Had my consumer unit changed from an older plastic wylex board with a single RCD to this newer metal BG board with all RCBOs in preparation for adding plug in solar. Any issues with the install?
Hi all, hoping some electricians/sparks here can sanity check my numbers before I get this oven installed. I've done the maths myself based on our EICR but want a second opinion before committing.
Setup:
Property: flat, UK, standard 230V single-phase supply
New appliance: 11.1kW electric oven, hardwired (no socket on the cooker connection unit — just isolator/hardwire)
Existing cooker circuit per our EICR (tested May 2026):
Cable: 6mm² live, 2.5mm² cpc
Protective device: 32A Type B RCBO
Measured (R1+R2): 0.17Ω
Measured Zs: 1.37Ω
Ze at origin: 0.23Ω
My working:
Full load current: 11,100W ÷ 230V = 48.26A
Applied cooker diversity (BS 7671): 10A + 30% of remainder = 10 + (0.3 × 38.26) = 21.48A design current (no +5A since there's no socket on the unit)
Breaker check: 21.48A design current vs 32A breaker — fine, ~10.5A headroom
Cable check: 32A breaker well within 6mm² T&E capacity — fine
Zs check: 1.37Ω measured vs 1.44Ω max permitted for 32A Type B — passes but only 0.07Ω margin, which feels tight to me
Cable length: not recorded on the EICR, so I back-calculated from the 0.17Ω (R1+R2) reading using standard copper resistance (3.08 mΩ/m for 6mm², 7.41 mΩ/m for 2.5mm²) → works out to roughly 16.2m
Voltage drop at that length: 7.3mV/A/m × 21.48A × 16.2m = 2.54V = 1.1% of 230V — well under the 3% limit
So on paper this all passes, but a few things I'd love opinions on:
Is the 0.07Ω Zs margin (1.37Ω vs 1.44Ω limit) actually as tight as it feels, or is that pretty normal/acceptable in practice?
Is back-calculating cable length from R1+R2 a reasonable approach, or is there something I'm missing that would throw this off (joints, connectors, etc.)?
Anything else on a job like this that wouldn't show up in the paperwork but you'd always check on-site before signing off? (e.g., condition of the isolator switch, terminal tightness, etc.)
Not trying to skip getting a qualified electrician to actually do the install and certify it — just want to go in with a solid understanding of what's involved and not get blindsided. Appreciate any thoughts
Hey guys, please forgive me if this is not appropriate or not, but I'm unsure on where to ask.
I have recently purchased my first home, and this is my current fuse box / consumer unit. I understand this is very dated.
What would you do in my position? Replace the consumer unit, or do I need a full rewire?
Money is tight as you can imagine, I'm curious as to how much this would cost to get back up to spec (whatever that may be)
Thanks all :)
Selling house. Buyer had survey done. Survey is saying that this board needs to be replaced, apparently. Haven't seen the survey myself. There is no history of electrical problems, such as breakers tripping, in this house for 10 years. Far as i know, the surveyor only eyeballed the panel. Buyer might be trying it on.
Is there anyway from just looking at this panel that a replacement can be justified?
How do chaps.
Back in 2010 I did my 17th Edition and bought the above meters brand new. Due to personal circumstances I never did anything sparkywise and they're unused. I now want to go back to College to do the 18th Edition and finally do something constructive. My question is are these still relevant for 18th Edition testing and if so, do they need to be recalibrated even though the've never been used ? Thanks for any advice and help I appreciate it
Why do extractor fan manufacturers insist on making their products so that they can only be fitted one way (without often telling you even on their own site where the cable entry point is).
I expect the dirt cheap ones to be so for a reason, but even the more expensive ones have major issues.
I needed one for a job this week, and found it impossible to determine where the cable entry point was for a vent axia fan, even from browsing their site.
Then when I bought it and it wasn't on the side I wanted (of course), I couldn't even install it upside down, because their cover will only fit one way due to their branding.
I've even bought round ones before, that would make perfect sense to be fittable in any orientation, only to find that the cover determines that they must go one way only.
Not to mention the "back draft shutters" made out of a plastic bag.
I tend to go inline by preference now to avoid many of the issues, and use the Envirovent Silent 100T as a standard when I have time to order one in for wall mounted jobs, but sometimes you need one quickly.
Anyone aware of a good quality wall mounted fan that has:
Entry point options on either side (or can be orientated any direction without the branding being at an angle)
Back draft shutters that are made of something more robust.
Please god help me. This heat alarm circuit is going off despite nothing being attached to it.
Over the months it’s been a new battery, new unit, leaving it unplugged. Now it’s just going off without an alarm even attached!
