I’m guessing that maybe this is 24V with a 100x offset (manual pages say something about 10x), but it’s a bit disconcerting and should be easy to fix.
Also, shouldn’t the health output include the system temperature?
[admin@MikroTik] > /system health print
voltage: 2416.9V
[admin@MikroTik] > /system resource print
uptime: 3d12h4m51s
version: 5.5
free-memory: 18608KiB
total-memory: 29708KiB
cpu: MIPS 24Kc V7.4
cpu-count: 1
cpu-frequency: 680MHz
cpu-load: 3%
free-hdd-space: 30828KiB
total-hdd-space: 61440KiB
write-sect-since-reboot: 163740
write-sect-total: 785095
bad-blocks: 0%
architecture-name: mipsbe
board-name: RB750G
platform: MikroTik
Firmware version is 2.29…