I'm trying to find a way to have one relay lock its state if the other is on.
Example, 2 relays total:
If relay 1 is on then relay 2 can't change state, either turn on or off. Meaning if relay 2 is on when you turn relay 1 on then you CAN NOT turn relay 2 back off. And, if relay 2 is off and you turn relay 1 on then you CAN NOT turn it on. Both relays need to be able to work independently i.e. no flipflop action or toggle action.
Practical application = Relay one is a 32v supply. Relay 2 is a series of relays that can flip a transformer around (swap primary and secondary) to flip step-up step-down function. You can turn on the 32v with relay 1 without consequence regardless of relay 2's state. However, if you already have relay 1 on and flip transformer around (relay 2) then you will damage the circuit from the voltage spikes. So, if relay 1 is on and you want to change the state of relay 2 you must first turn off relay 1.
It seems like something in the SR latch world may help but I'm having a tough time actually figuring the circuit out. The switches to activate the relays can be momentary or latching, as I can make either work.