Protection Circuit testing help
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This is kind of a loaded question. Are you trying to test for design validation purposes? Or are you trying to test to see if a device you have purchased is suitable?
When testing fuses on products I've designed, we complete a standardised set of short circuit tests.
Basically, you run the normal rated current through the device, for a few mins, then apply a short, using a high current rated switch soldered across a component in circuit. You do this for all components in circuit, making sure the fuse fails safely and without any components in circuit getting too hot and potentially starting a fire.
To protect ourselves during this testing, we took a storage tub (tupperware) and placed it upside down on top of whatever we were testing.
If you are doing testing on something designed to protect a battery, I suggest you do the testing with a bench power supply, not a battery. When completing the test, do it where any fire created is not going to cause any loss of property.
And last but not least, when you do this testing, use as much common sense as you can. I've come close to losing an eyeball or getting a shock, from being overconfident when working with mains.
When testing fuses on products I've designed, we complete a standardised set of short circuit tests.
Basically, you run the normal rated current through the device, for a few mins, then apply a short, using a high current rated switch soldered across a component in circuit. You do this for all components in circuit, making sure the fuse fails safely and without any components in circuit getting too hot and potentially starting a fire.
To protect ourselves during this testing, we took a storage tub (tupperware) and placed it upside down on top of whatever we were testing.
If you are doing testing on something designed to protect a battery, I suggest you do the testing with a bench power supply, not a battery. When completing the test, do it where any fire created is not going to cause any loss of property.
And last but not least, when you do this testing, use as much common sense as you can. I've come close to losing an eyeball or getting a shock, from being overconfident when working with mains.
It would be testing a new design for validation purposes, something like a Vape Safe but it is not a Vape Safe.
I appreciate the safety warning, it is always most important.
Since you are designing a device specifically to fail safely in the presence of a short circuit or other anomalous device behaviour, I suggest you try testing it quite thoroughly and in a variety of load conditions. Specifically a low level overcurrent situation where a battery might fail from prolonged high drain, but your fuse device might not blow.
I've always used appropriately rated fuses that someone else has designed, but I trust them to do stuff like check the I2T rating and how many pulse current cycles it will take. That's why all fuses are safety critical items and have to be properly tested to get approvals relevant to every market we intend on selling into.
If someone is going to buy your product to save them from potential personal injury, you'd best get your testing spot on. No one on this forum is that likely to have sufficient expertise to guide you. Try ringing up your local safety test house and asking them for the guidelines on how to test fuses for your intended application. The documents are dry and long, but the guys who do the testing are often happy to discuss the method of testing they employ.
It would actually be testing someone else's product to make sure that it does what it is supposed to do. Since this is something that does not yet have a reputation, it would need to be tested. That is the reason for the OP. I was hoping that someone, like yourself, with clear expertise would offer guidance. Thanks for responding, all of your answers make perfect sense. 
No problem, best of luck. Working out fuse ratings is actually quite a challenge, particularly given how key they are to the safety of a product. I know from first hand experience, i've had them explode like little fire crackers when doing short circuit testing. Won't forget that lesson any time soon.
Thanks again...this sounds like something that should be done by a professional.
Okay, I know this is off topic, and I apologize in advance. But the discussion in this thread brought something to mind that occurred when I first started working as an Electronic Tech way, way back in '79.
Like all new Techs at the company where I worked, I started working part-time while I was still in school earning my degree. All new Techs started working on the less expensive, less complicated devices. This shop repaired all types of electronic test equipment from HP scopes with gold plated circuit boards and switch contacts that cost $30,000, to clamp-on meters that cost $20.00.
One day I pull an Amprobe clamp-on from the repair shelf, first thing to do is take the ohm probe apart and check the fuse. HVAC people used these clamp-on meters and they were notorious for leaving the meter switched to check ohms and then checking voltage - not a good thing for the meter - as one HVAC man said one day, the circuit he was testing "must have had all kinds of ohms in it," when I asked him about how he blew-up his meter.
Anyway, I take the ohm probe apart, simple screw together plastic cylinder that holds an AA battery and a 1 amp fast-blow fuse in series. Sure enough the guy had blown the fuse, but this genius replaced the fuse with a live 22 long rifle shell. That's right he was using a device that you hold in your hand, frequently held just under your face or near your chest, with an unfired 22 shell in the device as the fuse. You can't fix stupid!
Like all new Techs at the company where I worked, I started working part-time while I was still in school earning my degree. All new Techs started working on the less expensive, less complicated devices. This shop repaired all types of electronic test equipment from HP scopes with gold plated circuit boards and switch contacts that cost $30,000, to clamp-on meters that cost $20.00.
One day I pull an Amprobe clamp-on from the repair shelf, first thing to do is take the ohm probe apart and check the fuse. HVAC people used these clamp-on meters and they were notorious for leaving the meter switched to check ohms and then checking voltage - not a good thing for the meter - as one HVAC man said one day, the circuit he was testing "must have had all kinds of ohms in it," when I asked him about how he blew-up his meter.
Anyway, I take the ohm probe apart, simple screw together plastic cylinder that holds an AA battery and a 1 amp fast-blow fuse in series. Sure enough the guy had blown the fuse, but this genius replaced the fuse with a live 22 long rifle shell. That's right he was using a device that you hold in your hand, frequently held just under your face or near your chest, with an unfired 22 shell in the device as the fuse. You can't fix stupid!
No, you can't fix stupid and this is a good reminder to maintain a priority of safety.
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