Inovance IS620P Series Servo Drive Design and Maintenance Manual Guide: Installation, Debugging, Tuning and Upkeep

Introduction to the IS620P Design and Maintenance Philosophy

The Inovance IS620P series servo drive is engineered for high-performance motion control applications across a broad spectrum of industrial automation scenarios. Unlike a quick-start user guide, this article draws exclusively from the IS620P Series Servo Design and Maintenance Manual to provide a comprehensive treatment of the mechanical and electrical installation process, commissioning workflows, tuning methodology, and preventive maintenance procedures. The goal is to equip maintenance engineers and system integrators with the knowledge required to maximize the operational lifespan of the servo system while minimizing unplanned downtime.

The IS620P drive family spans multiple frame sizes designated SIZE A through SIZE F, covering rated power outputs from 50W to 7.5kW. The drives support 20-bit incremental encoders and 23-bit absolute encoders depending on the motor pairing, and they offer three control modes: position (P), speed (S), and torque (T). Communication options include Modbus (RS-232/RS-485), CANlink, and CANopen, making the IS620P adaptable to diverse上位机 architectures. Understanding the full maintenance lifecycle from installation through component replacement is essential for achieving the theoretical service life of each subsystem.

1. Mechanical and Electrical Installation

1.1 Mechanical Installation Requirements

The IS620P drive is designed for installation inside a control cabinet. The mounting orientation must be vertical, with the drive’s heat dissipation fins oriented downward to promote natural convection. When multiple drives are installed side by side, a minimum lateral clearance must be maintained to prevent thermal stacking. For SIZE A and SIZE B drives, the recommended lateral spacing is 10mm; for SIZE C and above, at least 25mm is required. The top and bottom clearance should each be no less than 50mm to allow adequate airflow through the cooling ducts.

The ambient operating environment must satisfy the following conditions: temperature range of 0 to 55 degrees Celsius (with derating required above 40 degrees), relative humidity of 5% to 95% non-condensing, altitude below 1000m above sea level (derate 1% per 100m above 1000m, up to a maximum of 4000m), and vibration resistance of 4.9m/s squared or less. Installing the drive in an environment that exceeds these specifications will accelerate component aging, particularly of the electrolytic capacitors and cooling fan, and will void the warranty.

The drive must be mounted on a flat, rigid metal surface to ensure proper heat conduction through the rear panel. If the mounting surface is uneven, thermal contact will be compromised, leading to localized hot spots on the power module. Use mounting screws of the specified torque: M4 screws at 1.2 to 1.5 Nm for SIZE A/B, and M5 screws at 2.0 to 2.5 Nm for SIZE C and above. Do not overtighten, as this may deform the drive chassis and stress internal PCB standoffs.

1.2 Electrical Installation and Wiring

The IS620P drive features several terminal blocks that must be wired according to strict specifications. The main power terminals include L1C and L2C for the control circuit power supply, and R, S, T for the three-phase main circuit input (or L1, L2 for single-phase models). The motor output terminals are U, V, W. The DC bus terminals P+ and D are used for connecting the internal or external braking resistor, with a shorting bar between P+ and D when the internal resistor is used.

For the control circuit power supply (L1C, L2C), the acceptable voltage range is 220V AC plus or minus 10% (198V to 264V) for 220V-class drives, and 380V AC plus or minus 10% (342V to 484V) for 380V-class drives. The main circuit voltage specifications are identical. It is critical to verify that the correct voltage class drive is connected to the matching supply voltage. Connecting a 220V-class drive to a 380V supply will immediately damage the bus capacitors and may cause catastrophic failure.

The CN1 connector is a 44-pin terminal block that carries all digital input (DI), digital output (DO), analog input (AI), analog output (AO), and pulse interface signals. The CN2 connector is a DB9 interface for the encoder. The CN3 connector provides RS-232 communication, and the CN4 connector provides RS-485 communication. The CN5 connector (available on some models) provides CAN communication. All signal cables must use shielded twisted pair construction, with the shield grounded at the drive end only to prevent ground loops.

