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If one has some 216C 10A thermal fuses, could one wire two in parallel in order to fuse a 10A heated bed on a 3d printer? The bed is 110V and 1100W btw, so in normal operation it should draw 10A. Seeing as how this is right at the top of the current range, I thought I would put two side by side just to be safe.

I can't think of any reason this would not work, theoretically the current should be pretty evenly divided between the two, no?

edit: this is not a duplicate question! Why is everyone so quick to mark things duplicate on here before even reading the whole post?!? The "duplicate" question is even asking about fuses of different ratings- my fuses are identical.

The arguments linked in the other posts all have to do with current-limiting fuses. Thermal fuses blow at a particular temperature, and as long as they are within their rated current, one does not expect them to be used to limit current.

Again- two fuses in parallel, if given 10A, will theoretically each carry 5A. Even if the fuses are terribly mismatched, due to manufacturing irregularities, and one carries 8A and the other carries 2A, this is fine because we are concerned about max temp, not max current. As long as the second fuse takes at least 1A, then the other can take 9A and they will both be under the rated 10A. Then if the temperature happens to climb to 216C, they will blow. Why would this not work?

And if the answer is still no, at what current would they be acceptable to use in parallel?

cds333
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    Asked too often on here, no is the response. – Solar Mike Nov 08 '19 at 06:57
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    @SolarMike If it's asked 'too often' then you can find a duplicate question, right? – Bruce Abbott Nov 08 '19 at 11:15
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    @BruceAbbott I can use the search same as you and the op... – Solar Mike Nov 08 '19 at 11:27
  • See this for one, while the values are different the arguments are not : https://electronics.stackexchange.com/q/169413/152903 – Solar Mike Nov 08 '19 at 13:33
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    Possible duplicate of [Is it possible to combine two fuses together (with different current rating) to make a bigger fuse?](https://electronics.stackexchange.com/questions/282839/is-it-possible-to-combine-two-fuses-together-with-different-current-rating-to) –  Nov 08 '19 at 16:14
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    "my fuses are identical" - No, they're not. They are **nominally** the same, but nothing in practice is really the same. It makes no difference whether they are the same nominal value or different, the answer is the same. – Tom Carpenter Nov 24 '19 at 02:41
  • It is not true that this question is being "asked too often" here, nor is it a duplicate. There has never been a good general answer given on any question about a *reasonable* parallel use of breakers. By reasonable I mean same rating. After all, a breaker pair on a branch with 2 hot phases is also in a way "parallel", but they have their switches mechanically bonded, all interesting features to discuss. – Gunther Schadow Jul 08 '20 at 16:00

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