SEW MOVITRAC 31C Installation and Debugging

SEW MOVITRAC ®  31C Inverter: Complete Guide to Installation, Debugging, and Troubleshooting

In the field of industrial drive, SEW-EURODRIVE's MOVITRAC ®  The 31C series frequency converter is designed specifically for three-phase AC squirrel cage asynchronous motors and is widely used in industrial and commercial drive systems. This series of products covers a power range of 0.55 kW to 55 kW, offering two voltage levels of 230V and 400/500V, and supporting multiple option cards such as I/O expansion, speed detection, positioning control, fieldbus, etc. This article is based on the official operating manual (document number 0922 9019, version 01/99), and systematically reviews MOVITRAC ®  The installation specifications, electromagnetic compatibility (EMC) measures, UL compliance requirements, wiring diagrams, startup and debugging steps, parameter system, and fault diagnosis methods of 31C provide a detailed technical operation guide for automation engineers.

Product Overview and Model Identification

1.1 Model Naming and Nameplate

MOVITRAC ®  The model example of 31C (such as 31C005-503-4-00) includes the following information:

31C: Product Series

005: Power level (e.g. 005 represents 0.55 kW)

503: Voltage level (503=400/500V unit; 233=230V unit)

4: Extreme numbers or versions

00: Standard Design

The nameplate is located on the side of the equipment, indicating key parameters such as input/output current, power, and protection level. In addition, the device is also equipped with option labels to record the option cards (such as FEA31C, FEN31C, etc.) that were shipped or installed later.

1.2 Unit size and structure

MOVITRAC ®  31C offers five specifications from size 0 to size 4:

Size 0: Minimum power (such as 31C005~31C014), compact size, no X20/X21 option slot, but flat brake resistors (BW100-003 or BW200-003) can be installed internally.

Sizes 1 and 2: Medium power, equipped with X4 operation option slot (for FBG31C keyboard or USS21A serial interface) and X20/X21 option slot.

Sizes 3 and 4: High power (up to 31C450, 45 kW), larger structure, higher heat dissipation requirements.

All dimensions are installed vertically, with a minimum ventilation gap of 100mm reserved at the top and bottom.

Installation specifications

2.1 Mechanical installation requirements

Installation position: The frequency converter must be installed vertically and not horizontally or upside down.

Ventilation spacing: At least 100 mm (4 in) at the top and bottom, no spacing is required on the sides, and can be installed side by side.

Protection level: IP20 (NEMA1) before removing the front cover, IP00 after removing the cover, with hazardous voltage present inside.

Grounding: The equipment must be reliably grounded. The cross-section of the PE conductor must comply with EN 50178: if the cross-section of the power cord is less than 10 mm ², an additional PE wire of the same cross-section must be connected in parallel or a 10 mm ² copper PE wire must be used; If the cross-sectional area of the power cord is ≥ 10 mm ², the cross-sectional area of the PE wire should be the same as that of the power cord.

2.2 Power and motor wiring

Power input: L1, L2, L3 terminals (X1:1/2/3). The input fuse must be installed after the power branch point, and it is recommended to use D, DO, NH fuses or circuit breakers.

Motor output: U, V, W terminals (X1:4/5/6). The maximum length of the motor cable is 100 meters, and the cross-section should be selected according to the rated current.

Braking resistor: connected to X1:8 (R+) and X1:9 (R -). The wires should be twisted in pairs or closely arranged side by side, and the cross-section should be selected according to the rated current of the inverter. The surface temperature of the braking resistor is extremely high under rated load, and it needs to be installed on the top of the cabinet or other well ventilated areas. A bimetallic relay (F16) must be used for overload protection, and its tripping current can be found in the technical data of the braking resistor.

Brake connection: The brake rectifier must use a separate power lead and it is strictly prohibited to draw power from the motor voltage. For elevator applications, drives that require rapid braking response, and CFC/SERVO modes, the brakes must be simultaneously cut off on both the DC and AC sides. If the brake rectifier is installed in the control cabinet, the cable between it and the brake must be laid separately from other power cables; If it is necessary to share the same slot, other cables must be shielded.

