- Joined
- 10 Nov 2007
- Messages
- 162
- Reaction score
- 4
- Country
Hello,
Ex council terrace, built sometime between 1950- and 1970. The electrical supply is via a lead sheathed cable entering under the stairs, and the earth is bonded to the lead sheath:
http://www.flickr.com/photos/24994361@N03/8438845557/
The Economy 7 meter is being ripped out on Feb 20th and replaced with a normal single tariff affair. I've picked up a switchfuse (cheaper than an isolator at TLC) and some 25mm^2 tails for the cutout<>meter and meter<>switchfuse runs, and am going to ask the man from the electricity board nicely to connect to those when he changes the meter.
Switchfuse isolator:
http://www.tlc-direct.co.uk/Products/CGMSF100.html
The CU is a "Crabtree Starbreaker" and I've a lovely note and instructions from 1983 to explain what an RCCB is. Mainswitch feeds two 6A lighting circuits wired in 1.0mm^2, a 16A emergency immersion wired in 2.5mm^2, and a 40A cooker wired in 6mm^2. RCD feeds a 32A breaker for shower in 10mm^2, and two 32A ring mains wired in 2.5mm^2.
Kudos to the council for fitting the RCCB when rewiring the house in those days. Less kudos to whomever lost the blanking plates though:
http://www.flickr.com/photos/24994361@N03/8438844289/in/photostream
I'd like to fill that hole. I'd also like to run an electric shower (currently 8.5 kW, but would prefer 10.8kW) and an induction hob (3 zones; max rated input 6.9kW).
Shower:
http://www.plumbplanet.com/product/10068401
Hob:
http://www.aeg.co.uk/Products/Cooking/Hobs/Induction_hobs/HK953400FB
Q1: Are the current "starbreaker" MCBs and blanks backwards compatible? Will these fit the unit pictured?
http://www.tlc-direct.co.uk/Products/CB413slash236565B.html
Q2: Is 40A an appropriate MCB for 6mm^2 cable? It runs in bunched trunking for a metre or so, then inside the ceiling-floor void, and is then buried in the wall. (without trunking; it's an old installation) Is this cable appropriate for the induction hob?
I'm thinking a 32A breaker would be more appropriat, but the cable is ok, based on this TLC calculator:
http://www.tlc-direct.co.uk/Technic...230&length=10&submit=Calculate+Min+Cable+Size
Q3: Will that CU take a 50A breaker for a 10.8 kW shower? Is a 6m run of 10mm^2 cable ok at 10.8 kW? It runs again in mini trunking for a metre, across 2 metres of floor void, then up a cinderblock wall to the attic and 1 metre to the switch.
TLC calculator suggests 16mm^2 but that's pretty darn monstrous, no?
http://www.tlc-direct.co.uk/Technic...=230&length=6&submit=Calculate+Min+Cable+Size
(the 32A breaker is overloaded by the 8.5kW shower as-is; not my doing)
Q4: The cutout is fused at 60A at present. Who do I ask to upgrade that, and is it likely that they will do so or not?
I'll be DIYing then going via LABC for sign-off. (I've got an end gable that needs some lateral support and a chimney to come down and it can all go on the same ticket)
Bonus question: Any idea what the orange taped service is in this photo? Gas yellow and capped is obvious, but orange?
http://www.flickr.com/photos/24994361@N03/8438860671/
Cheers,
--
Marko
Ex council terrace, built sometime between 1950- and 1970. The electrical supply is via a lead sheathed cable entering under the stairs, and the earth is bonded to the lead sheath:
http://www.flickr.com/photos/24994361@N03/8438845557/
The Economy 7 meter is being ripped out on Feb 20th and replaced with a normal single tariff affair. I've picked up a switchfuse (cheaper than an isolator at TLC) and some 25mm^2 tails for the cutout<>meter and meter<>switchfuse runs, and am going to ask the man from the electricity board nicely to connect to those when he changes the meter.
Switchfuse isolator:
http://www.tlc-direct.co.uk/Products/CGMSF100.html
The CU is a "Crabtree Starbreaker" and I've a lovely note and instructions from 1983 to explain what an RCCB is. Mainswitch feeds two 6A lighting circuits wired in 1.0mm^2, a 16A emergency immersion wired in 2.5mm^2, and a 40A cooker wired in 6mm^2. RCD feeds a 32A breaker for shower in 10mm^2, and two 32A ring mains wired in 2.5mm^2.
Kudos to the council for fitting the RCCB when rewiring the house in those days. Less kudos to whomever lost the blanking plates though:
http://www.flickr.com/photos/24994361@N03/8438844289/in/photostream
I'd like to fill that hole. I'd also like to run an electric shower (currently 8.5 kW, but would prefer 10.8kW) and an induction hob (3 zones; max rated input 6.9kW).
Shower:
http://www.plumbplanet.com/product/10068401
Hob:
http://www.aeg.co.uk/Products/Cooking/Hobs/Induction_hobs/HK953400FB
Q1: Are the current "starbreaker" MCBs and blanks backwards compatible? Will these fit the unit pictured?
http://www.tlc-direct.co.uk/Products/CB413slash236565B.html
Q2: Is 40A an appropriate MCB for 6mm^2 cable? It runs in bunched trunking for a metre or so, then inside the ceiling-floor void, and is then buried in the wall. (without trunking; it's an old installation) Is this cable appropriate for the induction hob?
I'm thinking a 32A breaker would be more appropriat, but the cable is ok, based on this TLC calculator:
http://www.tlc-direct.co.uk/Technic...230&length=10&submit=Calculate+Min+Cable+Size
Q3: Will that CU take a 50A breaker for a 10.8 kW shower? Is a 6m run of 10mm^2 cable ok at 10.8 kW? It runs again in mini trunking for a metre, across 2 metres of floor void, then up a cinderblock wall to the attic and 1 metre to the switch.
TLC calculator suggests 16mm^2 but that's pretty darn monstrous, no?
http://www.tlc-direct.co.uk/Technic...=230&length=6&submit=Calculate+Min+Cable+Size
(the 32A breaker is overloaded by the 8.5kW shower as-is; not my doing)
Q4: The cutout is fused at 60A at present. Who do I ask to upgrade that, and is it likely that they will do so or not?
I'll be DIYing then going via LABC for sign-off. (I've got an end gable that needs some lateral support and a chimney to come down and it can all go on the same ticket)
Bonus question: Any idea what the orange taped service is in this photo? Gas yellow and capped is obvious, but orange?
http://www.flickr.com/photos/24994361@N03/8438860671/
Cheers,
--
Marko