1.3 Encoder Cable Wiring

The CN2 encoder connector uses a DB9 interface with the following pin assignment: Pin 1 is PS+ (encoder data positive), Pin 2 is PS- (encoder data negative), Pin 6 is +5V supply, Pin 8 is GND, and the shell is PE (protective earth). For 20-bit incremental encoders, the cable must be a double-shielded twisted pair with a maximum length of 20m. For 23-bit absolute encoders, an additional battery cable is required to maintain multi-turn position data during power-off states.

When fabricating custom encoder cables, verify pin-to-pin continuity at both ends using a multimeter. The most common encoder wiring failures are: PS+ and PS- swapped, 5V and GND reversed (which will burn the encoder), and broken wires due to insufficient strain relief at the connector. The impedance between PS+ and PS- at the motor side should measure approximately 100 ohms. The impedance between +5V and GND should measure approximately 2 kilohms. Infinite resistance indicates an open circuit; near-zero resistance indicates a short circuit.

1.4 Power Cable Wiring

The motor power cable connects the drive’s U, V, W terminals to the motor’s U, V, W terminals. The phase sequence must be strictly maintained: U to U, V to V, W to W. Reversed phase sequence will cause the motor to run in the opposite direction from the command, potentially triggering the Er.234 fly-run fault on vertical axes. The PE (protective earth) conductor must be connected at both the drive and motor ends to ensure safety and proper EMI performance.

For braking resistor connections, when using the internal resistor, short P+ and D with the provided shorting bar. When using an external resistor, remove the shorting bar and connect the external resistor between P+ and C. The external resistor’s resistance and power rating must be calculated according to the braking energy requirements of the application. The minimum allowable resistance is specified by parameter H02-21; setting a resistance below this value will damage the braking IGBT.

2. Commissioning and Auto-Tuning

2.1 Pre-Power Verification

Before applying power for the first time, perform a comprehensive verification checklist. First, disconnect all power cables from the drive and use a multimeter to measure the insulation resistance between each phase (R, S, T) and ground. The reading should be at the megohm level. Second, verify that the motor model number stored in parameter H00-00 matches the motor nameplate. Third, confirm that the drive model parameter H01-02 matches the actual drive nameplate. Fourth, check that all terminal screws are tightened to the specified torque, as loose power connections will cause overheating and arc damage.

After verification, apply control circuit power (L1C, L2C) first. The drive’s seven-segment display should show “rdy” (ready) after initialization. If the display shows “nrd” (not ready), the main circuit DC bus voltage is too low; this is normal if the main power has not yet been applied. Next, apply main circuit power. The display should remain “rdy” or transition to the run state when the servo-enable signal is activated.

2.2 Motor Parameter Configuration

The IS620P drive must be configured with the correct motor parameters before operation. Parameter H00-00 stores the motor number, which must match the motor nameplate exactly. Parameter H00-04 stores the encoder type: the first two digits indicate the encoder type, where 18 indicates a magnetic encoder and 23 indicates an optical encoder. If H00-00 is set to 14101, the motor is a magnetic-encoder type; otherwise, it follows the standard optical encoder configuration.

After setting the motor number, the drive automatically loads the corresponding motor parameters from its internal database, including rated current, rated torque, rated speed, rotor inertia, and encoder resolution. These parameters are critical for the current loop, speed loop, and position loop calculations. If the motor number is incorrect, the drive may exhibit excessive current draw, poor speed regulation, or immediate overcurrent faults (Er.201).

2.3 Angle Identification

For 23-bit absolute encoders, the initial electrical angle of the rotor must be identified before the drive can properly commutate the motor. This process is called angle identification. To perform angle identification, the motor must be mechanically disconnected from the load. Set parameter H0D-04 to 1 and press the SET key. The drive will inject current into the motor and rotate the shaft slightly to determine the rotor position. If the identification fails, the drive will report Er.602.

Common causes of angle identification failure include: the motor still connected to the load (which prevents free rotation), incorrect motor parameter settings (H01-24, H01-25, H01-27, H01-28), or excessive mechanical friction. After successful identification, the electrical angle is stored in non-volatile memory and does not need to be repeated unless the motor or encoder is replaced.

2.4 First Run and Jog Operation

After motor parameter configuration and angle identification, the servo can be enabled for the first time. Set the servo-enable signal (S-ON) to ON. The display should transition from “Rdy” to “Run.” To verify motor rotation, use the jog function: navigate to parameter H0D-00 and press the UP or DOWN key. The motor should rotate in the corresponding direction at the jog speed defined by H06-04 (default 10 rpm). If the motor does not rotate, check for mechanical jamming, brake engagement, or incorrect DI signal configuration.

