Danfoss VLT® Micro Drive FC 51

# Danfoss VLT® Micro Drive FC 51 Quick Reference Guide

## 1. Core Technical Specifications

* **1-Phase 200~240 V AC:** 0.18 ~ 2.2 kW (0.25 ~ 3 hp)

* **3-Phase 200~240 V AC:** 0.25 ~ 3.7 kW (0.33 ~ 5 hp)

* **3-Phase 380~480 V AC:** 0.37 ~ 22 kW (0.5 ~ 30 hp)

* **Control Mode:** Advanced Vector Control (VVC+), Built-in PI Controller, Smart Logic Controller (SLC)

* **Built-in Communication:** RS-485 interface supporting Modbus RTU and Danfoss FC Protocol

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## 2. Control Terminal Definitions

* **Terminal 12:** +24V DC Output (Used as supply voltage for digital inputs)

* **Terminal 18:** Digital Input 1 (Default: `[8]` Start)

* **Terminal 19:** Digital Input 2 (Default: `[10]` Reversing)

* **Terminal 27:** Digital Input 3 (Default: `[1]` Coast inverse)

* **Terminal 29:** Digital Input 4 (Default: `[14]` Jog)

* **Terminal 20:** Digital Ground (GND)

* **Terminal 50:** +10V DC Output (Used as supply voltage for external potentiometer)

* **Terminal 53:** Analog Input 1 (Voltage mode: 0 ~ 10V)

* **Terminal 60:** Analog Input 2 (Current mode: 0/4 ~ 20mA)

* **Terminal 55:** Analog Common (GND)

* **Terminals 68 (+), 69 (-):** RS-485 Serial Communication Interface

> **Note:** Hardware switches located just above the terminal block are used to toggle between PNP/NPN logic and Voltage/Current signal types for terminals 53 and 60. Check these switch positions before wiring.

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## 3. Essential Parameter Settings (Motor Nameplate & Basic Setup)

Configure the following parameters sequentially based on the motor nameplate during initial commissioning or after a motor replacement:

| Parameter | Parameter Description | Typical Setting / Note | Default Value |

| :--- | :--- | :--- | :--- |

| **1-20** | Motor Power | Match motor nameplate value (kW or hp) | Model dependent |

| **1-22** | Motor Voltage | Match motor nameplate value (e.g., 230V, 380V, 400V) | Model dependent |

| **1-23** | Motor Frequency | Match motor nameplate value (typically 50 Hz or 60 Hz) | 50 Hz |

| **1-24** | Motor Current | Match motor nameplate rated current (A) | Model dependent |

| **1-25** | Motor Nominal Speed | Match motor nameplate rated speed (RPM) | Model dependent |

| **1-29** | Automatic Motor Adaptation (AMA) | Set to **`[1]` Enable complete AMA**, then press **Hand On** key to start | `[0]` Off |

| **3-41** | Ramp 1 Ramp Up Time | Acceleration time from 0 Hz to nominal frequency (seconds) | 3.00 s |

| **3-42** | Ramp 1 Ramp Down Time | Deceleration time from nominal frequency to 0 Hz (seconds) | 3.00 s |

| **4-12** | Motor Speed Low Limit | Minimum output frequency allowed by the drive (Hz) | 0.0 Hz |

| **4-14** | Motor Speed High Limit | Maximum output frequency allowed by the drive (Hz) | 65.0 Hz |

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## 4. Control & Reference Source Configuration

Adjust the following parameter combinations to match your specific control scheme:

### Scheme A: Keypad Control (Local Control Mode)

* **0-02** = `[1]` (Local display unit set to Hz)

* **3-15** = `[21]` (Main Reference Resource 1 set to LCP potentiometer)

### Scheme B: External Terminal Start + External Potentiometer Speed Control (Most Common)

* **5-10** = `[8]` (Terminal 18 configured as "Start")

* **3-15** = `[1]` (Main Reference Resource 1 set to Analog Input 53)

* **6-10** = `0.07 V` (Terminal 53 Low Voltage scaling, typically keep default)

* **6-11** = `10.00 V` (Terminal 53 High Voltage scaling, typically keep default)

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## 5. Common Troubleshooting Faults & Alarms

When a fault occurs, the drive display flashes an alarm code. Refer to this list for rapid diagnosis:

* **W2 / AL2 (Live Zero Error):** The current signal on Terminal 60 dropped below 2mA. Check for a broken wire or open circuit in the 4-20mA loop from your sensor/PLC.

* **W7 / AL7 (Overvoltage):** Intermediate circuit (DC-bus) voltage is too high. This is typically caused by high regenerative energy during aggressive braking. Increase the ramp-down time in parameter **[3-42]**.

* **W8 / AL8 (Undervoltage):** The line supply voltage dropped below the minimum operating limit or suffered a power cutout. Check the stability of the incoming mains power.

* **W13 / AL13 (Overcurrent):** Inverter peak current limit exceeded. Check for mechanical binding or lock-up in the load, or inspect the motor cable for a short circuit.

* **W14 / AL14 (Earth Fault):** Discharge from the output phases to ground. Inspect the insulation condition of the cabling between the drive and the motor.

All items are Distributor Ready-stock Genuine Brand-new Supplying, please inform us if the other conditions are needed, Used, Open-box, Refurbished, etc.

Allen Bradley - CompactLogix; ControlLogix, Flex I/O, MicroLogix, etc.

Siemens - Simatic S7-300; S7-400; S7-1200; S7-1500; HMI 6AV etc.

ABB - Advant 800xA S800; S200; S400; S500; S600; S700; S900 etc.

GE Fanuc - 90-30; 90-70; PACSystems RX3i, etc.

Honeywell - Experion® PKS; ControlEdge™ HC900; etc.

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