VLT® Micro Drive FC 51 Operating Guide
1 Introduction
This operating guide provides the necessary information for qualified personnel to install and commission the frequency converter. Read and follow the instructions for safe and professional use of the frequency converter. VLT® is a registered trademark of Danfoss A/S.
Do not dispose of equipment containing electrical components with household waste. Dispose of them selectively according to local legislation.
2 Safety
Pay special attention to the general safety instructions and warnings to avoid the risk of death, serious injury, and damage to the equipment or other objects.
⚠️ ADVERTENCIA
HIGH VOLTAGE
Frequency converters contain high voltage when connected to an AC mains supply, a DC supply, or a shared DC bus.
ACCIDENTAL START
The motor can start from the LCP, I/O inputs, fieldbus, or MCT 10 configuration software at any time when the frequency converter is connected to the AC mains, a DC supply, or a shared DC bus.
DISCHARGE TIME
The converter contains DC-link capacitors that may remain charged even when the converter is switched off. High voltage may be present even if the warning indicator lights are off.
- Stop the motor, disconnect the AC mains, permanent magnet motors, and remote DC supply sources, including UPS systems, battery back-ups, and DC bus connections to other frequency converters.
- Wait for the capacitors to discharge completely and perform a relevant measurement before carrying out maintenance or repair work.
- The minimum waiting time is 4 minutes for M1, M2, and M3 converters, and 15 minutes for M4 and M5.
LEAKAGE CURRENT
Leakage currents from the converter exceed 3.5 mA. Ensure the frequency converter is properly grounded with a grounding cable of at least 10 mm² (8 AWG) and use an RCD of type B with a delay on the input.
3 Installation
3.1 Mechanical Dimensions
The following tables provide mechanical dimensions and power ratings for the VLT® Micro Drive FC 51.
| Housing Size | Height (mm [in]) A |
Width (mm [in]) B |
Depth [mm (in)](2) C |
Mounting Holes [mm (in)] a |
Mounting Holes [mm (in)] b |
Mounting Holes [mm (in)] D |
|---|---|---|---|---|---|---|
| M1 | 150 (5.9) | 205 (8.1) | 140.4 (5.5) | 70 (2.8) | 55 (2.2) | 148 (5.8) |
| M2 | 176 (6.9) | 230 (9.1) | 166.4 (6.6) | 75 (3.0) | 59 (2.3) | 168 (6.6) |
| M3 | 239 (9.4) | 294 (11.6) | 226 (8.9) | 90 (3.5) | 69 (2.7) | 194 (7.6) |
| M4 | 292 (11.5) | 347.5 (13.7) | 272.4 (10.7) | 125 (4.9) | 97 (3.8) | 241 (9.5) |
| M5 | 335 (13.2) | 387.5 (15.3) | 315 (12.4) | 165 (6.5) | 140 (5.5) | 248 (9.8) |
(1) Mounting plate included.
(2) For LCP with potentiometer, add 7.6 mm (0.3 in).
| Housing Size | Power (kW [HP]) 1 200-240 V |
Power (kW [HP]) 3 200-240 V |
Power (kW [HP]) 3 380-480 V |
Max Weight (kg [lb]) |
|---|---|---|---|---|
| M1 | 0.18-0.75 (0.24-1.0) | 0.25-0.75 (0.34-1.0) | 0.37-0.75 (0.5-1.0) | 1.1 (2.4) |
| M2 | 1.5 (2.0) | 1.5 (2.0) | 1.5-2.2 (2.0-3.0) | 1.6 (3.5) |
| M3 | 2.2 (3.0) | 3.0 (4.0) | 3.0-7.5 (4.0-10) | 3.0 (6.6) |
| M4 | 11.0-15.0 (15-20) | 6.0 (13.2) | ||
| M5 | 18.5-22.0 (25-30) | 9.5 (20.9) |
3.2 Power Connection and Motor
Mount the grounding cables to the PE terminal. Connect the motor to terminals U, V, and W. Connect the mains supply to terminals L1/L, L2, and L3/N (3-phase) or L1/L and L3/N (1-phase) and tighten.
