Danfoss VLT AutomationDrive FC 301 Guide

MAKING MODERN LIVING POSSIBLE
Design Guide
VLT®AutomationDrive FC 301/302
0.25–75 kW
www.danfoss.com/drives

Contents
1 Introduction 9
1.1 Purpose of the Design Guide 9
1.2 Additional Resources 9
1.3 Abbreviations, Symbols and Conventions 9
1.4 Definitions 10
1.5 Document and Software Version 11
1.6 Regulatory Compliance 11
1.6.1 CE Mark 11
1.6.1.1 Low Voltage Directive 11
1.6.1.2 EMC Directive 12
1.6.1.3 Machinery Directive 12
1.6.2 UL Compliance 12
1.6.3 C-tick Compliance 12
1.6.4 Marine Compliance 12
1.7 Disposal Instruction 12
1.8 Safety 12
2 Safety 13
2.1 Safety Symbols 13
2.2 Qualified Personnel 13
2.3 Safety Precautions 13
3 Basic Operating Principles 15
3.1 General 15
3.2 Description of Operation 15
3.3 Sequence of Operation 15
3.3.1 Rectifier Section 15
3.3.2 Intermediate Section 15
3.3.3 Inverter Section 15
3.3.4 Brake Option 16
3.3.5 Load Sharing 16
3.4 Control Interface 16
3.5 Wiring Schematic 17
3.6 Controls 19
3.6.1 Control Principle 19
3.6.2 FC 301 vs. FC 302 Control Principle 20
3.6.3 Control Structure in VVCplus 21
3.6.4 Control Structure in Flux Sensorless (FC 302 only) 22
Contents Design Guide
MG33BF22 Rev. 2014-04-04 All rights reserved.

3.6.5 Control Structure in Flux with Motor Feedback (FC 302 only) 23
3.6.6 PID 24
3.6.6.1 Speed PID Control 24
3.6.6.2 Tuning PID speed control 27
3.6.6.3 Process PID Control 27
3.6.6.4 Advanced PID Control 29
3.6.7 Internal Current Control in VVCplus Mode 29
3.6.8 Local (Hand On) and Remote (Auto On) Control 29
3.7 Reference Handling 31
3.7.1 References 31
3.7.2 Reference Limits 33
3.7.3 Scaling of Preset References and Bus References 34
3.7.4 Scaling of Analog and Pulse References and Feedback 34
3.7.5 Dead Band Around Zero 35
4 Product Features 39
4.1 Automated Operational Features 39
4.1.1 Short Circuit Protection 39
4.1.2 Overvoltage Protection 39
4.1.3 Missing Motor Phase Detection 40
4.1.4 Line Phase Imbalance Detection 40
4.1.5 Switching on the Output 40
4.1.6 Overload Protection 40
4.1.7 Locked Rotor Protection 40
4.1.8 Automatic Derating 41
4.1.9 Automatic Energy Optimization 41
4.1.10 Automatic Switching Frequency Modulation 41
4.1.11 Automatic Derating for High Carrier Frequency 41
4.1.12 Power Fluctuation Performance 41
4.1.13 Resonance Damping 41
4.1.14 Temperature-controlled Fans 41
4.1.15 EMC Compliance 42
4.1.16 Galvanic Isolation of Control Terminals 42
4.2 Custom Application Features 42
4.2.1 Automatic Motor Adaptation 42
4.2.2 Motor Thermal Protection 42
4.2.3 Line Drop-out 43
4.2.4 Built-in PID Controller 43
Contents Design Guide
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4.2.5 Automatic Restart 43
4.2.6 Flying Start 43
4.2.7 Full Torque at Reduced Speed 43
4.2.8 Frequency Bypass 44
4.2.9 Motor Preheat 44
4.2.10 Four Programmable Set-ups 44
4.2.11 Dynamic Braking 44
4.2.12 Open-loop Mechanical Brake Control 45
4.2.13 Closed-loop Mechanical Brake Control/Hoist Mechanical Brake 46
4.2.14 Smart Logic Control (SLC) 47
4.2.15 Safe Torque Off 48
4.3 Danfoss VLT®FlexConcept®48
5 System Integration 49
5.1 Ambient Operating Conditions 49
5.1.1 Humidity 49
5.1.2 Temperature 49
5.1.3 Temperature and Cooling 49
5.1.4 Manual Derating 50
5.1.4.1 Derating for Running at Low Speed 50
5.1.4.2 Derating for Low Air Pressure 50
5.1.5 Acoustic Noise 51
5.1.6 Vibration and Shock 51
5.1.7 Aggressive Atmospheres 51
5.1.7.1 Gases 51
5.1.7.2 Dust Exposure 52
5.1.7.3 Potentially Explosive Atmospheres 52
5.1.8 Maintenance 53
5.1.9 Storage 53
5.2 General Aspects of EMC 53
5.2.1 EMC Test Results 54
