lighting circuit that is on a 100mA RCD; that was done by a 'qualified' electrician (domestic and commercial). Depending on the circumstances, that may be a sensible design decision. The use of the 100mA RCD might be because the earthing system is TT and hence all circuits needed to be RCD protected (even in days before this was common) to ensure disconnection in the event of an earth fault. It's TN-C-S - updated about 25 years ago. If the pump is in a bathroom, there are quite possibly no other electrical circuits available near by, and the load from a pump is only likely to be a few hundred watts - so it will not stretch the supply. That's the same reason other small loads in bathrooms like extractor fans or shaver sockets are often fed from a lighting circuit. No circuits, but the taps are on copper pipe (mine's all plastic, so no Earth path) and the bonding's dodgey. My shower is off the 30mA RCD (same board and basic installation, done at the same time). Slightly worrying was that the pump was in a housing on the wall, the same as an electric shower, and the brushes were wearing out resulting in graphite visible around the joins and control - I don't know how conductive that would be. Perhaps best not to have the iron bath bonded to earth in this case. -- Peter. The gods will stay away whilst religions hold sway |
#65
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 02/06/2019 14:42, John Rumm wrote:
On 02/06/2019 08:34, PeterC wrote: On Sat, 1 Jun 2019 17:14:06 +0100, wrote: On 01/06/2019 13:23, PeterC wrote: On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote: On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. I am a very strong advocate of DIY by competent DIYers but sometimes we all need to recognise when it is best to "get someone in", perhaps this is a case when that would be wise. Please don't flame me for making the suggestion. These were done by the original electricians. Next door had a shower pump taken from the lighting circuit that is on a 100mA RCD; that was done by a 'qualified' electrician (domestic and commercial). Depending on the circumstances, that may be a sensible design decision. The use of the 100mA RCD might be because the earthing system is TT and hence all circuits needed to be RCD protected (even in days before this was common) to ensure disconnection in the event of an earth fault. If the pump is in a bathroom, there are quite possibly no other electrical circuits available near by, and the load from a pump is only likely to be a few hundred watts - so it will not stretch the supply. That's the same reason other small loads in bathrooms like extractor fans or shaver sockets are often fed from a lighting circuit. Most shower pumps require a 30mA RCD supply. -- Adam |
#66
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
|
#67
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On Saturday, 1 June 2019 19:40:05 UTC+1, wrote:
I have never seen a vertical and horizontal cable run between the isolation switch and junction box..... Mine is vertical - diagonal - vertical. Installed by the builders, at least it's in conduit. And at least since I moved in the conduit is now earthed. Owain |
#68
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
The diagonal cooker cables I see behind cookers are invariably under plastic capping... And is a single straight diagonal run.
So well done to the builder for using metal conduit and for you in earthing said conduit..... |
#69
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 02/06/2019 16:02, ARW wrote:
On 02/06/2019 14:42, John Rumm wrote: On 02/06/2019 08:34, PeterC wrote: On Sat, 1 Jun 2019 17:14:06 +0100, wrote: On 01/06/2019 13:23, PeterC wrote: On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote: On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. I am a very strong advocate of DIY by competent DIYers but sometimes we all need to recognise when it is best to "get someone in", perhaps this is a case when that would be wise. Please don't flame me for making the suggestion. These were done by the original electricians. Next door had a shower pump taken from the lighting circuit that is on a 100mA RCD; that was done by a 'qualified' electrician (domestic and commercial). Depending on the circumstances, that may be a sensible design decision. The use of the 100mA RCD might be because the earthing system is TT and hence all circuits needed to be RCD protected (even in days before this was common) to ensure disconnection in the event of an earth fault. If the pump is in a bathroom, there are quite possibly no other electrical circuits available near by, and the load from a pump is only likely to be a few hundred watts - so it will not stretch the supply. That's the same reason other small loads in bathrooms like extractor fans or shaver sockets are often fed from a lighting circuit. Most shower pumps require a 30mA RCD supply. These days yup... a historical install may not have specced it. -- Cheers, John. /================================================== ===============\ | Internode Ltd - http://www.internode.co.uk | |-----------------------------------------------------------------| | John Rumm - john(at)internode(dot)co(dot)uk | \================================================= ================/ |