Illustration 1: Mounting of the grounding cable, mains supply, and motor cables.
3.3 Shared Load / Brake
Use insulated 6.3 mm (0.25 in) Faston connectors designed to withstand high DC voltages (shared load and brake). Contact Danfoss or consult the VLT® 5000 Shared Load Instruction for shared load and the VLT® 2800/5000/5000 FLUX/FCD 300 Brake Instruction for brake.
Shared load: Connect terminals -UDC and +UDC/+BR.
Brake: Connect terminals -BR and +UDC/+BR (not applicable for M1 housing size).
AVISO: Between terminals +UDC/+BR and -UDC, DC voltage levels of up to 850 V can occur. No short-circuit protection.
3.4 Control Terminals
All control cable terminals are located under the terminal cover on the front of the converter. Remove the terminal cover using a screwdriver.
AVISO:
- Consult the terminal and switch diagram on the back of the terminal cover.
- The switches must not be operated with the frequency converter power connected.
- Adjust parameter 6-19 Terminal Mode 53 according to switch position 4.
Illustration 2: Removing the terminal cover.
Illustration 3: Switches S200 1-4.
- Switch 1: Off=terminals 29, PNP(1) On=terminals 29, NPN
- Switch 2: Off=terminals 18, 19, 27 and 33, PNP(1) On=terminals 18, 19, 27 and 33, NPN
- Switch 3: No function
- Switch 4: Off=0-10 V terminal 53(1) On=0/4-20 mA terminal 53
(1) This is the default setting.
The following illustration shows all control terminals of the frequency converter. When applying Start (terminal 18) and an analog reference (terminal 53 or 60), the frequency converter will start operating.
Illustration 4: Overview of control terminals with PNP configuration and factory settings.
Terminal Layout:
- Power Outputs: +10V DC, +24V
- Grounds: GND (earth connection)
- Digital Inputs: ENT A, ENT D, SAL A, SAL D (PNU 6-2*, PNU 6-1*, PNU 5-13, PNU 5-15, PNU 6-9*)
- Analog Inputs: 0-10 V, 0/4-20 mA (1 K Ohm)
- Digital Outputs/Functions: Fixed speed, Reverse, Start, Reset
- Communication: RS 485 (N, P, Com)
- Other Terminals: PNU 5-12, PNU 5-11, PNU 5-10, 61, 68, 69, 12, 18, 19, 20, 27, 29, 33, 42, 50, 53, 55, 60
4 Programming
Press [Menu] ☰ to select one of the following menus:
4.1 Local Control Panel (LCP)
Menu Types:
- Status Menu: Read-only data.
- Quick Menu: For accessing quick menus 1 and 2.
- Main Menu: For accessing all parameters.
Illustration 5: Description of LCP keys and display.
LCP Controls:
- Menu ☰: Select menu or parameter group.
- Back ◀️: Go to the previous step or level in the navigation structure.
- OK ✅: Select a parameter and accept setting changes.
- Navigation Keys (Arrows): Used to scroll through parameter groups, parameters, and values.
- Numeric Display: Shows parameter numbers, values, and status.
- Unit: Displays the unit of the selected parameter.
- Status LEDs: On, Warn, Alarm.
Function Keys:
- [Hand On] ?️▶️: Starts the motor and activates converter control via the LCP.
- [Off/Reset] ⏹️/?: Stops the motor. If in alarm mode, restarts the motor.
- [Auto On] ?▶️: The converter can be controlled via control terminals or serial communication.
LCP12 is another LCP with a potentiometer.
4.2 Automatic Motor Tuning (AMT)
Run AMT to optimize the compatibility between the frequency converter and the motor in VVC+ mode. The converter is based on a mathematical model of the motor to regulate the motor's output intensity, which increases motor performance.
- Enter the main menu.
