Fault diagnosis of LTi CDE/CDB3000

Fault diagnosis of LTi CDE/CDB3000

Product positioning and safety boundaries

CDE/CDB3000 is a positioning controller series launched by LTi DRiVES, with a current coverage of 2 A to 210 A, widely used in industrial machinery, automation production lines, servo drives, and positioning systems. This series includes two main models, CDE3000 and CDB3000. The former is typically used in situations that require higher dynamic performance, while the latter is more suitable for basic positioning and speed control. Regardless of the model, they belong to "components installed in fixed electrical systems or machines" and cannot be put into intended use until the entire machine complies with the EU Machinery Directive 2006/42/EEC. Debugging must comply with EMC Directive 2004/108/EEC, and the equipment itself must comply with Low Voltage Directive 2006/95/EC.

Safety is the first principle when using CDE/CDB3000. There is a dangerous voltage of 230 V/460 V inside the equipment, and the DC bus may still be charged within 10 minutes after cutting off the power supply. Rotating components, hot surfaces, and magnetic fields generated by permanent magnet motors can all cause harm. Installation, maintenance, and commissioning can only be carried out by personnel with electrical engineering qualifications and familiarity with accident prevention regulations. Pacemakers, metal implants, and hearing aid wearers should stay away from the installation, maintenance, and operation areas of the drive system. During equipment operation, ventilation openings must not be covered, and moisture, conductive substances, drilling debris, or foreign objects must not be allowed to enter. If used in explosive hazardous areas, additional standards such as EN 50014 and EN 50018 must be followed.

Mechanical installation and heat dissipation design

The mechanical installation method of CDE/CDB3000 directly affects heat dissipation and EMC performance. Common installation methods include wall mounted installation, cold plate installation, through wall radiator installation, and liquid cooling installation.

When installing on the wall, the installation hole position should be marked on the back panel first, and the positioning controller should be installed vertically after tapping. The backboard must have a shiny metal and good grounding. It is recommended to use galvanized or chromed backboards. If the back panel is painted, the coating on the contact area should be removed. The minimum spacing between controllers and between controllers and cabinet walls should be maintained: typically 200 mm at the top and bottom, and 50 mm on the sides; if side option modules need to be replaced, the spacing should be increased to 50 mm. For low-power models such as CDE/CDB32.003 and 32.004, they must be installed on galvanized/chromed backplates with a cooling area of 0.065 m ². If cold plate installation is used, the appropriate external heat sink HS3x.xxx should be selected according to the power.

The installation of through wall radiators is suitable for BG3 to BG6, with a protection level of IP54 on the radiator side and IP20 on the inside of the cabinet. During installation, the sealing rings around must be flat and not damaged. The power loss distribution is roughly as follows: the external radiator bears 70% to 80%, and the internal radiator bears 20% to 30%. The size of the through wall opening varies depending on the model, with BG3 being 75 × 305 mm, BG4 being 125 × 305 mm, BG5 being 175 × 305 mm, and BG6 being 200 × 355 mm. The liquid cooling model is suitable for BG6, BG7, and BG7a, with a maximum coolant pressure of 2 bar and a coolant temperature above 40 ° C to avoid condensation. Water, ethylene glycol mixture, oil, etc. can be used.

Regardless of the installation method, the cable between the main power filter and the controller should not exceed 30 cm. The cable between the line reactor and the controller should also be as short as possible. Motor cables must use shielded cables, with both ends of the shielding layer grounded to reduce interference emissions.

Electrical Installation and EMC Specification

The electrical installation of CDE/CDB3000 includes main power connection, motor connection, encoder connection, control terminal connection, and STO safety connection. The terminal layout varies for different BG sizes: BG1 to BG5 use X1 to connect the main power supply, motor, and braking resistor; BG6, BG7, and BG7a are connected to the main power supply using X1, and to the motor and DC bus using X21.

Before connecting the main power supply, the cable cross-sectional area must be determined, and suitable main fuses and circuit breakers must be selected. 230 V single-phase equipment uses 1 × 230 V AC, while 400/460 V three-phase equipment uses 3 × 400 V AC to 3 × 460 V AC. TN and TT networks are allowed to be used, but IT networks are prohibited from being used. If the power supply system does not meet overvoltage category III, line reactors must be used. Line reactors can also reduce harmonic distortion and extend the lifespan of DC bus capacitors. For CDE/CDB34.044 to 34.208, line reactors are necessary.