3. Rigidity Setting and Inertia Identification

3.1 Load Inertia Ratio Concept

The load inertia ratio (H08-15) is defined as the total mechanical load moment of inertia divided by the motor rotor’s moment of inertia. This parameter is fundamental to the servo system’s dynamic performance. An incorrectly set inertia ratio will cause the auto-tuning algorithm to generate inappropriate gain values, leading to either sluggish response (ratio too high) or unstable oscillation (ratio too low).

The IS620P provides two methods for determining the load inertia ratio: offline identification and online identification. Both methods rely on the drive’s ability to measure the motor’s dynamic response during controlled acceleration and deceleration cycles. The identification accuracy depends on several conditions: the motor must reach at least 150 rpm during the test, the acceleration rate must exceed 3000 rpm/s, the load torque must be relatively stable, and the actual load inertia ratio must not exceed 120 times the motor inertia.

3.2 Offline Inertia Identification

Offline inertia identification is performed using the drive’s operation panel without any external controller. Navigate to parameter H0D-02 and press the SET key to enable the identification function. Two modes are available: the forward-reverse triangular wave mode (H09-05=0) and the jog mode (H09-05=1).

In the triangular wave mode, pressing and holding the UP or DOWN key causes the motor to alternately rotate forward and reverse in a symmetric triangular wave pattern. The motor speed, acceleration time, wait time, and number of rotations are controlled by parameters H09-06 (maximum speed, default 500 rpm), H09-07 (acceleration time, default 1000 ms), H09-08 (wait time, default 200 ms), and H09-09 (number of rotations for complete identification). This mode is suitable for applications with limited travel distance.

In the jog mode, pressing the UP key rotates the motor forward and pressing the DOWN key rotates it reverse, with the user manually controlling the duration and number of cycles. This mode is suitable for applications with longer travel distances where manual control is feasible.

Before performing offline identification, ensure that limit switches are installed and that the motor has at least one full revolution of travel in each direction. If the actual load inertia ratio exceeds 30 and H08-15 is still at the default value of 1.00, the motor may respond too sluggishly for successful identification. In this case, pre-set H08-15 to an initial value of 5.00 and incrementally increase it until the panel display begins updating during identification. Alternatively, increase the rigidity level (H09-01) to improve motor responsiveness.

During identification, if vibration occurs, immediately release the key to stop the process and reduce the gain before retrying. After the panel display stabilizes, press and hold the SET key until “SAVE” appears, confirming that the identified inertia ratio has been written to H08-15.

3.3 Online Inertia Identification

Online inertia identification is performed while the motor is operating under normal production conditions, with commands from the upper-level controller. The drive continuously monitors the motor’s dynamic response and updates the inertia ratio in real time. This method is particularly useful for applications where the load inertia varies during operation, such as robotic arms with changing configurations or winding systems with accumulating material.

3.4 Rigidity Table and Auto Gain Adjustment

After obtaining an accurate load inertia ratio, the auto gain adjustment function can be used to automatically set the speed loop gain, speed loop integral time constant, position loop gain, and torque command filter time constant based on a single rigidity level parameter (H09-01). The rigidity level ranges from 0 to 31, where 0 represents the lowest rigidity (minimum gain) and 31 represents the highest rigidity (maximum gain).

The recommended rigidity levels based on load mechanism type are as follows: levels 4 to 8 for large machinery with high inertia and low bandwidth requirements; levels 8 to 15 for belt-driven systems and other applications with relatively low mechanical rigidity; levels 15 to 20 for ball screw drives, direct-coupled loads, and other applications with high mechanical rigidity. The default factory setting is level 12.

Two auto-tuning modes are available. In the parameter self-tuning mode (H09-00=1), the first gain group parameters (H08-00, H08-01, H08-02, H07-05) are automatically updated based on the selected rigidity level. This mode is suitable for the vast majority of applications. In the positioning mode (H09-00=2), both the first and second gain groups are automatically updated, with the second gain group’s position loop gain set one rigidity level higher than the first. This mode also enables automatic gain switching with fixed parameters: gain switching delay of 5.0ms, gain switching level of 50, and gain switching hysteresis of 30. The positioning mode is recommended for applications requiring very fast settling times.