2.3 Electronic Terminal Wiring

The X2 and X3 terminal blocks provide the following signals:

X2:31:+10V reference voltage (max 3 mA), used for setting the potentiometer value

X2:34/35: Simulate the set value input n2 (differential input), and select the voltage signal (0~10V or ± 10V) or current signal (0~20mA/4~20mA) through the S1 switch

X2:41: Binary Input 1 (Fixed Function: CW/Stop)

X3:42: Binary Input 2 (Factory Setting: CW/Stop)

X3:43: Binary input 3 (enable/quick stop)

X3:47: Binary input 4 (t1/t2 switching)

X3:61: Binary output 1 (fixed function: braking), maximum load 150 mA

X3:62: Binary output 2 (factory setting:/fault), maximum load 50 mA

X2:44:+24V auxiliary voltage output (max. 250 mA), used for external switching

X2:40: External 24V input (used to maintain option card diagnosis in case of main power failure)

X2:65: Measurement output (5V TTL, PWM 100 Hz), configurable to display actual frequency, etc

Binary input is optocoupler isolated, compatible with PLC (EN 61131-2), high level+13~+30V, low level -3~+5V.

2.4 EMC compliant installation

To achieve electromagnetic compatibility (compliant with EN 61800-3 Class B limits), the following measures need to be taken:

Control cable: Shielded cable must be used. Large area grounding at both ends of the shielding layer (through shielding clamps or metal cable joints). To avoid ground loops, a 220 nF/50V capacitor can be grounded at one end.

Power and motor cables: laid separately from electronic cables in different cable trays.

Input filter (NF...): Installed near the frequency converter (but not in a ventilated area), the connection between the input filter and the frequency converter should not exceed 400 mm, and unshielded twisted pair cables should be used. If multiple inverters share a filter, the filter must be installed at the entrance of the cabinet or adjacent to the inverter.

Output choke (HD...): Installed on the output side of the frequency converter, only the U, V, and W phases are passed through the choke (PE lines and shielding layers must not pass through). After using the output choke, the motor cable can be unshielded.

EMC module (EF... -503): Integrated with input filters and output chokes, it can be directly installed under or next to the frequency converter, simplifying EMC installation.

2.5 UL compliant installation

For UL certified installations, the following regulations must be followed:

Wire temperature grade:

MOVITRAC ®  31C005-300: Only use 60/75 ° C copper wire

MOVITRAC ®  31C370/450: Only use 75/90 ° C copper wire

Terminal torque:

Size 0:1.5 Nm (13.3 lb · in)

Size 1: 0.6 Nm (5.3 lb · in)

Size 2: 1.5 Nm (13.3 lb · in)

Size 3/4:3.5 Nm (31 lb · in)

Maximum short-circuit current and fuse:

230V unit: maximum 5000 AAC, fuse rated from 20 A (size 0) to 110 A (size 3)

400/500V unit: maximum 5000 AAC (size 0-3) or 10000 AAC (size 4), fuse from 16 A to 400 A

External 24V power supply: Units with limited output voltage (Umax=30V DC) and limited output current (Imax=8A) that have been tested must be used.

IT system: UL certification does not apply to ungrounded star shaped points (IT systems).

2.6 Installation of Option Cards

Size 0 unit without option slot. Units 1-4 in size support the following options:

FEA31C: I/O Expansion (Analog Differential Input, Analog Output, Binary Input/Output, RS-485)

FIO31C: Digital Input/Output Expansion (8 inputs, 4 outputs, RS-485)

FEN31C: Speed detection (incremental encoder interface)

FPI31C: Position detection (incremental encoder, supporting positioning control)

FIT31C: Evaluation of TF/TH Temperature Sensor

FFP31C/FFI31C/FFD31C: fieldbus interfaces (PROFIBUS, INTERBUS, DeviceNet)

FESS31C: Synchronous Operation Control

Before installing the option card, the main power supply and 24V power supply must be disconnected, and ESD protection measures (anti-static wristband) must be taken. To insert FEA/FIO/FES/FFP into slot X20, the system EPROM card needs to be removed first; To insert FEN/FPI/FIT into slot X21, the X14 terminal block needs to be removed first.

Start debugging

3.1 Preparation work

Check the installation to ensure all wiring is correct.

To prevent accidental starting of the motor, the X3 electronic terminal block can be temporarily unplugged.

Connect FBG31C keyboard to X4 slot (for on-site debugging) or connect PC to MC_SHELL software through USS21A option.

Connect the main power supply (and 24V external power supply), and the yellow LED V1 indicates that the frequency converter is ready.

