3. SIGNALS AND WIRING 
 
3 -  2 
 
POINT 
 
When you use a linear servo motor, replace the following left words to the right 
words. 
Load to motor inertia ratio   → Load to motor mass ratio 
Torque  → Thrust 
(Servo motor) speed   → (Linear servo motor) speed 
 
 
3.1 Input power supply circuit 
 
CAUTION 
Always connect a magnetic contactor between the power supply and the main 
circuit power supply (L1, L2, and L3) of the servo amplifier, in order to configure a 
circuit that shuts down the power supply on the side of the servo amplifier’s power 
supply. If a magnetic contactor is not connected, continuous flow of a large 
current may cause a fire when the servo amplifier malfunctions. 
Use ALM (Malfunction) to switch main circuit power supply off. Not doing so may 
cause a fire when a regenerative transistor malfunctions or the like may overheat 
the regenerative resistor. 
Check the servo amplifier model, and then input proper voltage to the servo 
amplifier power supply. If input voltage exceeds the upper limit of the 
specification, the servo amplifier will break down. 
The servo amplifier has a built-in surge absorber (varistor) to reduce noise and to 
suppress lightning surge. The varistor can break down due to its aged 
deterioration. To prevent a fire, use a molded-case circuit breaker or fuse for input 
power supply. 
Connecting a servo motor of the wrong axis to U, V, W, or CN2 of the servo 
amplifier may cause a malfunction. 
 
 
POINT 
 
EM2 has the same function as EM1 in the torque control mode. 
Connect the 1-phase 200 V AC to 240 V AC power supply to L1 and L3. One of 
the connecting destinations is different from MR-J3 Series Servo Amplifier's. 
When using MR-J4 as a replacement for MR-J3, be careful not to connect the 
power to L2. 
 
 
Configure the wirings so that the main circuit power supply is shut off and SON (Servo-on) is turned off after 
deceleration to a stop due to an alarm occurring, enabled servo forced stop, etc. A molded-case circuit 
breaker (MCCB) must be used with the input cables of the main circuit power supply.