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.