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more · 22-04-2024, 01:08

Quote:

Originally Posted by GILow

Yes, true.

I’ve decided to go with a 350 amp Class T for the main lithium bank and manufacturer spec rated ANLs for each of the inverters, I.e 200 and 100 amp respectively. At least if the surge capacity does blow the ANL fuses they are cheap to replace.

If my boat is subsequently replaced by a smouldering crater in the water then I’ll know I was wrong.

You are from Australia.
dont go with T-fuse this is american, australia use different fuse i think germany NH fuse is comon in Australia,easy to buy in australia .
ANL fuse i dont recommended nobody. for you better use RGS4b fuse. and far better mccb circuit breaker.
again fuse is short protection and overcurent protection for cable burn or melt.

far,far better MCCB circuit breaker with overcurent protection to safe brake overcurent to 200000 A
MCCB disadvantage is price like T-fuse but 6-10x more expensive
NH fuse,RGS4b,..

T-fuse,NH fuse,RGS4b is primitive fuse from ww2
MCCB is light year in front
https://eshop.se.com/in/blog/post/mc...%20flexibility.

more · 22-04-2024, 03:00

and watch this video. all this info is for all short protection and overload protection. i must go

https://www.youtube.com/watch?v=yzXR...M%26EEngineers

**s/v Jedi** · 22-04-2024, 03:55

Quote:

Originally Posted by GILow

Yes, true.

But my main question, which got lost in all the cable lectures, was about the fuse types as well as their current ratings.

And reasonably enough, the inverter manufacturer does not venture into the area of ANL vs Class T etc. And the inverter manufacturer doesn’t really consider how it their component interacts with other devices.

I think the scope of my original question is beyond this forum in the sense that is is bespoke to my setup. My hope was that others might have a similar setup and be able to share whether there were any pitfalls with all these variable power ratings.

I’ve decided to go with a 350 amp Class T for the main lithium bank and manufacturer spec rated ANLs for each of the inverters, I.e 200 and 100 amp respectively. At least if the surge capacity does blow the ANL fuses they are cheap to replace.

If my boat is subsequently replaced by a smouldering crater in the water then I’ll know I was wrong.

There is guidance on maximum current interrupt rating in ABYC. I have attached the relevant sections below

GILow · 22-04-2024, 05:40

Quote:

Originally Posted by s/v Jedi

There is guidance on maximum current interrupt rating in ABYC. I have attached the relevant sections below

Not sure HOW relevant. It explicitly states it is not applicable for lithium.

**s/v Jedi** · 22-04-2024, 15:26

Quote:

Originally Posted by GILow

Not sure HOW relevant. It explicitly states it is not applicable for lithium.

Which means you need to follow the big battery guidance, i.e. 100 times the 20hr capacity rating when the short circuit current Isc is unknown.

So in your case 304 * 100 = 30kA

GILow · 22-04-2024, 17:11

Quote:

Originally Posted by s/v Jedi

Which means you need to follow the big battery guidance, i.e. 100 times the 20hr capacity rating when the short circuit current Isc is unknown.

So in your case 304 * 100 = 30kA

Gotcha.

CaptainRivet · 22-04-2024, 20:02

Quote:

Originally Posted by GILow

Oh my goodness. For someon lecturing me on needing to read his posts, with lots and lots of exclamation points too, you clearly didn’t read my posts.

I read your post

GILow · 22-04-2024, 20:11

Quote:

Originally Posted by CaptainRivet

I read your post

Not very well. You missed this bit...

"However, the intention is not to run them both at once but instead to choose the inverter most suited to the needs at the time."

So the maximum load would be 4kW, not 6kW.

CaptainRivet · 22-04-2024, 20:42

Quote:

Originally Posted by GILow

Not very well. You missed this bit...

"However, the intention is not to run them both at once but instead to choose the inverter most suited to the needs at the time."

So the maximum load would be 4kW, not 6kW.

The intension is but how you makes sure that doesn't happen...intension is not enough when eg the admiral still can put both on...we had exactly that in another thread and suddenly 400A hit the system...

And the answers are all in my first post:
Single 200A JK BMS with 150A class T with min 30kA or NH fuse which has 80kA anyhow.
You decided for the wrong 350A class T....poor JK BMS will be dead soon...the 150A class T would have saved it.
Your solution is a 2nd battery with a 2nd BMS parallel. Then you can run your 4kw alone ot as well as 2kw.

