Do they make Power relay that shuts off when supply is reduced to 48v.

[kayellynn]

--My set up is: Four 48v strings of 12v 100ah batteries feed a 48v 4000 watt inverter.
--Inverter will not shut down until voltage is dropped to 42 volts. Auto transfer doesn't switch either.
--Batteries charge should not drop below 50% charge ---my setup draws batteries charge too low.

--Looking for power relay that shuts off power to inverter at when power from batteries drops to 48v.

--Is there such a relay that does this?

 

[wpns]

So you are looking for a low voltage cut out? How have you arranged the batteries so that they make 48 V strings? Are you using battery combiners or some kind of BMS across the entire 48 V string?

 

[kayellynn]

I have 4 strings. Each with 4 12v connected in series, thus 48v. Strings connect to lug bar and inverter also connect.
On each string I have a battery equalizer for 48v string. I can see voltage of all 16 batteries displayed on equalizers.

 

[kayellynn]

So it's called a "low voltage cut out" I think that's my answer.

 

[wpns]

So it's called a "low voltage cut out" I think that's my answer.

That's what you want, but again, without some kind of inter-battery combiner/BMS unit, that doesn't mean what you think it means

 

[DIYPV]

Something like this?

I don’t use it, but just happened to see it a couple of days ago.

https://a.co/d/adSml4h

 

[TommySr]

something like this?



relay

 

[kayellynn]

So it's called a "low voltage cut out" I

something like this?

View attachment 208057

relay

Interested in learning more about this relay. Can you provide a link?

 

[time2roll]

Instead of controlling the DC... consider using one of those relays to control a relay to switch the AC power.
Either control an independent transfer switch or switch power on to a charger to top up the battery.

48Vdc at close to 4000 watts is a lot of DC power to switch on the fly.

 

[kayellynn]

Something like this?

I don’t use it, but just happened to see it a couple of days ago.

https://a.co/d/adSml4h

Actually, I bought this. I installed after the return period, and f&*%$ thing didn't work. Lost $100. So cautious to try again. The second ats I bought works great but doesn't read battery levels.

 

[TommySr]

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[kayellynn]

Thanks to all responders. I know what yo do now. Really appreciate you!

 

[Marinepower]

Maybe try this 48 Volt Victron BatteryProtect?

https://www.victronenergy.com/upload/documents/Datasheet-Battery-Protect-48-V-100-A-EN.pdf

But i would put it on the inverter's on/off remote input (and not the DC load side) if your inverter is set up this way...