5.2.2 Emission Requirements 56
5.2.3 Immunity Requirements 57
5.2.4 Motor Insulation 58
5.2.5 Motor Bearing Currents 58
5.3 Line Power Supply Interference/Harmonics 59
5.3.1 The Effect of Harmonics in a Power Distribution System 59
5.3.2 Harmonic Limitation Standards and Requirements 60
5.3.3 Harmonic Mitigation 60
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5.3.4 Harmonic Calculation 60
5.4 Galvanic Isolation (PELV) 61
5.4.1 PELV - Protective Extra Low Voltage 61
5.5 Brake Functions 61
5.5.1 Selection of Brake Resistor 61
6 Product Specifications 64
6.1 Electrical Data 64
6.1.1 Line Power Supply 200–240 V 64
6.1.2 Line Power Supply 380–500 V 66
6.1.3 Line Power Supply 525–600 V (FC 302 only) 69
6.1.4 Line Power Supply 525–690 V (FC 302 only) 72
6.2 General Specifications 75
6.2.1 Line Power Supply 75
6.2.2 Motor Output and Motor Data 75
6.2.3 Ambient Conditions 76
6.2.4 Cable Specifications 76
6.2.5 Control Input/Output and Control Data 77
6.2.6 Derating for Ambient Temperature 81
6.2.6.1 Derating for Ambient Temperature, Enclosure Type A 81
6.2.6.2 Derating for Ambient Temperature, Enclosure Types B 81
6.2.6.3 Derating for Ambient Temperature, Enclosure Types C 84
6.2.7 Measured Values for dU/dt Testing 87
6.2.8 Efficiency 90
6.2.9 Acoustic Noise 90
7 How to Order 91
7.1 Drive Configurator 91
7.1.1 Type Code 91
7.1.2 Language 94
7.2 Ordering Numbers 95
7.2.1 Options and Accessories 95
7.2.2 Spare Parts 97
7.2.3 Accessory Bags 97
7.2.4 VLT AutomationDrive FC 301 98
7.2.5 Brake Resistors for FC 302 102
7.2.6 Other Flat Pack Brake Resistors 109
7.2.7 Harmonic Filters 111
7.2.8 Sine-Wave Filters 113
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7.2.9 dU/dt Filters 115
8 Mechanical Installation 117
8.1 Safety 117
8.2 Mechanical Dimensions 118
8.2.1 Mechanical Mounting 121
8.2.1.1 Clearance 121
8.2.1.2 Wall Mounting 121
9 Electrical Installation 123
9.1 Safety 123
9.2 Cables 124
9.2.1 Tightening Torque 124
9.2.2 Entry Holes 125
9.2.3 Tightening of the Cover after Connections are Made 129
9.3 AC line input connections 129
9.3.1 Fuses and Circuit Breakers 133
9.3.1.1 Fuses 133
9.3.1.2 Recommendations 133
9.3.1.3 CE Compliance 134
9.3.1.4 UL Compliance 137
9.4 Motor Connection 142
9.5 Ground Leakage Current Protection 144
9.6 Additional Connections 146
9.6.1 Relay 146
9.6.2 Disconnectors and Contactors 147
9.6.3 Load Sharing 148
9.6.4 Brake Resistor 148
9.6.5 PC Software 148
9.6.5.1 MCT 10 149
9.6.5.2 MCT 31 149
9.6.5.3 Harmonic Calculation Software (HCS) 149
9.7 Additional Motor Information 150
9.7.1 Motor Cable 150
9.7.2 Connection of Multiple Motors 150
9.8 Safety 153
9.8.1 High Voltage Test 153
9.8.2 EMC Grounding 153
10 Application Examples 154
Contents Design Guide
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10.1 Commonly Used Applications 154
10.1.1 Closed-loop Drive System 159
10.1.2 Programming of Torque Limit and Stop 159
10.1.3 Programming of Speed Control 160
11 Options and Accessories 162
11.1 Communication Options 162
11.2 I/O, Feedback and Safety Options 162
11.2.1 VLT®General Purpose I/O Module MCB 101 162
11.2.2 VLT®Encoder Option MCB 102 164
11.2.3 VLT®Resolver Option MCB 103 166
11.2.4 VLT®Relay Card MCB 105 168
11.2.5 VLT®Safe PLC Interface Option MCB 108 170
11.2.6 VLT®PTC Thermistor Card MCB 112 172
11.2.7 VLT®Extended Relay Card MCB 113 173
11.2.8 VLT®Sensor Input Option MCB 114 175
11.2.9 VLT®Safe Option MCB 15x 176
11.2.10 VLT®C Option Adapter MCF 106 180
11.3 Motion Control Options 180
11.4 Accessories 182
11.4.1 Brake Resistors 182
11.4.2 Sine-wave Filters 182
