SEW MOVITRAC 31C Installation and Debugging

After P870 (Manual operation)=YES, the frequency converter can be directly controlled through the keyboard without the need for external binary input signals. The direction is selected by the keyboard arrow keys, and the speed is adjusted by ↑/↓ with a rate of change of 150 rpm/s. The manual mode remains effective after power failure, but the inverter is in a disabled state after power is restored, and the directional keys need to be pressed again to start.

3.5 BOOST and I × R parameter adjustment

For non matching motors (motor power less than the recommended power of the frequency converter) or group drives, manual setting of P321 (BOOST 1) and P322 (I × R 1) is required:

First, set BOOST and I × R to 0% to enable driving.

Gradually increase BOOST until the motor accelerates to fmin and the current is approximately 80% of the rated current.

Gradually increase I × R until the current reaches the current limit (Imax, usually 150% IN).

Return BOOST to zero and then decrease I × R until the current exits the limit.

Finally, increase BOOST again to a current of 80% IN.

For group drivers (without common loads), simply set BOOST and keep I × R at 0.

The manual provides a BOOST and I × R reference value table for SEW motors (IEC and NEMA) under different wiring modes (star/double star) and fundamental frequencies (50/60/87/120 Hz) for engineers to quickly set.

3.6 Elevator Application

Special attention should be paid to the elevator drive:

Set P710 (Hoi st function 1) to YES (NO can be selected when there is a counterweight).

P326 (Premagnetization time)=200 ms (prevents rolling during startup).

Fmin is set to 10 Hz or higher, and fmax can be set to 70 Hz.

P260 (Start/stop frequency) is set to 1.5 times the rated motor slip.

BOOST is initially set to 100%, then reduced to the point where the motor can accelerate and the current is less than 100% IN; I × R is set to 75% of the BOOST value.

Speed monitoring (P510) and regeneration monitoring (P520) must be activated.

3.7 Speed control mode (with encoder)

FEN31C or FPI31C options need to be installed and connected to an incremental encoder (recommended ES1T/ES2T/EV1T, 1024 pulses/rev).

Start in V/f mode first (without speed loop).

Set P324 (pole pairs) and P773 (pulse numbers).

P770 (Operation mode) = SPEED CONTROL。

P774 (S × R)=YES can automatically determine BOOST and I × R.

Optimize speed loop: Increase P771 (P gain) until the system starts oscillating, and then slightly decrease it; Reduce P772 (Time constant) to cause 1-2 overshoot in the step response.

Overview of Parameter System

MOVITRAC ®  31C provides a complete set of parameters, divided into the following main groups (see Section 3.5 of the manual for a complete list):

Example of Parameter Group Content

P0_Show values (current, frequency, temperature, speed, etc.)

P1_Set value and ramp generator (analog input, fixed set value, ramp time, S-curve, motor potentiometer)

P2_ Frequency characteristics (fmin, fbase, fmax, frequency jump window)

P3-Motor parameters (rated current, BOOST, I × R, slip, PWM frequency, pre magnetization time, motor voltage)

P4_ Reference signal (frequency reference value, current reference value, set/actual value comparison)

P5_ Monitoring function (deceleration monitoring, speed monitoring, regeneration monitoring, motor protection, synchronous operation monitoring, fieldbus PD description)

P6_Terminal Allocation (Binary Input/Output Function Programming)

P7_Control Function (Enhanced Function, Quick Start, DC Braking, Heating Current, Synchronous Operation, Speed Control)

P8_Specific functions (parameter locking, saving, short menu, service information, parameter copying, factory settings, interface mode, language, reset mode, manual operation, master-slave operation, 4-quadrant operation)

The parameters can be modified through the FBG31C keyboard or MC_SHELL software. Parameters with "*" can be switched between parameter sets 1 and 2.

Operation display and fault diagnosis

5.1 LED status indication

Meaning of LED V1 color

Yellow main power present, frequency converter ready

Green rotating magnetic field on (in operation)

Red total fault

Yellow flashing self-test (≤ 5 seconds) or factory set running

Red yellow flashing limit switch activated

Red green flashing keeps control activated (IPOS)

5.2 Fault Storage and Reset

The fault memory P060-P064 non-volatile stores the last 5 faults (t-0 latest), including DC bus voltage, Ixt utilization, radiator temperature, I/O status, frequency, current, etc.

Shutdown response:

Immediate disconnection: The output stage is disabled, and the brake is immediately closed.

Quick parking: Reduce speed on the t13/23 slope and close the brake when the stopping frequency is reached.

Reset method:

Power on again after power outage (main contactor disconnected for at least 10 seconds)

Binary input programmed as' Reset '

Manual reset in MC_SHELL (P862=YES)

FBG31C keyboard press the<E>key (enter P862)

5.3 Common fault codes (optional)

Fault code description, possible causes, and countermeasures

1. If there is an overcurrent output short circuit/grounding, the motor is too large, or the output stage is damaged, eliminate the short circuit and replace the small motor. If it cannot be reset, contact SEW