Hi John,
Your comment on the inductance of breakers encouraged me to do a few quick tests as when I originally checked the breakers I have used for years, I recalled seeing lower values. I thought the results might be of interest to some readers.
All of the 3120, 3130, and their push-button series I checked show a slightly lower figure than you found, being in the region of 1+uH.
I guess that any nonlinearity will not be helped by the bi-metallic strip arrangement (recalling my earlier remarks on dissimilar metal interfaces used in 'signal' paths) and this was a concern to me when I first looked into these ETA breakers.
However, as I also said, I found that in practice that they were about as benign sonically as could be realistically expected, accepting that some protection is necessary.
Also interestingly, I put 5 (all new) rocker switches on the tester, one 16A high-inrush, three 16A 'normal', and a 10A 'Normal'.
All exhibited considerably higher inductance than the breakers, with the lowest being just under 3uH, and the highest at nearly 5uH. I wouldn't care to guess how 'stable' or linear this would be under extended use.
Bearing in mind the avoidance of a separate on-off switch if the 3120/3130 series ETA breakers are used, and assuming the switches I checked are representative, it could be said that these breakers look if anything 'better on paper' as well, where arranging overall appliance protection goes.
Regards,
Your comment on the inductance of breakers encouraged me to do a few quick tests as when I originally checked the breakers I have used for years, I recalled seeing lower values. I thought the results might be of interest to some readers.
All of the 3120, 3130, and their push-button series I checked show a slightly lower figure than you found, being in the region of 1+uH.
I guess that any nonlinearity will not be helped by the bi-metallic strip arrangement (recalling my earlier remarks on dissimilar metal interfaces used in 'signal' paths) and this was a concern to me when I first looked into these ETA breakers.
However, as I also said, I found that in practice that they were about as benign sonically as could be realistically expected, accepting that some protection is necessary.
Also interestingly, I put 5 (all new) rocker switches on the tester, one 16A high-inrush, three 16A 'normal', and a 10A 'Normal'.
All exhibited considerably higher inductance than the breakers, with the lowest being just under 3uH, and the highest at nearly 5uH. I wouldn't care to guess how 'stable' or linear this would be under extended use.
Bearing in mind the avoidance of a separate on-off switch if the 3120/3130 series ETA breakers are used, and assuming the switches I checked are representative, it could be said that these breakers look if anything 'better on paper' as well, where arranging overall appliance protection goes.
Regards,
Andre Visser said:
Absolutely!
Completely OT, but I like the TV adverts where viewers are shown a demo of the difference between HD and normal TV sets in use.
Presumably this is to encourage viewers to upgrade, but any prospective punters are surely most likely to be seeing these 'comparisons' on their normal TV sets, so how can they possibly truely appreciate how much better HD is? 😉
Regards,
Thanks Bob, very interesting and relevant postings. I will be sure to try the ETAs , and the transzorb idea will get a test too.
On the latter subject, googling 'transzorb' does not find much useful information. If you are still handing out sage advice, what rating would you advise for the UK, and would a power amp be different from, say, a CD player?
On the latter subject, googling 'transzorb' does not find much useful information. If you are still handing out sage advice, what rating would you advise for the UK, and would a power amp be different from, say, a CD player?
Sigurd Ruschkow said:
Sigurd:
Just curious, is the "unbleached" property of the cotton essential for an optimal sound? Have you tried bleached cotton and decided it's bad for the sound?
Hi float,
I'll take another chance, and cross my fingers!
These devices don't appear to deteriorate over time fortunately (with the number and amplitude of over-voltage strikes) like VDRs etc. do.
However, under excessive stress (like all components) they will fail, and as mentioned earlier they fail in the 'shorted' condition, unfortunately. This is why I said they should be located 'downstream' of the main protection device (the unit's integral breaker or input mains fuse). Otherwise, if they fail and this main protection device at the unit's input is not covering this, the consumer unit main breaker covering the ring main or spur (or perhaps in our country, but extremely rarely in my experience, the plug fuse) will take a hit, as these Transzorbs are located across the N & L lines.
I happen to live and do my work in a country area where further housing development is anticipated, and I guess to allow for this, the local mains supply 'step-down' transformer (50 yards away from us) was replaced shortly after I started using Transzorbs. I think it is very likely oversized currently as the proposed developments haven't yet fully-materialised, and I also guess that there is some regulation factor involved and presently this transformer is under-used. Why I think this is that our mains voltage is always very high, I have never measured it lower than 245v-ish, and mostly it sits around 248v AC.
Using what should theoretically be a suitable Transzorb (1.5KE 400CA) which was recommended by the UK agents for the UK-specified voltages, I once had one of these devices blow unexpectedy. When I checked the mains voltage at that time it was just over 250v RMS, and in spite of my continual complaints to the authorities, I have never seen any real improvement.