11.4.3 dU/dt Filters 182
11.4.4 Common Mode Filters 182
11.4.5 Harmonic Filters 182
11.4.6 IP21/Type 1 Enclosure Kit 183
11.4.7 Remote Mounting Kit for LCP 185
11.4.8 Mounting Bracket for Enclosure Types A5, B1, B2, C1 and C2 186
12 RS-485 Installation and Set-up 188
12.1 Installation and Set-up 188
12.1.1 Overview 188
12.2 Network Connection 189
12.3 Bus Termination 189
12.4 RS-485 Installation and Set-up 189
12.5 FC Protocol Overview 190
12.6 Network Configuration 190
12.7 FC Protocol Message Framing Structure 190
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12.7.1 Content of a Character (byte) 190
12.7.2 Message Structure 190
12.7.3 Message Length (LGE) 191
12.7.4 Adjustable Frequency Drive Address (ADR) 191
12.7.5 Data Control Byte (BCC) 191
12.7.6 The Data Field 192
12.7.7 The PKE Field 193
12.7.8 Parameter Number (PNU) 193
12.7.9 Index (IND) 193
12.7.10 Parameter Value (PWE) 194
12.7.11 Supported Data Types 194
12.7.12 Conversion 194
12.7.13 Process Words (PCD) 195
12.8 Examples 195
12.8.1 Writing a Parameter Value 195
12.8.2 Reading a Parameter Value 195
12.9 Modbus RTU Overview 196
12.9.1 Assumptions 196
12.9.2 What the User Should Already Know 196
12.9.3 Modbus RTU Overview 196
12.9.4 Adjustable Frequency Drive with Modbus RTU 196
12.10 Network Configuration 197
12.11 Modbus RTU Message Framing Structure 197
12.11.1 Adjustable Frequency Drive with Modbus RTU 197
12.11.2 Modbus RTU Message Structure 197
12.11.3 Start/Stop Field 197
12.11.4 Address Field 198
12.11.5 Function Field 198
12.11.6 Data Field 198
12.11.7 CRC Check Field 198
12.11.8 Coil Register Addressing 198
12.11.9 How to Control the Adjustable Frequency Drive 200
12.11.10 Function Codes Supported by Modbus RTU 200
12.11.11 Modbus Exception Codes 200
12.12 How to Access Parameters 201
12.12.1 Parameter Handling 201
12.12.2 Storage of Data 201
12.12.3 IND (Index) 201
Contents Design Guide
MG33BF22 Rev. 2014-04-04 All rights reserved.

12.12.4 Text Blocks 201
12.12.5 Conversion Factor 201
12.12.6 Parameter Values 201
12.13 Danfoss FC Control Profile 202
12.13.1 Control Word According to FC Profile (8-10 Control Profile = FC profile) 202
12.13.2 Status Word According to FC Profile (STW) (8-10 Control Profile = FC
profile) 203
12.13.3 Bus Speed Reference Value 204
12.13.4 Control Word according to PROFIdrive Profile (CTW) 205
12.13.5 Status Word according to PROFIdrive Profile (STW) 206
Index 208
Contents Design Guide
Rev. 2014-04-04 All rights reserved. MG33BF22

1 Introduction
1.1 Purpose of the Design Guide
The Design Guide provides information required for
integration of the adjustable frequency drive in a diversity
of applications.
VLT®is a registered trademark.
1.2 Additional Resources
Other resources are available to understand advanced
adjustable frequency drive operation, programming, and
directives compliance.
•The Instruction Manual provides detailed
information for the installation and start up of
the adjustable frequency drive.
•The Programming Guide provides greater detail in
how to work with parameters and many
application examples.
•The VLT
®
Safe Torque Off Instruction Manual
describes how to use Danfoss adjustable
frequency drives in functional safety applications.
•Supplementary publications and manuals are
available from Danfoss. See danfoss.com/Product/
Literature/Technical+Documentation.htm for
listings.
•Optional equipment is available that may change
some of the information described in these
publications. Be sure to see the instructions
supplied with the options for specific
requirements.
