Giandel 1200 watt inverter spec

[MrNatural22]

Humm when using a battery guard to disconnect the battery at a set voltage it seems this would present an issue of having to recharge the inverters caps again on reconnect which as previously discussed can be hard on switches and the BMS?
On dc loads from the battery the inverter wouldn’t disconnect only the dc load. ?
I’m not very happy with my Samlex pat 2000 24v LVD @20v I would prefer above 21v.
The settings are not programmable on the pst series.

 

[Danny]

One possible way is to turn off the inverter by the on off switch with a voltage sensitive relay at about 3.2 vpc. It is best to but an inverter with remote on/off built in and then get a Voltage sensitive relay / BMS to drive it the way you want. What follows is not recommended for most people. This is not easy with the G1200. I'd return it or not get it. Here is the way I rigged the on/off on my Xantrex 1500 inverter

. Here is a video using a low voltage disconnect on an inverter supporting the voltage shutoff you want

. Here is the G1200 switch that turns it on an off.

 

[gnubie]

Humm when using a battery guard to disconnect the battery at a set voltage it seems this would present an issue of having to recharge the inverters caps again on reconnect which as previously discussed can be hard on switches and the BMS?
On dc loads from the battery the inverter wouldn’t disconnect only the dc load. ?

That's right. You should really do a precharge, kinder on everything all round. Button pushing the Giandel with a microcontroller is a similar concept to where Will tapped into the toggle switch on the side of an MPP. The microcontroller/arduino approach was covered in another thread, including a simple (and untested) 'sketch' that I posted.

 

[John Frum]

Giandel's remote is usually just a parallel of the front panel soft button, not easy to control from the BP as it would require some smarts to press the button the right way (covered in another thread, done with an arduino)

I guessed maybe incorrectly that the ethernet connector probably only has two pins that just need to be shorted.
The battery protect has a 10k resistor on the remote signalling path.
Could be as simple as this

battery.pos->battery_protect_in->battery_protect_remote_pos->inverter_remote_positive_pin
battery.neg<-battery_protect_neg<-inverter_remote_positive_pin

 

[gnubie]

Yeah, the giandel remote is basically wired parallel with the panel. The two status LEDs and the button. Push > 1.5 secs to turn on, once on push > 250ms to turn off. The on LED can be monitored to determine the state and then carry out the button push action to comply with the BP (or what ever's) signalling.

 

[Mex Rider]

Does the charger have switch load output? It may be practical to use that to disconnect the AC load from the inverter with a relay. The Giandel's idle draw is 'less than an amp', so this may be an acceptable solution.

The charger is 400 watts of solar through mppt controller and when driving (not frequent) B2B at about 40 amps. Nothing sophisticated.

 

[John Frum]

Yeah, the giandel remote is basically wired parallel with the panel. The two status LEDs and the button. Push > 1.5 secs to turn on, once on push > 250ms to turn off. The on LED can be monitored to determine the state and then carry out the button push action to comply with the BP (or what ever's) signalling.

Well there is still the sterling relay.

 

[Mex Rider]

Honestly, you are both over my head

 

[gnubie]

The charger is 400 watts of solar through mppt controller and when driving (not frequent) B2B at about 40 amps. Nothing sophisticated.

Is that a standalone controller like an epever etc? Can you state the make / model?

 

[Mex Rider]

Is that a standalone controller like an epever etc? Can you state the make / model?

Kisae DMT 1250, gives me b2b and mppt

 

[gnubie]

There's no ability to switch a load, so that idea is out. You could still do it with a voltage sensor but then you'd still need the ability to 'push the button' on the Giandel, and given that a microcontroller / arduino can also measure voltages it could be done with just that. Unfortunately this does require a bit of experience with arduino boards etc or at least the effort put in to understand them a bit.

 

[Mex Rider]

Well, I am 55 years past my math education, and really a humanities guy, but I know what arduino boards are. I live in a small underserved fishing village in a second world country, and we are still locked down with the covid situation. So resources are limited. I am wanting to know what happens negatively to my cheap (Giandel 2200 watt) inverter if my BMS or a battery protect of some form or fashion cuts the power....does that hurt the inverter? The way I anticipate using the inverter probably precludes the event, but after 20 years of living and cruising on sailboats with AGM's, solar and related equipment, I know things don't always go according to plan and automatic cutoffs and safety features are much more dependable than human memory or intention. As I am in the beginning of building my system I still have some financial room to maneuver but I don't have the budget or abilities for over sophistication. Looking at Samlex and other high end inverters, the cutoffs are still below happiness for Lithium, most around 10.5 volts.

