Relays have output different ratings on their case.
Just For eg..output DC 100v 25 amp, 60 volt 45 amps.
Now, I would like to output 25 to 30 amps under 12v voltage DC supply. Since the rating (voltage and power)) is within the specified above intervals, any harm in supplying the relay with 12v DC to output 30 amps.
Thanks.