270ah DIY LiFePO4 build

[gregcope]

Fuses....

So my order of some T Class fuses delivery has been bumped again. Now April ...

What are peoples thoughts on HRC fuses that look similar (in terms of physical as well as spec);

315A TKF HRC Fuse (Sold in 1's)

Has a rated capacity of 40kA DC "Breaking Capacity" which seems similar to "Interrupt Capacity" capacity of blue sea 300A fuses 20000A @ 125V DC.

Plus the HRC fuses are in stock and about 1/4 of the price.

 

[Poey50]

Fuses....

So my order of some T Class fuses delivery has been bumped again. Now April ...

What are peoples thoughts on HRC fuses that look similar (in terms of physical as well as spec);

315A TKF HRC Fuse (Sold in 1's)

Has a rated capacity of 40kA DC "Breaking Capacity" which seems similar to "Interrupt Capacity" capacity of blue sea 300A fuses 20000A @ 125V DC.

Plus the HRC fuses are in stock and about 1/4 of the price.

I'm also waiting for April ... then ... and then ...

The AIC looks good, as you say. I'll see if they fit my Class T fuse holder.

 

[vas]

greg, I went for NH2 type fuses, warning they are bloody MASSIVE in size!!!
struggling to figure out how/where to fit them. They are meant to be suitable for such function (according to an el.eng friend)
this HRC looks good (and reasonably sized)

V.

 

[Poey50]

Fuses....

So my order of some T Class fuses delivery has been bumped again. Now April ...

What are peoples thoughts on HRC fuses that look similar (in terms of physical as well as spec);

315A TKF HRC Fuse (Sold in 1's)

Has a rated capacity of 40kA DC "Breaking Capacity" which seems similar to "Interrupt Capacity" capacity of blue sea 300A fuses 20000A @ 125V DC.

Plus the HRC fuses are in stock and about 1/4 of the price.

The hole centres on my Bluesea Class-T fuse holder are 47mm so those look like some big beasts at 111 mm hole centres. So I'm committed to waiting ... worse luck!

 

[vas]

The hole centres on my Bluesea Class-T fuse holder are 47mm so those look like some big beasts at 111 mm hole centres. So I'm committed to waiting ... worse luck!

my ΝΗ2 are 150mm long and lug terminals are 210mm apart, do I win?

 

[Poey50]

my ΝΗ2 are 150mm long and lug terminals are 210mm apart, do I win?

Definitely.

 

[gregcope]

My original plan was to have these fuses in the box just using lugs and bolts, so bolt centres not an issue.

However they do not fit in the box!!!

So next idea is to have them outside on the +VE cable again using bolts/lugs, however that leaves a +VE thing floating around. I was going to cover it with heatshrink which sounded like a good idea at the time.

 

[gregcope]

So HRC fuse holders seem to be made for Consumer units or other fuse holders.... Grh.

Might have to wait till April like @Poey50 ... if that is the actual date... At this rate it might be easier to import some from the US...

 

[Kelpie]

The hole centres on my Bluesea Class-T fuse holder are 47mm so those look like some big beasts at 111 mm hole centres. So I'm committed to waiting ... worse luck!

What are you using in the interim?

I wouldn't hold my breath for Cactus getting class T in stock. Weren't they supposed to have them back in July? Glad I cancelled my order.

 

[Poey50]

What are you using in the interim?

I wouldn't hold my breath for Cactus getting class T in stock. Weren't they supposed to have them back in July? Glad I cancelled my order.

I have MRBF which for my pack is probably enough already but more AIC headroom is welcome and I want to hit the emerging regulatory standards where possible and that means Class T for fusing.

 

[gregcope]

I wouldn't hold my breath for Cactus getting class T in stock. Weren't they supposed to have them back in July? Glad I cancelled my order.

I am starting to think the same. What are peoples thoughts on the difference between ANL, MEGA and MIDI. ANL look nice and small. I get they will not have the same AIC.

@vas. Your fuses win any size competition. Do you have some holders sorted?

 

[gregcope]

ANLs seem to have around 6000A AIC.
Mega/MIDI around 1000 to 2000 AIC

So seems ANLs are significantly better in that context.

