Voltage through dry contacts (BMS)

[Robbert]

I would like to program and use the dry contacts in my new JK-inverter BMS.
The purpose of this is to control a relay that switches AC-power-in to the inverter to 'ON' if the battery gets below a certain SOC.
That way the inverter is disconnected most of the time from the grid and only has AC power at the moment required.
Some relays use a low DC control voltage, while others accept 240v AC as control voltage.

In the dry contacts only miliamps will be flowing, since it is only to control the relay. Is it safe to do this with 240 volts?

 

[timselectric]

You would have to check the specs for the dry contacts. (Hopefully provided with your unit)

 

[Robbert]

You would have to check the specs for the dry contacts. (Hopefully provided with your unit)

Thanks, couldn't find that in the documentation from JK.

To be on the safe site, I think Ill get one that allows 12v DC, as control voltage. Only consequence, in that case, is that I need to get a dc to dc stepdown converter as well.

12volts sounds much safer anyway. ..

 

[timselectric]

Thanks, couldn't find that in the documentation from JK.

To be on the safe site, I think Ill get one that allows 12v DC, as control voltage. Only consequence, in that case, is that I need to get a dc to dc stepdown converter as well.

12volts sounds much safer anyway. ..

It just depends on what voltage the dry contacts are rated for.
Most of the ones I have seen are rated up to 250v.
But, that would have to be confirmed.