John,Im a semi retired heating engineer,who can use both a multi meter and megga tester,your vide os are a pleasure to watch and very imformative,you can never have too much knowledge when working on customers homes.
Here in the Netherlands - probably due to the Groningen gas strike in the late 50s - the standard house connection is still 35 amps. Some older houses still use a 25A connection, and even the “heavy standard” connection is 3x25. A 3x35 is already significantly more expensive let alone if you want 3x 50/65/80. But then again electric showers are completely unknown here.
Hi John. At a guess the reason for the slot along the cable entry on the brass contacts is because they're cut from an extrusion and it avoids another drilling operation. The four slotted holes for the lower cover bolts means they didn't have to drill and tap four holes in the base, and the 'red sealant' is probably the remains of asbestos-rubber washers. (First line edited to make sense.)
You are correct John, the labels in the cover, the phase barrier and the wire tube are indeed asbestos, often damaged due to age and interaction. I would advice, thought a little late to the party, 8 years too late (2015, now 2023) that you handle these with the strictest of care. I wonder what those white specs are on the compound 11:03.
Some older residential distribution system in Estonia used the triangle system (phase to phase voltage is 220V) and it required both incoming conductors to be fused because both were live compared to ground although sometimes the ground was completely missing rendering the whole grid floating or isolated. That system is still used in old part of Tallinn were modernization is too costly.
We used to have it in parts of the Netherlands, too, and you could recognize it by the double pole fusing in both cutout and the consumer unit. Also by being old AF, of course. I think the last of it was taken out of Delft in the 90s. We still use double pole switches in the consumer unit though, even though only one side is fused. I reckon the 3x127=220 arrangement (IIRC the math) is probably significantly safer than 1x230V (or it’s cousin 3x230=400). Much like the center tapped 220/240 equals 110/120 of our cousins across the pond is significantly more electrically safe, although less fire safe.
A while back I came across a three phase version of these being used in a building that dated from the 1930s, it was now being used for offices, and seemed to have become repeatedly sufficiently hot that the bitumen had been oozing out of the cable entry and was making a nasty black stalactite on the concrete below
It’s worth knowing that that cut out would last but the cut out today are available in cast-iron but they are about £4000 each. The plastic ones are about £10 in bulk so they’re not as high-quality but they shouldn’t have to withstand a lot of abuse
Regarding the load that one of these can take: because it’s a rewirable fuse, it can run for a considerable time at far more than its rating. I had one of these in a house many years ago: it had the legend “30A continuous, 60A fusing”. Modern new services are 100A, with a BS1361 fuse. A look at the curve for these shows that one can draw 130A for twenty minutes. I watched the jointers replace a TP&N cast iron cutout. They just gave the bitumen a bash with a hammer, and it crumbled. The replacement work was, as is usual, done live.
I tried to get one similar to this upgraded for a customer not too long ago, 3ph head using 1ph, leaking tar and open holes, the dno stuck some pink bubblegum over it and said it was low priority and would take 4 days to replace because they had to dig up the street isolate it? Then then energy supplier sent someone to install a isolator switch, turned up and stated he’s not qualified to disconnect old meters and left..
help......had a call out yesterday where the service head fuse had blown..i hooked my clamp meter over the main 16mm earth just to keep it handy then noticed there was current of nearly 2 amps...is this common ?..would it be mains voltage ?and could it effect the performance of an rcd on a tn-cs arrangement
damon btc It's fairly common, typically occurs on TN-C-S and is one reason why the main bonding on those has to be a minimum of 10mm. Usually caused by slight voltage differences on the combined earth/neutral between two or more adjacent properties, which in turn depends on the various loads in use. The voltage difference is small, only a few volts, so no risk of shock. RCDs won't be affected as they don't measure current in the earth, only any difference between L&N on the load side.
hello jw.....i hope you can answer my questions or provide me were to buy fuses from or any relevant information just bought old victorian house and the mains is fitted with revo ceramic fuses in a iron case similar to your video....there are three fuses one fitted to consumer box and other two not connected....there is also another one which is just a thin bar(is this neutral not sure) that is open view and screwed in at top and bottom....are these illegal to use or should they be replaced by distribution board......i dont know what fuse rateing they are but could i use 30amp wire on a 15amp porclein socket fuse to give me more amps.....is there a max amps that you can install fuse wire into holder say 30 40 50...were can i buy these fuses or best place to get spares or information from....is there a set time for mains supplier to come out and replace or cost....thanks for your videos very detailed
What you are describing will be over 70 years old and should have been replaced long ago. If it's before the electricity meter then the network operator will replace them, call 105 to contact them. Anything after the meter is your responsibility. There is no upgrade option for such old equipment, fuse wire rating is what it was originally designed for.
