Aerotech Ndrive CP maintenance replacement

Aerotech Ndrive CP maintenance replacement

In industrial motion control sites, replacing discontinued servo drives and troubleshooting safety circuits often test engineers more than debugging new equipment. Aerotech Ndrive CP is a compact PWM network digital driver, belonging to the high-performance discrete drive product of Automation 3200 motion system. It adopts dual precision floating-point DSP to control digital PID and current loop, supporting brushless motor, brushed motor and stepper motor. All control loop gains, system safety functions and configurations can be set through software parameters. For engineers who are maintaining old equipment, replacing discontinued modules, or expanding multi axis systems, understanding the specifications, wiring, feedback, I/O expansion, PSO laser triggering, and fault logic of Ndrive CP can significantly reduce downtime.

Model and core specifications

The Ndrive CP series includes three common power levels: CP10, CP20, and CP30-S. CP10 peak output 10 A, continuous 5 A; CP20 peak 20 A, continuous 10 A; CP30-S peak 30 A, continuous 10 A, with standard 40 W continuous internal shunt resistor. The motor power input is 14-240 VAC, 50-60 Hz, and the control power is 85-240 VAC, 50-60 Hz. The output voltage range is approximately 20-340 VDC, depending on the AC input and load. The PWM switching frequency is 20 kHz, and the maximum bandwidth of the power amplifier is 2500 Hz, which can be selected by software. The minimum load inductance is 0.1 mH at 160 VDC and 1 mH at 320 VDC. The efficiency is about 85% -95%, and the higher the output power, the higher the efficiency.

The protection functions include output short circuit, peak overcurrent, DC bus overvoltage, RMS overcurrent, over temperature, control power undervoltage, and power stage bias undervoltage. Optical and transformer isolation are used between the control and power stages. The user's power output is 5 VDC, 500 mA. These specifications determine that Ndrive CP is suitable for devices with small to medium power, cost sensitive, and requiring digital closed-loop and FireWire synchronization. If the original device uses a linear driver, it should be noted that the CP is a PWM power level, and the noise and heating characteristics are different; If lower noise is required, linear series should be evaluated.

Key points of power supply and wiring

Ndrive CP requires two power connections: control power and motor power. Control the power supply to TB106, requiring 85-240 VAC, with a minimum of 85 VAC to function properly. AC1 has a fuse inside, AC2 can be connected to the neutral line, and if connected to other voltage sources, an external 2A delay fuse is required. The control power supply is used to maintain communication when the motor power is removed, such as in an emergency stop state. The motor power supply is connected to TB102, and the internal fuses of AC1 are CP10 5 A and CP20/30 10 A. An external maximum delay fuse or circuit breaker of 15 A is also required. The motor power supply is 14-240 VAC and can be configured in single-phase or three-phase, but the CP manual mainly describes single-phase input.

To reduce noise, it is recommended to install line filters before controlling the power supply and motor power supply, and to be as close as possible to the driver. CE compliance typically requires external filters, such as Schaffner FN2080 or Aerotech UFM-ST. UFM-ST input and output 0-240 VAC, maximum continuous current 8 Arms convection cooling, 10 Arms forced air cooling, internal 10A fuse. The motor cable should use shielded cable, and the shielding layer should be connected to the metal D-type connector back shell or rack ground. The motor leads can be equipped with ferrite beads, such as Fair Rite # 2643002402 and # 2643250402. Encoders and signal lines must be physically isolated from motors, AC power sources, and other power lines.

If it is necessary to reduce the motor voltage or isolate, an external transformer can be used. TV0.3-28-56-ST can generate 28 or 56 VAC from 115/230 VAC, and after rectification, obtain 40 or 80 VDC bus. The TM3 and TM5 transformer modules can provide 300 W or 500 W power respectively for up to 4 drivers. TV0.3-28 generates 28 VAC corresponding to 40 VDC, TV0.3-56 generates 56 VAC corresponding to 80 VDC, TV1.5, TV2.5, and TV5 are 1.5/2.5/5 kVA isolation transformers. When using an isolation transformer, grounding the AC2 input tap can reduce electrical and audible noise and improve servo performance.

Motor connection and phase adjustment

Ndrive CP can control brushless, brushed, and stepper motors. When wiring the brushless motor, the A/B/C of the motor should be connected to the A/B/C of TB102, and the motor frame and shield should be grounded. Hall signal connected to J103: Hall A pin 10, Hall B pin 5, Hall C pin 11. The forward motion command should cause the motor to rotate clockwise when viewed from the mounting flange. If the direction is opposite, any two-phase motor wires can be exchanged. Brushless motor commutation relies on Hall and back electromotive force alignment. If using non Aerotech motors, it is recommended to confirm using oscilloscope method or power on phase method. The oscilloscope method requires a dual channel oscilloscope, a 5 V power supply, and six 10 k Ω resistors. Connect the three phases of the motor to the Wye neutral point, manually rotate clockwise, and observe the opposite electromotive forces and Hall state. The correct Hall state should be aligned with the back electromotive force, and if necessary, corrected with the Commutation Offset parameter.