A third option is the single-parameter robust mode (H09-00=3), where the user adjusts only the position response bandwidth parameter H09-01 (in Hz), and the drive internally calculates all other gain parameters. This mode simplifies tuning to a single intuitive parameter and is particularly useful for operators who are not servo tuning experts.

4. Vibration Suppression

4.1 Understanding Servo System Vibration Sources

Vibration in servo systems originates from two primary sources: mechanical resonance within the drive-train structure, and low-frequency oscillation caused by load disturbances and gain mismatch. The IS620P provides a comprehensive suite of vibration suppression tools organized into four frequency bands: mechanical resonance above 800Hz addressed by notch filters (NTF1 through NTF4), high-frequency vibration at 500Hz and above addressed by VIBSUP1, mid-frequency vibration at 300Hz and above addressed by VIBSUP2, and low-frequency vibration below 300Hz addressed by VIBSUP3.

4.2 Notch Filters for Mechanical Resonance

The IS620P provides four groups of notch filters. The first and second groups are manual notch filters, with parameters set entirely by the user. The third and fourth groups can be configured as either manual or adaptive notch filters via parameter H09-02. When H09-02 is set to 1, one adaptive notch filter is enabled; when set to 2, two adaptive notch filters are enabled. The adaptive notch filter automatically detects the resonance frequency during motor operation and sets the notch parameters accordingly.

Each notch filter group has three parameters: frequency (H09-12/H09-15/H09-18/H09-21, range 10 to 4000 Hz), width level (H09-13/H09-16/H09-19/H09-22, range 0 to 20), and depth level (H09-14/H09-17/H09-20/H09-23, range 0 to 32). When the frequency is set to the default value of 4000Hz, the notch filter is inactive. The recommended workflow is to first try the adaptive notch filter; if it is ineffective or insufficient, then manually configure the notch filter parameters based on frequency analysis data obtained from the InoServoShop debugging software’s oscilloscope function.

4.3 Torque Command Filter

The torque command filter (H07-05 for the first gain group, H07-06 for the second gain group) attenuates high-frequency components of the torque command above a cutoff frequency defined as fc = 1 / (2 * pi * H07-05 * 0.001) Hz. This is a simple first-order low-pass filter that reduces the overall gain at high frequencies. While effective for suppressing high-frequency resonance, it also reduces the system’s bandwidth and should be used judiciously. The default value is 0.50ms, corresponding to a cutoff frequency of approximately 318Hz.

4.4 Vibration Suppression Filters

The VIBSUP1 and VIBSUP2 filters target vibrations in the 500Hz and 300Hz ranges respectively. Each filter has three parameters: phase adjustment (H08-34 for VIBSUP1, H08-37 for VIBSUP2), frequency (H08-35 for VIBSUP1, H08-38 for VIBSUP2), and compensation (H08-36 for VIBSUP1, H08-39 for VIBSUP2). The VIBSUP3 filter targets low-frequency vibration below 300Hz with parameters H08-53 (frequency, 0.1Hz resolution, range 0 to 600.0Hz), H08-54 (compensation, range 0 to 200%), and H08-56 (phase adjustment, default 300).

When configuring vibration suppression filters, the phase adjustment parameter is typically left at the default value, as it controls the synchronization between the compensation signal and the vibration signal. The frequency parameter must be set to match the actual vibration frequency observed in the system. The compensation parameter controls the strength of the suppression; start with a low value and incrementally increase until the vibration is adequately suppressed without introducing new instability.

4.5 Practical Tuning Workflow

The recommended vibration suppression workflow is as follows: First, perform inertia identification and set the rigidity level using auto-tuning. If the motor produces audible noise or visible vibration at the desired rigidity level, enable one adaptive notch filter (H09-02=1) and allow the motor to run for several minutes. If the vibration persists, enable a second adaptive notch filter (H09-02=2). If vibration is still present, use the InoServoShop oscilloscope to capture the vibration frequency spectrum and manually configure the notch filter or VIBSUP parameters. As a last resort, reduce the rigidity level by one or two steps and re-evaluate.

