Can someone test the t class fuses? For littlefuse (blue sea) and south bend?

[time2roll]

What's their rating then if all of them pop at double the amps their number says?
& Yea I typically use a fuse for short circuit and breaker for overcurrent

https://www.bluesea.com/products/5112/Fuse_A3T___Class_T_110_Amp

I think the idea is to provide for surge current for inverters or powering a motor direct.
Very fast to open at short circuit amp values.

It is what it is. Design the system accordingly. And yes if the ampacity of the wire is not well above the Class T rating there could be an issue.
Looks like Class T will pass 150% rating for close to an hour. This is by design. Again I prefer to keep these a bit tight.

 

[Mattb4]

...

what is this mystery breaker?

Nothing mysterious. It is a NanQue who manufactures a large lineup of breakers. Their web page is https://nanquele.com/procategory/1

The breaker in question is this one NQCM1Z. https://nanquele.com/productdetail/25/circuit-breaker

ETA: Those folks that have to get permits and inspections likely could not use this Breaker in the USA. Though I do not know that for sure. Might be worth contacting the company.

 

[Hedges]

What's their rating then if all of them pop at double the amps their number says?

Their rating is the amps their number says.

If you want precise control of over-current protection, get a remote trip breaker, use a shunt or CT to measure current, have a logic or microprocessor controlled circuit implement the time-current response you want. Then it could be within a few percent.

This is a thing for large systems.

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At our scale, molded case circuit breakers take care of protecting wires. Electronics like inverters should have their own current limits to protect themselves.

 

[KITROBASKIN]

As a USA company, the likelihood of South Bend using cheap knockoffs is low. They would be sued out of business by now.

South Bend Components - Quality OEM Components Manufacturer

At South Bend Components we supply a broad array of high-quality components for the leading original equipment manufacturers ("OEMs") of leisure marine and recreational vehicles, and the related aftermarkets of those industries.

www.southbendcomponents.com

Although I was a bit snarky with the Amazon-presented South Bend T-Class fuse listing (twice they refused my review submission questioning their legitimacy; said I could not have a question in a review. Problem was their Amazon listing was not allowing questions to be posed at the time)

I contacted the two RV manufacturers they claimed used this T-Class fuse; could not reach anyone involved in the manufacturing that knew what was used for a fuse. Then I checked repair parts. One pushed me to another company that was clueless. The other company had a helpful lady who spent quite a bit of time trying to track down the replacement T-Class fuse. Not sure exactly as this was several months ago but she told me the replacement part was Eaton(?) Littlefuse(?)

Do we know if that Amazon fuse has been UL Listed? UL Tested? Don’t know.

Could it be a shady operator using the South Bend Components name on Amazon? Maybe.

diysolarforum advise given to me when first questioning this was to not go cheap with protection, using known reliability…

Not willing to throw more money at South Bend Components fuses.

 

[740GLE]

What I would love to see is AIC values of these BMS built DIY batteries and all the various connectors, to truly verify if class T fuses are overkill and at what voltage battery bank size is needed.

Start with a 280ah with 200a BMS in 12/24/48v configuration. Then double up batteries again and again until that ANL is turned into an arc light blinding your retinas.

Toss more economical fuses ANL, Mega, what have you) with a SCRAM kill switch to break the path in case the fuse isn’t able to extinguish the arc.

 

[time2roll]

I have yet to read a post of a fuse that continued to arc. Did I miss it?

 

[gotbeans]

Their rating is the amps their number says.

Not exactly, there's more to it, which is why things like this are true:

Looks like Class T will pass 150% rating for close to an hour. This is by design. Again I prefer to keep these a bit tight.

If you want precise control of over-current protection, get a remote trip breaker, use a shunt or CT to measure current, have a logic or microprocessor controlled circuit implement the time-current response you want. Then it could be within a few percent.

99% of people are using x amps to protect devices with x capabilities but they should be using smaller fuses if this is expected.
Most fuses I've used for decades pop at nearly their exact rating within a few seconds. As is expected by virtually everyone. Including the video in OP. People expect that of breakers too and it is what you get with nearly all breakers. (and most fuses)
Good tip though, shunt and breaker is a good idea, very easy to build too

I have yet to read a post of a fuse that continued to arc. Did I miss it?

I read probably 100 or more threads before making this one & I haven't seen one either (also watched many videos)

What I would love to see is AIC values of these BMS built DIY batteries and all the various connectors, to truly verify if class T fuses are overkill and at what voltage battery bank size is needed.

