Automatic Transfer Switch 48v

[P.B.R]

I am new to solar power can anyone help me please?

I have a 3Kw 48v photovoltaic system that has a 48v battery storage bank with a 230v/5000w inverter but it will not produce enough electricity for my needs

So I would like to automatically switch between the battery bank and mains when the voltage drops below 48v but as my inverter will only switch off at 40v much too lower voltage can anyone advise of a product or how I could manage this.

Thanks

[Willy T]

I am new to solar power can anyone help me please?

I have a 3Kw 48v photovoltaic system that has a 48v battery storage bank with a 230v/5000w inverter but it will not produce enough electricity for my needs

So I would like to automatically switch between the battery bank and mains when the voltage drops below 48v but as my inverter will only switch off at 40v much too lower voltage can anyone advise of a product or how I could manage this.

Thanks

If your Inverter has a Generator AGS ( auto start ) you can use it to trip a ATS sometimes. There are VCS's ( Voltage Controlled Switch ) made by Solar Converters that can also do it for $100 usd .

[P.B.R]

If your Inverter has a Generator AGS ( auto start ) you can use it to trip a ATS sometimes. There are VCS's ( Voltage Controlled Switch ) made by Solar Converters that can also do it for $100 usd .

Thanks for your quick reply my inverter has no charger and I will be switching to grid mains power when the battery bank drops below 48v

[Willy T]

Thanks for your quick reply my inverter has no charger and I will be switching to grid mains power when the battery bank drops below 48v

Google Solar Converters for a VCS-1AL. These VCS's have a 3 second delay that is not enough for all applications. You'll have to figure out the voltage you want the switch to operate at and how the batteries will rebound. It really needs some kind of a current draw sensor on the mains in series, so it won't be fluttering back and forth. You could have a charger on the grid side that would pull the batteries back up to some set level.

There 15 ways to skin a cat.

[P.B.R]

Google Solar Converters for a VCS-1AL. These VCS's have a 3 second delay that is not enough for all applications. You'll have to figure out the voltage you want the switch to operate at and how the batteries will rebound. It really needs some kind of a current draw sensor on the mains in series, so it won't be fluttering back and forth. You could have a charger on the grid side that would pull the batteries back up to some set level.

There 15 ways to skin a cat.

Hi thanks
I have had a look at the specs and as I understand it this would switch the dc with my system at 48v It would only be capable of 3A that would not be enough.

I was thinking more along the lines of transferring the 230v side from my 48v/230v inverter to the grid.

Any suggestion?

I think I may need two things in one

1) To sense when the battery voltage drops to below 48v and switch off the inverter.
and
2) To sense when the supply from the inverter output fails and transfer to the mains grid.

Is there such a thing?

[Willy T]

Hi thanks
I have had a look at the specs and as I understand it this would switch the dc with my system at 48v It would only be capable of 3A that would not be enough.

I was thinking more along the lines of transferring the 230v side from my 48v/230v inverter to the grid.

Any suggestion?

I think I may need two things in one

1) To sense when the battery voltage drops to below 48v and switch off the inverter.
and
2) To sense when the supply from the inverter output fails and transfer to the mains grid.

Is there such a thing?

It's 30 amps and that makes no difference because you can use it to drive a relay / contactor of any amp capacity or voltage you want to make the Mains transfer.

# 2 is a issue for that you need a different trigger switch. If your trying to do it in milliseconds like a UPS does , you have the wrong Inverter probably.

[P.B.R]

It's 30 amps and that makes no difference because you can use it to drive a relay / contactor of any amp capacity or voltage you want to make the Mains transfer.

# 2 is a issue for that you need a different trigger switch. If your trying to do it in milliseconds like a UPS does , you have the wrong Inverter probably.

Hi thanks again

It’s all becoming a bit clearer I think, I see what you are saying use the Solar Converters VCS-1AL for something like the Polaris Ranger EV Solenoid Switch Contactor and then I would need a normal transfer switch like the Go Power! TS-30 30 Amp Automatic Transfer Switch to switch the 230v feeds.

Am I making sense?

[Willy T]

Hi thanks again

It’s all becoming a bit clearer I think, I see what you are saying use the Solar Converters VCS-1AL for something like the Polaris Ranger EV Solenoid Switch Contactor and then I would need a normal transfer switch like the Go Power! TS-30 30 Amp Automatic Transfer Switch to switch the 230v feeds.

Am I making sense?

Yes, you got it !!!! The VCS is called a " Pilot " when used that way.