Transzorbs are chosen by their Reverse Stand-off Voltages, which in basic terms means that they shouldn't have any affect on the passing current below that level, and the above device has an R S V of 342v, which when divided by 1.4142 from this max peak voltage capability, the RMS value is 241.8v. These devices were all that could be obtained via the UK distributor at that time, and although I used a lot of them for several years without any problems, this one incident concerned me so I immediately went over to using 1.5KE440CA devices (R S V of 376v) which I had specially imported, to avoid any further problems.
Regrettably, with a higher R S V, inevitably the clipping of any unwanted spikes will commence at a higher level, but I didn't notice any real sonic differences after this change, so I have remained with these until maybe our mains level is more normal.
To complete the picture, if there is the odd peak in the mains short-term, there shouldn't be any problems with the lower-rated devices, as their minimum breakdown voltage is suposedly 380v (268.7v RMS), but when this event first occurred, I found that the remaining intact Transzorbs in my system (I use them everywhere) were running quite warm with this then higher voltage across them, and this is not normal. I contacted the agents about this, who put me on to the makers, but in (pre-Internet days, of course) I never received a satisfactory reply, so my guess is that the peaks of the normal AC waveform were being continously clipped which shouldn't normally happen, and accordingly the heat induced by this was probably responsible for the device breakdown.
The choice is yours, of course and I think that the lower-rated devices are probably still suggested for 'normal' UK usage. However, if you take the other option, Farnell part# 988-5080 is for the 1.5KE440CA generic substitution, and if you are interested the suffix 'A' or 'CA' is used to denote a bipolar device, which of course is required in this instance.
This series of devices are not very costly and have been satisfactory in use for all of my requirements over the years, and seem to handle everything from MC head amps up to power amps, and they will handle 1500 Watts Peak Pulse Power dissipation. Regrettably, it is not possible to go further into this capability right now as it is a little involved, but lesser P P P devices are also available, which might be cheaper if you can find them and more than adequate for some locations. I would have a look at the appropriate data sheets, though, which may help you to make your choice.
Regards,
I'll take another chance, and cross my fingers!
These devices don't appear to deteriorate over time fortunately (with the number and amplitude of over-voltage strikes) like VDRs etc. do.
However, under excessive stress (like all components) they will fail, and as mentioned earlier they fail in the 'shorted' condition, unfortunately. This is why I said they should be located 'downstream' of the main protection device (the unit's integral breaker or input mains fuse). Otherwise, if they fail and this main protection device at the unit's input is not covering this, the consumer unit main breaker covering the ring main or spur (or perhaps in our country, but extremely rarely in my experience, the plug fuse) will take a hit, as these Transzorbs are located across the N & L lines.
I happen to live and do my work in a country area where further housing development is anticipated, and I guess to allow for this, the local mains supply 'step-down' transformer (50 yards away from us) was replaced shortly after I started using Transzorbs. I think it is very likely oversized currently as the proposed developments haven't yet fully-materialised, and I also guess that there is some regulation factor involved and presently this transformer is under-used. Why I think this is that our mains voltage is always very high, I have never measured it lower than 245v-ish, and mostly it sits around 248v AC.
Using what should theoretically be a suitable Transzorb (1.5KE 400CA) which was recommended by the UK agents for the UK-specified voltages, I once had one of these devices blow unexpectedy. When I checked the mains voltage at that time it was just over 250v RMS, and in spite of my continual complaints to the authorities, I have never seen any real improvement.
Transzorbs are chosen by their Reverse Stand-off Voltages, which in basic terms means that they shouldn't have any affect on the passing current below that level, and the above device has an R S V of 342v, which when divided by 1.4142 from this max peak voltage capability, the RMS value is 241.8v. These devices were all that could be obtained via the UK distributor at that time, and although I used a lot of them for several years without any problems, this one incident concerned me so I immediately went over to using 1.5KE440CA devices (R S V of 376v) which I had specially imported, to avoid any further problems.
Regrettably, with a higher R S V, inevitably the clipping of any unwanted spikes will commence at a higher level, but I didn't notice any real sonic differences after this change, so I have remained with these until maybe our mains level is more normal.
To complete the picture, if there is the odd peak in the mains short-term, there shouldn't be any problems with the lower-rated devices, as their minimum breakdown voltage is suposedly 380v (268.7v RMS), but when this event first occurred, I found that the remaining intact Transzorbs in my system (I use them everywhere) were running quite warm with this then higher voltage across them, and this is not normal. I contacted the agents about this, who put me on to the makers, but in (pre-Internet days, of course) I never received a satisfactory reply, so my guess is that the peaks of the normal AC waveform were being continously clipped which shouldn't normally happen, and accordingly the heat induced by this was probably responsible for the device breakdown.
