1. Model Code Definition

• 3108A: Series & power rating – 31 = MOVITRAC 31 series, 08 = 7.5 kW, A = standard variant

• 403: Voltage class – 230 VAC (200–240 V)

• 4: Input type – 3‑phase AC

• 00: Standard firmware & hardware configuration

2. Electrical Ratings

• Rated output power: 7.5 kW (3‑phase motor)

• Input voltage: 3‑phase AC 200–240 V (nominal 230 V)

• Input frequency: 50 Hz / 60 Hz

• Rated output current: 34 A

• Output voltage: 0–230 VAC, 3‑phase

• Output frequency: 0–400 Hz

• Control mode: V/F open‑loop (voltage‑to‑frequency)

• Overload capacity: 150% / 60 s, 125% continuous

• Switching frequency: 2–16 kHz (adjustable)

• Power factor: ≥ 0.95 (at full load)

3. Mechanical & Environmental Data

• Protection class: IP20 (front panel)

• Cooling: Built‑in fan, vertical wall‑mounted

• Ambient temperature: 0 °C … +45 °C

• Storage temperature: −25 °C … +70 °C

• Relative humidity: 5–95 %, non‑condensing

• Altitude: ≤ 1000 m (no power derating)

• Vibration resistance: 10–55 Hz, 0.15 mm amplitude

• Dimensions (W×H×D): approx. 130 × 260 × 170 mm

• Weight: approx. 4.5 kg

4. Standard Interfaces & Terminals

• Communication: Onboard RS‑485 (supports Modbus RTU / SEW internal bus)

• Analog input: 0–10 V DC (speed reference, 12‑bit resolution)

• Digital inputs: 4 × programmable (24 V DC, sink/source)

• Relay outputs: 1 × programmable (250 V AC / 30 V DC, 3 A)

• Motor thermistor input: PTC/KTY (motor overheat protection)

• Brake resistor connection: Internal dynamic braking unit (DBU)

• Control terminals: Multi‑step speed, start/stop, forward/reverse, reset

5. Main Functions

• Adjustable acceleration/deceleration: 0.1–600 s

• Dynamic braking + DC injection braking: For rapid stop & holding

• Energy‑saving mode: Automatic voltage reduction at light load

• Control sources: Local keypad / external terminals / RS‑485 communication

• Slip compensation: Improves speed accuracy under load

• Soft start/soft stop: Reduces mechanical shock & inrush current

• Built‑in PID controller: For constant pressure, flow, or speed

• Multi‑step speed: Up to 8 preset speeds via digital inputs

• Parameter copy: Save/load parameters via keypad or communication

6. Protection Features

• Overcurrent (instantaneous & thermal)

• Overvoltage / undervoltage

• Input phase loss

• Inverter overtemperature (IGBT & heatsink)

• Motor overload (electronic thermal relay)

• Output short circuit & earth fault

• Stall prevention

• Reverse polarity protection

• ESD protection on control terminals

7. Installation & Wiring

7.1 Mechanical Installation

• Mount vertically on a flat, vibration‑free surface

• Keep ≥ 100 mm clearance above and below for airflow

• Avoid direct sunlight, dust, oil mist, and corrosive gases

7.2 Electrical Wiring

• Power cables: Use 4‑core shielded cables (L1/L2/L3/PE)

• Motor cables: Shielded, 3‑phase + PE, max length 50 m

• Control cables: Twisted pair, shielded, separate from power cables

• Grounding: Connect PE terminal to main earth (≤ 4 Ω)

• Brake resistor: Connect to DBU terminals (optional, for high inertia loads)

8. Commissioning Steps

1. Pre‑check: Verify wiring, voltage, and motor nameplate data

2. Power‑on: Display shows “rdy” (ready)

3. Motor parameter setting:

   • Rated voltage (230 V)

   • Rated current (match motor)

   • Rated frequency (50/60 Hz)

   • Rated speed

4. Control mode selection: Terminal / Keypad / Communication

5. Accel/decel time setting: 5–10 s (typical)

6. No‑load test: Run motor at 50 Hz, check direction & noise

7. Load test: Gradually apply load, monitor current & temperature

8. Save parameters: Write settings to non‑volatile memory

9. Maintenance

• Regular cleaning: Every 3–6 months, clean fan & heatsink

• Terminal check: Tighten power & control terminals annually

• Fan replacement: If noisy or failed (use original SEW part)

• Insulation test: Every 2 years (disconnect motor first)

• Firmware update: Via RS‑485 (use SEW software)

10. Compliance & Standards

• CE marking (Low Voltage Directive 2014/35/EU)

• EMC compliant (EN 61800‑3, Category C2)

• RoHS compliant (2011/65/EU)

• UL 508C (optional)

• ISO 9001 certified manufacturing

11. Application Examples

• Conveyors & material handling

• Fans & pumps (energy‑saving speed control)

• Textile machinery

• Packaging machines

• General‑purpose industrial drives