5. Preventive Maintenance Procedures

5.1 Daily Inspection Checklist

Daily inspections are performed under the assumption of an average ambient temperature of 30 degrees Celsius, an average load rate below 80%, and daily operating time under 20 hours. The daily inspection checklist includes the following items: verify that the ambient temperature, humidity, dust level, and foreign matter are within acceptable ranges; listen for abnormal vibration or noise from the drive and motor; check that the power supply voltage is within specification; detect any unusual odors that may indicate overheating components; inspect ventilation openings for fiber or lint accumulation; check the cleanliness of the drive’s front panel and connectors; and verify that no foreign matter has entered the load-side mechanism.

5.2 Annual Inspection Checklist

Annual inspections should be performed at least once per year, preferably during scheduled maintenance shutdowns. The annual checklist includes: checking all fastening points for loosening due to thermal cycling and vibration; inspecting for signs of overheating such as discoloration of terminal blocks or wiring insulation; examining terminal blocks for physical damage; and verifying that all terminal screws are still at the specified torque. Any components showing signs of thermal stress should be replaced proactively, as continued operation will lead to failure.

5.3 Component Replacement Schedule

The IS620P design and maintenance manual specifies standard replacement periods for critical wear components. These periods are reference values based on typical operating conditions; actual replacement timing should be adjusted based on the specific operating environment and load profile. The replacement schedule is as follows:

Component	Category	Standard Replacement Period
Drive bus filter capacitor	Drive	Approximately 5 years
Drive cooling fan	Drive	2 to 3 years (10,000 to 30,000 hours)
Drive PCB aluminum electrolytic capacitor	Drive	Approximately 5 years
Drive power-on buffer relay	Drive	Approximately 100,000 operations
Drive buffer resistor	Drive	Approximately 20,000 operations
Motor bearing	Motor	3 to 5 years (20,000 to 30,000 hours)
Motor oil seal	Motor	5,000 hours
Motor encoder	Motor	3 to 5 years (20,000 to 30,000 hours)
Absolute encoder battery	Motor	Varies; refer to battery documentation

It is emphasized that these are standard replacement periods only. If any abnormality is detected during daily or annual inspections, the affected component must be replaced immediately, regardless of whether the replacement period has been reached. Conversely, components operating in benign environments with light duty cycles may exceed the standard period, but this should be validated through inspection rather than assumed.

5.4 Cooling Fan Maintenance

The cooling fan is the most frequently replaced component in the IS620P drive. Fan failure will cause the drive’s internal temperature to rise rapidly, triggering the Er.650 heatsink overheat fault. To check fan operation, observe the fan blade rotation while the drive is powered on. If the fan is not rotating or is rotating abnormally slowly, inspect for physical obstructions such as dust buildup or foreign objects lodged in the blade housing. Clean the fan and heatsink fins using compressed air at low pressure (below 0.1 MPa). If the fan does not resume normal operation after cleaning, the drive must be replaced or returned for service.

To extend fan life, ensure that the cabinet’s external ventilation system is adequate. The cabinet’s internal temperature should not exceed 45 degrees Celsius under normal operating conditions. If multiple drives are installed in the same cabinet, consider adding cabinet-level forced air cooling or air conditioning to reduce the thermal load on each drive’s internal fan.

5.5 Bus Capacitor Degradation

The DC bus filter capacitors degrade over time due to electrolyte evaporation and internal chemical changes. Capacitor degradation manifests as increased equivalent series resistance (ESR) and decreased capacitance, leading to higher bus voltage ripple and reduced energy absorption capacity for regenerative braking. In severe cases, capacitor failure can cause bus voltage instability, triggering Er.410 (undervoltage) faults even under light load conditions, or physical swelling and leakage that damages adjacent components.

To assess capacitor health, monitor the DC bus voltage ripple using the InoServoShop software’s oscilloscope function under steady-state operating conditions. A significant increase in ripple amplitude compared to baseline measurements indicates capacitor degradation. Additionally, if the drive reports Er.410 during light-load operation or if the bus voltage (H0B-07) reads abnormally low after power-on, capacitor replacement should be scheduled.

