Hi everyone, I want to use a relay to cut off the voltage of 230V DC and the current is about 30 A and controlled by esp 32. Is there any suggestion of module or circuit for this? because I am very confused when choosing a relay. Thank you

 

There are many power relays that support 30A currents, I dont know what is availible where you are right now. More important is that between your output pin and the relay you must have another stage, a transistor that will drive the relay coil. Something like this:

 

There are many power relays that support 30A currents, I dont know what is availible where you are right now. More important is that between your output pin and the relay you must have another stage, a transistor that will drive the relay coil. Something like this:
View attachment 342709

what type of relay module is used? maybe you can mention the specifications?

 

I was presenting you a schematic how to wire the output of your ESP32 to the coil of the relay.
As I said I dont know what is availible to you. From the top of the google here is a relay from (I guess) Canadian store:
https://www.progressiveautomations.ca/products/ac-31-30-24

 

I was presenting you a schematic how to wire the output of your ESP32 to the coil of the relay.
As I said I dont know what is availible to you. From the top of the google here is a relay from (I guess) Canadian store:
https://www.progressiveautomations.ca/products/ac-31-30-24

Actually I am still confused about the concept of this relay. For my input is 230 V DC, if I use that, can it still work well? because it says the input voltage is 24 V DC. This 225 V DC is from a 70 Cell series battery. Sorry I am still a layman regarding things like this. and maybe if there are other suggestions are allowed.

 

24VDC is the voltage needed to activate the coil, not the limit of the voltage that you switch.
If the basic concept of relay is not familiar to you, due to your safety, I would not advise you to proceed on this quest alone. Find a more skilled dude that can help you. Even if we give you 100% of the schematic and the components, you can mess up something building your setup, and 200+VDC is not a joke.

 

hi mhi,
Look over this PDF.
What voltage is the Vcc on your diagram?
E

 

I want to use a relay to cut off the voltage of 230V DC and the current is about 30 A

This is a concerning issue, 230VDC @ 30A. If the contacts are rated for 30A at 240VAC then they are NOT rated for 230VDC. With AC you get a self extinguishing arc every time the voltage crosses zero volts. You don't get that extinguishing with DC. You can get an arc that will hold 230VDC even though they've opened up. ESPECIALLY at high currents. The contacts will burn away until the relay goes into complete failure.

I'm not aware of DC relays at that high a voltage AND current. I have seen mercury relays that handle high current but the highest voltage I've seen has been at 32VDC.

Here's a demonstration of high voltage and high current both in AC and DC configurations. Notice how the DC arcs. The same thing will be occurring on your relay contacts IF they are not rated for 240VDC @ 30A

 

Solid state relay or thyristor? Just what is your relay activation voltage?

 

SamR

I want to use a relay to cut off the voltage of 230V DC and the current is about 30 A

I don't think a relay has been chosen yet. I believe these are the parameters the TS is in search of.