The smoke/heat detector requires only 23 mA from a power source while standing by and monitoring for smoke or heat. The current requirements jumps to 51 mA once smoke or heat has been detected and the alarm is sounding. Please note that the smoke/heat detector does not receive its power from the NMEA 2000 network. The smoke/heat detector must be wired to its own power source, which means it can remain operational even though the NMEA 2000 network is powered down.