Selection Of Main Circuit Power Supply/Control Circuit Power Supply - Mitsubishi Electric MR-J4-10A(-RJ) Instruction Manual

18. MR-J4-03A6(-RJ) SERVO AMPLIFIER

18.3.3 Selection of main circuit power supply/control circuit power supply

The inrush current at power on will be large because a resistance for protecting inrush current is not built-in
in the main circuit power supply of the servo amplifier. The main circuit capacitor capacity of the servo
amplifier is approximately 270 μF. When the load characteristic (overcurrent protection criteria) of the power
unit is current fold back method, the power cannot be started. Be careful when selecting a power. Especially
when the power is turned ON/OFF on the power unit output side, approximately 100 μs to 300 μs
instantaneous current will flowed at power on due to capacitor charge. Therefore, a power unit such as one
which operates overcurrent at 1 ms or less cannot be used.
A circuit to protect inrush current at power on is built-in in the control circuit power supply of servo amplifier.
In addition, when using main circuit power supply and control circuit power supply, use a reinforced
insulating type.
18.3.4 Power-on sequence
(1) Power-on procedure
1) When wiring the power supply, use a circuit protector for the power supply (24/PM). Configure up
an external sequence so that the relay connected to PM turns off when an alarm occurs.
2) Switch on the control circuit power supply (24/0) simultaneously with the main circuit power
supply (PM/0) or before switching on the main circuit power supply. If the main circuit power
supply is not on, the display shows the corresponding warning. However, by switching on the
main circuit power supply, the warning disappears and the servo amplifier will operate properly.
3) The servo amplifier receives the SON (Servo-on) within 2.5 s to 3.5 s after the main circuit power
supply is switched on. Therefore, when SON (Servo-on) is switched on simultaneously with the
main circuit power supply, the base circuit will switch on in about 2.5 s to 3.5 s, and the RD
(Ready) will switch on in further about 5 ms, making the servo amplifier ready to operate. (Refer
to (2) in this section.)
4) When RES (Reset) is switched on, the base circuit is shut off and the servo motor shaft coasts.
(2) Timing chart
Main circuit
power supply
Control circuit
Base circuit
SON (Servo-on)
RES (Reset)
RD (Ready)
ALM
(Malfunction)
POINT
The voltage of analog monitor output, output signal, etc. may be unstable at
power-on.
SON (Servo-on) accepted
(2.5 s to 3.5 s)
ON
OFF
ON
OFF
ON
OFF
ON
OFF
5 ms
ON
OFF
No alarm (ON)
Alarm (OFF)
10 ms
95 ms
10 ms 5 ms
2.5 s to 3.5 s
18 - 22
10 ms 95 ms
10 ms 5 ms 10 ms