Contact a Danfoss supplier or go to www.danfoss.com for
additional information.
1.3 Abbreviations, Symbols and
Conventions
Conventions
Numbered lists indicate procedures.
Bullet lists indicate other information and description of
figures.
Italicized text indicates
•cross reference
•link
•footnote
•parameter name, parameter group name,
parameter option
60°AVM 60°Asynchronous Vector Modulation
A Ampere/AMP
AC Alternating current
AD Air discharge
AI Analog Input
AMA Automatic Motor Adaptation
AWG American wire gauge
°CDegrees Celsius
CD Contant discharge
CM Common mode
CT Constant torque
DC Direct current
DI Digital Input
DM Differential mode
D-TYPE Drive Dependent
EMC Electro Magnetic Compatibility
ETR Electronic Thermal Relay
fJOG Motor frequency when jog function is
activated
fMMotor frequency
fMAX The maximum output frequency the
adjustable frequency drive applies on its
output.
fMIN The minimum motor frequency from
adjustable frequency drive.
fM,N Nominal motor frequency
FC Adjustable frequency drive
g Gram
Hiperface®Hiperface®is a registered trademark by
Stegmann
hp Horsepower
HTL HTL encoder (10–30 V) pulses - High-voltage
Transistor Logic
Hz Hertz
IINV Rated Inverter Output Current
ILIM Current limit
IM,N Nominal motor current
IVLT,MAX The maximum output current
IVLT,N The rated output current supplied by the
adjustable frequency drive
kHz Kilohertz
LCP Local Control Panel
lsb Least significant bit
m Meter
mA Milliampere
MCM Mille Circular Mil
MCT Motion Control Tool
mH Millihenry Inductance
Introduction Design Guide
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11

min Minute
ms Millisecond
msb Most significant bit
ηVLT Efficiency of the adjustable frequency drive
defined as ratio between power output and
power input
nF Nanofarad
NLCP Numerical Local Control Panel
Nm Newton Meters
nsSynchronous Motor Speed
Online/Offline
Parameters
Changes to online parameters are activated
immediately after the data value is changed.
Pbr,cont. Rated power of the brake resistor (average
power during continuous braking)
PCB Printed Circuit Board
PCD Process Data
PELV Protective Extra Low Voltage
PmAdjustable frequency drive nominal output
power as HO
PM,N Nominal motor power
PM motor Permanent Magnet motor
Process PID The PID regulator maintains the desired speed,
pressure, temperature, etc.
Rbr,nom The nominal resistor value that ensures a
braking energy on motor shaft of 150/160%
for 1 minute
RCD Residual Current Device
Regen Regenerative terminals
Rmin Minimum permissible brake resistor value by
adjustable frequency drive
RMS Root Mean Square
RPM Revolutions Per Minute
Rrec Resistor value and resistance of the brake
resistor
s Second
SFAVM Stator Flux-oriented Asynchronous Vector
Modulation
STW Status Word
SMPS Switch Mode Power Supply
THD Total Harmonic Distortion
TLIM Torque limit
TTL TTL encoder (5 V) pulses - Transistor Transistor
Logic
UM,N Nominal motor voltage
V Volts
VT Variable Torque
VVCplus Voltage Vector Control
Table 1.1 Abbreviations
The following symbols are used in this document:
WARNING
Indicates a potentially hazardous situation which could
result in death or serious injury.
CAUTION
Indicates a potentially hazardous situation which could
result in minor or moderate injury. It may also be used
to alert against unsafe practices.
NOTICE!
Indicates important information, including situations that
may result in damage to equipment or property.
1.4 Definitions
Coast
The motor shaft is in free mode. No torque on motor.
Brake Resistor
The brake resistor is a module capable of absorbing the
braking energy generated in regenerative braking. This
regenerative braking energy increases the intermediate
circuit voltage and a brake chopper ensures that the
power is transmitted to the brake resistor.
CT Characteristics
Constant torque characteristics used for all applications
such as conveyor belts, displacement pumps and cranes.
Initializing
If initialization is carried out (14-22 Operation Mode), the
adjustable frequency drive returns to the default setting.
Intermittent Duty Cycle
An intermittent duty rating refers to a sequence of duty
cycles. Each cycle consists of an on-load and an off-load
period. The operation can be either periodic duty or non-
periodic duty.
Set-up
Save parameter settings in four set-ups. Change between
the four parameter set-ups and edit one set-up, while
another set-up is active.
Slip Compensation
The adjustable frequency drive compensates for the motor
slip by giving the frequency a supplement that follows the
measured motor load, keeping the motor speed almost
constant.