Start with a 280ah with 200a BMS in 12/24/48v configuration. Then double up batteries again and again until that ANL is turned into an arc light blinding your retinas.

Toss more economical fuses ANL, Mega, what have you) with a SCRAM kill switch to break the path in case the fuse isn’t able to extinguish the arc.

The arcs are just going to melt the fuses and house/connections instantly anyway. You can short a lead acid battery with the typical sized wires in a vehicle and the battery will still work after blowing up the wire too.

Do we know if that Amazon fuse has been UL Listed? UL Tested? Don’t know.

Amazon has no quality control, it is the same as aliexpress. The only difference is more vendors that actually do have quality control sell on amazon.

Could it be a shady operator using the South Bend Components name on Amazon? Maybe.

no, those actually get taken care of

It is very possible the fuses are crap though, hence the wanting stuff tested. Claiming UL list etc is pretty easy to do and there's pretty much 0% chance they'd be sued by now if nobody is going to even test the fuses themselves.

 

[Hedges]

The fuse is "rated" the number of amps printed on its label.

I've tested a few cheap automotive fuses (after reading of recalls, and different ratings all carrying same high current), also thermal-magnetic and magnetic-hydraulic breakers. They performed as expected, carrying overcurrent for the documented time, except for some second-hand Schneider Multi-9 breakers, which apparently due to aging tripped below their rating.

Your wiring needs to have ampacity of at least that many amps. Ampacity is derated based on number of current carrying conductors in a cable or bundle, ambient temperature, allowed temperature of terminals it goes to (often 75C).
If you design your system according to UL listings and NEC, the wires will be protected by the fuses, even though the fuses will pass more than 100% of their rating for a period of time.
You need to design a system that doesn't put continuous current greater than 80% of fuse rating through it, to avoid nuisance blowing. There is no guarantee the fuse won't blow at 100%, given enough time.

You can get magnetic-hydraulic breakers guaranteed not to trip under 105%, guaranteed to trip over 130%. Others, not trip under 100%, to trip over 125%.

So long as you buy UL listed fuses or breakers though trusted sources (avoiding counterfeit, which does happen) you can have confidence they will meet their specs.

 

[12VoltInstalls]

99% of people are using x amps to protect devices with x capabilities but they should be using smaller fuses if this is expected.

You aren’t protecting devices. They will/can only draw what they can use. It’s fire protection that we use fuses and breakers for.

the wires will be protected by the fuses, even though the fuses will pass more than 100% of their rating for a period of time.

 

[gotbeans]

You aren’t protecting devices. They will/can only draw what they can use. It’s fire protection that we use fuses and breakers for.

No, fuses are used to protect devices all over the world. 10 amp fuse in multimeters too.
The traces will burn out if not, which won't cause a fire. So no reason to have a fuse then if they're not to protect the device (according to you guys)
I have used them in my PCB design for many years too, to protect the traces, lmao. As hedges numbers show, that's pretty much how they're used in PCB. blowing at 100% is good

 

[Mattb4]

...
You need to design a system that doesn't put continuous current greater than 80% of fuse rating through it, to avoid nuisance blowing. ...

It is a question of what constitutes nuisance blowing. I like to fuse a system to protect components also and not just wires. It is why I have a 125a fuse for my 3kW AIO. The fuse costs me a couple of bucks. The AIO cost hundreds of dollars.

Your response does make me wonder about the costs of fuses influencing someone to oversize it to avoid it blowing out.

They taught me that you never replace a fuse with a fuse of greater amperage. Only replace with same or less. I was also taught that a fuse blows for a reason and you should know what that is (if possible).

 

[gotbeans]

Nothing mysterious. It is a NanQue who manufactures a large lineup of breakers. Their web page is https://nanquele.com/procategory/1

The breaker in question is this one NQCM1Z. https://nanquele.com/productdetail/25/circuit-breaker

ETA: Those folks that have to get permits and inspections likely could not use this Breaker in the USA. Though I do not know that for sure. Might be worth contacting the company.

Well I meant mysterious jokingly because you kept talking about it / posting specs but not showing the breaker lol

This is it here?

https://www.aliexpress.us/item/3256804018842639.html

basically this is only competition at that range?

Nader DC Circuit Breaker | 48V 125 Amp

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

 

[Hedges]

Fuse should never blow and breaker should never trip except in case of a fault (short). Any other is nuisance blowing.

There are "semiconductor" fuses meant to protect things like inverter/VFD. But such devices should never create a short through their transistors anyway.

