need help sourcing correct components

[littleharbor]

Interesting though. This may be from an older manual I got online but it is pretty clear about Keeping the battery connected till solar has been removed.

To Power-down WARNING: Risk of Damage ONLY disconnect the battery from the TriStar MPPT 150V AFTER the solar input has been disconnected. Damage to the controller may result if the battery is removed while the TriStar MPPT 150V is charging.

Also typically you would have a higher amp breaker on the output of the MPPT controllers in relation to the higher voltage/lower current input. Do they make tandem DC rated breakers in dual amp ratings?

[littleharbor]

Inquired with Morningstar regarding this and this was their response;

For Morningstar charge controllers you will want to have separate circuit breakers (Single Pole Breaker), 1 each for the solar input and battery input. This gives you the ability to Disconnect the Solar while leaving the battery connected. Disconnecting the battery prior to disconnecting solar, or disconnecting both battery and solar simultaneously can damage the charge controller.

Hope this provides clarity.

Regards,

MS Tech Support

[NochiLife]

Well, it turns out my Morningstar Tristar manual was dated 2010...and the new one is dated 2018. First of all, my old download says that it has to have a "minimum battery fuse/circuit breaker rating" of 75A. The new manual says that "...These protection devices are external to the TriStar MPPT 150V controller, and must be a maximum of. ..90 amps for the TS-MPPT-60/M." And in the new manual, I can't find any reference to tandem breakers.

(I did notice that the new manual does specify, "Damage to the controller may result if the battery is removed while the TriStar MPPT 150V is charging." Putting it in disconnect mode technically stops it from charging. But that's only possible with a MODBUS/RS-232 connection.)

Guess now I need to find some different breakers...

It wouldn't make any difference if a tandem breaker had dual amp ratings--you couldn't trip a properly rated breaker with solar if you tried, as the maximum power current is generally very close to the short-circuit amps. The breaker there simply provides a disconnect--well, and maybe protect the solar panels if the MPPT goes berzek. The thing I like about tandem breakers is that if the battery breaker trips, it will also cut the solar. But evidently that method isn't kosher anymore.

[littleharbor]

Got a follow up reply from Morningstar tech yesterday. It seems there was originally a recommendation to use tandem breakers in the TS-MPPT instructions which they had realized was potentially dangerous. Removed from further manuals.


Yes I did have a chance to read through most of that forum post. The excerpt in the manual he is referring to was from the original operation manual(from about 10 years ago) for the TS-MPPT. This excerpt has since been removed from the manual and it is recommended to have separate disconnects, one for PV and one for the battery. To be transparent we have seen failures in the past due to improper shut down/startup(battery removal with solar connected and/or reconnecting the battery with solar still connected) with the TS-MPPT. Typically we did not see these failures with double pole breakers but we still thought it would be beneficial to change the manual and be on the safe side. It also makes system troubleshooting significantly easier when each(PV and battery) has their own breaker/disconnect.





Another comment in response to his/other posts. When he states disconnect mode I assume he is referring to a coil command where you can 'disconnect' solar. This is a charging disconnect coil command which will stop charging but it obviously cannot physically disconnect solar from the controller, it will just leave solar in an open state(should measure Voc on solar panels). Disconnecting the battery with input power still applied (while the controller is still charging) can damage the battery circuit of the controller because the remaining power in its inductors and capacitors can no longer be dissipated in the output to the battery. This will result in a sudden high voltage transient back feeding through the battery circuit as they discharge ultimately damaging the controller.





Regards,





Joe Marcellino


MS Technical Support


Morningstar Corporation


www.morningstarcorp.com

[NochiLife]

Aha, yes, Joe Marcellino, who I have contacted in the past (actually regarding the warranty on my unit). Yes, I was referring to the "disconnect" coil command.

[Mcmullen7242]

Ok so me and my brother are a little tight on cash so we are looking to get the following and then slowly upgrade the amount of panels and batteries in the future.
the panels: (going to have 2 to start)
peak power 305 watts
voltage 54.7
current 5.58
open circuit voltage 64.2
short circuit current 5.96
maximum series fuse 15

[Mcmullen7242]

2 of these:
https://www.amazon.com/gp/aw/d/B01KN...?ie=UTF8&psc=1

then this solar inverter/charger
https://www.amazon.com/MPP-SOLAR-Inv.../dp/B078746PG3

[NochiLife]

Just curious...did something happen to the 305W panels at the start of the conversation...?

EDIT: will mention that if you plan to expand the system down the road, it might be wise to try to find a reliable source for solar panels (not Joe Buck with a couple surplus panels for sale)...mixing and matching panels is not the best way to get the most power out of the system. I personally got my panels from a Joe Buck...and guess what: for the life of me, I couldn't find a replacement panel when my racking gave way under high wind loads several years later.

[Mcmullen7242]

Just curious...did something happen to the 305W panels at the start of the conversation...?

EDIT: will mention that if you plan to expand the system down the road, it might be wise to try to find a reliable source for solar panels (not Joe Buck with a couple surplus panels for sale)...mixing and matching panels is not the best way to get the most power out of the system. I personally got my panels from a Joe Buck...and guess what: for the life of me, I couldn't find a replacement panel when my racking gave way under high wind loads several years later.

Sorry I mixed up my photos of the stats but I will be going for the 305 watt ones as previously stated but the inverter/charger and batteries just posted. And the person has them regularly, so I won't have to be mixing up different panels in future

[Mike90250]

2 of these:
https://www.amazon.com/gp/aw/d/B01KN...?ie=UTF8&psc=1

These appear to be called GEL batteries. AGM are much better for solar use, because they can accept high charge rates


[/QUOTE]then this solar inverter/charger
https://www.amazon.com/MPP-SOLAR-Inv.../dp/B078746PG3[/QUOTE]
This is out of stock, but that might be a good thing.
*Note: please be careful this unit does NOT work with 220-240v load nor can it be used in a "split phase" application.

[Mcmullen7242]

The solar inverter/charger just went out of stock last night so looking for another option that will work with these panels
peak power 305 watts
voltage 54.7
current 5.58
open circuit voltage 64.2
short circuit current 5.96
maximum series fuse 15
and these batteries:
https://www.walmart.com/ip/Renogy-De...xoCBZIQAvD_BwE

i am trying to find an inverter with 1500-2000w and a charger I want it to be under $550 total

[sdold]

Don't buy batteries thinking that you'll use them for a while and then add more, all of the batteries in the system need to be bought at the same time and used equally. Adding another bank of batteries to an existing system is like a viking ship with all of the old oarsmen on one side and a new young batch on the other side. You'll be making a big circle...back to the store for more batteries.

[Mcmullen7242]

Don't buy batteries thinking that you'll use them for a while and then add more, all of the batteries in the system need to be bought at the same time and used equally. Adding another bank of batteries to an existing system is like a viking ship with all of the old oarsmen on one side and a new young batch on the other side. You'll be making a big circle...back to the store for more batteries.

Ok thanks I'll buy some cheap used agm batteries off Facebook and then when I can afford to buy all the batteries I want new I'll upgrade then.

[sdold]

Why AGM? Flooded are cheaper, last longer and allow you to use a hydrometer to check state of charge.

[Mcmullen7242]

Because Mike said they charge at higher rate and Someone sells them cheap near me. The Gel batteries I was looking at said they last over 1000 cycles with 50% discharge, is that better than flooded?