Where I live, the standard circuit breaker current at the property border is 25A and one has to pay monthly to get a larger value (just for a stronger circuit breaker, the kWhs are counted normal). If that sounds outrageous to you, hear this: In Austria, the standard house input is limited to 16A!!! That's because they banned nuclear power plants, green-brained hippies! Mind what you wish for, you might get it!
+zwz • zdenek What, 16A? That is creazy. Most flats in Poland would have 25A total, with split to 16/10/6 A for different use (kitches, sockets, lights). For standalone homes, it would probably be 40A standard, but you should be able to get more, but I think you pay just once, unless you live in some strange place, where they cannot do that without rebuilding infrastructure, or you are sole user (end of the line). Just my guess.
It's just fascinating to me how differently we do things in the United States. Most modern residential service in the United States is about 200-225 amps, but as it's 120/240V, that would equate to about 100A in a European service. (So, that's about the same.) We like lots and lots of circuits. Fewer than a dozen circuits is unheard of except in the oldest homes. In modern construction of stand-alone dwellings, 30-50 separate circuits is common. These circuits are typically dedicated to individual rooms or pairs of rooms, and now also typically separate lighting and receptacles.
@@jovetj yes, but Aircon is also much more common in America, so some of it has to go for that right? Fusing low and often is likely wise as it keeps the fault current low, but at least Britain in particular had copper shortages strongly affect the design choices made (ring circuits and fused plugs and so on) so loads of wiring probably wouldn't have been feasible when the standards were being set out.
@@AngDavies Some of it does go to air conditioning, yes. I grew up in a home that had electric heat, and the electric heat circuits were over twice the rating as the air conditioning.
Why are two fuses not allowed in your country? Is it in case only the neutral line goes it will still be live? I ask because we don't have neutral line where I live and there is always two or three (for three phase) fuses. Of course in modern setups they are tied together so if one goes all of them goes.
lollandster Yes, it's because of the neutral one failing and leaving items live. Two fuses also increases cost and complexity for no additional benefit.
+lollandster I do not think so, you will usually have single fuse for single phase. and no fuse (breaker) on neutral line at all. You might have additional double switch before the switch, but it is not a breaker (fuse). For the 3 phase, you will have interlocked 3 fuses / breakers. Sometimes, especially if you do have multiple appliances with 3 phases supplies, or in bigger distributions, separate interlocked switch (not breaker, but sometimes with additional higher rated breaker too) before other split breakers. All interlocked between phases. There is a separate John video, where he shows ,that double fuses on many installations these days, are actually less safe than single fuse.
+movax20h Where I live (Norway) there is no neutral line, but two 110V lines alternating with 180deg from each other creating a 220V potential (RMS voltages). Therefor there are two breakers needed to stop live from passing through.
+lollandster It is uncommon in other parts of Europe. The setup like yours was used before 1950 in UK, or something like that. And the video presents a double fuse designed for such system. But nobody is building such systems since 50s anymore.
+lollandster I think the split supply is only used on construction sites, with isolation transformer, step down to 110V, and the split to 55V, so there is only 55V between any live wire and ground. For safety reasons, as construction sites are often wet.
Well I think the c shaped cable terminals in the fuse are to allow for expansion. If it expands i'm thinking the back will give, like a spring, and it's less likely that the screw would work loose.
John,Im a semi retired heating engineer,who can use both a multi meter and megga tester,your vide os are a pleasure to watch and very imformative,you can never have too much knowledge when working on customers homes.
Here in the Netherlands - probably due to the Groningen gas strike in the late 50s - the standard house connection is still 35 amps. Some older houses still use a 25A connection, and even the “heavy standard” connection is 3x25. A 3x35 is already significantly more expensive let alone if you want 3x 50/65/80.
But then again electric showers are completely unknown here.
