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diy solar

I keep blowing 400 amp t-fuses when charging at 240 amps

@JedTheFed, height matters. I'm getting ready to connect my Class T fuse holder to another device with a 1/4" copper bus bar (flat bar). The copper isn't going to bend one bit, especially not over the 4" length. If the two mating surfaces aren't on the exact same plane then the connection won't be good.

When using cables, there is a fair amount of give to them and you should be able to them to flex to match the mating surfaces. But if the distance is short, they'll flex only so much.

When I made connections with my 2/0 cables, I made sure to match the surface heights as close as I could and then rotate the lugs 180° on each end to give me more height difference if that was called for.
 
JedTheFed said:
Go power 400 amp fuse. I blew 3 of them

www.invertersupply.com

Go Power F-400 - Inverter Supply

Shop for Go Power F-400 at Inverter Supply for best prices online. Go Power F-400, Go Power, F-400, 400 Amp Slow Blow Fuse Class T, Go Power Replacement Fuses
www.invertersupply.com
Click to expand...
Do you have the holder that is shown in data sheet?
If yes are you using it with fine strand wire without a ferrule?
I think that might be the cause of your heat problem.
 
HRTKD said:
@JedTheFed, height matters. I'm getting ready to connect my Class T fuse holder to another device with a 1/4" copper bus bar (flat bar). The copper isn't going to bend one bit, especially not over the 4" length. If the two mating surfaces aren't on the exact same plane then the connection won't be good.

When using cables, there is a fair amount of give to them and you should be able to them to flex to match the mating surfaces. But if the distance is short, they'll flex only so much.

When I made connections with my 2/0 cables, I made sure to match the surface heights as close as I could and then rotate the lugs 180° on each end to give me more height difference if that was called for.
Click to expand...
smoothJoey said:
Do you have the holder that is shown in data sheet?
If yes are you using it with fine strand wire without a ferrule?
I think that might be the cause of your heat problem.
Click to expand...
Yes the holder is the one on the data sheet and I am using 4/0 weilding cable and noalox.
 
sunshine_eggo said:
400A breakers are harder to find and a lot more expensive. Few have a suitable AIC rating equivalent to Type-T fuses.
Click to expand...
I was looking at something like this

www.ebay.ca

400-AMP 1/0, 0, 1, 2, GAUGE AWG WIRE CIRCUIT BREAKER HEAVY DUTY CAR AUDIO MARINE | eBay

Find many great new & used options and get the best deals for 400-AMP 1/0, 0, 1, 2, GAUGE AWG WIRE CIRCUIT BREAKER HEAVY DUTY CAR AUDIO MARINE at the best online prices at eBay! Free shipping for many products!
www.ebay.ca
 
sunshine_eggo said:
You made my point for me. That is a steaming pile of shit.
Click to expand...
No need to be rude. I was just starting to research a breaker and thought if I showed you something and you would steer me in the right direction. That comment does not help at all.
 
JedTheFed said:
No need to be rude.
Click to expand...

We have different definitions of the word.

JedTheFed said:
I was just starting to research a breaker and thought if I showed you something and you would steer me in the right direction. That comment does not help at all.
Click to expand...

I already gave you guidance:

sunshine_eggo said:
400A breakers are harder to find and a lot more expensive. Few have a suitable AIC rating equivalent to Type-T fuses.
Click to expand...

A $25 breaker on ebay fits none of the 3 criteria above.

You came back with:

Cheaper than the Class-T fuse
Something easy to find on ebay
No Type-T equivalent AIC rating (No voltage rating either)

So basically, you ignored everything I said and came back with "what about this?" I'M the rude one?

It's people like you that make me question the time spent here.

Good luck.

Unsubbed.
 
JedTheFed said:
No need to be rude. I was just starting to research a breaker and thought if I showed you something and you would steer me in the right direction. That comment does not help at all.
Click to expand...
I agree with the waffle man's assessment of that breaker.
I don't know any quality breakers that are rated past ~200 amps and that breaker isn't quality at any ampacity.
To use 4/0 welding cable with that class t fuse and holder you should use a ferrule.
Put the wire in the ferrule and let the mechanical lug deform the ferrule to get a good connection.
Tighten the mechanical lug down good and tight.
Re-tighten the lug after a few days to make sure its still tight.

Realistically for 2 of those inverters you should have 2 4/0 wires in parallel each with a 400 amp fuse.
For 12 volts its not essential that they are class t.
ANL is likely fine.
Even more fine if your batteries are lead acid.
 
sunshine_eggo said:
We have different definitions of the word.



