Without the holder, when the short occurs, the body is superheated, and the fiberglass surround has very little strength. The holder keeps the parts together so the sand can extinguish the arc plasma.
Use a fuse - and wear safety glasses... This could have been very bad.
- Thread starter upnorthandpersonal
- Start date
mrzed001
Voice of reason
The fuse holder's only function is to hold the fuse. Nothing more. https://www.eaton.com/us/en-us/prod...q/fuse-holder-frequently-asked-questions.html
Better fuse holders can disconnect fuses. For a simple fuseholder (2 contactor and a backplate really) you need a fuse remover.
If a fuse blows (explodes) as you described it then it was too weak (poor choice, not designed for that operation), or damaged (like broken body)
The fuses are designed that when a high Amp (max short circuit it is rated) blow happens then the sand in the fuse body will blow out the arch. The body must remain intact after that.
Also the fuse body for this high Amp fuses are usually ceramic.
So inline setting a fuse can be OK if the contacts are right, fuse mechanical and touch protection exists.
from the link you provided…
“
What is a panel mount fuse holder?
Panel mount fuse holders are a type of fuse holder that is mounted through an enclosure or on a back plane of an enclosure. They are generally wire-in, wire-out/line and load, and can provide protection for people from electrical hazards when installed properly.”
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I couldn’t get your link to work… I searched the company faq, and this link should work.
www.eaton.com
Fuse holder FAQs
Learn more about fuse holders and the common questions asked about the technology.
mrzed001
Voice of reason
Please don't bee that person who claims a fuse will explode without the fuse holder
and then cite something completely off-topic ...
This is FUD:
You made 3 completely untrue statement
1, Fuse body is not superheated ! That would be complete madness.
2, Body is not fiberglass. Glass for small fuses, ceramic for strong fuses.
3, The holder only holds the fuse on its place ... does not hold anything together
The fuse will not explode without a holder.
Here are some fuseholders:
What do you think how would it protect you from exploding plasma fuses ?
Well… if you look at the video on post #1 that is the subject of this thread.Please don't bee that person who claims a fuse will explode without the fuse holder
and then cite something completely off-topic ...
This is FUD:
You made 3 completely untrue statement
1, Fuse body is not superheated ! That would be complete madness.
2, Body is not fiberglass. Glass for small fuses, ceramic for strong fuses.
3, The holder only holds the fuse on its place ... does not hold anything together
The fuse will not explode without a holder.
Here are some fuseholders:
What do you think how would it protect you from exploding plasma fuses ?
a fiberglass T-Fuse is bolted to cable ends and the lugs are heat shrinked… in the event of a massive short, that fuse can indeed form a serious DC sustained arc, burning through the fiberglass… if the body of the fuse is not held down… in a holder… the body can fail, there can be arc enough to destroy the fuse body, leaving the cable free to flail and short further…
If a proper fuse holder contains the fuse body, the sand fill will extinguish the arc… if the fuse is not in a holder… the sand won’t work.
As an electrician with over 36 years in the field… I assure you… fuses need the holder… I have seen FAR too many destroyed fuses…Please don't bee that person who claims a fuse will explode without the fuse holder
and then cite something completely off-topic ...
This is FUD:
You made 3 completely untrue statement
1, Fuse body is not superheated ! That would be complete madness.
2, Body is not fiberglass. Glass for small fuses, ceramic for strong fuses.
3, The holder only holds the fuse on its place ... does not hold anything together
The fuse will not explode without a holder.
Here are some fuseholders:
What do you think how would it protect you from exploding plasma fuses ?
I understand you are not fully fluent in the English language, I’m not sure if you are translating or using a translator, or if you can read on your own what is written… but the fuse is not exploding because it isn’t in a holder. The fuse is exploding because of a short… the holder helps the fuse do it’s job to extinguish the arc. Without the holder, this may not happen.
mrzed001
Voice of reason
Maybe you should focus on that video too ... because the fuse did what it supposed to do.
Did not catch fire, no plasma explosion ... nothing.
It did work as it should.
No. It is a JLLN 200 Class T fuse and that has melamine body.
I more like the NT - NH fuses. Ceramic body, bigger, cheaper, better. But that Class T is fine too.
In that case the fuse is too weak, so the installer did not know what he is doing.
The fuse has an interrupt capacity. And it has to interrupt bellow that. Engineers designed and then quality control tested it.
Also it is always wise to oversize V and interrupt capacity ... only Amps stay.
Until you hit it with a hammer or drag it in the road ... that fuse will be fine.
And waaaay better than ANL or MEGA fuse in any fuseholder
The sand is inside the fuse body. Pressed. No need for any fuse holder for it to do its work.
Or maybe you do not want to hear any other arguments than yours.
What are you debating about?
Did the fuse work? Yes.
Without holder? Yes.
Better in a holder? Off course. But even without a holder light years better than anything most people use here.
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curiouscarbon
Science Penguin
- Joined
- Jun 29, 2020
- Messages
- 3,022
where is photonicinduction with a T-class fuse blow with no holder?!
Also by using a proper holder for a Class-T you have a couple other benefits:
- All the high current holders have separate locations to fasten the fuse and the input/output lugs separately. This allows you to replace the fuse without have to undo the wire lugs and having a direct battery feed loose and floating around. All wires can remain in place during a fuse replacement. The ability to service the system safely is improved.
- By properly mounting the fuse in a holder it's not allowed to bounce around potentially causing premature failure due to mechanical stress; or causing the lugs to loosen due to this movement causing a poor connection on a high current line.