Hi John. At a guess the reason for the slot along the cable entry on the brass contacts is because they're cut from an extrusion and it avoids another drilling operation.
The four slotted holes for the lower cover bolts means they didn't have to drill and tap four holes in the base, and the 'red sealant' is probably the remains of asbestos-rubber washers.
(First line edited to make sense.)
You are correct John, the labels in the cover, the phase barrier and the wire tube are indeed asbestos, often damaged due to age and interaction. I would advice, thought a little late to the party, 8 years too late (2015, now 2023) that you handle these with the strictest of care. I wonder what those white specs are on the compound 11:03.
Some older residential distribution system in Estonia used the triangle system (phase to phase voltage is 220V) and it required both incoming conductors to be fused because both were live compared to ground although sometimes the ground was completely missing rendering the whole grid floating or isolated. That system is still used in old part of Tallinn were modernization is too costly.
We used to have it in parts of the Netherlands, too, and you could recognize it by the double pole fusing in both cutout and the consumer unit. Also by being old AF, of course. I think the last of it was taken out of Delft in the 90s. We still use double pole switches in the consumer unit though, even though only one side is fused.
I reckon the 3x127=220 arrangement (IIRC the math) is probably significantly safer than 1x230V (or it’s cousin 3x230=400). Much like the center tapped 220/240 equals 110/120 of our cousins across the pond is significantly more electrically safe, although less fire safe.
A while back I came across a three phase version of these being used in a building that dated from the 1930s, it was now being used for offices, and seemed to have become repeatedly sufficiently hot that the bitumen had been oozing out of the cable entry and was making a nasty black stalactite on the concrete below
that old stuff was made to last,not like todays crap ,good vid like all your vids cheers.
It’s worth knowing that that cut out would last but the cut out today are available in cast-iron but they are about £4000 each. The plastic ones are about £10 in bulk so they’re not as high-quality but they shouldn’t have to withstand a lot of abuse
Great video - Seen many on my travels and always had the DNO get rid of them. Fascinating to see one disected through, cheers John 👍
Regarding the load that one of these can take: because it’s a rewirable fuse, it can run for a considerable time at far more than its rating. I had one of these in a house many years ago: it had the legend “30A continuous, 60A fusing”. Modern new services are 100A, with a BS1361 fuse. A look at the curve for these shows that one can draw 130A for twenty minutes. I watched the jointers replace a TP&N cast iron cutout. They just gave the bitumen a bash with a hammer, and it crumbled. The replacement work was, as is usual, done live.
In the netherlands, my house build in 2011, has only a 35A cutout fuse (single phase).
However, central heating and hot water are gas fired.
Erik Bruijn Most heating and DHW is gas in the UK too, however an 80 or 100A cutout is common.
Neat, well-designed piece of equipment!
I tried to get one similar to this upgraded for a customer not too long ago, 3ph head using 1ph, leaking tar and open holes, the dno stuck some pink bubblegum over it and said it was low priority and would take 4 days to replace because they had to dig up the street isolate it? Then then energy supplier sent someone to install a isolator switch, turned up and stated he’s not qualified to disconnect old meters and left..
John how is the earthed sheath of the cable connected to the body of the cut out?
help......had a call out yesterday where the service head fuse had blown..i hooked my clamp meter over the main 16mm earth just to keep it handy then noticed there was current of nearly 2 amps...is this common ?..would it be mains voltage ?and could it effect the performance of an rcd on a tn-cs arrangement
damon btc It's fairly common, typically occurs on TN-C-S and is one reason why the main bonding on those has to be a minimum of 10mm.
Usually caused by slight voltage differences on the combined earth/neutral between two or more adjacent properties, which in turn depends on the various loads in use. The voltage difference is small, only a few volts, so no risk of shock.
RCDs won't be affected as they don't measure current in the earth, only any difference between L&N on the load side.
Metal clad cut out with asbestos barrier and asbestos fuse sleeve !!
Meter operators can't install new meters until cut out removed
Anyone know what the white toll covering the fuse wire is made from ?
you'd be one kickass instructor!
The output side kind of looks like it would be used with, what we call in the U.S., knob-&-tube wiring...