The key measures for EMC installation include: using star shaped connections for protective conductors, and connecting all protective conductor terminals to the PE row inside the cabinet; Separate the wiring of motor cables, power cables, and control cables; Use double copper braided shielded cables with a coverage rate of 60% to 70%; Shielded cables must be used for analog input and output; Inductive loads such as contactors, relays, and solenoid valves must be equipped with suppression circuits and placed as close as possible to the coils; The signal line should enter the cabinet from one side as much as possible. The control terminal must use shielded cables with a maximum cross-sectional area of 1.5 mm ². The encoder cable cannot be disconnected or connected through terminals. The TTL/SSI encoder uses the X7 interface, the Resolver uses the X6 interface, and the HTL encoder can be connected through the X2 terminal.

STO (Safe Torque Off) is an important safety feature of CDE/CDB3000. CDE3000 achieves dual channel shutdown through ENPO and ISDSH inputs, while CDB3000 and SH achieve it through ENPO and ISD00 inputs. STO complies with EN 61800-5-2, EN 954-1 Category 4, EN ISO 13849-1 PL e, and EN 61508 SIL 3. In the STO state, the motor, main power cable, braking resistor, and DC bus cable still carry dangerous voltage without electrical isolation. If there is a suspended load or external force, additional mechanical brakes, safety bolts, or clamping devices must be used. STO must be retested after calibration, system wiring changes, or equipment replacement. Feedback relay RSH or OSD02 is used to diagnose whether two channels are operating simultaneously.

Debugging steps and preset solutions

Before debugging, it is necessary to confirm that all electrical connections are correct and ENPO is at a low level to prevent accidental motor start-up. After power on, the device will perform a self check, with LED H1, H2, and H3 displaying red, yellow, and green status respectively.

Debugging can be done through DRIVE MANAGER software, KEYPAD KP300, or SMARTCARD. When batch debugging, you can first fully debug the first drive, save the data to a file, and then download it to other drives with the same configuration in sequence. During initial debugging, DRIVE MANAGER will guide the user to select a preset solution. There are 20 preset solutions, covering analog speed control, fixed speedometer, CANopen, PROFIBUS, PLC control, table positioning, DSP402 mode, etc. Common presets include SCT_1 (± 10 V analog, I/O terminal start), SCC_2 (fixed speedometer, CANopen), SCB-2 (fixed speedometer, PROFIBUS), PCT2 (table positioning, I/O terminal), etc.

After selecting the preset solution, it is necessary to set up the motor and encoder. The motor database contains parameters for LTi motors and third-party motors. After selecting the correct data, motor protection, control circuits, and electrical parameters will be automatically configured. Encoder settings require selecting an encoder combination, such as TTL motor encoder+TTL position encoder, Resolver+TTL, SSI+TTL, etc. When checking the encoder, manually rotate the motor shaft and observe the actual speed displayed in DRIVE MANAGER: clockwise should be positive, counterclockwise should be negative. If the direction is incorrect, check the encoder cable and type.

The basic settings include reference value scaling, speed curve, limiting, stopping slope, etc. For example, analog input+10 V corresponds to 100%, and -10 V corresponds to -100%. After setting up, you must click "Store setting in device" to save. During the test run, first enable STO, then enable ENPO, select speed control through DRIVE MANAGER, set 100 rpm, and observe the step response. The solver system has an overshoot of about 20%, and the incremental encoder has an overshoot of about 30%. If the torque setting value reaches its maximum, the speed step should be reduced. The test run can determine whether the motor phase sequence, encoder connection, and parameters are correct.

LED status and error codes

The front panel of CDE/CDB3000 has three LEDs: H1 red, H2 yellow, and H3 green. Green lights up when the power is turned on; After ENPO is enabled, the green and yellow colors become bright; Yellow flashing during operation or self-tuning; Yellow flashing during warning; Red flashes when there is an error. The flashing frequency of the red LED corresponds to the error code, and KEYPAD will display the abbreviation.

Common error codes:

1 blink: E-CPU, comprehensive error, specific code needs to be read through KEYPAD or DRIVE MANAGER.

2 flashes: E-OFF, undervoltage shutdown, check the power supply, normal power outage may also occur briefly.

Three flashes: E-OC, current overload shutdown, possible short circuit, ground fault, motor coil fault, parameter error, or improper slope setting.

4 flashes: E-OV, voltage overload shutdown, check the main power supply voltage; If it is caused by regenerative braking, the braking ramp can be slowed down or a braking resistor can be used.

5 flashes: E-OLM, motor protection turned off, motor overload, check process cycle and motor selection.

6 flashes: E-OLI, device safety shutdown, device overload, check for selection or use of larger devices.

7 flashes: E-OTM, motor temperature too high, check PTC connection and parameter settings, allow motor cooling.

8 flashes: E-OTI, overheating of positioning controller, improving ventilation inside the cabinet, checking load and braking resistance.