Just wanna make sure everything is compliant and I haven't missed anything before the plasterboard is dotted on.
Ring 2.5mm, lights 1.5mm, heat alarm 3 core 1.5mm, hob 10mm, oven 4mm, cat6 for ceiling WiFi AP.
I will cap some of the cables with galvanised steel as I will be installing the kitchen.
Thanks.
For conext - yes I am an electrician 😄
A question that isn't largely important but just piqued my interest as i haven't come across this elsewhere.
I grew up in a street built ariund 1980-1983. My 'rents still live there, and i've done work in a fair few of the houses - and the setup is the same throughout so i know the history and know its original to the build.
All the houses have detatched garages (only slightly, like 15cm from the house). The original Wylex 3036 DB's all had about 10m worth of 2 core SWA (all terminated without a gland at the house end 🤣, just a few strands of armour shoved into the earth bar) from a 15a fuse that feed a 2 way Wylex metal DB in the garage (lights & socket).
Herin lies my question. The SWA feeding the garage DB's is weird. It's definitley SWA - has normal CW20 glands
on the garage end...steel armour...inner insulation....and then the 2 inner black/red conductors.....but the weirdness is that the cores themselves are single strand....ie the same as in modern 1.0-2.5mm twin and earth. Not like any other SWA i've ever seen which is all 7 strand copper. I can't even gauge the size...it looks like 1mm (which i dont think has ever existed as an SWA). All the garages ive been in have had paint slapped over the cable so cant make out any data on the cable.
Wondered if anyone has come across SWA like this before?
I’m thinking of giving agency work a go and I’d like to know everyone’s experience with it.
Thanks
Company is supplying power tools, but have I missed anything urgently needed? I have a tape and drill bit box on the outside of the bag.
Cheers
Thanks for all the comments on my previous post. So the noise is coming from either the connector or within the ceiling about. The heat alarm itself and no other linked alarms are sounding. But unscrewing this cable stopped it. What the hell is happening?
Can anyone cite a regulation as to why potentially this is wrong or even dangerous?
I'm purchasing a 1950s renovation project and this is the electrical set up. Id like to know if a full rewire is always required?
I have no idea what I’m looking at. The downstairs plugs looked newer than upstairs and there is a rear and side extension.
Happy to hear what everyone thinks…
This is quite common here in Italy. I have yet to see a domestic board with a busbar, neutral and earth bar. All the earths are bunched together into one connector block, the same with all the neutrals. Instead of a busbar, they loop the feeds along the bottom of the board. That means if you want to add an mcb between two others, you have to isolate the board and break into the loop. This is the first floor board, its worse on the ground floor.
Do electricians actually use torque screwdrivers when installing consumer units or is it just one of those things that everyone says you should do but nobody actually does onsite?
I'm just asking as I'm currently doing a course where the lecturer mentioned the use of these when clamping protection devices to the cables in consumer units but didn't even know these screwdrivers even existed.
Thanks
Hi all, apologies bit of a long one:
23 years old, qualified for a year and basically been thrown right into the thick of it running jobs with an apprentice. I’ve really struggled mentally with it, constantly overthinking and second guessing myself. I was hoping it was one of those things that would go away after a few months but even after a whole year I’m still not any different. I know myself that I still lack loads of knowledge, and that doesn’t help my confidence.
I was just wondering if anyone’s been in a similar position and managed to turn it around? I quite liked being an apprentice, but the stress of being out by myself has really got to me, and having an apprentice to worry about definitely doesn’t help. I just feel like I don’t enjoy this job anymore, I know I’m in a lucky position to be qualified and I have a great employer but I just can’t help brining the job home with me and spending all evening doubting what I’ve done. I’m a complete shell of myself.
Feel like a bit of a failure tbh, see people my age on the tools who seem to be loving it so it makes me feel like somethings wrong with me.
If I was to change career, I’d have to go back down to a lower wage which just feels backwards at my age as I’m lucky to be earning more than the average.
Anyone got any good advice or thoughts to help me get through this?
Apologies it’s long, I had to get it off my chest. really appreciate any replies
About to start a new job
Industrial spark uses the Megger MET1000, was looking at getting the same one. He's a megger fan.
He comes from an industrial background but we work in public EV charger space, installs and maintaining them.
They want to put me through an NVQ.
60a main fuse.
100a 5419 DP switch isolator
2 x 10mm twin and earth feeding the CU under the stairrs...
The hot tub plug blew!
It gets dusted off and plugged in during the summer. We've barely used it this year, I don't think we've turned the heating part on at all but it's left on and the pump goes through a cycle for two hours a day to keep the water moving and clean.
Would the fault likely be with the hot tub motor unit, the plug or the socket?
