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Fuse calculation
On Tuesday, 20 March 2018 10:11:38 UTC, Dave Plowman (News) wrote:
In article , Brian Gaff wrote: Yes most people who set questions in exams have not experienced the real world very much has been my suspicion for a while now. They are steeped in the maths but know little about the real world. It is the real world which says no new appliance should require a less than 13 amp fuse in a plug. Because if a lower value blows, many will just replace it with what is to hand, so likely a 13 amp one. Good point and they may not even have a fuse, so perhaps a paper clip ;-) |
Fuse calculation
whisky-dave wrote:
On Monday, 19 March 2018 18:38:42 UTC, Roger Hayter wrote: whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 10A . But 13A is fine. So we both got it wrong then because the answer is 5A. I think the answer is wrong, or at best a matter of opinion. If they had asked which of the stated fuses has a current rating nearest to and above the current drawn by an ideal theoretical 1.15kW heater which was rated at 240V then it would have been a less ambiguous question. -- Roger Hayter |
Fuse calculation
In article ,
Martin Brown wrote: There is power where the kettles should go, but the tea ladies sometimes do strange things to avoid walking about 3m to the kitchen bench. The extension was coiled up and being used essentially as a 2 way adaptor so they could plug in multiple kettles at once on a nearby table instead. I'd say you shouldn't make such an extension available in a public place. Use single outlet ones only. And not cable reels as they tend not to get fully unwound. I once noticed such a coiled up reel under the breakfast bar at a Premier Inn, it was feeding the conveyor toaster. My complaint fell on deaf ears. -- Graham. %Profound_observation% |
Fuse calculation
On Tuesday, 20 March 2018 11:39:34 UTC, Roger Hayter wrote:
whisky-dave wrote: On Monday, 19 March 2018 18:38:42 UTC, Roger Hayter wrote: whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 10A . But 13A is fine. So we both got it wrong then because the answer is 5A. I think the answer is wrong, or at best a matter of opinion. If they had asked which of the stated fuses has a current rating nearest to and above the current drawn by an ideal theoretical 1.15kW heater which was rated at 240V then it would have been a less ambiguous question. Well they should have stated whether the person deciding on what fuse to instal; was a desginier of the equipment where the fuse was and who employed you because if I were to replace the fuse I'd have to use a 13 amp. This is why I don't think it's a good question. Other Qs include list 3 examples of household objects that use purely AC. and 3 that use AC converted to DC. and another I don't really like. If a light bulb was connected to a 240V AC supply would it be brighter, the same or dimmer if the light bulb was connected to 240V DC. |
Fuse calculation
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Fuse calculation
In article ,
Graham. wrote: The idea that anyone (particularly PAT testers) will correlate the faint markings on the cable sheath with the fuse fitted is vanishing small. An experienced PAT person should be able to tell by the outside size of the flex. -- *Rehab is for quitters Dave Plowman London SW To e-mail, change noise into sound. |
Fuse calculation
On 20/03/2018 10:01, Dave Plowman (News) wrote:
In article , Martin Brown wrote: There is power where the kettles should go, but the tea ladies sometimes do strange things to avoid walking about 3m to the kitchen bench. The extension was coiled up and being used essentially as a 2 way adaptor so they could plug in multiple kettles at once on a nearby table instead. I'd say you shouldn't make such an extension available in a public place. Use single outlet ones only. And not cable reels as they tend not to get fully unwound. I'm surprised they didn't ban the sale of rewwindable cable reels (*) when harmonised colours and part P came in. (*) 240V ones, for domestic use. |
Fuse calculation
On 20/03/2018 11:39, Roger Hayter wrote:
whisky-dave wrote: On Monday, 19 March 2018 18:38:42 UTC, Roger Hayter wrote: whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 10A . But 13A is fine. So we both got it wrong then because the answer is 5A. I think the answer is wrong, or at best a matter of opinion. If they If it had been a 1kW halogen lamp then there would be a real risk of the initial cold filament surge current taking out the fuse. But a 1.15kW radiant electric fire bar would have a cold resistance of around 40R and a hot one about 50R. So it would initially draw over 5A (nearly 6A) until it first started to glow red. The fuse working life will be shortened as a result but not by all that much. had asked which of the stated fuses has a current rating nearest to and above the current drawn by an ideal theoretical 1.15kW heater which was rated at 240V then it would have been a less ambiguous question. You are assuming here that a 5A fuse does what it says on the tin. That is normally not the case - most mains fuses will stand a 25% overload condition almost indefinitely - but the plug will run warm as a result. -- Regards, Martin Brown |
Fuse calculation
On Tuesday, 20 March 2018 10:15:28 UTC, The Other Mike wrote:
On Mon, 19 Mar 2018 12:33:03 -0700 (PDT), tabbypurr wrote: On Monday, 19 March 2018 18:28:56 UTC, The Natural Philosopher wrote: 13A. Remember the fuse is to protect the wiring that is downstream of it only. that garbage is much trotted out. With a BS1363 plug top to IEC 60320 C13 connector with both the cable (BS EN 50525 sized at 1mm^2) and the end connector rated at 10A which fuse would be fitted by the manufacturer? With a BS1363 plug top to IEC 60320 C13 connector with the cable BS EN 50525 sized at 0.75mm^2) rated at 5A and the end connector rated at 10A which fuse would be fitted by the manufacturer? The limit of supply by the manufacturer in both cases is the BS1363 plug top with a BS1362 fuse, the cable to BS EN 50525 and the IEC 60320 C13 connector as a tested and complete assembly to be offered for sale in the UK. In the real world I've seen the following in new IEC leads many times: 13A 10A 7A 5A 3A noncompliant chinese fuses of who knows what rating, some of which bear no marking at all and may well not be fuses. NT |
Fuse calculation
On Tuesday, 20 March 2018 13:30:27 UTC, Dave Plowman (News) wrote:
In article , Graham. wrote: The idea that anyone (particularly PAT testers) will correlate the faint markings on the cable sheath with the fuse fitted is vanishing small. An experienced PAT person should be able to tell by the outside size of the flex. as well as the markings on the plug NT |
Fuse calculation
On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote:
In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. -- Graham. %Profound_observation% |
Fuse calculation
On 20/03/2018 19:15, Graham. wrote:
On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote: In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. What is it, a parallelogram? A trapezium? A quadrilateral perhaps. -- Max Demian |
Fuse calculation
On 20/03/2018 12:21, whisky-dave wrote:
On Tuesday, 20 March 2018 11:39:34 UTC, Roger Hayter wrote: whisky-dave wrote: On Monday, 19 March 2018 18:38:42 UTC, Roger Hayter wrote: whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 10A . But 13A is fine. So we both got it wrong then because the answer is 5A. I think the answer is wrong, or at best a matter of opinion. If they had asked which of the stated fuses has a current rating nearest to and above the current drawn by an ideal theoretical 1.15kW heater which was rated at 240V then it would have been a less ambiguous question. Well they should have stated whether the person deciding on what fuse to instal; was a desginier of the equipment where the fuse was and who employed you because if I were to replace the fuse I'd have to use a 13 amp. This is why I don't think it's a good question. Other Qs include list 3 examples of household objects that use purely AC. and 3 that use AC converted to DC. and another I don't really like. If a light bulb was connected to a 240V AC supply would it be brighter, the same or dimmer if the light bulb was connected to 240V DC. Presumably the same, near as dammit, if it's an incandescent. -- Max Demian |
Fuse calculation
Graham. wrote:
On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote: In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. Gawaaan, Ill bite. What do you call it? Tim -- Please don't feed the trolls |
Fuse calculation
On 20/03/2018 20:01, Tim+ wrote:
Graham. wrote: On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote: In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. Gawaaan, Ill bite. What do you call it? Tim Presumably, as it does have thickness, it could be termed a cuboid. What you would call it unless it was laid flat on a table though I don't know. It could be any shape - including a hat, a broach, etc.! SteveW |
Fuse calculation
On Tuesday, 20 March 2018 19:38:20 UTC, Max Demian wrote:
On 20/03/2018 19:15, Graham. wrote: On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote: In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. What is it, a parallelogram? A trapezium? A quadrilateral perhaps. It's a square that someone sat on :-) -- Max Demian |
Fuse calculation
On 20/03/2018 20:01, Tim+ wrote:
Graham. wrote: On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote: In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. Gawaaan, I’ll bite. What do you call it? Tim Presumably, as it does have thickness, it could be termed a cuboid. Precisely that. -- Graham. %Profound_observation% |
Fuse calculation
On 21/03/18 20:15, Graham. wrote:
On 20/03/2018 20:01, Tim+ wrote: Graham. wrote: On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote: In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. Gawaaan, Ill bite. What do you call it? Tim Presumably, as it does have thickness, it could be termed a cuboid. Precisely that. Well as it has roughness, no it couldn't. It is an indeterminate solid. And thus your pedantry is exposed. If you excuse the surface torigness to make it approximately a perfect cuboid, the thickness can be excused as well to make it a perfect rectangle. With the ability to cherry pick properties like that you belong in politics or climate science. -- €œit should be clear by now to everyone that activist environmentalism (or environmental activism) is becoming a general ideology about humans, about their freedom, about the relationship between the individual and the state, and about the manipulation of people under the guise of a 'noble' idea. It is not an honest pursuit of 'sustainable development,' a matter of elementary environmental protection, or a search for rational mechanisms designed to achieve a healthy environment. Yet things do occur that make you shake your head and remind yourself that you live neither in Joseph Stalins Communist era, nor in the Orwellian utopia of 1984.€ Vaclav Klaus |
Fuse calculation
In article ,
The Natural Philosopher wrote: I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. Gawaaan, I‘ll bite. What do you call it? Tim Presumably, as it does have thickness, it could be termed a cuboid. Precisely that. Well as it has roughness, no it couldn't. It is an indeterminate solid. And thus your pedantry is exposed. If you excuse the surface torigness to make it approximately a perfect cuboid, the thickness can be excused as well to make it a perfect rectangle. You can cut paper to provide a perfect line? Much better than any surface roughness? With the ability to cherry pick properties like that you belong in politics or climate science. Pot, kettle. HTH. -- *When everything's coming your way, you're in the wrong lane * Dave Plowman London SW To e-mail, change noise into sound. |
Fuse calculation
Graham. Wrote in message:
On 20/03/2018 20:01, Tim+ wrote: Graham. wrote: On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote: In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. Gawaaan, I’ll bite. What do you call it? Tim Presumably, as it does have thickness, it could be termed a cuboid. Precisely that. -- Graham. %Profound_observation% Except that one is a common term that everyone understands in the frame of reference mentioned, whist the other is "clever dickery". I suppose you would call a triangular piece of paper a prism and a circular piece a cylinder? ;-) Tim -- |
Fuse calculation
On Thursday, 22 March 2018 11:39:46 UTC, Tim+ wrote:
Graham. Wrote in message: On 20/03/2018 20:01, Tim+ wrote: Graham. wrote: On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote: In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. Gawaaan, Ill bite. What do you call it? Tim Presumably, as it does have thickness, it could be termed a cuboid. Precisely that. -- Graham. %Profound_observation% Except that one is a common term that everyone understands in the frame of reference mentioned, whist the other is "clever dickery". I suppose you would call a triangular piece of paper a prism and a circular piece a cylinder? ;-) and that the earth is flat because it curves less than a 1/4 wavelenght of light, which for opticians means Earth is optically flat :-) Tim -- |
Fuse calculation
On 21/03/2018 20:15, Graham. wrote:
On 20/03/2018 20:01, Tim+ wrote: Graham. wrote: I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. Gawaaan, Ill bite. What do you call it? Tim Presumably, as it does have thickness, it could be termed a cuboid. Precisely that. Only if it happens to be flat at the time. -- Max Demian |
Fuse calculation
In article , Graham.