KEYPAD operation errors include ATT1 to ATT7 and ERROR, which respectively indicate that the parameters cannot be changed, the motor cannot be controlled through the CTRL menu, error status, parameter values are not allowed, too high, too low, the card is unreadable, and the password is incorrect. SMARTCARD errors include ERR91 to ERR99, indicating write protection, checksum error, model mismatch, parameter incompatibility, disconnected connection, invalid data, insufficient memory, region not present, etc.

Reset is divided into parameter reset and device reset. Parameter reset restores the current parameter to the last saved value; Reset the device to restore factory settings. KEYPAD can reset parameters by pressing two cursor keys simultaneously; Pressing both cursor keys simultaneously when powering on can restore the factory settings. In DRIVE MANAGER, "Active device>Reset to factory setting" can also restore factory settings. Note that the factory settings will clear the preset solution, and the terminal allocation needs to be rechecked.

Practical troubleshooting of common faults

Problem 1: No response after power on, all LEDs turn off. Possible reason: Frequent switching of the main power supply has caused the equipment to enter high resistance isolation protection. Solution: Wait for a few minutes and then power on again. If there is still no response, check the main fuse, circuit breaker, power supply voltage, and line reactor.

Question 2: The red LED flashes 3 times and displays E-OC. Check whether the motor cable is short circuited or grounded, whether the motor coil is damaged, and whether the neutral wire and grounding are normal. Check the control loop parameters, slope settings, and motor data. If the motor cable is too long, an output reactor needs to be installed.

Question 3: The red LED flashes 4 times and displays E-OV. Check if the main power supply voltage is too high. If it occurs during braking, it indicates excessive regenerative energy, and the braking ramp should be extended or a braking resistor should be installed. If using internal braking resistors, ensure that temperature monitoring is normal; If an external braking resistor is used, the Klixon temperature switch must be used to cut off the main power supply in case of overheating.

Question 4: Motor temperature alarm E-OTM. Check if the motor PTC is correctly connected to X3 or X6, and if the MOPTC parameter matches the PTC type. If the motor is indeed overheating, check the load, cooling, and selection. Allow the motor to cool down before resetting.

Problem 5: Encoder direction error or abnormal speed feedback. Check if the encoder cable matches the encoder type, if the shielding layer is grounded at both ends, and if A, B, R or CLK, DATA are twisted in pairs. Rotate the motor shaft manually and observe the speed symbol. If the direction is opposite, A, B can be exchanged or parameters can be adjusted. If using a second encoder, note that X7 is used for position control and X2 is used for commutation and auxiliary speed control.

Problem 6: STO cannot be reset. Check the timing of ENPO and ISD00/ISDSH. When canceling STO, ISDSH or ISD00 should be set to high level before ENPO or simultaneously with ENPO. If the order is incorrect, restart suppression cannot be lifted. Check if the status of feedback relay RSH or OSD02 is consistent with both channels. If there is inconsistency, it indicates that there is an error in the system and it must be shut down for inspection.

Question 7: DRIVE MANAGER cannot connect. Check if the RS232 cable CCD-SUB90X is connected to X4, with a length not exceeding 3 meters. It is recommended to use an optical isolator to prevent transient current from damaging the controller or PC. Check the COM port and DRIVE MANAGER version V3.4 or above.

Problem 8: When switching motor cables, the contactor burns or overcurrent shuts off. The motor cable must be switched in a no current state. When using the ENMO function, parameter 247-TENMO sets a delay to ensure that the contactor closes first before enabling the power level, and closes the power level before disconnecting the contactor when stopping.

Maintenance and spare parts recommendations

CDE/CDB3000 is designed for fixed installation, with a protection level of IP20, terminal IP00, and wall heat sink IP54. Environmental temperature: 5 ° C to 40 ° C during operation (relative humidity 5% to 85% non condensing), storage -25 ° C to+55 ° C. The installation height should not exceed 1000 meters, and if exceeded, the capacity should be reduced to a maximum of 2000 meters. The equipment does not support the use of non fixed devices.

Spare parts include main fuse, line reactor, main filter, braking resistor, radiator KEYPAD KP300、SMARTCARD、 Encoder cables, motor cables, STO relays, etc. Before replacing the module, the power must be turned off and wait for the DC bus voltage to drop below 60 V. After replacement, it is necessary to check the parameters, terminal allocation, and STO function. If using SMARTCARD, pay attention to ERR91 to ERR99 errors to avoid write protection, model mismatch, or invalid data.

For the replacement of discontinued or outdated driver modules, CDE/CDB3000 provides good compatibility: preset solutions, DRIVE MANAGER parameter sets, and SMARTCARD can be quickly migrated. When replacing, it is necessary to verify the current level, voltage level, cooling method, encoder interface, and STO variant. If the original system uses third-party motors, it is necessary to select or manually input nameplate data in the motor database.