The choice is yours, of course and I think that the lower-rated devices are probably still suggested for 'normal' UK usage. However, if you take the other option, Farnell part# 988-5080 is for the 1.5KE440CA generic substitution, and if you are interested the suffix 'A' or 'CA' is used to denote a bipolar device, which of course is required in this instance.
This series of devices are not very costly and have been satisfactory in use for all of my requirements over the years, and seem to handle everything from MC head amps up to power amps, and they will handle 1500 Watts Peak Pulse Power dissipation. Regrettably, it is not possible to go further into this capability right now as it is a little involved, but lesser P P P devices are also available, which might be cheaper if you can find them and more than adequate for some locations. I would have a look at the appropriate data sheets, though, which may help you to make your choice.
Regards,
Bobken, did you measure electromagnetic circuit breakers, or just thermal ones? In any case, I know that the DC electromagnetic circuit breakers that I used in a power amp design, rang like crazy, until I damped them.
Hi Bobken,
ask your mains supplier to temporarily reduce the tapping on your transformer until the expected load comes on line.
The maximum "normal" tolerance on the UK supply system is 254Vac.
Do not use 230/240/250Vac rated absorbers on a UK mains system.
Use 275Vac. They are designed to absorb/pass the transients without passing "normal" voltages.
ask your mains supplier to temporarily reduce the tapping on your transformer until the expected load comes on line.
The maximum "normal" tolerance on the UK supply system is 254Vac.
Do not use 230/240/250Vac rated absorbers on a UK mains system.
Use 275Vac. They are designed to absorb/pass the transients without passing "normal" voltages.
john curl said:
Hi John,
No, merely the ETA thermal types, and I haven't found the need to try any others in the 25 or more years since I became disenchanted with fuses. As mentioned, there is a good range of different styles and mountings, and ETA will make them to order in any sensible breaking values I have required.
I usually use the 3120 series as I can open them up in 10 secs., just with my thumbnails, to apply Cramolin to the contacts. The 3130 series are very similar, but they also have a rivet which needs drilling out first, which is a fag to do and then remake and replace.
I read before your opinions on Cramolin, but wonder if you were perhaps influenced a bit by Enid L? Having observed what adding Cramolin does to reduce (mostly completely eliminating) sparking on commutators so many times, I always apply a dose before use, to get the best out of their useful life.
Regards,
AndrewT said:
Hi Andrew,
Thanks a lot for that advice which I would never have worked out for myself! 😉
I mean no offence but didn't you read what I said?
When I first started using Transzorbs, the 1.5KE400CA was the highest R S V device of this particular type made by anyone in the world actually, as only the originators GSI made them. The data book of the time stops at this value, and the UK agents told me I wouldn't get anything higher-rated as these were intended for use in the UK who had the highest voltage mains anywhere in the world.
However, with a bit of persuation I managed to get a large supply of higher-rated units direct from Square 'D', the parent company, as quite by chance I found out that these had just been manufactured.
Regrettably, I gave up wasting time even talking to our local electricity suppliers, and I don't have any problems anyway, as already advised. 🙂
Regards,
EDIT. I forgot to mention that 2 Sundays ago we had in excess of 20 (!) albeit short-term losses of power in our location. It's no wonder light bulbs don't last very long with these surges!
Bob,Bobken said:
this is misleading bordering on plain lies.
In the UK the main breaker is usually 80A to 100A.
The MCBs are rated for the type of circuit they are intended to supply.
6A is usually reserved for lighting and dedicated spurs to low power equipment eg, Central heating controls or security, etc.
The power distribution around UK residences is usually protected at the consumer unit by MCBs rated from 16A to 32A, 32A being the most common as this suits the 2.5sqmm two core + earth that we generally use as a ring feeder.
It is expected that the downstream side cabling MUST be RATED in excess of the MCB rating.
Any lower rated cabling MUST be protected by a further appropriately rated fuse before downsizing the cable.
Have you seen the size of a >32A mains flexible lead? I haven't even tried to find a stockist because I suspect such does not exist and it certainly won't fit a 1363 plug top. Even a 2.5sqmm flex is quite difficult to fit into a Plug top.
Most three core flexibles are rated 6A to 10A. The fuse upstream of these "normal flexible cables" MUST be smaller than the flex rating. This fuse can conveniently be located inside the BS1363 plug top but MUST be located before the flex.
That cable size variation is why the BS1362 fuses are available in ratings from 1A to 13A and should be chosen appropriately for the CABLE not necessarily for the appliance rating.
Keep in mind that fuses are there to prevent the cable and equipment and their surrounds catching fire. They are NOT there to prevent further damage to faulty equipment.
Ask your household insurance broker if there will be any change in the premium if you tell them you are considering dispensing with the plug top fuses. And do please come back and tell us their response.
I did read and I'm suggesting that you back to your supplier and insist on an adjustment to your mains supply voltage.Bobken said:
Neither your Transorb spec/details nor the following enquiry mentions 275Vac rated devices.
