John, Harlow started life in the late 40s and the eleventh edition of the regs was still in use. By the 80’s from Google the last house was finished in Harlow but the fifteen edition was released in 81. It’s now 2024 give or take you could be looking at 70 years - ish.. did you pass it??
Hi mate, so you've seen things get better/worse depending on your opinion 😅 As for the property, it's my in-laws. And they're not interested in rewiring anything, so it'll carry on until they're no more I suppose 😅 the cable will out live them!
Interesting video, John, thank you. As you have already acknowledged elsewhere in the comments, the service cable *is* protected upstream by a substation fuse. The video doesn't give us any information on the sort of location - rural or urban - you were attending but assuming the house is in a typical town or city, there is a pretty good chance that the fuses protecting the LV feeder for that supply are J-type 400A rated to BS88. You mentioned a PFC of 900A, (presumably measured during your inspection), and correctly observed that a phase-earth fault would go off 'like a bomb'. The clearance time of the substation fuse if presented with a fault at that cutout would depend on the pre-fault loading conditions on that feeder but if we assume a load of 200A/ph immediately before the 'bomb' goes off, the substation fuse should operate in about 2 seconds - that's still a big bang!!! Two seconds is a long time when you're staring at an LV fault! However, if the feeder was lightly loaded, that fault could take about 2 MINUTES to operate the substation fuse, even for an 'ideal' bolted-fault condition. Again, as you correctly observed, the fault conditions would change due to the considerable heat and explosion most likely blowing a hole in the cutout plate, effectively clearing the fault. The important point being - if anyone is unfortunate enough to ever experience a flashover at a cutout - NEVER assume the substation fuse has actually operated just because the arcing appears to have stopped - it could flashover again. Always contact the DNO for an emergency disconnection and keep everyone clear, including the fire service.
Perfect video Brilliant Well done Very nice I have learned a lot. Very happy I am subscribed to this channel With MR JOHN ❤❤❤❤❤❤. God bless you Thank you ❤❤❤❤
Very informative video - re. Cut Out’s the DNO should change old “biscuit tin” types see the guidance from the Energy Network Association if you google Energy Network Association Metal Cut Outs a 12 page document from them can be viewed. Black Bakelite cut outs can be an issue for both bitumen leaks and also surface voltage as saw dust was often mixed into the Bakelite during manufacture and it can degrade and become conductive with excess heat and/or moisture.
Yeah, in the Czech Republic we do not use metal backboxes because you can quite easily nick the wires. Our national standards prohibit this. Instean we use a special non-flammable plastic boxes. Also, no ring circuits, only radial. I understand when you design ring circuits, it enables you to use thinner wires. We are obliged to use 1,5 mm2 wires for lighting and 2,5 mm2 for 230V 16A sockets.
Be thankful you never found old rubber 2 core stuff with round bakelite switches and twisty pendant wires, our house had that till the late 90's, it exploded spectacularly! I suppose our old 50's Wylex fuse box is still compliant, it seems to work the router allowing me to watch this video😁 As you say about the multistrand stuff, it's defo 60's.
I’d definitely be doing an asbestos survey before rewiring. If the wiring was done in 60’s it’s almost certain the plastering was. So that artex is likely to be asbestos.
Few points... metal service head down here in SSEN territory is a change order for the head. And John mate, you know better ;) there's a fuse in the substation LV board, but it's huge, and the fault likely won't take it out, or did your DNO not have substation LV fuses? I have one of those cutouts and the associated fuseboard. We had SSEN change in to change the head during a rewire, and the chap let me keep it, so got the complete setup on an old meter board :) Even got the original logbook that was kept with it, with the meter readings and signatures from meter readers going back to the 50s :) It used Pullcap fuses, the kind where the holder is round and pulls apart to expose the fuse once removed from the carrier. They were also widely used in stage equipment :) , take standard BS1361 fuses
@TheChipmunk2008 A TN-S system ain't blowing jack at a substation due poorer earth path and slow blow capacity of the fuse. The Ze there was 0.38 so it would more likely blow a chunk of metal off than cut the power. I've seen the fall out of this type of fault and believe me, sub fuses done Jack! 😂 I worked for SSE. However I worked in a ukpn area so had no say in the service cutout.