I rather like the pitch as a potting compound. Fully reusable! If messily.
hello jw.....i hope you can answer my questions or provide me were to buy fuses from or any relevant information
just bought old victorian house and the mains is fitted with revo ceramic fuses in a iron case similar to your video....there are three fuses one fitted to consumer box and other two not connected....there is also another one which is just a thin bar(is this neutral not sure) that is open view and screwed in at top and bottom....are these illegal to use or should they be replaced by distribution board......i dont know what fuse rateing they are but could i use 30amp wire on a 15amp porclein socket fuse to give me more amps.....is there a max amps that you can install fuse wire into holder say 30 40 50...were can i buy these fuses or best place to get spares or information from....is there a set time for mains supplier to come out and replace or cost....thanks for your videos very detailed
What you are describing will be over 70 years old and should have been replaced long ago.
If it's before the electricity meter then the network operator will replace them, call 105 to contact them.
Anything after the meter is your responsibility.
There is no upgrade option for such old equipment, fuse wire rating is what it was originally designed for.
Where I live, the standard circuit breaker current at the property border is 25A and one has to pay monthly to get a larger value (just for a stronger circuit breaker, the kWhs are counted normal). If that sounds outrageous to you, hear this: In Austria, the standard house input is limited to 16A!!! That's because they banned nuclear power plants, green-brained hippies! Mind what you wish for, you might get it!
+zwz • zdenek What, 16A? That is creazy. Most flats in Poland would have 25A total, with split to 16/10/6 A for different use (kitches, sockets, lights). For standalone homes, it would probably be 40A standard, but you should be able to get more, but I think you pay just once, unless you live in some strange place, where they cannot do that without rebuilding infrastructure, or you are sole user (end of the line). Just my guess.
It's just fascinating to me how differently we do things in the United States. Most modern residential service in the United States is about 200-225 amps, but as it's 120/240V, that would equate to about 100A in a European service. (So, that's about the same.) We like lots and lots of circuits. Fewer than a dozen circuits is unheard of except in the oldest homes. In modern construction of stand-alone dwellings, 30-50 separate circuits is common. These circuits are typically dedicated to individual rooms or pairs of rooms, and now also typically separate lighting and receptacles.
@@jovetj yes, but Aircon is also much more common in America, so some of it has to go for that right? Fusing low and often is likely wise as it keeps the fault current low, but at least Britain in particular had copper shortages strongly affect the design choices made (ring circuits and fused plugs and so on) so loads of wiring probably wouldn't have been feasible when the standards were being set out.
@@AngDavies Some of it does go to air conditioning, yes. I grew up in a home that had electric heat, and the electric heat circuits were over twice the rating as the air conditioning.
Why are two fuses not allowed in your country? Is it in case only the neutral line goes it will still be live? I ask because we don't have neutral line where I live and there is always two or three (for three phase) fuses. Of course in modern setups they are tied together so if one goes all of them goes.
lollandster Yes, it's because of the neutral one failing and leaving items live. Two fuses also increases cost and complexity for no additional benefit.
+lollandster I do not think so, you will usually have single fuse for single phase. and no fuse (breaker) on neutral line at all. You might have additional double switch before the switch, but it is not a breaker (fuse).
For the 3 phase, you will have interlocked 3 fuses / breakers. Sometimes, especially if you do have multiple appliances with 3 phases supplies, or in bigger distributions, separate interlocked switch (not breaker, but sometimes with additional higher rated breaker too) before other split breakers. All interlocked between phases.
There is a separate John video, where he shows ,that double fuses on many installations these days, are actually less safe than single fuse.
+movax20h Where I live (Norway) there is no neutral line, but two 110V lines alternating with 180deg from each other creating a 220V potential (RMS voltages). Therefor there are two breakers needed to stop live from passing through.
+lollandster It is uncommon in other parts of Europe. The setup like yours was used before 1950 in UK, or something like that. And the video presents a double fuse designed for such system. But nobody is building such systems since 50s anymore.
+lollandster I think the split supply is only used on construction sites, with isolation transformer, step down to 110V, and the split to 55V, so there is only 55V between any live wire and ground. For safety reasons, as construction sites are often wet.
Well I think the c shaped cable terminals in the fuse are to allow for expansion. If it expands i'm thinking the back will give, like a spring, and it's less likely that the screw would work loose.
mmmm delicious asbestos
OK I have to call u out pitch is a super viscous liquid its not a solid check the pitch experiment