Smart Logic Control (SLC)
The SLC is a sequence of user-defined actions executed
when the associated user-defined events are evaluated as
true by the Smart Logic Controller. (Parameter group 13-**
Smart Logic.
Introduction Design Guide
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1

FC Standard Bus
Includes RS-485 bus with FC protocol or MC protocol. See
8-30 Protocol.
Thermistor
A temperature-dependent resistor placed where the
temperature is to be monitored (adjustable frequency drive
or motor).
Trip
A state entered in fault situations, e.g., if the adjustable
frequency drive is subject to an overtemperature or when
the adjustable frequency drive is protecting the motor,
process or mechanism. Restart is prevented until the cause
of the fault has disappeared and the trip state is canceled
by activating reset or, in some cases, by being
programmed to reset automatically. Trip may not be used
for personal safety.
Trip Locked
A state entered in fault situations when the adjustable
frequency drive is protecting itself and requiring physical
intervention, e.g., if the adjustable frequency drive is
subject to a short circuit on the output. A locked trip can
only be canceled by cutting off line power, removing the
cause of the fault, and reconnecting the adjustable
frequency drive. Restart is prevented until the trip state is
canceled by activating reset or, in some cases, by being
programmed to reset automatically. Trip may not be used
for personal safety.
VT Characteristics
Variable torque characteristics used for pumps and fans.
Power Factor
The True Power Factor (lambda) takes all the harmonics
into consideration and is always smaller than the Power
Factor (cos-phi) that only considers the 1st harmonics of
current and voltage.
cos ϕ =
P kW
P kVA =
Uλ x Iλ x cos ϕ
Uλ x Iλ
Cos-phi is also known as displacement power factor.
Both lambda and cos-phi are stated for Danfoss VLT®
adjustable frequency drives in chapter 6.2.1 Line Power
Supply.
The power factor indicates to which extent the adjustable
frequency drive imposes a load on the line power supply.
The lower the power factor, the higher the IRMS for the
same kW performance.
In addition, a high power factor indicates that the different
harmonic currents are low.
All adjustable frequency drives have built-in DC coils in the
DC link to have a high power factor and to reduce the
THD on the main supply.
1.5 Document and Software Version
This manual is regularly reviewed and updated. All
suggestions for improvement are welcome. Table 1.2 shows
the document version and the corresponding software
version.
Edition Remarks Software version
MG33BFxx Replaces MG33BExx 6.72
Table 1.2 Document and Software Version
1.6 Regulatory Compliance
Adjustable frequency drives are designed in compliance
with the directives described in this section.
1.6.1 CE Mark
The CE mark (Communauté européenne) indicates that the
product manufacturer conforms to all applicable EU
directives. The three EU directives applicable to the design
and manufacture of adjustable frequency drives are the
directive low-voltage, the EMC directive, and (for units with
an integrated safety function) the machinery directive.
The CE mark is intended to eliminate technical barriers to
free trade between the EC and EFTA states inside the ECU.
The CE mark does not regulate the quality of the product.
Technical specifications cannot be deduced from the CE
mark.
1.6.1.1 Low Voltage Directive
Adjustable frequency drives are classified as electronic
components and must be CE-labelled in accordance with
the low-voltage directive. The directive applies to all
electrical equipment in the 50–1000 V AC and the 75–1600
V DC voltage ranges.
The directive mandates that the equipment design must
ensure the safety and health of people and livestock are
not endangered and the preservation of material worth so
long as the equipment is properly installed, maintained,
and used as intended. Danfoss CE labels comply with the
low-voltage directive and provide a declaration of
conformity upon request.
Introduction Design Guide
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1.6.1.2 EMC Directive
Electromagnetic compatibility (EMC) means that electro-
magnetic interference between apparatus does not hinder
their performance. The basic protection requirement of the
EMC Directive 2004/108/EC states that devices that
generate electromagnetic interference (EMI), or whose
operation could be affected by EMI, must be designed to
limit the generation of electromagnetic interference and
shall have a suitable degree of immunity to EMI when
properly installed, maintained, and used as intended.
An adjustable frequency drive can be used as stand-alone
device or as part of a more complex installation. Devices
used as stand alone or as part of a system must bear the
CE mark. Systems must not be CE-marked but must
comply with the basic protection requirements of the EMC
directive.
1.6.1.3 Machinery Directive
Adjustable frequency drives are classified as electronic
components subject to the low-voltage directive; however,
adjustable frequency drives with an integrated safety
function must comply with the machinery directive
2006/42/EC. Adjustable frequency drives without the safety
function do not fall under the machinery directive. If an
adjustable frequency drive is integrated into machinery
system, Danfoss provides information on safety aspects
relating to the adjustable frequency drive.