- Adjust parameter group 1-** Load and motor, parameter group 1-2* Motor Data, and parameter 1-29 Automatic Motor Tuning (AMT).
- Press [OK] ✅. The test starts automatically and indicates when it has finished.
5 Parameter Summary
The VLT® Micro Drive FC 51 offers a comprehensive set of parameters organized into the following main groups:
- 0-** Func./Display
- 1-** Load and motor
- 2-** Brakes
- 3-** Ref./Ramps
- 4-** Limits/Warnings
- 5-** Digital I/O
- 6-** Analog I/O
- 7-** Controllers
- 8-** Communication & Options
- 13-** Smart Logic Controller
- 14-** Special Functions
- 15-** Drive Information
- 16-** Data Readings
- 18-** Extended Motor Data
Each parameter is identified by a number and a descriptive name. Due to the extensive nature of this list, only the main categories are presented here. For detailed descriptions of all parameters, please refer to the VLT® Micro Drive FC 51 Programming Guide or Danfoss technical documentation.
6 Troubleshooting
This table lists common error codes, their descriptions, and potential causes.
| Number | Description | Warning | Block/Alarm | Error Alarm | Cause of Problem |
|---|---|---|---|---|---|
| 2 | Active zero error | X | X | The signal from terminal 53 or 54 is below 50% of the value set in: • Parameter 6-10 Terminal 53 low voltage. • Parameter 6-12 Terminal 53 low current. • Parameter 6-22 Terminal 54 low current. |
|
| 4 | Supply phase loss(1) | X | X | X | Loss of a phase in the mains supply or the voltage imbalance is too high. Check the supply voltage. |
| 7 | DC overvoltage(1) | X | X | The DC-link voltage exceeds the limit. | |
| 8 | DC undervoltage(1) | X | X | The DC-link voltage drops below the undervoltage warning limit. | |
| 9 | Overload inv. | X | X | X | Load exceeds 100% for too long. |
| 10 | Motor overtemperature ETR | X | X | X | The motor has overheated due to a load exceeding 100% for a long time. |
| 11 | Motor thermistor overtemperature | X | X | X | The thermistor (or its connection) is disconnected. |
| 12 | Torque limit | X | X | Torque exceeds the value set in parameter 4-16 Torque limit motor mode or in parameter 4-17 Torque limit generator mode. | |
| 13 | Overcurrent | X | X | X | The inverter's peak current limit has been exceeded. |
| 14 | Ground fault connection | X | X | X | Discharge from output phases to ground. |
| 16 | Short circuit | X | X | Short circuit in the motor or its terminals. | |
| 17 | Ctrl code TO | X | X | X | No communication with the converter. |
| 25 | Brake resistance short-circuited | X | X | The brake resistor has short-circuited, and consequently, the brake function is disconnected. | |
| 27 | Brake chopper short-circuited | X | X | The brake transistor has short-circuited, and consequently, the brake function is disconnected. | |
| 28 | Brake check | X | X | The brake resistor is not connected or not functioning. | |
| 29 | Power plate overtemperature | X | X | X | The heatsink's trip temperature has been reached. |
| 30 | Motor phase U missing | X | X | Motor phase U is missing. Check the phase. | |
| 31 | Motor phase V missing | X | X | Motor phase V is missing. Check the phase. | |
| 32 | Motor phase W missing | X | X | Motor phase W is missing. Check the phase. | |
| 38 | Internal fault | X | X | Contact your local Danfoss distributor. | |
| 47 | Control voltage fault | X | X | The 24 V DC supply is overloaded. | |
| 51 | Check AMA Unom & Inom | X | X | Incorrect motor voltage and/or current settings. | |
| 52 | AMA Inom low | X | X | Motor current is too low. Check settings. | |
| 59 | Current limit | X | X | X | The converter is overloaded. |
