I’m connecting two power sources to one output, One is a positive output and the other is a negative output. It works when one is on at a time.
I’m trying to protect it so that both power sources don't accidentally get turned on at the same time.

So, I’ve added a high/low trigger relay module. I got the first relay to work just fine. I’ve connected the DC+ to IN1 because when the power source gets turned on the relay turns on.

By connecting the second power source, in the same way, continuity makes both IN1 and IN2 triggers, and both relays turn on.

If I'm using the right type of module what can I do about the wiring? Or, is there another type of module I can research?
FYI- I've attached a pic of my connections.

 

Just use IN1 and IN2 on their own and it will work. You need to wire the relay contacts across the supply and use the Com terminals to feed the load.

 

I would use a simple approach: Single pole, double throw switch. That way only one power supply can be connected at a time and they are (supposedly) never connected to each other.

 

Just use IN1 and IN2 on their own and it will work.

This is what I would like.

You need to wire the relay contacts across the supply and use the Com terminals to feed the load.

I'm so sorry, but I'm not getting it. Can you please tell me what to what? I've written out what I tried, on the left side. No Power.
(Left Side)
Power + to IN1
IN1 to NO1
Power - to DC -
DC - to NC1
Com 1 to Device +
NC1 to Device -

 

I would use a simple approach: Single pole, double throw switch. That way only one power supply can be connected at a time and they are (supposedly) never connected to each other.

I could have, but I'm needing an automated approach.

 

To automate it, you need to prioritize which supply should be connected if they are both present. Once you have done that, it is simple relay logic.

 

I’m connecting two power sources to one output, One is a positive output and the other is a negative output.

Please explain this in more detail. Manufacturer / part numbers would help. Post #3 assumes that the common or return or GND connections of the two supplies can be connected together, and a SPDT switch selects which + output goes to the load. My read of your post is that the two supplies cannot be common-grounded, so you need the equivalent of a DPDT relay. This can be two SPDT relays if connected correctly.

Here's the question:

If both supplies (we'll call then PS1 and PS2) are active at the same time, which one powers the load?

ak