3.2 FBG31C keyboard operation

The keyboard has 5 keys: ↑ (Add/Previous menu), ↓ (Reduce/Next menu), → (Enter submenu/Edit), ← (Return/Exit Edit), Q (Return to Basic Display), E (Fault Reset).

Language selection: Press ↓ three times under the short menu to P850, press → to enter editing, select language (DE/EN/FR), press ← to exit, press Q to return.

Short menu: Factory activated, with a "/" mark after the parameter number, containing only the most commonly used parameters. You can switch to the complete parameter menu through P802.

3.3 Quick Start Process

Set minimum frequency, fundamental frequency, and maximum frequency:

P200 (fmin1)=2-6 Hz (initially set to 5 Hz)

P201 (fbase1)=motor nameplate fundamental frequency (e.g. 50 Hz)

P202 (fmax1)=required maximum frequency (such as 50 Hz or higher)

Enable Drive: Apply+24V signal to X3:43 (Enable) and X2:41 (CW/stop). The motor runs in fmin.

Check the rotation direction: If the direction is incorrect, power off and exchange any two-phase motor wires.

Increase frequency setting value: Increase the frequency to the desired value through analog input or keyboard (manual mode).

Set the ramp time: P120 (t11 ramp up) and P121 (t11 ramp down) based on project data (e.g. 5-10 seconds).

3.4 Manual mode

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

2 DC bus overvoltage deceleration slope too short prolongs deceleration time

3. High regenerative power of the brake chopper and open circuit of the brake resistor. Check the wiring and technical data of the brake resistor

4. Continuous overload Ixt utilization rate>125% reduces load

6. Overheating inverter reduces power and improves ventilation due to thermal overload

7. Input phase loss (P530 needs to be activated) Check power supply

10 direction error encoder A/A and B/B exchange, motor reverse exchange encoder channel or motor phase line

11 Speed detection encoder connection error or FEN31C not installed. Check the encoder wiring and install the correct option

26. Communication interruption with keyboard or PC without connection. Re plug and unplug the keyboard

27 external terminal programmable input receives external fault troubleshooting source, reprogram terminal

28 INTERBUS fault on-site bus monitoring signal error check bus connection

During the timeout monitoring period of the 34 fieldbus, if there is no master-slave communication, check the communication of the master station and extend P571 or turn off the monitoring

41 FRS lag error encoder polarity error, slope too short, P gain too small Change encoder polarity, extend slope, increase P gain

43 binary output fault output overload (>150mA or>50mA) check output load

54 motor overload, high motor utilization, reduced load, extended slope

59. The target position of the software limit switch exceeds the limit range (IPOS). Check the software limit setting

For unresolved faults, please contact SEW Electronic Services. When repairing, it is necessary to provide equipment serial number, model, service code, application description, motor data, fault symptoms, etc.

Technical Data Summary

6.1 General Technical Data

Protection level: IP20 (EN 60529/NEMA1)

Environmental temperature: 0 ° C~+45 ° C (without derating), derating from+45 ° C~+60 ° C by 3.0% I2 per K

Storage temperature: -25 ° C~+70 ° C; long-term storage requires power on for at least 5 minutes every 2 years

Installation altitude: ≤ 1000 meters without derating; 1000~2000 m, 1% reduction per 100 m

6.2 230V Unit (optional)

Model size Rated output current Recommended motor power (constant torque)

31C005-233 0 3.2 AAC 0.55 kW

31C022-233 1 8.6 AAC 2.2 kW

31C037-233 2 16 AAC 3.7 kW

31C075-233 3 22 AAC 7.5 kW

6.3 400/500V Unit (optional)

Model size Rated output current Recommended motor power (constant torque)

31C005-503 0 2.0 AAC 0.55 kW

31C015-503 1 4.0 AAC 1.5 kW

31C040-503 2 9.6 AAC 4.0 kW

31C110-503 3 24 AAC 11 kW

31C300-503 4 61 AAC 30 kW

When the input voltage is 3 × 500V, the input/output current needs to be reduced by 20% according to the rated value.

6.4 Electronic Data

Analog input resolution: 9-bit ± 20 mV (voltage), 8-bit ± 0.08 mA (current)

Binary input sampling time: 5 ms

Auxiliary 24V output: maximum 250 mA

External 24V input range: 19.2~30V DC

Measurement output: 5V TTL, 100 Hz PWM