Mitsubishi Electric C70 Connection Manual page 13

(5) Troubleshooting
Use a servomotor with electromagnetic brakes or
establish an external brake mechanism for the
purpose of holding; this serves as countermeasures
for possible hazardous situation caused by power
failure or product fault.
Use a double circuit structure for the
electromagnetic brake's operation circuit so that the
brakes will activate even when the external
emergency stop signal is issued.
The machine could suddenly restart when the power is restored after an instantaneous power failure, so stay
away from the machine. (Design the machine so that the operator safety can be ensured even if the machine
restarts.)
To secure the absolute position, do not shut off the servo drive unit's control power supply when its battery
voltage becomes low (warning 9F)
If the battery voltage drop warning alarm occurs, make sure to back up the machining programs, tool data and
parameters, etc. with the input/output device before replacing the battery.
Depending on the level of voltage drop, there is the possibility of memory loss. Reload all the data backed up
before the alarm occurrence.
CAUTION
Shut off with motor
brake control output
Servomotor
Electro-
magnetic
brake
Shut off with CNC
brake control PLC
output
MBR EMG
24VDC