| 63 | Brake mech. low | X | X | Actual motor current has not exceeded the brake release current value within the start delay time window. | |
| 80 | Converter initialized to default | X | X | All parameter settings revert to their default values. | |
| 84 | LCP connection lost | X | Communication has been lost between the LCP and the frequency converter. | ||
| 85 | Key disabled | X | Refer to parameter group 0-4* LCP. | ||
| 86 | Copy failed | X | An error occurred during copying from the converter to the LCP or vice versa. | ||
| 87 | LCP data incorrect | X | This situation occurs when copying from the LCP if the LCP contains erroneous data or if no data has been loaded to the LCP. | ||
| 88 | LCP data incompatible | X | This occurs when copying from the LCP if data is transferred from one converter to another and there is a significant difference between the software versions of both converters. | ||
| 89 | Read-only parameter | X | This situation occurs when attempting to write to a parameter that only allows reading. | ||
| 90 | Parameter database busy | X | The LCP and the RS-485 connection are attempting to update parameters simultaneously. | ||
| 91 | Parameter not valid in this mode | X | This situation occurs when attempting to write a value that is not permitted for a given parameter. | ||
| 92 | Parameter value exceeds min./max. limits | X | This situation occurs when attempting to set a value that is outside the specified range. | ||
| nw run | Not during run | X | Parameters can only be changed when the motor is stopped. | ||
| Err. | Incorrect password entered | X | This situation occurs when entering an incorrect password to modify a password-protected parameter. |
(1) These errors are caused by mains disturbances. Install a Danfoss line filter to correct this problem.
7 Specifications
Table 2: 1x200-240 V AC Mains Supply
Normal 150% overload for 1 minute
| Converter | Shaft output typical [kW (HP)] | Enclosure protection rating IP20 | Output current | Max cable size (Supply and motor) [mm²/AWG] | Max input current | Estimated power loss [W], most favorable/typical(1) |
|---|---|---|---|---|---|---|
| PK18 | 0.18 (0.25) M1 | IP20 | Continuous (1~200-240 V) [A] | 4/10 | Continuous (1~200-240 V) [A] | 12.5/15.5 |
| PK37 | 0.37 (0.5) M1 | Intermittent (1~200-240 V) [A] | Intermittent (1~200-240 V) [A] | |||
| PK75 | 0.75 (1) M1 | Continuous (3~200-240 V) [A] | Continuous (3~200-240 V) [A] | |||
| P1K5 | 1.5 (2) M2 | Intermittent (3~200-240 V) [A] | Intermittent (3~200-240 V) [A] | |||
| P2K2 | 2.2 (3) M3 | IP20 | Continuous (3~200-240 V) [A] | 4/10 | Continuous (3~200-240 V) [A] | 20/25 |
| P3K7 | 3.7 (5) M3 | IP20 | Intermittent (3~200-240 V) [A] | 4/10 | Intermittent (3~200-240 V) [A] | 36.5/44 |
Table 3: 3x200-240 V AC Mains Supply
Normal 150% overload for 1 minute
| Converter | Shaft output typical [kW (HP)] | Enclosure protection rating IP20 | Output current | Max cable size (Supply and motor) [mm²/AWG] | Max input current | Estimated power loss [W], most favorable/typical(1) |
|---|---|---|---|---|---|---|
| PK25 | 0.25 (0.33) M1 | IP20 | Continuous (3~200-240 V) [A] | 4/10 | Continuous (3~200-240 V) [A] | 14/20 |
| PK37 | 0.37 (0.5) M1 | Intermittent (3~200-240 V) [A] | Intermittent (3~200-240 V) [A] | |||
| PK75 | 0.75 (1) M1 | Continuous (3~200-240 V) [A] | Continuous (3~200-240 V) [A] | |||
| P1K5 | 1.5 (2) M2 | Intermittent (3~200-240 V) [A] | Intermittent (3~200-240 V) [A] | |||
| P2K2 | 2.2 (3) M3 | Continuous (3~200-240 V) [A] | Continuous (3~200-240 V) [A] | |||
