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Wiring question

Shinzul

Solar Enthusiast
Joined
Jul 6, 2022
Messages
141
Hey all,

99% sure I've decided on using 4x growatt 5k ES (in total) connected to 1200ah of batteries (2 different server racks in parallel).

Each server rack bus bar is rated for 600 amps. I need 2 different bus bars to connect the battery racks (one positive, one negative). Does this mean I need 2 different bus bars, each rated for 1200 amps? That seems insane... I can't really find any off the shelf versions at all, but it seems you can make your own with the right dimensions out of copper if you tin it yourself I guess?

@Will Prowse has a video where he has one of these server rack battery banks, but his bus bars are only rated for 300 amps... does this imply that you don't actually need to measure for the max capacity of the battery banks in parallel, and instead you should plan for the max current draw that your system would ever need? Reference image taken from Will's website here.

1657655735467.png
 
Last edited:
Hey all,

99% sure I've decided on using 4x growatt 5k ES (in total) connected to 1200ah of batteries (2 different server racks in parallel).

Each server rack bus bar is rated for 600 amps. I need 2 different bus bars to connect the battery racks (one positive, one negative). Does this mean I need 2 different bus bars, each rated for 1200 amps? That seems insane... I can't really find any off the shelf versions at all, but it seems you can make your own with the right dimensions out of copper if you tin it yourself I guess?

@Will Prowse has a video where he has one of these server rack battery banks, but his bus bars are only rated for 300 amps... does this imply that you don't actually need to measure for the max capacity of the battery banks in parallel, and instead you should plan for the max current draw that your system would ever need? Reference image taken from Will's website here.

View attachment 102350
Correct
It should be sized and protected according to expected load, plus 25%.
 
Correct
It should be sized and protected according to expected load, plus 25%.
Awesome! Thank you for the input!

And just to make sure I'm not missing anything - let's say there are 2 main breaker panels, each rated at 200 amps which would be pulling from the batteries. If both breakers maxed out their 400 amps, then you would need a 500 amp rated bus bar in between the batteries to the inverters, right? (In addition to, and assuming a fuse or breaker switch in between the batteries and the bus bar(s))
 
I think that you are confusing AC output and DC input.
Are these breaker panels for DC distribution?
 
A Growatt SPF-5000-ES requires 150a DC input.
A bus bar supplying 4 of them, will be expected to carry 600a.
Plus 25% puts you at 750a.
 
A Growatt SPF-5000-ES requires 150a DC input.
A bus bar supplying 4 of them, will be expected to carry 600a.
Plus 25% puts you at 750a.
Ahhh of course, I wasn't considering that is DC from the battery to the inverters, of course.
 
A Growatt SPF-5000-ES requires 150a DC input.
A bus bar supplying 4 of them, will be expected to carry 600a.
Plus 25% puts you at 750a.
By the way, where did you find that the Growatt 5k-ES requires 150a DC input? I didn't see that in the spec sheet or the manual.
 
By the way, where did you find that the Growatt 5k-ES requires 150a DC input? I didn't see that in the spec sheet or the manual.
In the manual.
At the bottom of page 24.
"Recommended DC breaker"
Interestingly, on the next page it says 200a per unit in parallel.
 
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