It seemed to be worth stating that this rating does exist and is suitable for UK domestic use.
Hi Andrew,
We have moved on from this topic, but what I said is certainly not plain lies.
In my experience, and certainly in my area, 16A is most common nowadays for domestic ring mains, but it is unimportant as I did NOT at any time suggest that ANYONE should follow what I mentioned.
Perhaps you should write to the TV companies whenever they show violence on the screens in case that gives people some bad ideas.
You and others have made an issue out of this which also reinforces my own comments in several places that safety is very important, I have done my best, and there is no need for this to be protracted.
Regards,
We have moved on from this topic, but what I said is certainly not plain lies.
In my experience, and certainly in my area, 16A is most common nowadays for domestic ring mains, but it is unimportant as I did NOT at any time suggest that ANYONE should follow what I mentioned.
Perhaps you should write to the TV companies whenever they show violence on the screens in case that gives people some bad ideas.
You and others have made an issue out of this which also reinforces my own comments in several places that safety is very important, I have done my best, and there is no need for this to be protracted.
Regards,
Well.
we do want to have a dielectric as close to air as possible and cotton's dieelectric is close to air's dielectric constant. The more air inside the cotton, the closer we get.
The bleached cottons I have seen are more compact/dense, so we get less close to air's dielectric.
I am no chemist, but I wonder if the bleach stuff (chlorine?) that remains in the cotton will affect the silver wire negatively over time.
Sigurd
we do want to have a dielectric as close to air as possible and cotton's dieelectric is close to air's dielectric constant. The more air inside the cotton, the closer we get.
The bleached cottons I have seen are more compact/dense, so we get less close to air's dielectric.
I am no chemist, but I wonder if the bleach stuff (chlorine?) that remains in the cotton will affect the silver wire negatively over time.
Sigurd
syn08 said:
Can we assume you did inform your insurers of your practice of dispensing with Plug Top fuses?AndrewT said:
Why then keep their reply private?
I would allow the thread to move on but firstly, your comments and experiences are here in black and blue.
Secondly, your Email is turned off and no way to contact you privately.
Andrew,
These are my final words on this issue.
Firstly, the details of the part-commercial Insurance Cover in existence on my property (which was changed when I started working from home some years ago) are none of your business, and they are entirely irrelevant to any other members like yourself.
Secondly, you are still missing the point in continually referring to "275V ac rated devices" with implied criticism of my comments.
If you knew anything about these devices you would appreciate that the MINIMUM breakdown voltage of the device I suggested is actually 418v or 295.6v RMS (with a max of 462v) which far exceeds your "275v".
Incidentally, I still believe but haven't had the need to enquire lately, that the original devices are probably still recommended for UK use and should normally be satisfactory, with their minimum breakdown voltage of 380v, which I have already mentioned.
It is only relatively recently that any higher-rated such units have been shown in Major UK suppliers catalogues, so I guess that there haven't been too many disasters when using these lower-rated devices in the meantime.
Regards,
These are my final words on this issue.
Firstly, the details of the part-commercial Insurance Cover in existence on my property (which was changed when I started working from home some years ago) are none of your business, and they are entirely irrelevant to any other members like yourself.
Secondly, you are still missing the point in continually referring to "275V ac rated devices" with implied criticism of my comments.
If you knew anything about these devices you would appreciate that the MINIMUM breakdown voltage of the device I suggested is actually 418v or 295.6v RMS (with a max of 462v) which far exceeds your "275v".
Incidentally, I still believe but haven't had the need to enquire lately, that the original devices are probably still recommended for UK use and should normally be satisfactory, with their minimum breakdown voltage of 380v, which I have already mentioned.
It is only relatively recently that any higher-rated such units have been shown in Major UK suppliers catalogues, so I guess that there haven't been too many disasters when using these lower-rated devices in the meantime.
Regards,
Edmond Stuart said:
I made no comment about audibility by anyone.
If the circuit is well designed then the power supply should act as a barrier to audible effects, including fuses, switches, power cords, etc.
IMO, if different power switches is audible, then the PS needs attention.
How in the world do you propose we notice the extremely subtle sound differences we are discussing, when the test sounds are so grossly mutilated?
Hi Bob,Bobken said:
pointing out the likely Insurers response to your Plug Top fusing suggestions is not entirely irrelevant to our Forumites. It would be enlightening to hear from some insurers if they are reading this since you are not prepared to divulge this type of information.
My posts 7589 & 7593 imply no criticism of your Transorb comments.
I respect your design and build expertise. I have followed many of your posts and recognise the authority you rightly hold as a "good" designer/builder/listener. We agree on many points, more accurately almost all of your beliefs and findings.
But, I disagree strongly with your guarded advice on considering dispensing with Plug Top fuses by any UK enthusiast and/or newbie.
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