| P3K7 | 3.7 (5) M3 | Intermittent (3~200-240 V) [A] | Intermittent (3~200-240 V) [A] |
Table 4: 3x380-480 V AC Mains Supply
Normal 150% overload for 1 minute
| Converter | Shaft output typical [kW (HP)] | Enclosure protection rating IP20 | Output current | Max cable size (Supply and motor) [mm²/AWG] | Max input current | Estimated power loss [W], most favorable/typical(1) |
|---|---|---|---|---|---|---|
| PK37 | 0.37 (0.5) M1 | IP20 | Continuous (3~380-440 V) [A] | 4/10 | Continuous (3~380-440 V) [A] | 18.5/25.5 |
| PK75 | 0.75 (1) M1 | Intermittent (3~380-440 V) [A] | Intermittent (3~380-440 V) [A] | |||
| P1K5 | 1.5 (2) M2 | Continuous (3~440-480 V) [A] | Continuous (3~440-480 V) [A] | |||
| P2K2 | 2.2 (3) M2 | Intermittent (3~440-480 V) [A] | Intermittent (3~440-480 V) [A] | |||
| P3K0 | 3.0 (4) M3 | Continuous (3~380-440 V) [A] | Continuous (3~380-440 V) [A] | |||
| P4K0 | 4.0 (5.5) M3 | Intermittent (3~380-440 V) [A] | Intermittent (3~380-440 V) [A] | |||
| P5K5 | 5.5 (7.5) M3 | Continuous (3~380-440 V) [A] | Continuous (3~380-440 V) [A] | |||
| P7K5 | 7.5 (10) M3 | Intermittent (3~380-440 V) [A] | Intermittent (3~380-440 V) [A] | |||
| P11K | 11 (15) M4 | Continuous (3~440-480 V) [A] | Continuous (3~440-480 V) [A] | |||
| P15K | 15 (20) M4 | Intermittent (3~440-480 V) [A] | Intermittent (3~440-480 V) [A] | |||
| P18K | 18.5 (25) M5 | Continuous (3~380-440 V) [A] | Continuous (3~380-440 V) [A] | |||
| P22K | 22 (30) M5 | Intermittent (3~380-440 V) [A] | Intermittent (3~380-440 V) [A] |
(1) This applies to the frequency converter's cooling dimensioning. If the switching frequency is higher than the default settings, power losses may increase. Typical power consumptions of the LCP and the control card are included. For power loss data according to EN 50598-2, refer to the MyDrive® ecoSmart website.
8 Special Conditions
8.1 Derating Due to Ambient Temperature
The ambient temperature measured over 24 hours must be at least 5 °C (9 °F) lower than the maximum ambient temperature. If the converter is used at a high ambient temperature, reduce the constant output current. The frequency converter is designed to operate at a maximum ambient temperature of 50 °C (122 °F) with a motor size smaller than nominal. Continuous full-load operation at 50 °C (122 °F) ambient temperature reduces the service life of the frequency converter.
8.2 Derating Due to Low Atmospheric Pressure
Air cooling capacity decreases as atmospheric pressure decreases. Below 1000 m (3280 ft) altitude, no derating is necessary, but above 1000 m (3280 ft) the ambient temperature or the maximum output current must be reduced. For altitudes above 2000 m (6560 ft), contact Danfoss regarding PELV. Reduce the output by 1% for every 100 m (328 ft) of altitude above 1000 m (3280 ft) or reduce the maximum ambient temperature by 1 °C (1.8 °F) every 200 m (656 ft).
8.3 Derating for Low Speed Operation
When connecting a motor to a frequency converter, check if the motor cooling is adequate. A problem may arise at low speeds in constant torque applications. Continuous operation at low speeds (below half the motor's rated speed) may require additional cooling air. Alternatively, choose a larger motor (one size up).
9 Technical Documentation
Scan the QR code to access additional technical documentation for the FC 51. Or, after scanning the QR code, click Global English on the website to select your local region's website and search for FC 51 to find documents in your language.
Danfoss A/S
Ulsnaes 1
DK-6300 Graasten
vlt-drives.danfoss.com
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