#70
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 02/06/2019 22:20, John Rumm wrote:
On 02/06/2019 16:02, ARW wrote: On 02/06/2019 14:42, John Rumm wrote: On 02/06/2019 08:34, PeterC wrote: On Sat, 1 Jun 2019 17:14:06 +0100, wrote: On 01/06/2019 13:23, PeterC wrote: On Sat, 1 Jun 2019 09:15:11 +0100, dennis@home wrote: On 01/06/2019 08:17, PeterC wrote: On Sat, 1 Jun 2019 03:24:56 +0100, John Rumm wrote: On 31/05/2019 15:42, dennis@home wrote: On 31/05/2019 08:52, PeterC wrote: Next door had the same problem. He used just steel capping and RCD so that it's all covered by just the plaster. As in my house, some runs are not in Safe Zones - but do go to sockets or switches and are all vertical or horizontal. Should be easy to detect - a decent magnet would do it! They are in safe zones then as they extended from switches and sockets in the vertical and horizontal directions. Yup, like in the pictures: http://wiki.diyfaq.org.uk/index.php/...lectric_cables But some aren't within 150mm of edges. But you said they were vertical and horizontal not bent. They are straight but not within 150mm of an edge. I am a very strong advocate of DIY by competent DIYers but sometimes we all need to recognise when it is best to "get someone in", perhaps this is a case when that would be wise. Please don't flame me for making the suggestion. These were done by the original electricians. Next door had a shower pump taken from the lighting circuit that is on a 100mA RCD; that was done by a 'qualified' electrician (domestic and commercial). Depending on the circumstances, that may be a sensible design decision. The use of the 100mA RCD might be because the earthing system is TT and hence all circuits needed to be RCD protected (even in days before this was common) to ensure disconnection in the event of an earth fault. If the pump is in a bathroom, there are quite possibly no other electrical circuits available near by, and the load from a pump is only likely to be a few hundred watts - so it will not stretch the supply. That's the same reason other small loads in bathrooms like extractor fans or shaver sockets are often fed from a lighting circuit. Most shower pumps require a 30mA RCD supply. These days yup... a historical install may not have specced it. And you know my views on using a RCD as protection vs supplementary bonding. -- Adam |
#71
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 2019-06-03, ARW wrote:
On 02/06/2019 22:20, John Rumm wrote: On 02/06/2019 16:02, ARW wrote: Most shower pumps require a 30mA RCD supply. These days yup... a historical install may not have specced it. And you know my views on using a RCD as protection vs supplementary bonding. I don't but I'll bite --- why? |
#72
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 04/06/2019 10:02, Adam Funk wrote:
On 2019-06-03, ARW wrote: On 02/06/2019 22:20, John Rumm wrote: On 02/06/2019 16:02, ARW wrote: Most shower pumps require a 30mA RCD supply. These days yup... a historical install may not have specced it. And you know my views on using a RCD as protection vs supplementary bonding. I don't but I'll bite --- why? RCDs fail. Supplementary bonding doesn't. -- Adam |
#73
Posted to uk.d-i-y
|
|||
|
|||
Consumer Units with RCBOs
On 2019-06-04, ARW wrote:
On 04/06/2019 10:02, Adam Funk wrote: On 2019-06-03, ARW wrote: On 02/06/2019 22:20, John Rumm wrote: On 02/06/2019 16:02, ARW wrote: Most shower pumps require a 30mA RCD supply. These days yup... a historical install may not have specced it. And you know my views on using a RCD as protection vs supplementary bonding. I don't but I'll bite --- why? RCDs fail. Supplementary bonding doesn't. Fair point. |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Adding RCBOs to Wyler Split Load CU | UK diy | |||
Thoughts on fitting RCBOs | UK diy | |||
Why do some RCBOs have an earth wire and some don't? | UK diy | |||
RCBOs and Clipsal Box | UK diy | |||
RCBOs - the wiggly blue madness! | UK diy |