@@John_Faultless Interesting John, thank you... Yeah i know the fuses in the sub are for overload only, have you seen that video of the fault in Market Lavington? ua-cam.com/video/GKSocxyIf1U/v-deo.html Not sure at the end if the sub fuses finally went or if the DNO cut the power, or a mix, as that was a 3ph riser. The guy narrating makes a few booboos but his advice to switch off is sound, 230 appliances don't like to see 415 LOL. Plus with the lead sheath gone, any tn-c-s'd supplies on that would've seen fun voltages on the PEN!
@@kevxsi16v Must be interesting work mate, i wish i did more interesting work, usually my work day is EICRs (Hi John!) and adding a few sockets here and there, got a full occupied rewire next week so my tune will change lmao. John, what would you do with a circuit you can't find, on an eicr...we want to FI, but we actually decided, turn it off and disconnect, as the customer is moving out in 2 months, and issue a satisfactory EICR, then reinstate the circuit when the property is vacant after we've located it, and issue a minor works?
@@John_Faultless So... use to work for a DNO eh. Did they strip search you b4 you left, for that box of meter seals & numbered crimps that just happened to 'vanish' too? [😉😉....🤫] ________ 😂
we had one of those in our old house i touched it one day and got thrown across the other side of the room i had put a nice new fuse board in back in the early seventies one day the Electric board turned up to take that mass out and they did but they also stole my nice new fuse board
If the svc head has a fuse in the neutral instead of a link, should not the dno replace? Also with the age of that pvc cable I’m surprised there is no sign of green goo.
@johnmaguire9305 potentially there could be a fused neutral. It was normally the slightly older green ones that were more likely to have a fused neutral. But we're not supposed to open them to check and the dno never pop by to see how things are going. Normally only picked up during a meter change unfortunately
The main reason for wiring regs we are told is for our safety ie electric shock and fire etc.These regs are regularly updated to such an extent that it come to a time for the expensive cost of a full house rewire,even though the wiring is rarely disturbed. Yet the main street cabling,which is much older than household wiring,subjected to far worse environmental conditions than house wiring is rarely ever replaced except were there has been a underground fault.Don`t you think it`s a bit of a money racket for house owners having to pay for.
@jamesholdsworth5503 I should've been clearer really. Basically on a TN-S system the fault path isn't normally sufficient to blow and external fuse. You'll get a big bang that blows clear before they would go usually. The Ze was 0.38ohms and PFC 680A. On a PME system the fault current would be a lot higher. But please continue to add bits and correct me. I want this to be a place for learning and no one knows everything and appreciate the help of fellow sparks to help teach learners
@posei3960 Cheers mate. Any info on this and future videos is much appreciated. I'm not claiming to know everything by any stretch of the imagination. I wanna develop a encyclopedia of information that might die with some of the "Jurassic Sparks" that taught me and many other's. So please add all the info you can 👊
@@John_Faultless it was a form of HDPE/MDPE style plastic. Shiny with a slightly greasy feel to the insulation. Tinned stranded cores, probably late 60s. Absolute pain to strip
@@John_Faultless the metal bracket in the wooden back box is an MK3840 Zic. Still available and a good 'get out of jail card' originally designed to provide fixings within a flush cast metal conduit light switch box. These boxes housed an early MK switch , similar to Mutac, which had smaller fixing centres
@posei3960 You're deffo right about the stripping. Absolute nightmare and the old boys of yesteryear seamed to be on a budget as the cable is always tight AF to replace a socket/switch. From what I've investigated from the IET, a cpc at every point became mandatory in 1966. So that's my reasoning. The house was built in 1956 so I'm guessing that's the original wiring. It's mad it's still in use!
@posei3960 Yeah, the gap between fixings are way off for a modern switch, so most get one fixing on the the bracket and one on the crumbling lathe and plaster wall 😅
That earth cable is not in the right place according to regs, but to me it would make MORE sense to bond where the service enters the building! Ah you explained it, they can't link over in their standard way. Given that gas guys aren't sparks Did it ever give you the heebie jeebies with tiny board cupboards like that.? if things go south, egress is a huge issue. I think 17th didn't allow the non rcd socket, but too lazy to get up and get the book :)
I suppose with a lot of stuff you are assuming the installer did it properly. Maybe the earth was just ignored by a cowboy but it was done after the reg change?