I already gave you guidance:



A $25 breaker on ebay fits none of the 3 criteria above.

You came back with:

Cheaper than the Class-T fuse
Something easy to find on ebay
No Type-T equivalent AIC rating (No voltage rating either)

So basically, you ignored everything I said and came back with "what about this?" I'M the rude one?

It's people like you that make me question the time spent here.

Good luck.

Unsubbed.
Click to expand...
This is a common issue I find in forums. If you are trying to learn something and ask the wrong question you are suddenly treated poorly. How am I supposed to learn if all my questions are not perfect? When I ran my own business and forum in a completely different topic, I never treated anyone like that. No loss that he unsubbed.
 
smoothJoey said:
I agree with the waffle man's assessment of that breaker.
I don't know any quality breakers that are rated past ~200 amps and that breaker isn't quality at any ampacity.
To use 4/0 welding cable with that class t fuse and holder you should use a ferrule.
Put the wire in the ferrule and let the mechanical lug deform the ferrule to get a good connection.
Tighten the mechanical lug down good and tight.
Re-tighten the lug after a few days to make sure its still tight.

Realistically for 2 of those inverters you should have 2 4/0 wires in parallel each with a 400 amp fuse.
For 12 volts its not essential that they are class t.
ANL is likely fine.
Even more fine if your batteries are lead acid.
Click to expand...
Thank you. That does make sense. So split the cable from the batteries on a bus bar to two 400 amp fuses, one to each inverter. Each connected using ferrules on each connection. I’ll have to research ANL fuses.
 
Thank you, I was hoping someone would show me something similar but more suitable. I guess I understand now that is not possible.

Gary

HRTKD said:
If it says it's for car audio, then there is a very high chance that it is not suitable for what we're doing here on this forum.
Click to expand...
 
I am trying to wrap my head around how to wire this now. Currently my 4/0 cable comes off the batteries, through a switch, then the t-fuse and to a busbar. On that busbar, two cables come off and one goes to each inverter. Also on that busbar is a cable that connects to the original 12v system in my RV . My RV is a 45 ft class A coach with slideouts, hydraulic jacks, furnace etc. all on 12v. So one fuse was easy. Now it seems a bit challenging.

The original 12v system was not connected to the original batteries with a fuse. So maybe that part could become unfused and just the two 400 amp fuses going to the inverters should work. The changes required sound a lot easier to rewire than it will be considering where the wires run now. Back to the drawing board…
 
JedTheFed said:
Thank you. That does make sense. So split the cable from the batteries on a bus bar to two 400 amp fuses, one to each inverter. Each connected using ferrules on each connection. I’ll have to research ANL fuses.
Click to expand...
The fuses should be as close to the battery positive as possible.
With ANL fuses you should use compression lugs not mechanical lugs, especially with that much current.

For 8 batteries at that current you should be using either posts or busbars as described on page 18 of https://www.invertersupply.com/media/data/Go-Power_SPC_FBL_vB.pdf
 
Blue Sea Systems makes a Class T fuse holder that you would put a cable lug on. Go Power makes one like that also, but I haven't looked for it. The cable lug interface solves your problem, if the fuse holder/welding wire connection was the problem.
 
smoothJoey said:
I don't know any quality breakers that are rated past ~200 amps
Click to expand...
www.invertersupply.com

Schneider Electric RNW8651065 - Inverter Supply

Shop for Schneider Electric RNW8651065 at Inverter Supply for best prices online. Schneider Electric RNW8651065, Schneider Electric, RNW8651065, Schneider Electric - RNW8651065 - Breaker For Use With Conext XW Conext SW, Schneider Accessories
www.invertersupply.com www.invertersupply.com
EATON HEINEMANN 250 amp GJ series breaker. A Canadian company. Very old school and very industrial quality. Maybe one each per inverter to bussbar and a seperate similar breaker for the Coach 12 volt system. The only thing lacking is the "cheap" part.
 
HRTKD said:
Blue Sea Systems makes a Class T fuse holder that you would put a cable lug on. Go Power makes one like that also, but I haven't looked for it. The cable lug interface solves your problem, if the fuse holder/welding wire connection was the problem.
Click to expand...
I will look for that. I assume you mean I could still use one 400 amp t-fuse if it was a cable lug connection. this would simplify the rewiring.
 
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