My air compressor motor got its starting windings cooked, I think due to brownout (I connected it to L1 and L2 of a multi-wire branch circuit, may have seen 120V after one breaker tripped.) I'm now using magnetic-hydraulic breaker because I think that provides tighter time-current limit, can trip without overheating windings first.

Motor-starters for 3-phase seem to be thermal overload maybe sized better to protect the motor. Mine was on 20A breakers, and motor is rated 11A. I'm now using 15A Midnight/CBI breaker.

 

[Mattb4]

Well I meant mysterious jokingly because you kept talking about it / posting specs but not showing the breaker lol

This is it here?

https://www.aliexpress.us/item/3256804018842639.html

basically this is only competition at that range?

Nader DC Circuit Breaker | 48V 125 Amp

Signature Solar provides solar panels, off-grid solar systems, grid-tie, and hybrid systems. Quality solar inverters, bifacial solar panels, complete solar kits, solar batteries. Featuring brands such as EG4 Electronics with their solar battery, LifePower4 and EG4 LLifePower4 and EG4 LL

signaturesolar.com

Yes that is the Breaker. The SS is not of the same type (Din rail MCB not MCCB) or range as it is an AC rated breaker that allows DC.

 

[time2roll]

Any fuse to protect a device is built into the device. Multimeter, some microwaves, a few inverters, some holiday light strings etc have built-in fuses.

An external fuse or breaker on a general circuit is to protect the wire. Device protects this fuse.

 

[Mattb4]

Fuse should never blow and breaker should never trip except in case of a fault (short). Any other is nuisance blowing.

...

Sorry to disagree slightly with you Hedges. High current transients are not always due to short conditions and require protection from Breakers and fuses. Take for instance your circuit that has 5 outlets on it but is a 15a one. The breaker will trip if you plug in too many items. This does protect the wires but also other items on the circuit with no short being involved.

 

[Mattb4]

Any fuse to protect a device is built into the device. Multimeter, some microwaves, a few inverters, some holiday light strings etc have built-in fuses.

An external fuse or breaker on a general circuit is to protect the wire. Device protects this fuse.

In the case of DIY component setups we are the folks designing protection. We have to take into account that as part of the overall planning.

 

[gotbeans]

Any fuse to protect a device is built into the device. Multimeter, some microwaves, a few inverters, some holiday light strings etc have built-in fuses.

An external fuse or breaker on a general circuit is to protect the wire. Device protects this fuse.

Maybe that's how you view them. I'd say 98% of people don't. We're trying to protect everything on the circuit, including the wire.
Virtually everyone wants their fuse to blow, breaker to blow, hell even their breaker to explode and melt, before anything else is damaged.
I'd rather my breakers and fuses to blow a hole through my wall than anything else to be touched.
I just asked my electronics chat and nobody agreed. Many of us have been hobby/professional designing electronics for decades too.

Yes we have fuses on the pcb themselves, and all the devices on that circuit are only as good as the weakest fuse/device

 

[gotbeans]

Yes that is the Breaker. The SS is not of the same type (Din rail MCB not MCCB) or range as it is an AC rated breaker that allows DC.

The one I linked seems to be identical to the one you linked: https://nanquele.com/productdetail/25/circuit-breaker

But did you mean

https://www.aliexpress.us/item/3256804138465243.html

This one?
It's DZ47Z-63K DZ47Z-125K not NQCM1Z

What do you mean by AC rated that allows DC? On their website and aliexpress they have DC ratings too.

Nader is more like an AC rated that has DC, they only list DC in their specs sheet, also home depot / lowes now carries the Nader brand but it's pretty similar (another asian brand that most people here wouldn't say is reputable/trustworthy)

 

[Mattb4]

The one I linked seems to be identical to the one you linked: https://nanquele.com/productdetail/25/circuit-breaker

But did you mean

https://www.aliexpress.us/item/3256804138465243.html

This one?
It's DZ47Z-63K DZ47Z-125K not NQCM1Z

What do you mean by AC rated that allows DC? On their website and aliexpress they have DC ratings too.

Nader is more like an AC rated that has DC, they only list DC in their specs sheet, also home depot / lowes now carries the Nader brand but it's pretty similar (another asian brand that most people here wouldn't say is reputable/trustworthy)

The one I use is NQCM1Z-160. The DZ47Z are din rail MCB style. and do not carry the same interrupt ratings.

What I mean by AC rated is if you look at the breaker it is marked for AC voltage and amperage. It does have going for it that it is UL listed.