- Lastly, most fuse holders come with a cover. As someone who services a lot of systems I can tell you that while a class-T fuse is not supposed to vent and emit slag during it opening they often do in the real world. With a fuse holder and cover that slag is contained splattered all over the cover and holder. Without it that molten hot slag would spatter on whatever is in it's path which could cause a secondary issue.
To me skipping the holder is a sign of saving a few bucks in the wrong place. Safety should never be compromised; and good fuse holders are part of the overall safety system in a power system design.
I am trying to understand your mission on this forum.
a member asked what benefit or harm COULD happen without a holder… I gave a admittedly worst case scenario… one I have seen a great many times…
you come on and claim the holder’s one and only purpose is to mount the fuse.
Seriously… why are you arguing about these points?
Sure, the fuse in the video didn’t fail or melt down or anything of the sort… it was an EXTREMELY brief short. It could have been far worse.
Simi 60
New Member
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- Jul 10, 2021
- Messages
- 159
I have a can of this onboard
Seems to be good stuff
Comes in black and red
Liquid Electrical Tape/Thread Locker - Black | Jaycar Electronics
This liquid can be used instead of insulation tape. Simply brush it on and it will insulate and seal out moisture.
www.jaycar.com.au
mrzed001
Voice of reason
To teach and to combat inaccuracies.
I am also translating my summary doc (to post or pdf ... donno yet) where I show (almost) all inverter usage possibilities like grid-tie (central inverter, microinverter, with and without limiter, Balkonkraftwerk), off-grid, off-grid with grid support (with inner limiter and with double conversion), hybrid systems like DC coupled, AC coupled (with auto transfer switch), single unit hybrid, grid-tie + UPS hybrid ... and all its benefits pros and cons with connection diagrams.
To have a common ground when someone writes grid-tie or hybrid.
To show users the possibilities to expand there system (even DIY in many scenario).
First I made this a hybrid study ... because every other day a different user came and asked that : "I have solar in my roof (GT) and still sitting in a dark in a blackout" (GT is used a lot here, OG is almost not known)
And what is your agenda?
I am all about safety. But you misunderstanding the FUNCTION of the fuseholder.
Like you could say that Do not use extension cables ... because in a worst case they can go up in flames.
Yes, they can, seen it. And we still use them because 99.99999% of the time they don't.
Because it is the fuseholder sole purpose. And to make easier to replace the fuse. There are cable fuses where you have to replace a piece of the cable with the fuse. It was a user made variant of that.
Most fuse holders are open. Do not have any plexy on the user side (sometimes the cabinet has that the fuseholder is placed but that is only for touch protection).
Really only 2 contactor. And, I showed you them, put in pics.
Have a backplate ... only to be a single unit. Like in first pic only a little backplate. And that is for a strong 160-400A NH1 fuse I think !
It was a brief short BECAUSE the fuse blow.
See, here are some NH1 fuses I use too. This is a solar power plant. Also there is a dissection in the end.
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curiouscarbon
Science Penguin
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- Jun 29, 2020
- Messages
- 3,022
personally I’ve never seen a T-class fuse blow before..
this person shared their oops
personally, I think it’s inadvisable to leave out the holder because stresses from big cable could warp or compromise the thin shell of the T-class fuse.
not doubting that molten slag can come out, perhaps it’s something people with 25kWh+ banks and stuff need to worry about
this person shared their oops
personally, I think it’s inadvisable to leave out the holder because stresses from big cable could warp or compromise the thin shell of the T-class fuse.
not doubting that molten slag can come out, perhaps it’s something people with 25kWh+ banks and stuff need to worry about
mrzed001
Voice of reason
If there is a mechanical stress on the fuse then yes a holder is absolutely needed.
If not then not. Or you can even DIY one, it is just a plastic and 2-4 screws. Have seen worst.
That is not a thin shell. At least 2-3 mm
Teaching moment ?
You know why there is sand in it? Not only because sand directly blocks the arch.
The main problem with sandless fuses (like a glass fuse) are that the melted metal can evaporate in a blow and make a plating in the glass inner.
And that plating is conductive so again an arch happens. Many times sandless fuses (even it should have sand in it like faulty or cheap clone) explode because of it. So the sand catches the blown metal.
If you watch the dissection video you can see the 4 connection points inside the fuse. There are weakened, the soft points the connection needs to break.
And the connecting parts (conductors) all 4 are intact.
So ... this fuse easily blocked the short circuit with little stress. If it were a high stress to the fuse then the connecting parts were melted.
(and now I am gone to holiday
)
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svetz
Works in theory! Practice? That's something else
Edited a few posts that were getting out of line, please be respectful of your fellow members.
If I missed anything you thought particularly offensive please click the report button on it so it can be reviewed.
If I missed anything you thought particularly offensive please click the report button on it so it can be reviewed.
mrzed001
Voice of reason
Thank you for the correction, perfect. Was a bit on hurry. Sorry
TorC
Solar Enthusiast
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- Jan 13, 2022
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- 514
I hope she still has that fuse. It's in perfect condition. If you look at 36:50, the shorted terminal is the same one her battery wire is on, so she had a dead short with no protection at all. Reflexes to pull the thing off are all that saved her.
Looks to me like a dead short from positive to negative. Her positive terminal is at the other side of the box, red wire with fuse in the middle, and then the switch - that's all main positive. Then shorting to the main negative pole on the battery (right side of the cell with all the blue wires coming out). I believe she also confirmed the fuse to be dead in a later video.