 

[gnubie]

No, no harm to inverter, and no harm to BMS when power is disconnected. Everything just goes dark and quiet. The real question is what happens when you turn it all back on. The inverter has a fair amount of capacitance across the DC input so dropping it straight onto your lithium battery's terminals will allow quite high currents to flow. That might cause the BMS to trip off, and it may cause those input capacitors to degrade over repeated dead connects. This is why you'll see a fair bit of discussion on the forum about pre-charging.

If you have no other option, you aren't going to outright kill things but there is the scope for damage in the long term.

 

[John Frum]

I am wanting to know what happens negatively to my cheap (Giandel 2200 watt) inverter if my BMS or a battery protect of some form or fashion cuts the power....does that hurt the inverter?

No.

Looking at Samlex and other high end inverters, the cutoffs are still below happiness for Lithium, most around 10.5 volts.

The Samlex evo line will have configurable low voltage cutoff.
I am waiting on deliver of my Samlex pst-1500-24 and it supports remote on/off by signal wire.
I will trigger that cutoff by a chain of bms and victron battery protect.

 

[John Frum]

The real question is what happens when you turn it all back on. The inverter has a fair amount of capacitance across the DC input so dropping it straight onto your lithium battery's terminals will allow quite high currents to flow. That might cause the BMS to trip off, and it may cause those input capacitors to degrade over repeated dead connects. This is why you'll see a fair bit of discussion on the forum about pre-charging.

@FilterGuy wrote up a good solution https://diysolarforum.com/resources/inverter-disconnect-switch-with-precharge.60/

 

[Mex Rider]

No, no harm to inverter, and no harm to BMS when power is disconnected. Everything just goes dark and quiet. The real question is what happens when you turn it all back on. The inverter has a fair amount of capacitance across the DC input so dropping it straight onto your lithium battery's terminals will allow quite high currents to flow. That might cause the BMS to trip off, and it may cause those input capacitors to degrade over repeated dead connects. This is why you'll see a fair bit of discussion on the forum about pre-charging.

If you have no other option, you aren't going to outright kill things but there is the scope for damage in the long term.

If the BMS cuts the power on a low voltage event and then I turn the inverter off until batteries are recharged how does one go about pre-charging the capacitors? If the breaker to the inverter is closed to allow current flow but the inverter is turned off, does that allow the capacitors to pre-charge?...without long term damage?

 

[gnubie]

Manually, very easy. All you need is a resistor, say 50-100 ohms, 5 watts. Connect that across your breaker for several seconds, then remove, close the breaker and turn inverter on. Exact values of the resistor vary depending on voltage but 50-100 ohms is good enough.

If you want to watch a video ...

 

[Mex Rider]

Manually, very easy. All you need is a resistor, say 50-100 ohms, 5 watts. Connect that across your breaker for several seconds, then remove, close the breaker and turn inverter on. Exact values of the resistor vary depending on voltage but 50-100 ohms is good enough.

If you want to watch a video ...

Thanks so much

 

[Mex Rider]

Manually, very easy. All you need is a resistor, say 50-100 ohms, 5 watts. Connect that across your breaker for several seconds, then remove, close the breaker and turn inverter on. Exact values of the resistor vary depending on voltage but 50-100 ohms is good enough.

If you want to watch a video ...

Ok, thanks again for that, now I understand the how and why but taking it to the next step.... I have an inverter connected to a battery bank through a 300 amp breaker which I was actually hoping to use as my master switch for my whole system. If we want to go off hiking for the day I would open the breaker to shut everything down, does that mean in order to close the breaker on returning to the van (home) I need to pre-charge the the capacitors again? and could I do that by putting the resistor across the two contacts on the 300 amp breaker before closing it? Somehow sounds like there should be a better way to have an inverter available in your system?? Thanks for your help.

 

[gnubie]

That'd be the ideal thing, when ever applying DC to the inverter precharge it. You could put it across the breaker in that situation but only if you don't have any other loads connected at the time as they will try to run via the resistor and will also discharge the capacitors in the inverter once you remove the resistor (you could turn the breaker on while the resistor is still in place).

There is a better way. You'd have a 3 position switch in line with the breaker. The breaker goes before the switch. The three positions are off, pre-charge, on. The resistor goes permanently between the pre-charge and on positions, DC from the battery goes to the common terminal on the switch. The inverter goes to the on position. Then it's just a case of move switch to pre-charge position, wait a bit, move to on position and you are ready to turn the inverter on, when you leave rotate switch to off position (if ytou want to turn the inverter off that is)

This isn't perfect as there is the potential for the BMS to turn back on automatically but it's good enough for most things.