I said i'd stop but one point, the rubber insulation and pvc overlapped for quite a long time. Our house was built in the 60s, but had VIR cable, but i've seen 50s stuff with PE insulation! (for me PE insulation is a C2, because it's a fire hazard, worse than rubber.) I even came across some metric VIR once! 1.5mm single core VIR, tinned copper, braided cotton cover, brand new in the stores, made by BICC. I got it for a pound (the uni i trained at was clearing out the stores of absolutely obsolete rubbish) in the late 80s
C3 meter tails not supported to prevent undue strain on the terminations :)... I'll stop now, but you said it made YOU feel it old Tinned imperial cable predates the 14th i believe, so 60s? No earth on lighting, so 60s :) i was right LOL (or late 50s)
Great video john, its refreshing to have some educational content on here, your experience really shines through in the content!
@residualelectrical cheers mate, I appreciate it 👊
John,
Harlow started life in the late 40s and the eleventh edition of the regs was still in use. By the 80’s from Google the last house was finished in Harlow but the fifteen edition was released in 81. It’s now 2024 give or take you could be looking at 70 years - ish.. did you pass it??
Hi mate, so you've seen things get better/worse depending on your opinion 😅 As for the property, it's my in-laws. And they're not interested in rewiring anything, so it'll carry on until they're no more I suppose 😅 the cable will out live them!
Interesting video, John, thank you. As you have already acknowledged elsewhere in the comments, the service cable *is* protected upstream by a substation fuse. The video doesn't give us any information on the sort of location - rural or urban - you were attending but assuming the house is in a typical town or city, there is a pretty good chance that the fuses protecting the LV feeder for that supply are J-type 400A rated to BS88.
You mentioned a PFC of 900A, (presumably measured during your inspection), and correctly observed that a phase-earth fault would go off 'like a bomb'. The clearance time of the substation fuse if presented with a fault at that cutout would depend on the pre-fault loading conditions on that feeder but if we assume a load of 200A/ph immediately before the 'bomb' goes off, the substation fuse should operate in about 2 seconds - that's still a big bang!!! Two seconds is a long time when you're staring at an LV fault!
However, if the feeder was lightly loaded, that fault could take about 2 MINUTES to operate the substation fuse, even for an 'ideal' bolted-fault condition. Again, as you correctly observed, the fault conditions would change due to the considerable heat and explosion most likely blowing a hole in the cutout plate, effectively clearing the fault. The important point being - if anyone is unfortunate enough to ever experience a flashover at a cutout - NEVER assume the substation fuse has actually operated just because the arcing appears to have stopped - it could flashover again. Always contact the DNO for an emergency disconnection and keep everyone clear, including the fire service.
Thanks man another very useful video, cheers 👍
Nice one again John, and useful as not everyone has come across the older kit like the biscuit tin heads.
Fantastic video. Brilliant tips. Top man
Perfect video
Brilliant
Well done
Very nice
I have learned a lot. Very happy I am subscribed to this channel
With MR JOHN ❤❤❤❤❤❤.
God bless you
Thank you ❤❤❤❤
Your content is brilliant and really informative. Keep up the great work.
@@esfae8250 cheers mate
Brilliant video again John keep them coming always look forward to seeing your work
Nice one John
Lovely vid. Great example why EICR’s should only be done by experienced engineers
Interesting stuff. Glad you started your own channel, subscribed.
Good video,..
Seen them all during my time, but good to know
Ive seen around a hundred wooden back boxes , never seen one scorched- let alone charcoaled 🔥🔥🔥
Always good when Johns on my TV! The squeeky landing really made me chuckle for some reason 😂 Great video as always 👍
Very informative video - re. Cut Out’s the DNO should change old “biscuit tin” types see the guidance from the Energy Network Association if you google Energy Network Association Metal Cut Outs a 12 page document from them can be viewed. Black Bakelite cut outs can be an issue for both bitumen leaks and also surface voltage as saw dust was often mixed into the Bakelite during manufacture and it can degrade and become conductive with excess heat and/or moisture.
Yeah, in the Czech Republic we do not use metal backboxes because you can quite easily nick the wires. Our national standards prohibit this. Instean we use a special non-flammable plastic boxes. Also, no ring circuits, only radial. I understand when you design ring circuits, it enables you to use thinner wires. We are obliged to use 1,5 mm2 wires for lighting and 2,5 mm2 for 230V 16A sockets.
Great work John! I've got a notes file on my phone just from the info you give. Thank you.
