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Automatic transfer switch?

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pda1

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Here goes again. I'm now in the market, again, for an automatic transfer switch so it can switch between grid and PV (inverter output) instantly so the computers or refrigerator wont shut off.

I read about MOES but want to stay away from it- have read too many complaints.

Another possibility is- it would be nice to be able to manually switch from PV to grid and back (no delay to avoid devices shutting down). Some sort of push button on the device.

The Victron Quatro II (I think that's the number) sounds like good choice but rather expensive

Any ideas?
 
Its doubtful that any mechanical transfer switch can react fast enough to give you an instant transition to the other power source. An ATS is usually programmed with a short delay to verify loss of power and to prevent nuisance transfers if there is only a momentary voltage sag. Also, the mechanical switch takes some time to move from one position to the other.

If you are looking for near seamless back-up power you will need to install a capable inverter with a built in transfer switch directly into your incoming main wiring. A quality inverter can turn on and pick up the load in 8 to 10 mS.
 
pda1 said:
Here goes again. I'm now in the market, again, for an automatic transfer switch so it can switch between grid and PV (inverter output) instantly so the computers or refrigerator wont shut off.

I read about MOES but want to stay away from it- have read too many complaints.

Another possibility is- it would be nice to be able to manually switch from PV to grid and back (no delay to avoid devices shutting down). Some sort of push button on the device.

The Victron Quatro II (I think that's the number) sounds like good choice but rather expensive

Any ideas?
Click to expand...
How many amps are you transferring?
I'm using a DPDT relay to transfer parts of my system.

TWTADE/JQX-62F-2Z Coil Voltage AC 220V 80A DPDT Electronmagnetic Relay,High Power Relay (AC 220V) https://a.co/d/2e5Ep1h
 
Inverter- Giandel 2kWPS-2000 KAR
Input- 24vdc Output- 2 kw

I suppose I'd need to switch, at most, 10 amps.

As a side note, and this has nothing to do with our solar system, we have a Generac 10kW backup generator. The transfer switch is mechanical and automatic and AFTER grid power is restored the transfer doesn't interrupt the computers or refrigerator we use.

Oh, to clarify, our Solar system is off grid using 2 BB batteries in series that feed the inverter. I'm not trying to feed the grid.

'Hope that helps.
 
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One issue is the possibility/probability that the sign wave phase will not be in sync with a manual transfer.

My Victron Multiplus delays the transfer by 30 seconds so it can sync up the sign wave phase and deliver an unnoticed transfer.
 
Uh oh. With the Multiplus you mentioned, is there an interruption of power to any devices? Example- refrigerator?
 
No interruptions of power on a Multiplus.
My residential fridge can’t tell - the computer monitors don’t flicker, computers can’t tell.

Both ways no problem- adding shore power or shore gets cut off. The house stuff just runs.

I full-time in a MotorHome so I often add/remove shore power or start/stop the generator. None of this causes any of the electronic any issues.

The only reason I have to reset the Microwave clock is because we overload the inverter sometimes - (running the microwave and then put toast in the toaster or the wife starts the hairdryer). All the A/C power stops. My Victron CCGX BEEPS! Then 20 seconds or so later the power comes back on - and we are more careful for a while…

My prior comment I should add that when adding power (shore/generator) the Multiplus delays the adding of the power until it can sync up the sign wave forms. When the outside power is cut, it automatically starts inverting the power and there is no flicker.
 
Run on 100% inverter power for critical items. Multiplus should also be a good solution to avoid double conversion when the utility is up.
 
Thanks for clarifying that about your inverter sync-up.
Our system's MPPT is Victron and so is the BMV battery monitor.

Should I chose the Multiplus 24v/3000 ? (our array is 2.5 kW feeding the 24v batteries)

Here's another question about the Multiplus-

- Can it be configured so that when a certain battery discharge (or voltage) level is reached it switches to grid?

- Presently, I use an old smartphone and Victron connect to monitor the MPPT and BMV. Can VC be used with the Mulitplus? If not, what extra monitoring parts do I need?

Thank you
 
You have to be synchronous to instantly transfer between two AC sources. A good hybrid inverter will release its pass-through relay within about 5 milliseconds of a grid source collapse which is usually good enough of most devices. The inverter will already have been synchronized to what grid AC phase was.

An independent immediate transfer switch runs the very high risk of transferring when there is not synchronization between the two AC sources. That can be like throwing your car in reverse while driving forward at moderate speed. Not good for refrigerator compressor motors.
 
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I just ordered a Multiplus 24/2000 from BattleBorn.
Hopefully this'll work out alright.
 
The OP asked for a transfer switch to power the freezer (and computer) I also use a DPDT relay but it's just for the freezer and fridge. It kicks in after around 5secs of a mains power shortage, simple and cheap solution !
 
Expensive? You're right. Everything solar is expensive. I can sell the existing inverter on ebay.

I don't want interruption of power- computers (7 of them) must be on all the time. Refrigerator and freezer (not mentioned) don't want to cycled off and on too much manually.
 
Because you already have the Victron BMV, mppt and now a Multiplus- there are three ways to control the Multiplus:

1. Cerbo and touch. (Or roll your own with a raspberry pi). After connecting all your devices to this GX device - it gives great amazing info. Also, if you have internet there- you can monitor the system anywhere anytime (with VRM). You can also program the Multiplus via VRM and upload it to the Multiplus.

2. If you just want to monitor on your phone, you will need a VE.Bus Smart Dongle.

3. There is a manual control panel called a DSU. (Save your money and buy either #1 or #2).

The best option is the GX device (Cerbo). I have the older unit a CCGX, watch a few YouTubes on it.

You may need to change a few settings (or did BattleBorn do that for you?).
 
I also purchased the Ve bus smart dongle and the MK3 interface.

I'll look at the Cerbo and see if that'll do well.

No, BattleBorn has made any changes to the Multiplus but has sent a description of the changes that need to be made.

I run Debian and have Windows 10 in virtualbox.....so we'll see how it all goes.

For the moment I'll just use Victron Connect to monitor the system. It would be nice to view data remotely via internet but there's a annual fee...isn't there?
 
I don't want an interruption in power- all the computers will shut down.
 
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