Inverters use ANL Fuse speced for the cable used to connect the inverter, if giandel specs 100 and 200A that is ok for the cable they suggest too. For cable and therfor fuse the surge is irrelevant.
The Giandel have thier own internal fuses that protect the inverters, the fuse is for the cable.

GILow · 22-04-2024, 21:19

Quote:

Originally Posted by CaptainRivet

The intension is but how you makes sure that doesn't happen...intension is not enough when eg the admiral still can put both on...we had exactly that in another thread and suddenly 400A hit the system...

And the answers are all in my first post:
Single 200A JK BMS with 150A class T with min 30kA or NH fuse which has 80kA anyhow.
You decided for the wrong 350A class T....poor JK BMS will be dead soon...the 150A class T would have saved it.
Your solution is a 2nd battery with a 2nd BMS parallel. Then you can run your 4kw alone ot as well as 2kw.

Inverters use ANL Fuse speced for the cable used to connect the inverter, if giandel specs 100 and 200A that is ok for the cable they suggest too. For cable and therfor fuse the surge is irrelevant.
The Giandel have thier own internal fuses that protect the inverters, the fuse is for the cable.

Mate, we know how to manage power. I'm happy with our setup.

Wandering1 · 23-04-2024, 03:35

Quote:

Originally Posted by CaptainRivet

The intension is but how you makes sure that doesn't happen...intension is not enough when eg the admiral still can put both on...we had exactly that in another thread and suddenly 400A hit the system...

And the answers are all in my first post:
Single 200A JK BMS with 150A class T with min 30kA or NH fuse which has 80kA anyhow.
You decided for the wrong 350A class T....poor JK BMS will be dead soon...the 150A class T would have saved it.
Your solution is a 2nd battery with a 2nd BMS parallel. Then you can run your 4kw alone ot as well as 2kw.

Inverters use ANL Fuse speced for the cable used to connect the inverter, if giandel specs 100 and 200A that is ok for the cable they suggest too. For cable and therfor fuse the surge is irrelevant.
The Giandel have thier own internal fuses that protect the inverters, the fuse is for the cable.

Not hard if you install a rotary changeover switch

CaptainRivet · 23-04-2024, 04:15

Quote:

Originally Posted by Wandering1

Not hard if you install a rotary changeover switch

Perfect to kill BMS...
Seperate switches with pre charge resistor as i also posted in my first answer, to keep inrush current low to protect BMS. 4kw inverter has some beefy capacitors that are waiting to kill mosfets...same reason victron states not to use battery protects, which are smart SSR containing mosfets as disconnect switch for inverters.
Well with a 350A class T i expect the BMS dead soon, we can start posting bets when...
@GILow do you have a gauge 4/0 or 150mm2 battery cable or how did you spec for 350A fuse rating????

Wandering1 · 23-04-2024, 04:43

Quote:

Originally Posted by CaptainRivet

Perfect to kill BMS...
Seperate switches with pre charge resistor as i also posted in my first answer, to keep inrush current low to protect BMS. 4kw inverter has some beefy capacitors that are waiting to kill mosfets...same reason victron states not to use battery protects, which are smart SSR containing mosfets as disconnect switch for inverters.
Well with a 350A class T i expect the BMS dead soon, we can start posting bets when...
@GILow do you have a gauge 4/0 or 150mm2 battery cable or how did you spec for 350A fuse rating????

Are you assuming that somebody would use the rotary switch under load?

CaptainRivet · 23-04-2024, 06:42

Quote:

Originally Posted by Wandering1

Are you assuming that somebody would use the rotary switch under load?

sure if 1000% wanna kill BMS, do it under load from 2kw to 4kw inverter…and please switch directly one to two, so you blow min 1 inverter too.
And by the way how do you sync both inverter to run it parallel…only Victron, Mastervolt (maybe Xantex?) and Studer can work parallel or use power assist staging them syncs the inverters, Giandel not. You can only run completly seperate circuits in AC and switchboards.

Just do it from off…best first 4kw inverter then 2kw inverter

and you wanna switch to 2nd inverter. please do a video showing the 200A JK BMS while you doing it, so everyone can watch what’s happening then…

and book the resulting cost under lessons learned..some just need to learn it the hard way….

I suggest for his own sake and his ship OP should post circuit diagram containing AC and DC so we can see how all is set up incl fuses etc. also to avoid misunderstanding.
We just wanna help here…