Be thankful you never found old rubber 2 core stuff with round bakelite switches and twisty pendant wires, our house had that till the late 90's, it exploded spectacularly!
I suppose our old 50's Wylex fuse box is still compliant, it seems to work the router allowing me to watch this video😁
As you say about the multistrand stuff, it's defo 60's.
I’d definitely be doing an asbestos survey before rewiring. If the wiring was done in 60’s it’s almost certain the plastering was. So that artex is likely to be asbestos.
Gaaaaaaaaaaaaaayyyyyyy
Get right in there with a Covid mask on
Are you up to date with your boosters sweet pants? 😂
Few points... metal service head down here in SSEN territory is a change order for the head. And John mate, you know better ;) there's a fuse in the substation LV board, but it's huge, and the fault likely won't take it out, or did your DNO not have substation LV fuses? I have one of those cutouts and the associated fuseboard. We had SSEN change in to change the head during a rewire, and the chap let me keep it, so got the complete setup on an old meter board :) Even got the original logbook that was kept with it, with the meter readings and signatures from meter readers going back to the 50s :)
It used Pullcap fuses, the kind where the holder is round and pulls apart to expose the fuse once removed from the carrier. They were also widely used in stage equipment :) , take standard BS1361 fuses
@TheChipmunk2008 A TN-S system ain't blowing jack at a substation due poorer earth path and slow blow capacity of the fuse. The Ze there was 0.38 so it would more likely blow a chunk of metal off than cut the power. I've seen the fall out of this type of fault and believe me, sub fuses done Jack! 😂
I worked for SSE. However I worked in a ukpn area so had no say in the service cutout.
@@John_Faultless Interesting John, thank you... Yeah i know the fuses in the sub are for overload only, have you seen that video of the fault in Market Lavington? ua-cam.com/video/GKSocxyIf1U/v-deo.html
Not sure at the end if the sub fuses finally went or if the DNO cut the power, or a mix, as that was a 3ph riser. The guy narrating makes a few booboos but his advice to switch off is sound, 230 appliances don't like to see 415 LOL. Plus with the lead sheath gone, any tn-c-s'd supplies on that would've seen fun voltages on the PEN!
@@TheChipmunk2008I do the repairs for NG after they have had this kind of fault.
@@kevxsi16v Must be interesting work mate, i wish i did more interesting work, usually my work day is EICRs (Hi John!) and adding a few sockets here and there, got a full occupied rewire next week so my tune will change lmao.
John, what would you do with a circuit you can't find, on an eicr...we want to FI, but we actually decided, turn it off and disconnect, as the customer is moving out in 2 months, and issue a satisfactory EICR, then reinstate the circuit when the property is vacant after we've located it, and issue a minor works?
it helpfully is labelled 'socket'
Brilliant coming from an original 1890 house. The house was refurbished in the 1960ish this all this looks very familiar 🧐🙂🇮🇪☘️
Great video
Great vlog.
Great video i could you thinking this needs a rewire but if It passes will the customer wear it
I have never seen a service head that isn’t backed up by a fuse at some point normally a 400A back at the transformer
Love the light bulbs--lol... What the craziest thing you've seen in a house?
A poo covered strap on
@Honest_Reviewer. Nothing I could write about in the comments 😂 let's just say I heard it before I saw it 😅
John I'm 58 and think i am also pasted it. lol. Great video mate
@@AndrewBrownEngTechTMIET 😂😂😂
What about the green goo plasticiser my house is riddled with it.
M8, love your comment at 2:53.
Ripe, you say eh? Is that speaking from first hand experience 🤔 .
😂😂😂
@@Sparks1Plumbers0 I don't know what you're talking about 👀
@@John_Faultless So... use to work for a DNO eh. Did they strip search you b4 you left, for that box of meter seals & numbered crimps that just happened to 'vanish' too? [😉😉....🤫] ________ 😂
we had one of those in our old house i touched it one day and got thrown across the other side of the room i had put a nice new fuse board in back in the early seventies one day the Electric board turned up to take that mass out and they did but they also stole my nice new fuse board
If the svc head has a fuse in the neutral instead of a link, should not the dno replace? Also with the age of that pvc cable I’m surprised there is no sign of green goo.