writes On 20/03/2018 20:01, Tim+ wrote: Graham. wrote: On Monday, 19 March 2018 17:02:42 UTC, Dave Plowman (News) wrote: In article , whisky-dave wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v If you're talking a plug fuse, the load is irrelevant. As it is to protect the flex etc. In other words, a table light with a 20 watt bulb would be fine with a 13 amp fuse if the cable was rated at 13 amps. But that wasn't the question was it. This was a mid-term test, so you would got this question wrong. Often with examination question, the right answer is the one the examiner is expecting. I have had that dilema many times. I hand my grandson a sheet of A4 paper and ask him what shape it is, he replies it's a rectangle. Wrong. Gawaaan, Ill bite. What do you call it? Tim Presumably, as it does have thickness, it could be termed a cuboid. Precisely that. In geometry, a cuboid is a convex polyhedron bounded by six quadrilateral faces, whose polyhedral graph is the same as that of a cube. While mathematical literature refers to any such polyhedron as a cuboid,[1] other sources use "cuboid" to refer to a shape of this type in which each of the faces is a rectangle (and so each pair of adjacent faces meets in a right angle); this more restrictive type of cuboid is also known as a rectangular cuboid, right cuboid, rectangular box, rectangular hexahedron, right rectangular prism, or rectangular parallelepiped {sorry couldn't resist it} https://en.wikipedia.org/wiki/Cuboid Who would have thought such a simple question could produce such a complicated set of answers. -- bert |
Fuse calculation
On Tuesday, March 20, 2018 at 2:48:07 AM UTC+11, Graham. wrote:
Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 1150/240=4.79 so theoretically a 5A fuse shoud do. -- Graham. %Profound_observation% May be 5A will do, as "cold" heater element resistance would be higher than normal heating. |
Fuse calculation
On Thu, 22 Mar 2018 18:50:17 -0700, gopalansampath wrote:
On Tuesday, March 20, 2018 at 2:48:07 AM UTC+11, Graham. wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 1150/240=4.79 so theoretically a 5A fuse shoud do. -- Graham. %Profound_observation% May be 5A will do, as "cold" heater element resistance would be higher than normal heating. Surely it's the other way round. -- My posts are my copyright and if @diy_forums or Home Owners' Hub wish to copy them they can pay me £1 a message. Use the BIG mirror service in the UK: http://www.mirrorservice.org *lightning surge protection* - a w_tom conductor |
Fuse calculation
On Friday, 23 March 2018 01:50:20 UTC, wrote:
On Tuesday, March 20, 2018 at 2:48:07 AM UTC+11, Graham. wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 1150/240=4.79 so theoretically a 5A fuse shoud do. -- Graham. %Profound_observation% May be 5A will do, as "cold" heater element resistance would be higher than normal heating. But according to regulations in the UK on changing fuses it should be either a 3A for below 720W or a 13amp for above 720W . https://www.rospa.com/home-safety/uk...hoosing-fuses/ |
Fuse calculation
whisky-dave wrote:
But according to regulations in the UK on changing fuses it should be either a 3A for below 720W or a 13amp for above 720W . https://www.rospa.com/home-safety/uk...hoosing-fuses/ ROSPA doesn't represent "regulations", it's just advice, based on the ratings of fuses they expect people to have at hand, and even that page suggests 5A for some appliances ... |
Fuse calculation
On Friday, 23 March 2018 13:37:35 UTC, Andy Burns wrote:
whisky-dave wrote: But according to regulations in the UK on changing fuses it should be either a 3A for below 720W or a 13amp for above 720W . https://www.rospa.com/home-safety/uk...hoosing-fuses/ ROSPA doesn't represent "regulations", it's just advice, based on the ratings of fuses they expect people to have at hand, and even that page suggests 5A for some appliances ... As I said it's a bad question and in this university we have the regulations which tell us we must only use 3 & 13amp fuses, about 10 years ago I and others had the job of checking all fuses and replacving them with the 'correct ones' i.e 3 or 5, this is one reason why I have dozens of 5, 7 and 10 amp fuses, I even have 1 amp and 2 amp that I used in angle poised lamps with 40 or 60w bulbs. ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable. |
