Author Topic: Using Classic aux settings to switch on/off grid input?  (Read 478 times)

jwb

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #15 on: May 19, 2019, 01:07:43 AM »
Hi - not sure if a hyperlink will work in the forum, but here's what the inverter looks like:
https://www.wholesalesolar.com/cms/schneider-sw4048-na-charger-inverter-3270368753.jpg

To address boB's question, the battery temp sensor is not connected. The lithium batteries are exposed to a relatively narrow ambient temperature range, and thus far I haven't noticed them getting even the least bit warm, even when we're running relatively high loads (e.g. 1500 watts) and/or the charger is putting in 2000+ watts.

bee88man makes a point that hardware cost can be a deal killer. Our inverter's grid input is split-phase 240v AC from a tandem 30a breaker in our main box. I have been running downstairs and flipping that breaker on/off manually as needed. It seems like there must be an affordable relay that could do that for me, controlled by the Classic aux port. Alas, wishful thinking? If no 240v tandem relay were available, I could try disconnecting L2 and using just single-phase 120v input on L1. I think that's how off-grid systems with smaller  back-up generators do it. Charge and pass-through capacity would be limited, but solar is doing most of the charging. Maybe it would be easier to find a 120v relay for just L1 rather than a tandem (?) Then grid input could be switched on only when batteries were getting low, and it would switch off once a certain SOC was reached. Does anyone know of such a relay?

Thanks again!

Schneider SW4048 with Midnite Classic 200SL
2 Chevy Volt 48v 12s 50ah modules, voltage range 36-48v
2kw Panasonic HIT 6-panel array
grid support, no genny

boB

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #16 on: May 19, 2019, 02:42:19 AM »

That link points to the newer Schneider SW4048 which is a current product.

You might try a Crydom SSR like this ...
https://www.digikey.com/product-detail/en/sensata-crydom/D2450/CC1007-ND/139480

You would need two for 120/240 VAC

And how about that...  Looks like Sensata (Magnum) now owns Crydom !  That was news to me.

Yes, I agree the name can be confusing.  HOWEVER, notice the battery terminals.  Those are the exact same terminal design that Robin (from MidNite Solar) designed for the old Trace SW4048 and their other SW inverter/chargers.  Just a bit of trivia.

And Tecnodave, I think you are right about the TR series. It, I believe is the newer version of the DR which was modified square-wave.

K7IQ

Matrix

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #17 on: May 19, 2019, 10:40:48 AM »
Oops ... you are correct.  I assumed Schneider Conext SW.  Guess I should not always do that.  CSW is all I know any thing about (even what little I do know)
Grid-Assist Off-Grid
REC TwinPeak 2 285W 3S-3P 2565w-STC 1926w-NMOT Array / Classic 150 / Conext SW 4024 Inverter
Trojan L16H-AC 435Ah bank 4S  with 7' of 4/0 cable
24 volt system /  Need 3200Whs Daily
My System Install

jwb

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #18 on: May 20, 2019, 10:47:30 AM »
That Crydom SSR looks promising, thanks! I think 120v AC input on L1 would be plenty for us in most situations. But if we decided to put separate relays on both L1 and L2 to maintain 240v in, would we wire the relays in series, or would they need parallel connections to the Classic aux port? It looks like aux control is 12v, and the SSR input range is 3~32VDC.

Thanks,

Schneider SW4048 with Midnite Classic 200SL
2 Chevy Volt 48v 12s 50ah modules, voltage range 36-48v
2kw Panasonic HIT 6-panel array
grid support, no genny

mike90045

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #19 on: May 20, 2019, 11:25:53 AM »
When using SSR's  -  be sure to read all the tech notes regarding surge suppression, and heat sinking.    Inductive surges from ordinary DC wires can be enough to blow the devices

UPDATE: here's a link to a lengthy SSR handbook
https://www.galco.com/techdoc/crdm/ckrd4830_crdmh1.pdf
 about page 100, the protection circuit discussion starts
« Last Edit: May 21, 2019, 12:56:15 PM by mike90045 »
http://tinyurl.com/LMR-Solar

Classic 200| 2Kw PV, 160Voc | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph )| Listeroid 6/1, st5 gen head | XW6048 inverter/chgr | midnight ePanel & 4 SPDs | 48V, 800A NiFe battery bank | MS-TS-MPPT60 w/3Kw PV

boB

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #20 on: May 21, 2019, 12:34:23 AM »

I would wire the two 12V inputs of the SSRs in parallel.
K7IQ

jwb

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #21 on: May 26, 2019, 12:37:56 AM »
Thanks again for the coaching. Digi-key tech support helped me put together an order with the D2450 SSR along with a heat sink and other mounting items. The add-ons more than doubled the total cost, but overall it wasn't a big expense (compared to buying a new inverter, batteries, house, etc.) Our plan is to install just one SSR on L1. If there's eventually a need for 240v grid input, we'll replicate our existing SSR install with parallel control wiring from the Classic, as boB recommended.

As for surge suppression, would it work to install a Midnite surge arrestor like this upstream from the SSR?
https://www.altestore.com/store/enclosures-electrical-safety/lightning-protection/midnite-solar-surge-protection-device-300vdc-and-120240-vac-p9042/

Cheers,
Schneider SW4048 with Midnite Classic 200SL
2 Chevy Volt 48v 12s 50ah modules, voltage range 36-48v
2kw Panasonic HIT 6-panel array
grid support, no genny

jwb

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #22 on: July 07, 2019, 01:29:08 AM »
Update: with aux1 control from the Classic, the SSR seems to be working well and has helped us harness more solar watts. The heat sink advice was crucial and much appreciated. Under full 120v charging, the heat sink gets up to about 110 F. We also put in a surge arrestor upstream from the SSR.
However, with just 120v input on L1, the Schneider SW4048 does behave strangely for us. If the charger is disabled, the SW intermittently drops AC outpul to L2. If battery voltage drops below about 43v, the SW throws erroneous "dead battery detected" faults, at which point it won't recharge the batteries unless L2 input is also switched on. Our lithium batteries are rated for discharge down to 36v, so they're definitely not dead at 42v. Also, AC Support on SOC will now draw down the batteries to below the minimum voltage setting, so we need to make sure the charger is enabled. We've found work-arounds with the settings, so things are now working much better.
Thanks again for the good help from this forum.

bee88man

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #23 on: July 07, 2019, 09:31:18 AM »
How is the surge protector wired to circuit?

Was thinking it were to be paraelled to SSR line and load, but truthfully didn't read Mike's provided reference materials...

FNG

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Re: Using Classic aux settings to switch on/off grid input?
« Reply #24 on: July 09, 2019, 07:33:00 AM »
The TR was Xantrex's attempt at a better DR, Sadly that failed also. The DR was the toughest inverter I have ever seen, yes it was modified sine wave but damn that thing was a tank..