SniperX
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I know. Would not want anything under 60V
400A 160VDC T-Class Fuse Holder Melted
- Thread starter mwcolo
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SniperX
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I have a bluesea 400A Class T fuse/holder. Just searching for the DC breaker the manual calls for. I have a Growatt 12kw 120A 250VDC AIO
SniperX
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THANK YOU! I have been searching for ABB but I will go investigate that. I really appreciate the tip.
Thanks rhino and Lt. Dan.
HalfBaked
Ever the student
Can confirm, I have the Blue Sea classT fuse holder with South Bend fuse. They fit together well.
SniperX
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I requested a quote for 300A and I will come back and let everyone know what they go for currently. Appreciate all your help!
?$$?
Hedges
I See Electromagnetic Fields!
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I wouldn't feel bad using a 48V rated switch to isolate 60V, where the source is a battery, not something like grid that might carry kV transients.
I just wouldn't want to switch it under load. If inverter is shut off (or at least all AC loads disconnected), or fuse blown, then OK to open switch.
I have a strong suspicion that < 50V rating is because the part hasn't been UL tested for safety to keep little fingers away from higher voltages.
"Safe" voltage may have been revised upwards recently.
Extra-low voltage - Wikipedia
What is the difference between SELV, PELV and FELV? | Your Questions Answered | Electrical Safety First
What is the difference between SELV, PELV and FELV? Find out from our team of experts on Your Questions Answered by Electrical Safety First.
www.electricalsafetyfirst.org.uk
Blue sea makes nice stuff. Their breakers are pretty good, however as mentioned they are probably better kept under 48volts. The only time the contacts can get out of the arc quickly is when they trip. Making contact isn’t the issue, it’s breaking contact under load manually when the contacts move at the rate you twist the lever. The Dehool brand and the Watts247 rebadged version have a huge arc chute and whether it trips or manually changes state, it does it very quickly. So quickly that the resounding clank can wake the dead. The beaker can’t replace a fast blow T class fuse and quality holder. This beaker should be thought of as simply a good DC disconnect and the last measure SHTF event save.
Just for reference my NOARK 250A M2 MCCB Lug version was $223 last year. They are pricey but believe they are one of the best/safest breakers you can get. Also note the "busbar" version is the one that allows you to use lugs on the end of your cables and bolt it down. The "lug" version of the breaker is one with the compression screw that you probably don't want. Other thing to to note is you have to think about how to mount it since only thing you can get for mounting from NOARK is a din rail plate. I used a heavy duty din rail and simply used the enclosed long screws that came with it and fastened it to din rail with nuts.
Hedges
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Noark 250A 500V DC Circuit Breaker 2 Pole (NRK-N28905)
The Noark 250Amp 500V DC 2 Pole Moulded Case Circuit Breaker (MCCB) primarily used on battery banks, provides high current breaking capabilities for DC circuits. FEATURES 250A 500VDC Moulded Case Circuit Breaker MCCB (2 Pole) Non-Polarized - EX9MD2B TM DC250 2P The Ex9 Series - M offers: Frame...
ntsecostore.com
"Breaking Capacity: 25kA"
Good enough for at least one string of 280 Ah LiFePO4 cells. Maybe more.
Would also work for a high-voltage battery.
$215.63 in the states. What would really be great is if they could get them UL approved.Noark 250A 500V DC Circuit Breaker 2 Pole (NRK-N28905)
The Noark 250Amp 500V DC 2 Pole Moulded Case Circuit Breaker (MCCB) primarily used on battery banks, provides high current breaking capabilities for DC circuits. FEATURES 250A 500VDC Moulded Case Circuit Breaker MCCB (2 Pole) Non-Polarized - EX9MD2B TM DC250 2P The Ex9 Series - M offers: Frame...
"Breaking Capacity: 25kA"
Good enough for at least one string of 280 Ah LiFePO4 cells. Maybe more.
Would also work for a high-voltage battery.
SniperX
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still waiting...they must be related to SS
SniperX
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oh, I don't want it unless UL Approved...ugh. Asked for a quote and no response. Moving on...
George Mitchell
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Whenever these high current fuses are installed they should checked while active at maximum current flow. If they are hot, you need to know where that heat is coming from and get it fixed. When looking at this design, the terminals that connect to external cable concerns me. Specifically the included lugs look very insufficient and dangerous. The first thing I would do when hooking it up is replace those lugs with heavy duty COPPER lugs capable of loads significantly higher than 400 amps and make sure those connections are well crimpt with a high quality crimping tool. Where the cables meet the device is usually where the problems begin. I had a similar experience which involved stranded wiring connecting to a tube with a set screw. I learned from that to NEVER connect stranded cable to a set screw connector. Instead I crimp the stranded cable to an uninsulated solid copper wire with AWG that closely fits the tube that it is to be connected to. That way the set screw will not penetrate into the stranded wiring an create heat. All of these connections should receive immediate maintenance if they get warm otherwise you are asking for trouble. I like stranded wire because it is very flexible, but it is especially vulnerable to these kinds of problems and so are cheap lightweight lugs this is the one that burned up on me and took the whole battery bank down with it...
George Mitchell
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You got it exactly. That is what looks to me like the root of this mess. The lug included with the device has no where near the current capacity of the fuse itself. I am constantly throwing out components of these kinds of devices and replacing them with components that fit the load. In this case that would be a substantially heavier copper lug rated substantially higher than the expected current load. Save the other one for low current sensors or something like that. I do this all the time with the crap we have to buy in order to make something work.Is that a nut under the ring terminal?
And about 10 awg terminal?
If you are in the USA you can request quote for Noark breakers from https://www.wolfautomation.com/ if you provide the exact part #. Don't try ordering from that Australian store if in US.
George Mitchell
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Another post on this forum regarding this same issue comes with a photo of the damage revealing the exact cause of these burn outs. That would be the lugs that come with the fuse holder. Those lugs are no where near the capacity necessary for this device. Whenever you are dealing with a post connecter like this, be sure to check the lugs that come with it. I have thrown out those lugs on multiple devices and replaced them with much heavier copper lugs that more than satisfy the capacity necessary. Often it is not worth the risk to use the cheap lugs provided with these fuse holders. And if the cable you use with this fuse holder does not have that 175+ amp capacity and/or does not fit easily in the hole at the end of the lug, you need to upgrade the lug to one that does fit your cable. These connecters should not even get seriously warm let alone hot.
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