5.6 Absolute Encoder Battery Replacement

For motors equipped with 23-bit multi-turn absolute encoders, an external battery (model S6-C4, 3.6V lithium) maintains the multi-turn position data when the drive is powered off. The battery’s theoretical service life is calculated as battery capacity divided by annual consumption: 2600mAH / 70mAH = approximately 37 years. However, actual battery life is significantly shorter due to self-discharge, temperature effects, and circuit leakage.

The battery alarm voltage threshold is 2.85V to 3.15V. When the battery voltage drops to this range, the drive will report Er.731 (encoder battery failure). To replace the battery, use only the specified S6-C4 model. The battery cable polarity must be strictly observed: the blue wire connects to positive and the blue-black wire connects to negative. Reversed polarity will damage the encoder. After replacing the battery, set H0D-20 to 1 to clear the fault.

5.7 Parameter Backup and Drive Replacement

When replacing a faulty drive, it is essential to transfer all user-configured parameters from the old drive to the new one before beginning operation. Use the InoServoShop software to upload parameters from the old drive, then download them to the new drive. Critical parameters that must be transferred include: motor number (H00-00), drive model (H01-02), control mode (H02-02), DI/DO assignments (H03 group), electronic gear ratio (H05 group for position mode), speed and torque parameters (H06 group), gain parameters (H07 and H08 groups), auto-tuning settings (H09 group), and communication parameters (H10 through H31 groups).

After parameter transfer, perform angle identification (H0D-04=1) if the motor has a 23-bit absolute encoder, as the electrical angle data is specific to the motor-encoder pairing and is stored in the drive. Verify that the motor number (H00-00) and encoder type (H00-04) match the motor nameplate before performing angle identification. After identification, jog the motor to verify correct rotation direction and smooth operation before reconnecting the mechanical load.

5.8 Insulation Resistance Testing

Periodic insulation resistance testing is recommended for motors operating in humid or contaminated environments. Before performing the test, disconnect all cables from the drive to prevent damage to internal electronics. Use a 500V megohmmeter to measure insulation resistance between each motor phase winding (U, V, W connected together) and the motor frame (PE). The insulation resistance should exceed 100 megohms for a new motor. If the reading is below 10 megohms, the motor windings are contaminated or degraded and the motor should be serviced or replaced.

Do not perform insulation resistance testing on the drive itself. The drive’s internal components, particularly the IGBT modules and control circuitry, are not designed to withstand megohmmeter voltages and will be permanently damaged. If drive-side insulation is suspected, contact Inovance technical support for diagnostic assistance.

6. Communication System Maintenance

6.1 Modbus RS-485 Bus Maintenance

The IS620P supports Modbus communication via RS-232 (CN3) or RS-485 (CN4). For RS-485 multi-drop configurations, the recommended bus topology is a daisy-chain (hand-in-hand) connection. Star topology is explicitly prohibited as it causes signal reflections and communication errors. Branch lines from the main bus to individual nodes should not exceed 3 meters in length. The bus must use twisted pair shielded cable, with the shield connected to PE at both ends.

Terminal resistors of 120 ohms should be installed at both ends of the RS-485 bus to prevent signal reflection. If communication errors occur, first verify the physical wiring topology, then check for proper grounding (a dedicated PE conductor should connect all nodes, not just the shield), and finally verify that the baud rate (H10-03) and station address (H10-00) settings are unique and correct for each node on the bus.

6.2 CANlink and CANopen Communication

For CANlink and CANopen communication, the CAN bus uses CN5 with CANH and CANL signals. The bus must be terminated with 120-ohm resistors at both physical ends. If the CAN communication LED on the drive blinks rapidly or remains solid, it indicates a communication error. Common causes include: missing termination resistors, excessive bus length (maximum 40m at 1Mbps), too many nodes (maximum 30 for CANlink, 127 for CANopen), or electrical interference from nearby power cables.

Conclusion

The IS620P series servo drive is a robust and capable platform that rewards disciplined installation and maintenance practices. By following the mechanical installation guidelines, performing thorough commissioning and auto-tuning procedures, implementing appropriate vibration suppression strategies, and adhering to the preventive maintenance schedule, system integrators and maintenance engineers can achieve reliable operation over the full designed service life of the equipment. The key principles are: verify before powering, identify before tuning, tune before running, and inspect regularly to prevent rather than react. When component replacement becomes necessary, always transfer parameters from the old drive and perform angle identification before returning the system to production.