@johnmaguire9305 potentially there could be a fused neutral. It was normally the slightly older green ones that were more likely to have a fused neutral. But we're not supposed to open them to check and the dno never pop by to see how things are going. Normally only picked up during a meter change unfortunately
The main reason for wiring regs we are told is for our safety ie electric shock and fire etc.These regs are regularly updated to such an extent that it come to a time for the expensive cost of a full house rewire,even though the wiring is rarely disturbed.
Yet the main street cabling,which is much older than household wiring,subjected to far worse environmental conditions than house wiring is rarely ever replaced except were there has been a underground fault.Don`t you think it`s a bit of a money racket for house owners having to pay for.
Most are protected by a 250a fuse or mccb at the substation ?
@jamesholdsworth5503 I should've been clearer really. Basically on a TN-S system the fault path isn't normally sufficient to blow and external fuse. You'll get a big bang that blows clear before they would go usually. The Ze was 0.38ohms and PFC 680A. On a PME system the fault current would be a lot higher.
But please continue to add bits and correct me. I want this to be a place for learning and no one knows everything and appreciate the help of fellow sparks to help teach learners
The cables are not PVC but Polythene which is why they look shiny.
Shiny cable was Asathene
@posei3960 Cheers mate. Any info on this and future videos is much appreciated. I'm not claiming to know everything by any stretch of the imagination. I wanna develop a encyclopedia of information that might die with some of the "Jurassic Sparks" that taught me and many other's. So please add all the info you can 👊
@@John_Faultless it was a form of HDPE/MDPE style plastic. Shiny with a slightly greasy feel to the insulation. Tinned stranded cores, probably late 60s. Absolute pain to strip
@@John_Faultless the metal bracket in the wooden back box is an MK3840 Zic. Still available and a good 'get out of jail card' originally designed to provide fixings within a flush cast metal conduit light switch box. These boxes housed an early MK switch , similar to Mutac, which had smaller fixing centres
@posei3960 You're deffo right about the stripping. Absolute nightmare and the old boys of yesteryear seamed to be on a budget as the cable is always tight AF to replace a socket/switch.
From what I've investigated from the IET, a cpc at every point became mandatory in 1966. So that's my reasoning. The house was built in 1956 so I'm guessing that's the original wiring. It's mad it's still in use!
@posei3960 Yeah, the gap between fixings are way off for a modern switch, so most get one fixing on the the bracket and one on the crumbling lathe and plaster wall 😅
That earth cable is not in the right place according to regs, but to me it would make MORE sense to bond where the service enters the building! Ah you explained it, they can't link over in their standard way. Given that gas guys aren't sparks
Did it ever give you the heebie jeebies with tiny board cupboards like that.? if things go south, egress is a huge issue. I think 17th didn't allow the non rcd socket, but too lazy to get up and get the book :)
Dno came here to upgrade the fuse as the heat on the older smaller fuse would melt the tar
The dogs older than the electrics
I suppose with a lot of stuff you are assuming the installer did it properly. Maybe the earth was just ignored by a cowboy but it was done after the reg change?
Key meter with no seal 🫣👀
I said i'd stop but one point, the rubber insulation and pvc overlapped for quite a long time. Our house was built in the 60s, but had VIR cable, but i've seen 50s stuff with PE insulation! (for me PE insulation is a C2, because it's a fire hazard, worse than rubber.) I even came across some metric VIR once! 1.5mm single core VIR, tinned copper, braided cotton cover, brand new in the stores, made by BICC. I got it for a pound (the uni i trained at was clearing out the stores of absolutely obsolete rubbish) in the late 80s
Did a rewire one time and it had mixed cable, rubber and pvc, must have been using the old rubber up I guess.
@@TheYohtube yes there was a 10 yr overlap, same with the change from red/black to brown/blue, people have stock of cable
the rubber twin and earth in our house was fine, not crumbly at all, but the ends were fried and cut way too short, so rewire it was
I could tell it was old, just a hunch
Rewire needed all day long.
ok
C3 meter tails not supported to prevent undue strain on the terminations :)... I'll stop now, but you said it made YOU feel it old Tinned imperial cable predates the 14th i believe, so 60s? No earth on lighting, so 60s :) i was right LOL (or late 50s)
Depressed me watching that😂😂
Re-wire?
silly to whine about earth for plastic lamp. also RCD is a horrible idea for a fridge. enjoy melted items. Uk has the weirdest electric code
It's not whining mate. I'm there to inspect the installation and determine if it's safe for continued use. That's all.