Nickj
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Hi All,
I have my ELECSA assessment in a few weeks time. I was going to install an in-line water heater at a friends house but am now considering a board change at another friends house as this seems to be what they really want to see.
I am trying to back up everything I do with regulation numbers (in case I get asked questions relating to it).
I have had a brief look at the house and have found the following:
- Switch wires at light switches are not identified: the house is currently entirely red and black cabling, the black switch wires at the sockets should be sleeved in red? Electricians guide to building regs 11.2.1 (a) The CPC is sleeved in solid green. Should I change this to green/yellow?
- Cooker isolator is directly above the cooker, it should be at least 100mm from the cooker - Part P - elec guide to building regs figure 5.2.2 (Incidentally how would you reference this on an EICR?)
To rectify this I think I will run a new cooker cable as it is a small house, however, is it acceptable to join new cabling onto existing inside the current isolator,put blank plate on and run the new length in trunking 100mm+ from cooker and re-terminate into new isolator? From what I can see in the regulations this would be fine as the reason for it not being above the cooker is to do with people reaching over.
-Main earth conductor undersized, currently 6mm^2, need to be 16mm^2 - 542.3.1 BYB
-Main bonding conductors undersized, currently 4mm^2, need to be 10mm^2 Table 54.8 BYB
-Meter tails undersized, currently 16mm^2, need to be 25mm^2 514.3 BYB, OSG 2.2.3
The issue I have here is an issue of demarcation. Where is the demarcation point to which I need to ensure the above complies. I have attached a photo of the incoming supply. I have read somewhere that my demarcation point for the meter tails is the isolator, I cannot find a regulation or official guidance for this? Or do I need to take it to the meter?
For the earthing conductor do I take it only to the connection shown in the picture or do I need to ensure it goes into the cut out?
-The meter tails currently run out of the back of the fuse board through the cavity and into the supply enclosure outside. Research is once again proving difficult on this, some say this is allowed for meter tails only but they must be in flexible conduit? Others say no cables allowed in cavity..I can find nothing in the guide to building regs about it. Any pointers would be much appreciated.
One final point is about maximum demand:
The house currently has:
- One ring final
- One lighting Circuit
- One cooker circuit
- One immersion heater
After a board change that would be: 32A ring final, 6a Lighting, 32A cooker, 16A immersion
Applying diversity, as per OSG, to cooker gives (10.8Kw cooker with plug) 26A, diversity to lighting (9 pendants in house - 100w per (osg)) - 3.5A, no diversity for ring final or immersion heater allowed (32 +16)
Total: 77.5A
The OSG states other methods are allowed to be used and their method is only a guide. Clearly this installation is not overloaded and so I here others use what is apparently a DNO rule of thumb of 40% of the total value of breakers, this brings it down to 34.5A. Would an assessor allow that?
Sorry for the wall of text and thanks in advance for any help,
Nick
I have my ELECSA assessment in a few weeks time. I was going to install an in-line water heater at a friends house but am now considering a board change at another friends house as this seems to be what they really want to see.
I am trying to back up everything I do with regulation numbers (in case I get asked questions relating to it).
I have had a brief look at the house and have found the following:
- Switch wires at light switches are not identified: the house is currently entirely red and black cabling, the black switch wires at the sockets should be sleeved in red? Electricians guide to building regs 11.2.1 (a) The CPC is sleeved in solid green. Should I change this to green/yellow?
- Cooker isolator is directly above the cooker, it should be at least 100mm from the cooker - Part P - elec guide to building regs figure 5.2.2 (Incidentally how would you reference this on an EICR?)
To rectify this I think I will run a new cooker cable as it is a small house, however, is it acceptable to join new cabling onto existing inside the current isolator,put blank plate on and run the new length in trunking 100mm+ from cooker and re-terminate into new isolator? From what I can see in the regulations this would be fine as the reason for it not being above the cooker is to do with people reaching over.
-Main earth conductor undersized, currently 6mm^2, need to be 16mm^2 - 542.3.1 BYB
-Main bonding conductors undersized, currently 4mm^2, need to be 10mm^2 Table 54.8 BYB
-Meter tails undersized, currently 16mm^2, need to be 25mm^2 514.3 BYB, OSG 2.2.3
The issue I have here is an issue of demarcation. Where is the demarcation point to which I need to ensure the above complies. I have attached a photo of the incoming supply. I have read somewhere that my demarcation point for the meter tails is the isolator, I cannot find a regulation or official guidance for this? Or do I need to take it to the meter?
For the earthing conductor do I take it only to the connection shown in the picture or do I need to ensure it goes into the cut out?
-The meter tails currently run out of the back of the fuse board through the cavity and into the supply enclosure outside. Research is once again proving difficult on this, some say this is allowed for meter tails only but they must be in flexible conduit? Others say no cables allowed in cavity..I can find nothing in the guide to building regs about it. Any pointers would be much appreciated.
One final point is about maximum demand:
The house currently has:
- One ring final
- One lighting Circuit
- One cooker circuit
- One immersion heater
After a board change that would be: 32A ring final, 6a Lighting, 32A cooker, 16A immersion
Applying diversity, as per OSG, to cooker gives (10.8Kw cooker with plug) 26A, diversity to lighting (9 pendants in house - 100w per (osg)) - 3.5A, no diversity for ring final or immersion heater allowed (32 +16)
Total: 77.5A
The OSG states other methods are allowed to be used and their method is only a guide. Clearly this installation is not overloaded and so I here others use what is apparently a DNO rule of thumb of 40% of the total value of breakers, this brings it down to 34.5A. Would an assessor allow that?
Sorry for the wall of text and thanks in advance for any help,
Nick