Mitsubishi Electric MELSEC A Series User Manual page 46

POINTS
*1 : Overcurrent protection
(a) The overcurrent protection device shuts off the 5VDC, 24VDC
ladder and stops the system if the current flowing in the ladder
exceeds the specified value.
When this device is activated, the power supply module LED is
switched off or dimly lit.
(b) If this happens, eliminate the cause of the overcurrent  for
example insufficient current capacity or short ladder  then
start up the system.
When the current has returned to normal, the system
undergoes an initial start.
*2 : Overvoltage protection
The overboltage protection device shuts off the 5 VDC ladder and
stops the system if an excessive voltage in the range 5.5 to 6.5V is
applied to this ladder.
When this device is activated, the power supply module LED is
switched off. If this happens, switch the input power OFF, then
back ON to restart the system.
If the system is not booted and the LED remains off, the power
supply module must be changed.
*3 : Allowable momentary power interruption time
The PC CPU allowable momentary power interruption time varies
according to the type of power supply module.
In the case of the A63P module, the allowable momentary power
interruption time is defined as from when the 24VDC stabilized
primary supply is cut off until the 24VDC voltage drops to the
defined voltage (15.6VDC).
33