EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: ruibca on July 17, 2020, 10:57:51 am
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Hello all,
I need to replace both fuses on a Hioki DT4282 which requires a 11A 1000V 10.3 x 38mm ceramic fuse and a 630mA 1000V 10.3 x 38mm ceramic fuse. I can only find the same make (HOLLY) on peaktech and they only seem to do up to 10A. Is is ok to use a 10A fuse instead of 11A?
Many thanks,
Rui
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It's a specialized multimeter fuse and it does not necessarily need to be ceramic. For example you could use Busmann DMM-B-11A which is also sold as Fluke F-11A. Or Littlefuse 0FLU011.T, Siba 50 199 06.11, just don't buy it from dodgy places, ebay is full of counterfeits. 10A fuse most likely is simply a usual fast acting fuse which is not nearly as fast as multimeter fuse.
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Thank you wrapper. PeakTech seem to be a reputable company. I've ordered the 630mA 1000v from their "Fuses for Multimeters" section (https://peaktech-rce.com/en/fuses-for-multimeters/543-peaktech-7520-ceramic-fuse-ff-630ma-1000v-103x38mm-10-pieces.html).
What you're saying is that it's best not to use the 10A fuse if the meter asks for 11A? Even if on the outside of the meter is says 10A FUSED.
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What is the fuse protecting?
Seems like it is just protecting the 10A current measurement input. So using a lower amperage fuse is fine -- it will only reduce the maximum current you can measure.
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What is the fuse protecting?
Seems like it is just protecting the 10A current measurement input. So using a lower amperage fuse is fine -- it will only reduce the maximum current you can measure.
Nope, as I said multimeter fuses are much faster than usual fuses.
What you're saying is that it's best not to use the 10A fuse if the meter asks for 11A? Even if on the outside of the meter is says 10A FUSED.
It's multimeter nominal input rating, not fuse rating. Again, multimeter fuses are different from usual fuses, even if they are HRC type.
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Seems like it is just protecting the 10A current measurement input.
Yes, it's just for the A input. The mA and µA have a 630mA socket (image attached).
It's multimeter nominal input rating, not fuse rating. Again, multimeter fuses are different from usual fuses, even if they are HRC type.
I don't mind if it can only handle 9A instead of 10A as I use it exclusively for small electronics projects. I just want to make sure it's safe to do so (for me and the multimeter). The ones I was looking into seem to be specific for multimeters and seem to be good quality - the same that came with the multimeter - and a good price for 10 pieces (https://peaktech-rce.com/en/fuses-for-multimeters/545-peaktech-7530-ceramic-fuse-ff-10a-1000v-103x38mm-10-pieces.html). Unfortunately they don't seem to do 11A.
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You could try https://www.tester.co.uk/catalogsearch/result/?q=fuse&p=2 (https://www.tester.co.uk/catalogsearch/result/?q=fuse&p=2) for the UK .They have the Fluke 803293 Fuse - A:11A (F), V:1000V, IR:20kA, 10.3x38.1 mm . When I checked they had one in stock.
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The question: "What is the fuse protecting?" is really an important one, as it determine what type of fuse is to be used.
For the fuse in series with the 10A current range, its main purpose is to protect the user and cut off the current when user connects the test leads across a voltage source by mistake. Its secondary function is to interrupt the current should a dumb user tried to pass excess current through the meter continously.
While the fault current in homes are usually limited, one can expect current of thousands of amps if the meter is used wrongly on system busbar. This mistake would easily means live or dead for the user. Thus the critical data to check on the replacement fuse is fault interrupting capacity, expressed in KA. The replacement fuse should have the same or higher KA than the original. Chances are they are already being the highest KA type available.
With that done, then the voltage and current rating come into consideration.
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Thank you eblc1388. The interrupting capacity is a useful bit of information. I was wondering what that was. On the original fuse there are values for AC and DC: l1=50KA AC and l1=30KA DC.
On the new one there's only one value: l1=50kA (image attached - old and new fuse). Not sure if the 50kA applies for both AC and DC in this case. But like I mentioned, I'm not planning to measure ac current any time soon. However, as I understand 4S LiPo batteries (14.8V) can put out a lot of current as well (possibly more than 10A).
So back to my original question, can I assume that, based on everything else being the same, it's safe to use a 10A fuse instead of a11A fuse? Many thanks.
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The important thing is that the fuse is fast so it interrupts before the tracks and semiconductors in the multi meter explodes.
This is designated by the "diode" icon on the fuse which is for the "aR" rating, which means semiconductor fuse.
That takes care of the protection of the multi meter and is also explained by Dave in the video linked below.
But the more important designation is breaking capacity as has already been discussed in this thread.
So that the fuse is also able to quench an plasma arc formed if you by mistake short out a high energy circuit.
So these are the two most important factors when selecting a multi meter fuse, not its ampere rating...
EEVblog #376 (https://www.youtube.com/watch?v=ne_Prn0eGQE)
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Brilliant! I guess that sums up all the parameters in a fuse. Thank you for the insight Per Hansson and everyone else for their input.
This is my first post in this forum and I'm well impressed with the generosity!
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The important thing is that the fuse is fast so it interrupts before the tracks and semiconductors in the multi meter explodes.
This is designated by the "diode" icon on the fuse which is for the "aR" rating, which means semiconductor fuse.
That takes care of the protection of the multi meter and is also explained by Dave in the video linked below.
But the more important designation is breaking capacity as has already been discussed in this thread.
So that the fuse is also able to quench an plasma arc formed if you by mistake short out a high energy circuit.
So these are the two most important factors when selecting a multi meter fuse, not its ampere rating...
EEVblog #376 (https://www.youtube.com/watch?v=ne_Prn0eGQE)
Indeed. I have a suspicion that the oddball 440mA and 11A values (which don’t seem to exist outside of DMM fuses) are specifically to discourage people from substituting other fuse types.