 

[vas]

I am starting to think the same. What are peoples thoughts on the difference between ANL, MEGA and MIDI. ANL look nice and small. I get they will not have the same AIC.

@vas. Your fuses win any size competition. Do you have some holders sorted?

yep massive and fugly :-(
there's a decent holder that's also reasonably well insulated but it's for 3Phase setup only. Mine is meant to be placed (I guess) at an industrial rack/cabinet, cannot be any uglier and difficult to manage:


seriously thinking of taking them back, but what are my options?

edit, maybe if I can find a disconnect switch housing would be a nice idea, would work as an emergency disconnect of the whole bank:
Swe-Check sell OEZ 1 Pole Disconnect Switches for NH fuses


V.

 

[vas]

on another issue,

noticed that after 40days on the road, my cells made it to the EU (not GR but at least they are not in China anymore!)
Means time is coming for me to built the fixing plates etc. Means I have to finally decide where I'll fit the lot.
Looks like they wont fit where I wanted initially (under a small 2seater salon sofa) as they're too tall and by the time you get the busbars, bms pcbs, cabling etc you're at cushion level
So safest second bet is under a bed in port cabin. plenty of space, easy to mount, easy route to where the rest of the el. kit live.
Any reasons not to fit them in a cabin?

V.

 

[Kelpie]

I went with ANL, but found the AIC figures could vary between brands. I also read somewhere that they are rated for a certain voltage and using then at 12v would translate in to a higher AIC. I can't remember the exact details and I may have misunderstood it to begin with.

 

[Alan S]

Take a look back at post 902, Cooper Busmann LET fuses, I think are better value, DC rated, high interrupt rating. Don't think you would need to worry about these not passing any regulations.

 

[gregcope]

Oh @vas your fuses are fabulous!

 

[gregcope]

Take a look back at post 902, Cooper Busmann LET fuses, I think are better value, DC rated, high interrupt rating. Don't think you would need to worry about these not passing any regulations.

Thanks Alan. Will have a look.

 

[vas]

bringing the thread up to the top

after almost two months I received my 8 304Ah EVE cells from Amy. Arrived very well packed, safe with their busbars.
Decided to fit them in one long line 600mm long by 173wide and 203+posts et al high. I'm building an 8S 24V system.
bought 2mm thick industrial rubber 1m wide, will cut in pieces and fit between the cells (173X203)
bought 4 8mm bolts to hold the two 20mm thick ply endplates.
bought matching 12mm o/d plastic clear hose to cover and insulate the bolts.
Will cut the endplates tomorrow and clamp the lot up before tightening the busbars, bolting the diyBMS balancer/monitoring modules on top and start test charging the lot using my old victron centaur at the beginning followed by a 5A bench supply on a most likely per cell basis. Guess will take a week to complete
endplates look like this:



cell is red, ply is the larger thing around it with the 20mm wide handle on top - thing will be circa 50kg...
Trying to make sure that a. cells wont be sitting on the floor, b. cells wont move about so two lower bolts are under the cells, the others just clear on the sides. Got to get the cables on the side for the temp sensor (one on each cell)
Should be able to show the pack bolted together tomorrow.

cheers

V.

 

[vas]

pack built and slowly being top balanced. Very slowly...


excuse the general mess. You have the 8cells in one straight line (suits where I'm going to fit them) wont suit my back that much though, will get son to help.
if anyone plans to copy my endplates, go ahead, just change the M8 rods for M10. Also on assembling them get a suitable spacer under the two bottom rods to keep them straight till the bolts are tightened. The 2mm rubber sheet between the cells is fine, BUT wont let you nudge the cells to have them look nice in a straight line. Maybe a hard plastic sheet is more suitable.
On top of the busbars are the monitoring/passive balancing pcbs capable of burning up to 1.2A in each cell.

On the stool above and in the teleflex packaging (v.handy!) is the diyBMS controller (featuring an ESP32S board and a touch screen) the white box which is a PEAKCAN USB converter so that the BMS can communicate and on the fly configure the Victron kit which is wired up to the raspberry pi4 on the top left. The 1U grey thingie is a 2.5A 5V supply for the BMS (feeding it from the battery itself)

will post the s/w screen once balancing is done.

thanks all for the great work, tips and support!

V.