Fuse calculation
On 23 Mar 2018 09:55:54 GMT, Bob Eager wrote:
On Thu, 22 Mar 2018 18:50:17 -0700, gopalansampath wrote: On Tuesday, March 20, 2018 at 2:48:07 AM UTC+11, Graham. wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 1150/240=4.79 so theoretically a 5A fuse shoud do. -- Graham. %Profound_observation% May be 5A will do, as "cold" heater element resistance would be higher than normal heating. Surely it's the other way round. AIUI the type of heater that is in an incandescent lamp - filament, of course - has low initial resistance so that it comes on 'instantaneously' whereas an electric fire/kettle/shower is pretty well constant. Cold inrush to a 3kW kettle+bad idea. The 2 elements in my electric shower, measured when cold of course, have the resistance corellating to the rated power. The electric kettle stays the same, although the meter won't show the power for the first cycle or two. -- Peter. The gods will stay away whilst religions hold sway |
Fuse calculation
ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable. Nonsense! |
Fuse calculation
On Friday, 23 March 2018 17:46:17 UTC, Sam wrote:
ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable. Nonsense! Fact. |
Fuse calculation
On 23/03/2018 17:57, whisky-dave wrote:
On Friday, 23 March 2018 17:46:17 UTC, Sam wrote: ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable. Nonsense! Fact. Your view is too simplistic. Any fuse value below the rating of the cable will protect it. Therefore a "univeral" cable rated at say 5amps feeding an appliance rated at say 2 amps will still be protected by using a fuse suitable for the appliance. |
Fuse calculation
On 23/03/2018 18:07, Sam wrote:
On 23/03/2018 17:57, whisky-dave wrote: On Friday, 23 March 2018 17:46:17 UTC, SamÂ* wrote: Â*Â* ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable. Nonsense! Fact. Your view is too simplistic. Any fuse value below the rating of the cable will protect it. Therefore a "univeral" cable rated at say 5amps feeding an appliance rated at say 2 amps will still be protected by using a fuse suitable for the appliance. If an appliance needs a fuse for protection it should be in the appliance. Plug fuses are not there to protect the appliance and can't be relied on to do so. |
Fuse calculation
On 23/03/2018 18:16, dennis@home wrote:
On 23/03/2018 18:07, Sam wrote: On 23/03/2018 17:57, whisky-dave wrote: On Friday, 23 March 2018 17:46:17 UTC, SamÂ* wrote: Â*Â* ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable. Nonsense! Fact. Your view is too simplistic. Any fuse value below the rating of the cable will protect it. Therefore a "univeral" cable rated at say 5amps feeding an appliance rated at say 2 amps will still be protected by using a fuse suitable for the appliance. If an appliance needs a fuse for protection it should be in the appliance. Plug fuses are not there to protect the appliance and can't be relied on to do so. So? |
Fuse calculation
On 23/03/2018 18:17, Sam wrote:
On 23/03/2018 18:16, dennis@home wrote: On 23/03/2018 18:07, Sam wrote: On 23/03/2018 17:57, whisky-dave wrote: On Friday, 23 March 2018 17:46:17 UTC, SamÂ* wrote: Â*Â* ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable. Nonsense! Fact. Your view is too simplistic. Any fuse value below the rating of the cable will protect it. Therefore a "univeral" cable rated at say 5amps feeding an appliance rated at say 2 amps will still be protected by using a fuse suitable for the appliance. If an appliance needs a fuse for protection it should be in the appliance. Plug fuses are not there to protect the appliance and can't be relied on to do so. So? So a 13A fuse is perfect protection if the cable is thick enough and a 3A if it isn't. Its illegal to supply anything unsafe for use with a 3A fuse. It may even be illegal to supply leads that are unsafe with a 13A fuse if the regulations have been passed. |
Fuse calculation
On Friday, March 23, 2018 at 8:55:58 PM UTC+11, Bob Eager wrote:
On Thu, 22 Mar 2018 18:50:17 -0700, gopalansampath wrote: On Tuesday, March 20, 2018 at 2:48:07 AM UTC+11, Graham. wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 1150/240=4.79 so theoretically a 5A fuse shoud do. -- Graham. %Profound_observation% May be 5A will do, as "cold" heater element resistance would be higher than normal heating. Surely it's the other way round. -- My posts are my copyright and if @diy_forums or Home Owners' Hub wish to copy them they can pay me £1 a message. Use the BIG mirror service in the UK: http://www.mirrorservice.org *lightning surge protection* - a w_tom conductor OOps! I stand corrected. Surely fuse rating shall be higher than % Amps. |
Fuse calculation
On Saturday, March 24, 2018 at 7:19:46 AM UTC+11, dennis@home wrote:
On 23/03/2018 18:17, Sam wrote: On 23/03/2018 18:16, dennis@home wrote: On 23/03/2018 18:07, Sam wrote: On 23/03/2018 17:57, whisky-dave wrote: On Friday, 23 March 2018 17:46:17 UTC, SamÂ* wrote: Â*Â* ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable. Nonsense! Fact. Your view is too simplistic. Any fuse value below the rating of the cable will protect it. Therefore a "univeral" cable rated at say 5amps feeding an appliance rated at say 2 amps will still be protected by using a fuse suitable for the appliance. If an appliance needs a fuse for protection it should be in the appliance. Plug fuses are not there to protect the appliance and can't be relied on to do so. So? So a 13A fuse is perfect protection if the cable is thick enough and a 3A if it isn't. Its illegal to supply anything unsafe for use with a 3A fuse. It may even be illegal to supply leads that are unsafe with a 13A fuse if the regulations have been passed. Makes sense absolutely. |
Fuse calculation
On Friday, 23 March 2018 13:05:57 UTC, whisky-dave wrote:
On Friday, 23 March 2018 01:50:20 UTC, wrote: On Tuesday, March 20, 2018 at 2:48:07 AM UTC+11, Graham. wrote: Which is the best fuse to use (3A, 5A or 13A) with a 1.15kW electric fire at a potential difference of 240v 1150/240=4.79 so theoretically a 5A fuse shoud do. -- Graham. %Profound_observation% May be 5A will do, as "cold" heater element resistance would be higher than normal heating. But according to regulations in the UK on changing fuses it should be either a 3A for below 720W or a 13amp for above 720W . incorrect. https://www.rospa.com/home-safety/uk...hoosing-fuses/ ROSPA is not regulations. |
Fuse calculation
On Friday, 23 March 2018 18:17:55 UTC, Sam wrote:
On 23/03/2018 18:16, dennis@home wrote: On 23/03/2018 18:07, Sam wrote: On 23/03/2018 17:57, whisky-dave wrote: On Friday, 23 March 2018 17:46:17 UTC, SamÂ* wrote: Â*Â* ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable.. Nonsense! Fact. Your view is too simplistic. Any fuse value below the rating of the cable will protect it. Therefore a "univeral" cable rated at say 5amps feeding an appliance rated at say 2 amps will still be protected by using a fuse suitable for the appliance. If an appliance needs a fuse for protection it should be in the appliance. Plug fuses are not there to protect the appliance and can't be relied on to do so. So? The idea that the plug fuse is solely to protect the flex is a pov much promoted, but a proper look at it shows it doesn't really add up. Of course you can take that approach, but fitting better chosen fuses does improve safety and costs zero extra, so is the more sensible thing to do. As the owner of many historic electrical goods & the occasional 3rd world import I'd hate to run any of them on a 13A fuse. As ever such ideas lead to idiocy like people being ordered to replace appropriate fuses with higher rated ones etc. NT |
Fuse calculation
On Friday, 23 March 2018 18:07:13 UTC, Sam wrote:
On 23/03/2018 17:57, whisky-dave wrote: On Friday, 23 March 2018 17:46:17 UTC, Sam wrote: ANd don;t forget the FUSE is to protect the cable NOT the item of equipent so it really doesnlt matter what current rating the electric fire is, you put the fuse in that is correct for the cable. Nonsense! Fact. Your view is too simplistic. It;s the one that is used. Any fuse value below the rating of the cable will protect it. So what, that wasn't thw question, not putting any fuse in would protect the cable even more. Therefore a "univeral" cable rated at say 5amps What's a universal cable ? feeding an appliance rated at say 2 amps will still be protected by using a fuse suitable for the appliance. That wasn't the question, and you don't feed the appliance, thatr's one thing our studetns get wrong too, the appliance takes current , current doesn't get pushed into thre appliance. |
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