TVs more than anything else have internal fuses appropriate to their circuits. And TVs are also used extensively in other countries straight off a 16 amp circuit.
Fuse size, how often does one check it?
- Thread starter ericmark
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TVs more than anything else have internal fuses appropriate to their circuits. And TVs are also used extensively in other countries straight off a 16 amp circuit.
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Ok.
No. I said that boilers are used on the continent straight off 16 amp circuits. Not bullshit, but the truth.
And I said ok. No one's saying you're wrong.
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Quite probably but, as I said (and although I believe in using the small possible fuse appropriate to a load), by the time a 1A, 0.5A or probably even 0.1A fuse has blown, at least some of the electronics will almost always be dead.
Kind Regards, John
That makes two of us, then!
Mind you, that wasn't in my real 'youth' - I was probably into my teens before I first handled a BS1363 plug or socket!
Kind Regards, John
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I have a collection of 1, 2, 3, 5, 7, 10 and 13A 1362 fuses.
I used to regularly fit ADE alarm systems and put a 2A fuse in the FCU. Why?
The manufacturer stated so in the instructions.
I used to regularly fit ADE alarm systems and put a 2A fuse in the FCU. Why?
The manufacturer stated so in the instructions.
Same here, but my collection 'majors' on the lowest two or three ones!
Kind Regards, John
The manufacturer surely should have known that only 3 and 13 amp fuses are officially recognised.
The manufacturer surely fitted the correct fuse internally. What did he sat when he sold those systems overseas?
Manufacturers instructions are a guidance and don't have to be followed, especially when they are wrong.
I don't understand why "That's what I was taught" is supposed to indicate correctness.
Your teacher was wrong.
Your teacher was wrong.
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The idea of 16A fuse to a row of fluorescent fittings each with it's own 3A fuse fitted inside is clearly OK, however ceiling roses are normally rated 5 amp, and BA22d bulb holders at 2A since the bulb should have an internal fuse the 2A bulb holder is OK, but where the ceiling rose is used as a junction box, technically one is limited to 5 amp, although can't really see problem with 6 amp.
I have in the past been caught out with 2A lamp holders on a 16A MCB, theory is OK, should be fuse built into bulb, but practice an ikea CFL went short circuit and the bulb welded its self to holder, so instead of simply swapping a bulb I had to renew holder, since that I have been careful to keep to no more than 6A with BA22d lamp holders.
Be it a 30 mA RCD feeding a 30 mA RCD or a 13A fuse feeding a 13A fuse I feel it is both pointless and likely to cause problems if the device should fail, if you find a 13A fuse protecting something you don't tend to look for another 13A fuse protecting that fuse, so in my case, if lights not working in garage, and I check the fuse with is OK and 13A, then I would be looking for an MCB feeding that fuse, not another FCU in the bedroom.
I'm not aware of anyone having suggested that it does. As for myself, 'what I was taught' seemed to make complete sense to me, so that's what I have generally continued doing ever since.
I don't really think that there is a 'wrong' or 'right' in relation to the aspect of fuse sizing we are discussing - rather, there are differing opinions/viewpoints.
Using a fuse which is lower in rating than would be required to protect just the cable may or may not offer some protection to the load in some circumstances and I cannot see why such a practice should be regarded as 'wrong'. In what sense and/or circumstances could doing that have any downside**, or result in any problems/harm??
If it might conceivably, on some occasions, offer some protection to the load and has no downsides, then I have to ask "why not?".
[** for the extreme nit-pickers around, use of a lower-rate fuse will result in an increase in 'wasted energey', but that would be so minute that it surely is not worth even considering? ]
Kind Regards, John
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It does seem today we simply follow the regulations, where when I was an apprentice we used what we considered as common sense. There have been a few changes which may seem niggling, however to my mind go down hill, including names, I always considered a spur to be a branch from the main supply using a smaller cable, there was no such thing as a fused spur, that was called a radial, as any other supply from a overload protection device.
As to volt drop across a fuse, I have only once noted the volt drop across a fuse, some one had fitted a RCBO with 4.7kA limit supplying a charger for a radio in the main control box for a crane, however the PSSC was above that limit, so it was to be replaced with a fuse, but on fitting the fuse found the resistance of the fuse actually brought down the PSSC to within limits.
I understand two many fuses can cause too much volt drop with items like freezers, they have a overload device to trip out should the pressure be too high on a restart, and so are vulnerable to volt drop, however I can't think of any other device which is so vulnerable to volt drop.
I had a problem getting a re-wire, I had very limited time, too short to do a DIY, and only found 2 firms able to do the work one twice the price to other, and I took the cheaper, they put one guy full time on the job with a mate, however he over ran on time, so job was flooded on the last day, to finish it, and most the faults it seemed happened on that last day. However it was ready for mother to move back in, so all in all it was the right choose.
As to volt drop across a fuse, I have only once noted the volt drop across a fuse, some one had fitted a RCBO with 4.7kA limit supplying a charger for a radio in the main control box for a crane, however the PSSC was above that limit, so it was to be replaced with a fuse, but on fitting the fuse found the resistance of the fuse actually brought down the PSSC to within limits.
I understand two many fuses can cause too much volt drop with items like freezers, they have a overload device to trip out should the pressure be too high on a restart, and so are vulnerable to volt drop, however I can't think of any other device which is so vulnerable to volt drop.
I had a problem getting a re-wire, I had very limited time, too short to do a DIY, and only found 2 firms able to do the work one twice the price to other, and I took the cheaper, they put one guy full time on the job with a mate, however he over ran on time, so job was flooded on the last day, to finish it, and most the faults it seemed happened on that last day. However it was ready for mother to move back in, so all in all it was the right choose.
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That, surely, is the general implication and reason for saying it.
Well, if you were taught that it must be done, then it is wrong.
If told you may do it if you want, then that is not being taught to do it.
I didn't say doing it was wrong - being taught that you must or should do it is wrong.
"Might conceivably" - You can if you want but you don't have to.
I wasn't taught that I must or should do it - merely that it made total sense so to do. I agreed, and therefore have generally followed that practice ever since.
I'm still waiting for someone to tell me about the downside(s) of using a fuse smaller in rating than is necessary to protect just the cable.
Kind Regards, John
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