[P.B.R]

Yes, you got it !!!! The VCS is called a " Pilot " when used that way.

Just one more thing! do you know if I need Solenoid Switch Contactors with the Go Power! TS-30 or POWERMAX PMTS-50 are they inside already?

[Willy T]

Just one more thing! do you know if I need Solenoid Switch Contactors with the Go Power! TS-30 or POWERMAX PMTS-50 are they inside already?

Their switching is already already in them, all you have to do is supply the signal ( at their driving voltage ) from the VCS relay. All the VCS does is make the circuit to engage it at your trigger voltage (48 Vdc say ).

The logic would be, at 48V the VCS would make the transfer to grid. To get it to switch back you have to set another trigger point, say (50V ) dc from the batteries. Again, I don't know what your exactly trying to do. The switch back point is only based on battery bank voltage with this set up.

Using the Low Voltage Disconnect ( LVD ) is stressful on a Inverter, it's a point that the Inverter cannot keep the voltage stabilized and is hard on the electronics, not to mention the batteries.

[P.B.R]

Their switching is already already in them, all you have to do is supply the signal ( at their driving voltage ) from the VCS relay. All the VCS does is make the circuit to engage it at your trigger voltage (48 Vdc say ).

The logic would be, at 48V the VCS would make the transfer to grid. To get it to switch back you have to set another trigger point, say (50V ) dc from the batteries. Again, I don't know what your exactly trying to do. The switch back point is only based on battery bank voltage with this set up.

Using the Low Voltage Disconnect ( LVD ) is stressful on a Inverter, it's a point that the Inverter cannot keep the voltage stabilized and is hard on the electronics, not to mention the batteries.

Ok maybe I haven’t quite got it yet

So I am using the pilot to trigger the ATS directly, but I thought that the ATS just sensed when the power was cut and switched to an alternative, can I tell the ATS that the power has been cut through the Solar Converters VCS-1AL.

Am I looking at a deferent type of ATS?

Can you suggest an ATS to go with the Solar Converters VCS-1AL please

[Willy T]

Ok maybe I haven’t quite got it yet

So I am using the pilot to trigger the ATS directly, but I thought that the ATS just sensed when the power was cut and switched to an alternative, can I tell the ATS that the power has been cut through the Solar Converters VCS-1AL.

Am I looking at a deferent type of ATS?

Can you suggest an ATS to go with the Solar Converters VCS-1AL please

I don't think you can use any of the ATS's you mentioned, they are for 240V split phase power ( USA ), your 230V / 50. You could use a double throw relay with a 230v coil where you have a NO / NC contact. If you want a delay in the switching you'll have to use two relays with a timer cube to delay the closure of the second relay. Check with a electrician in Spain to see how they would do it.

[paulcheung]

The ATS won't has any problem with the split 120/240 or 230 volt in the Europe. How the ATS work is the primary power source hold the coil that make the contact with the load and the primary power source, when the primary source cut off, the coil drop to the secondary source and connect to the load. For the 230 volts all you have to do is connect the two live line and leave the neutral wire alone.

Any good Inverter has adjustable low battery cut off will work with the ATS and it should has some time delay for momentary voltage drop by heavy load to prevent premature shut off, if the inverter the OP has don't has adjustable LVD, he need to get other means to cut off the inverter.

[P.B.R]

I don't think you can use any of the ATS's you mentioned, they are for 240V split phase power ( USA ), your 230V / 50. You could use a double throw relay with a 230v coil where you have a NO / NC contact. If you want a delay in the switching you'll have to use two relays with a timer cube to delay the closure of the second relay. Check with a electrician in Spain to see how they would do it.

Hi

My inverter doesn’t have a adjustable LVC it is set at 40V which is much to low for the health of my batteries,

I think I understand that - I must not cut the 48Vdc supply to the inverter as this will shock the inverter and the batteries.

What I can do is to us the VCS-1AL to sense when the battery bank drops to 48Vdc it will then send a 48Vdc signal to operate a solenoid to cut the 230Vac power between the inverter and the ATC

Now I am a bit confused would I need a 48Vdc solenoid switch which can switch 230Vac?

I have been looking but with no luck can anyone suggest a make model could use?

[Willy T]

Now I am a bit confused would I need a 48Vdc solenoid switch which can switch 230Vac?

The coil voltage does not matter as long as it's something you have present. 48v coil relays are hard to find, 230v should be easy in Spain. The VCS's relay does not care what voltage it switches, it's just a contact closure.

You seem to be over your head with this, seek some on-site help before you damage something.