FNDC Question

[jmktexas]

No not the gvfx. I probably should take that off my profile. It just confuses people. The gvfx and radians don’t even know each other exists.

I working on the two radians right now.

[raysun]

No not the gvfx. I probably should take that off my profile. It just confuses people. The gvfx and radians don’t even know each other exists.

I working on the two radians right now.

Are the two Radians the same model and firmware release?

[jmktexas]

Ah Rayson, the things I have learned in past 3 days.

Yes they are the same models with same firmware and Outback has been holding my hand.

First, I know you cannot use the bypass in the gslc. You have to build an external 100 amp bypass. Did that. What I never thought of was you have to take the old bypass out whether you are using it or not. That was my first error. Had some other little glitches I manage to self inflict. Got all that straightened out. We have confirmed both radians operate independently of each other with no problems. How ever when I try to output from both radians as master/slave I get an immediate AC output short. I wired output from each radian to a busbar to create the 100 amp line to sub panel. Seemed like that should work. Nope. After studying wiring diagram which is incidentally the same you showed me, the output from slave feeds into master output busbar then to loads. Seemed like the same thing I had created outside the gslc but I guess not.

I’ve just stepped away from it today, I was getting flustered and I’ve learned over the years to just take a breath. Thing I have to watch out for is I’m making more solar than just one radian can handle so I’m having to choke that back too. I am correct one radian isn’t going to be able to handle 12kw, right?

FNDC is not reading correctly right now but I think that’s a shunt issue. Tackle that later.

Folks at Outback have been very patient with me but I’m pretty sure they’re ready for me to figure this also.

Another thing I didn’t know is if you switch from gridtie to mini grid outback tells me I have to switch both radians independently of each other. The master/slave connection doesn’t do that.

[raysun]

Thing I have to watch out for is I’m making more solar than just one radian can handle so I’m having to choke that back too. I am correct one radian isn’t going to be able to handle 12kw, right?

The PV arrays / Charge Controllers feed current to the battery bus, and from there to the battery (for charging) and to loads (the inverters in this case.)
I'm not grid-tied so can't speak directly to this, but if the PV/CCs have charged the battery to the point selling will occur, then PV harvest will be automatically throttled to meet the demands of the loads. My off grid system works this way with no intervention or adjustment by me, the CCs simply pass enough power from the arrays to maintain Float. I'd expect Radian selling to the grid would behave the same way. (In fact, the FlexMax controllers have code in their firmware Grid Tied library to enable dynamic throttling of the CCs.)
Set the CCs charge current as is appropriate for battery charging during Bulk, and they will take care of modulating output during selling.

[jmktexas]

Thanks, I sort of thought CC’s would do that but I’ve kind of gotten gun shy about overloading anything right now. I just knew inverter made the ac and was only rated for so much output. I saw 10kw+ on mate today and started worrying. Would hate to blow it all up before I got it all working.

[raysun]

The big question regarding Charge Controller output is: what is the maximum current the battery will safely accept?
I see a 30kW(H?) battery listed in your profile. What is the specific brand/model makeup of the battery?

[jmktexas]

Rayson, I have 6 of those cheap EG4LL batteries, 48v 100ah. They are supposed to handle a C1 charge or 100 amps but I don’t believe it. I charge them at 20 amps each. If I understand correctly that’s 120 amps under mate’s maximum charge. I’ve never observed any of the batteries getting more than 26 amps at one time. I could probably bump that up but tech I talked to suggested 30-40 amps max. Typically I’ll run in mini grid until batteries drop to low 40% and go back to grid tie but unless it’s really really cloudy inverter charger stays off regardless.
I try to not keep them at 100% but the last few days have been problematic. I haven’t been able to run all loads because I can’t get inverters to run as master/slave so I’m making a lot more solar than I can use right now. That’s why I was worried about 10-12kw going to system. When I get get a full sun day that’s going to go up to 15kw.

FNDC is saying batteries are all fully charge 24/7 and I know that’s not right. I’m thinking I didn’t install shunts right when all four CC went on same shunt. I have the oversized shunt Outback suggested but obviously something ain’t right. Once I get the two inverters playing nice then I’ll tackle that problem.

I’ve read about a lot of problems with these batteries but I’ve not had any problems with them. I feel their bms is a little over protective but they start my radians fine and don’t seem to have a problem with air conditioning or pump surges. I think the secret is to buy a little more capacity than you need. I mean, they’re cheap enough.

Time will tell on that, but I don’t buy green bananas anymore either.