Machinery Directive 2006/42/EC covers a machine
consisting of an aggregate of interconnected components
or devices of which at least one is capable of mechanical
movement. The directive mandates that the equipment
design must ensure the safety and health of people and
livestock are not endangered and the preservation of
material worth so long as the equipment is properly
installed, maintained, and used as intended.
When adjustable frequency drives are used in machines
with at least one moving part, the machine manufacturer
must provide declaration stating compliance with all
relevant statutes and safety measures. Danfoss CE labels
comply with the machinery directive for adjustable
frequency drives with an integrated safety function and
provide a declaration of conformity upon request.
1.6.2 UL Compliance
UL-listed
Figure 1.1 UL
NOTICE!
Adjustable frequency drives of enclosure type T7
(525–690 V) are not certified for UL.
The adjustable frequency drive complies with UL508C
thermal memory retention requirements. For more
information, refer to the section Motor Thermal Protection
in the Design Guide.
1.6.3 C-tick Compliance
1.6.4 Marine Compliance
1.7 Disposal Instruction
Do not dispose of equipment containing
electrical components together with
domestic waste.
Collect it separately in accordance with
local and currently valid legislation.
Table 1.3 Disposal Instruction
1.8 Safety
Adjustable frequency drives contain high-voltage
components and have the potential for fatal injury if
handled improperly. Only trained technicians should install
and operate the equipment. No repair work should be
attempted without first removing power from the
adjustable frequency drive and waiting the designated
amount of time for stored electrical energy to dissipate.
Refer to the Instruction Manual, shipped with the unit and
available online for:
•discharge time, and
•detailed safety instructions and warnings.
Strict adherence to safety precautions and notices is
mandatory for safe operation of the adjustable frequency
drive.
Introduction Design Guide
12 Rev. 2014-04-04 All rights reserved. MG33BF22
1
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2 Safety
2.1 Safety Symbols
The following symbols are used in this document:
WARNING
Indicates a potentially hazardous situation which could
result in death or serious injury.
CAUTION
Indicates a potentially hazardous situation which could
result in minor or moderate injury. It may also be used
to alert against unsafe practices.
NOTICE!
Indicates important information, including situations that
may result in damage to equipment or property.
2.2 Qualified Personnel
Correct and reliable transport, storage, installation,
operation and maintenance are required for the trouble-
free and safe operation of the adjustable frequency drive.
Only qualified personnel is allowed to install or operate
this equipment.
Qualified personnel is defined as trained staff, who are
authorized to install, commission, and maintain equipment,
systems and circuits in accordance with pertinent laws and
regulations. Additionally, the personnel must be familiar
with the instructions and safety measures described in this
document.
2.3 Safety Precautions
WARNING
HIGH VOLTAGE
Adjustable frequency drives contain high voltage when
connected to AC line power. Failure to perform instal-
lation, start-up, and maintenance by qualified personnel
could result in death or serious injury.
•Installation, start-up, and maintenance must be
performed by qualified personnel only.
WARNING
UNINTENDED START
When the adjustable frequency drive is connected to AC
line power, the motor may start at any time, causing risk
of death, serious injury, equipment, or property damage.
The motor can start by means of an external switch, a
serial bus command, an input reference signal from the
LCP, or after a cleared fault condition.
1. Disconnect the adjustable frequency drive from
line power whenever personal safety consider-
ations make it necessary to avoid unintended
motor start.
2. Press [Off] on the LCP before programming
parameters.
3. The adjustable frequency drive, motor, and any
driven equipment must be in operational
readiness when the adjustable frequency drive
is connected to AC line power.
Safety Design Guide
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22

WARNING
DISCHARGE TIME
The adjustable frequency drive contains DC link
capacitors which can remain charged even when the
adjustable frequency drive is not powered. Failure to
wait the specified time after power has been removed
before performing service or repair work could result in
death or serious injury.
1. Stop motor.
2. Disconnect AC line power, permanent magnet
type motors, and remote DC link power
supplies, including battery backups, UPS, and
DC link connections to other adjustable
frequency drives.
3. Wait for the capacitors to discharge fully before
performing any service or repair work. The
duration of waiting time is specified in
Table 2.1.
