Does adding extra charge controllers increase the size of busbar needed?

[MartyByrde]

Keeping the load the same but want to speed up battery recharge time by adding another SCC. Does adding extra charge controllers increase the size of busbar needed? Since more amps will be flowing in.

 

[Rednecktek]

Only if your total amps are pushing what the bus bar is capable of, but it takes a LOT of charging power to push that limit. Most of the "low end" bus bars I've seen are good for 300a.

 

[BentleyJ]

Depends on if the bus bar is already maxed out with the existing SCC's. You need to compare the bus bar rating to the maximum charge current your existing SCC's can deliver.

 

[timselectric]

Yes
If it's more than your current bus bars are rated for.

 

[timselectric]

Jinx lol

 

[MartyByrde]

300A busbar

Existing:
Growatt 3000TL LVM-ES = 80A
Growatt SC48120 = 120

Adding another Growatt SC48120 would bring me to 320A so I need a bigger busbar, correct?

 

[timselectric]

I doubt that you will be pulling a continuous 320a.
Maybe just a momentarily surge, occasionally.
I wouldn't worry about it.
Also you are fusing for 220a.

 

[MartyByrde]

I doubt that you will be pulling a continuous 320a.
Maybe just a momentarily surge, occasionally.
I wouldn't worry about it.
Also you are fusing for 220a.

So even though if all three were charging at max amps (320A) the busbar would be okay?

 

[timselectric]

So even though if all three were charging at max amps (320A) the busbar would be okay?

All 3?

 

[MartyByrde]

All 3?

The inverter and two charge controllers I mentioned above. If the three were charging at max

 

[timselectric]

That could be considered as a continuous load, if it's sustained. (Doubtful) You may need to upgrade the bus bars.

 

[MartyByrde]

That could be considered as a continuous load, if it's sustained. (Doubtful) You may need to upgrade the bus bars.

Do I fuse the batteries based on the total charging amps with 320A fuses from the batteries to the busbar?

 

[rmaddy]

Your other question and this one are tightly related. They really should be discussed as one.

Blue sea class T VDC?

Using a growatt SPF 3000TL LVM-ES. Would this fuse be too large at 110 A? Using 80amp output * 1.25 = 100 amp fuse recommended. Also this fuse shows max 125 VDC. Would this work with a 48v system? https://www.bluesea.com/products/5112/Fuse_A3T___Class_T_110_Amp

diysolarforum.com

 

[timselectric]

I think that @rmaddy is already answering this in the other thread. This is getting confusing with two threads.

 

[MartyByrde]

I think that @rmaddy is already answering this in the other thread. This is getting confusing with two threads.

They were two separate questions but merging into one lol. Essentially I was just wondering if charging Amps is factored in for busbar size? I’ve heard people say to base it on the load but in my case charging amps are higher than the load.

 

[JRH]

Keeping the load the same but want to speed up battery recharge time by adding another SCC. Does adding extra charge controllers increase the size of busbar needed? Since more amps will be flowing in.

If you have to buy new ones , it’s been my experience on boats systems one always grows , upgrades stuff or needs more room for connections…. try to build in for future growth on everything. Buy big , buy brand name , and get good covers .. they will outlast most owners.

 

[HRTKD]

They were two separate questions but merging into one lol. Essentially I was just wondering if charging Amps is factored in for busbar size? I’ve heard people say to base it on the load but in my case charging amps are higher than the load.

Charge or load, it doesn't matter. Amps in or amps out, it's all the same. If your bus bar doesn't support the amps, it has to be replaced. Also consider if the bus bar is real copper of if it's made from brass then plated. My first set of four stud bus bars were brass. They were rated to 250 amps. I replaced them with bigger bus bars made from copper (I needed more studs). I probably have less resistance now, but it's not something that I bothered to measure.

 

[Shinzul]

On a related question, let's say you have an inverter connected to a bus bar connected to a battery bank, and you add a charge controller to connect to the same bus bar to the same battery bank. Does the wire you connect from the new charge controller to the bus bar need to be the same size as the wire connected from the inverter to the bus bar?

Or is the wire size from the new charge controller to the bus bar independent from the inverter->bus bar wire size, only sized according to the amps it's sending the batteries from the PV array?

 

[cs1234]

Keeping the load the same but want to speed up battery recharge time by adding another SCC. Does adding extra charge controllers increase the size of busbar needed? Since more amps will be flowing in.

Smart butt answer..

Adding another solar charge controller changes nothing, unless you have some panels to go with them.

 

[cs1234]

Or is the wire size from the new charge controller to the bus bar independent from the inverter->bus bar wire size, only sized according to the amps it's sending the batteries from the PV array?

This is correct. You only need to size the wire from the charge controller to the bus bar based on the charge controllers output.