MITSUBISHI MDS-B servo troubleshooting

75 L overvoltage NR (NC reset) L+and L - voltage exceeds 410V, check the input voltage and regeneration resistor

6B surge relay fused PR relay contact not disconnected, power supply unit needs to be replaced

Special note: After alarm 73 occurs, even if NC is restarted immediately, it cannot be resolved. The control power supply (L11, L21) must be kept powered on for more than 15 minutes to allow internal heat accumulation to dissipate. Frequent alarm 73 may cause a fire due to overheating of the external regenerative resistor. Do not blindly switch on the power repeatedly.

4.2 External emergency stop function (newly added to MDS-B)

The B series has added an external emergency stop input terminal to the CN23 connector, which can achieve dual protection:

Enabling conditions: Set the rotary switch to 4 (contactor valid) or 5 (contactor invalid), and increase the parameter PTYP by 0040 (hexadecimal)

Action logic: If the external emergency stop input lasts for more than 200ms and no NC contactor OFF command is received within 30 seconds, CV will forcibly cut off the contactor itself

Related alarms:

Display "76": External emergency stop setting error (rotation switch does not match PTYP)

Display 'q6F': External emergency stop input is valid but NC does not provide an emergency stop status

Key parameters and debugging of servo drive (MDS-B-V1)

5.1 Special treatment of dynamic brakes

The MDS-B-V1-110/150 (11kW/15kW) drive unit does not have a built-in dynamic brake and must be externally connected to the MDS-B-DBU-150 dynamic brake unit. When wiring, two modes should be distinguished:

Only use dynamic braking: Connect DB1/DB2 of DBU in series to the main circuit DC bus, and connect the control coil to 24VDC

Dynamic braking+electromagnetic braking combination: A dual protection sequence needs to be designed to ensure delayed release of electromagnetic braking after dynamic braking action

5.2 Current Limit Parameters (SV013 ILMT1)

SV013 is set as a percentage of the rated current for motor stalling. If the maximum output torque of the driver is required, set it to 500%. The maximum current reference values for each motor are as follows:

Motor model locked rotor current (A) maximum current (A) maximum torque (N · m)

HA40N 3.6 17 14.2

HA80N 6.6 28 25.5

HA100N 14 42 42

HA200N 22 57 60

HA300N 37 85 87

HA053 1.4 3.9 0.69

Reducing SV013 can limit torque output and is suitable for debugging or light load protection.

5.3 Resolution Setting of Position Detector (SV019/SV020)

Proper settings are required when using different encoders:

Encoder type resolution RNG1 RNG2

OHE25K-6 / OSE104 25000p/rev 100 100

OSE105 / OSA105 1,000,000p/rev 1000 1000

Built in motor (HA053/13) 2500p/rev 10 10

When mixing MP scales, SV019/SV020 should be set according to the actual resolution.

The Use and Sequence Design of Electromagnetic Brakes

6.1 Brake characteristic data

Motor model: Static friction torque release, delayed braking, delayed single allowable braking power

HA053B/13B 0.39 N·m 0.03s 0.10s 5.6 J

HA23NB/33NB 1.96 N·m 0.05s 0.20s 49 J

HA40NB/80NB 5.88 N·m 0.07s 0.24s 294 J

HA100NB~300NB 29.42 N·m 0.10s 0.27s 980 J

6.2 Vertical axis safety sequence

To prevent the vertical axis from slipping due to power failure, the following sequence must be used:

NC issues servo OFF command

The dynamic brake immediately activates (decelerates)

After the motor speed drops below the brake action threshold, cut off the excitation of the electromagnetic brake

The servo main circuit can only be closed after the electromagnetic brake is fully closed (with a delay time of about 0.1~0.27s)

It is strictly prohibited to directly cut off the excitation of the electromagnetic brake in the servo ON state, otherwise it will cause excessive wear of the brake liner.

6.3 Preparation of excitation power supply for brake

The brake requires an external 24VDC power supply, and the current capacity is selected according to the motor model:

HA053B/13B：≥0.5A

HA23NB/33NB：≥0.7A

HA40NB/43NB/80NB/83NB：≥0.9A

HA100NB~900NB：≥1.5A

Unit heat dissipation and installation spacing

7.1 Heat Calculation

The heat generation of each unit (unit: W) is as follows (typical values of B series):

|Power supply unit| CV-37:55 | CV-55:65 | CV-75:80 | CV-110:125 | CV-150:155 | CV-185:195 | CV-220:210 | CV-260:260 | CV-300:320 |

|Spindle drive| SP-04:30 | SP-15:50 | SP-37:80 | SP-75:140 | SP-110:185 | SP-150:240 | SP-185:350 | SP-220:375 | SP-300:635 |

|V1 servo| V1-01:20 | V1-05:35 | V1-20:80 | V1-45:160 | V1-70:245 | V1-90:285 | V1-110:400 | V1-150:550 | — |

When fully enclosed, the heat emitted outside the cabinet is (heat generation constant) × 0.85. A fan for forced convection should be installed inside the cabinet to avoid heat accumulation at the top.

7.2 Installation Space Requirements

The spacing between units should be ≤ 3cm. If it exceeds 3cm, it should be handled according to the requirements of Section 4.3 (busbar length ≤ 50cm, and double line binding)

Servo drive units and spindle drive units above 11kW must be installed adjacent to the power supply unit, with the priority order being: V1-150>V1-110>SP-300>SP-260>

Small power units (9kW and below) can be installed separately, but it is necessary to ensure that the bus voltage drop is acceptable