Voltage [V] Minimum waiting time (minutes)
4 7 15
200–240 0.34–5 hp
[0.25–3.7 kW]
7.5–50 hp
[5.5–37 kW]
380–500 0.34–10 hp
[0.25–7.5 kW]
15–100 hp
[11–75 kW]
525–600 1–10 hp
[0.75–7.5 kW]
15–100 hp
[11–75 kW]
525–690 2–10 hp
[1.5–7.5 kW]
15–100 hp
[11–75 kW]
High voltage may be present even when the warning LED
indicator lights are off.
Table 2.1 Discharge Time
WARNING
LEAKAGE CURRENT HAZARD
Leakage currents exceed 3.5 mA. Failure to ground the
adjustable frequency drive properly could result in death
or serious injury.
•Ensure correct grounding of the equipment by
a certified electrical installer.
WARNING
EQUIPMENT HAZARD
Contact with rotating shafts and electrical equipment
can result in death or serious injury.
•Ensure that only trained and qualified
personnel perform installation, start-up, and
maintenance.
•Ensure that electrical work conforms to national
and local electrical codes.
•Follow the procedures in this manual.
CAUTION
WINDMILLING
Unintended rotation of permanent magnet motors
causes risk of personal injury and equipment damage.
•Ensure that permanent magnet motors are
blocked to prevent unintended rotation.
CAUTION
POTENTIAL HAZARD IN THE EVENT OF INTERNAL
FAILURE
Risk of personal injury when the adjustable frequency
drive is not properly closed.
•Before applying power, ensure all safety covers
are in place and securely fastened.
Safety Design Guide
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22

3 Basic Operating Principles
3.1 General
This chapter provides an overview of the adjustable
frequency drive’s primary assemblies and circuitry. It is
intended to describe the internal electrical and signal
processing functions. A description of the internal control
structure is also included.
Also described are automated and optional adjustable
frequency drive functions available for designing robust
operating systems with sophisticated control and status
reporting performance.
3.2 Description of Operation
The adjustable frequency drive supplies a regulated
amount of AC line power to a standard 3-phase induction
motor to control the motor speed. The adjustable
frequency drive supplies variable frequency and voltage to
the motor.
The adjustable frequency drive is divided into four main
modules.
•Rectifier
•Intermediate circuit
•Inverter
•Control and regulation
In chapter 3.3 Sequence of Operation, these modules are
covered in greater detail and describe how power and
control signals move within the adjustable frequency drive.
Figure 3.1 Internal Control Logic
3.3 Sequence of Operation
3.3.1 Rectifier Section
When power is first applied to the adjustable frequency
drive, it enters through the input terminals (L1, L2, and L3)
and on to the disconnect and/or RFI filter option,
depending on the unit's configuration.
3.3.2 Intermediate Section
Following the rectifier section, voltage passes to the
intermediate section. This rectified voltage is smoothed by
an sine-wave filter circuit consisting of the DC bus inductor
and the DC bus capacitor bank.
The DC bus inductor provides series impedance to
changing current. This aids the filtering process while
reducing harmonic distortion to the input AC current
waveform normally inherent in rectifier circuits.
3.3.3 Inverter Section
In the inverter section, once a run command and speed
reference are present, the IGBTs begin switching to create
the output waveform. This waveform, as generated by the
Danfoss VVCplus PWM principle at the control card,
provides optimal performance and minimal losses in the
motor.
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33

3.3.4 Brake Option
For adjustable frequency drives equipped with the
dynamic brake option, a brake IGBT along with terminals
81(R-) and 82(R+) are included for connecting an external
brake resistor.
The function of the brake IGBT is to limit the voltage in
the intermediate circuit whenever the maximum voltage
limit is exceeded. It does this by switching the externally
mounted resistor across the DC bus to remove excess DC
voltage present on the bus capacitors. Excess DC bus
voltage is generally a result of an overhauling load causing
regenerative energy to return to the DC bus. This occurs,
for example, when the load drives the motor causing the
voltage to return to the DC bus circuit.
Placing the brake resistor externally has the advantages of
selecting the resistor based on application need,
dissipating the energy outside of the control panel, and
protecting the drive from overheating if the brake resistor
is overloaded.
The brake IGBT gate signal originates on the control card
and is delivered to the brake IGBT via the power card and
gate drive card. Additionally, the power and control cards
monitor the brake IGBT and brake resistor connection for
short circuits and overloads.
3.3.5 Load Sharing
Units with the built-in load sharing option contain
terminals (+) 89 DC and (–) 88 DC. Within the adjustable
frequency drive, these terminals connect to the DC bus in
front of the DC link reactor and bus capacitors.
The use of the load sharing terminals can take on two
different configurations.
In one method, the terminals are used to tie the DC bus
circuits of multiple adjustable frequency drives together.
This allows one unit that is in a regenerative mode to
share its excess bus voltage with another unit that is
running a motor. Load sharing in this manner can reduce
the need for external dynamic brake resistors while also
saving energy. In theory, the number of units that can be
connected in this way is infinite; however, each unit must
be the same voltage rating. In addition, depending on the
size and number of units, it may be necessary to install DC
reactors and DC fuses in the DC link connections and AC
reactors on line power.
Attempting such a configuration requires specific consider-
ations and should not be attempted without first
consulting Danfoss application engineering.
In the second method, the adjustable frequency drive is
powered exclusively from a DC source. This is a bit more
complicated. First, a DC source is required. Second, a
means to soft charge the DC bus at power-up is also
required. Last, a voltage source is required to power the
fans within the unit. Again such a configuration should not
be attempted with out first consulting Danfoss application
engineering.
3.4 Control Interface
3.4.1 Control Principle
The adjustable frequency drive receives control input from
several sources.
•Local control panel (hand mode)
•Programmable analog, digital, and analog/digital
control terminals (auto mode)
•The RS-485, USB, or serial communication ports
(auto mode)
When wired and properly programmed, the control
terminals provide feedback, reference, and other input
signals to the adjustable frequency drive; output status
and fault conditions from the adjustable frequency drive,
relays to operate auxiliary equipment, and serial communi-
cation interface. A 24 V common is also provided. Control
terminals are programmable for various functions by
selecting parameter options through the local control
panel (LCP) on the front of the unit or external sources.
Most control wiring is customer supplied unless factory
ordered.
Basic Operating Principles Design Guide
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33

3.5 Wiring Schematic
130BD599.10
3-phase
power
input
DC bus Switch Mode
Power Supply
Motor
Analog Output
Interface
relay1
relay2
ON=Terminated
OFF=Open
Brake
resistor
91 (L1)
92 (L2)
93 (L3)
PE
88 (-)
89 (+)
50 (+10 V OUT)
53 (A IN)
54 (A IN)
55 (COM A IN)
0/4-20 mA
12 (+24 V OUT)
13 (+24 V OUT)
37 (D IN)
18 (D IN)
20 (COM D IN)
10 V DC
15 mA 130/200 mA
+ - + -
(U) 96
(V) 97
(W) 98
(PE) 99
(COM A OUT) 39
(A OUT) 42
(P RS-485) 68
(N RS-485) 69
(COM RS-485) 61
0 V
5V
S801
0/4-20 mA
RS-485
RS-485
03
+10 V DC
0/-10 V DC -
+10 V DC
+10 V DC
0/4-20 mA
0/-10 V DC-
240 V AC, 2 A
24 V DC
02
01
05
04
06
24 V (NPN)
0 V (PNP)
0 V (PNP)
24 V (NPN)
19 (D IN)
24 V (NPN)
0 V (PNP)
27
24 V
0 V
(D IN/OUT)
0 V (PNP)
24 V (NPN)
(D IN/OUT)
0 V
24 V
29
24 V (NPN)
0 V (PNP)
0 V (PNP)
24 V (NPN)
33 (D IN)
32 (D IN)
1 2
ON
S201
ON
21
S202
ON=0/4-20 mA
OFF=0/-10 V DC -
+10 V DC
95
P 5-00
21
ON
S801
(R+) 82
(R-) 81
: Chassis
: Ground
**
240 V AC, 2 A
400 V AC, 2 A
*
*
*
Figure 3.2 Basic Wiring Schematic
A=Analog, D=Digital
*Terminal 37 (optional) is used for Safe Torque Off. For Safe Torque Off installation instructions, refer to the Safe Torque Off
Instruction Manual for Danfoss VLT
®
Adjustable Frequency Drives. Terminal 37 is not included in FC 301 (except enclosure type
A1). Relay 2 and terminal 29 have no function in FC 301.
**Do not connect cable shield.
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33

130BD529.11
1
2
3
4
5
6
7
8
PE
U
V
W
9
L1
L2
L3
PE
10
11
1 PLC 7 Motor, 3--phase and PE (shielded)
2 Adjustable frequency drive 8 Line power, 3--phase and reinforced PE (non-shielded)
3 Output contactor 9 Control wiring (shielded)
4 Cable clamp 10 Potential equalization min. 16 mm2(0.025 in2)
5 Cable insulation (stripped) 11 Clearance between control cable, motor cable and line
cable: Min. 7.9 in [200 mm]
6 Cable connector
Figure 3.3 EMC-compliant Electrical Connection
For more information about EMC, see chapter 4.1.15 EMC Compliance.
Basic Operating Principles Design Guide
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