Danfoss VLT FC 103 Guide

MAKING MODERN LIVING POSSIBLE
Design Guide
VLT®Refrigeration Drive FC 103
1.1–90 kW
vlt-drives.danfoss.com

Contents
1 Introduction 7
1.1 Purpose of the Design Guide 7
1.2 Organisation 7
1.3 Additional Resources 7
1.4 Abbreviations, Symbols and Conventions 8
1.5 Safety Symbols 9
1.6 Denitions 9
1.7 Document and Software Version 10
1.8 Approvals and Certications 10
1.8.1 CE Mark 10
1.8.1.1 Low Voltage Directive 10
1.8.1.2 EMC Directive 10
1.8.1.3 Machinery Directive 11
1.8.1.4 ErP Directive 11
1.8.2 C-tick Compliance 11
1.8.3 UL Compliance 11
1.8.4 Marine Compliance (ADN) 11
1.8.5 Export Control Regulations 12
1.9 Safety 12
1.9.1 General Safety Principles 12
2 Product Overview 14
2.1 Introduction 14
2.2 Description of Operation 17
2.3 Sequence of Operation 18
2.3.1 Rectier Section 18
2.3.2 Intermediate Section 18
2.3.3 Inverter Section 18
2.4 Control Structures 19
2.4.1 Control Structure Open Loop 19
2.4.2 Control Structure Closed Loop 19
2.4.3 Local (Hand On) and Remote (Auto On) Control 20
2.4.4 Reference Handling 21
2.4.5 Feedback Handling 23
2.5 Automated Operational Functions 24
2.5.1 Short-circuit Protection 24
2.5.2 Overvoltage Protection 24
2.5.3 Missing Motor Phase Detection 24
2.5.4 Mains Phase Imbalance Detection 25
Contents Design Guide
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2.5.5 Switching on the Output 25
2.5.6 Overload Protection 25
2.5.7 Automatic Derating 25
2.5.8 Automatic Energy Optimisation 25
2.5.9 Automatic Switching Frequency Modulation 25
2.5.10 Automatic Derating for High Switching Frequency 26
2.5.11 Automatic Derating for Overtemperature 26
2.5.12 Auto Ramping 26
2.5.13 Current Limit Circuit 26
2.5.14 Power Fluctuation Performance 26
2.5.15 Motor Soft Start 26
2.5.16 Resonance Damping 26
2.5.17 Temperature-controlled Fans 26
2.5.18 EMC Compliance 26
2.5.19 Current Measurement on All Three Motor Phases 27
2.5.20 Galvanic Isolation of Control Terminals 27
2.6 Custom Application Functions 27
2.6.1 Automatic Motor Adaptation 27
2.6.2 Motor Thermal Protection 27
2.6.3 Mains Drop-out 27
2.6.4 Built-in PID Controllers 28
2.6.5 Automatic Restart 28
2.6.6 Flying Start 28
2.6.7 Full Torque at Reduced Speed 28
2.6.8 Frequency Bypass 28
2.6.9 Motor Preheat 28
2.6.10 Four Programmable Set-ups 29
2.6.11 DC Braking 29
2.6.12 Sleep Mode 29
2.6.13 Run Permissive 29
2.6.14 Smart Logic Control (SLC) 29
2.6.15 Safe Torque O Function 30
2.7 Fault, Warning and Alarm Functions 31
2.7.1 Operation at Overtemperature 31
2.7.2 High and Low Reference Warning 31
2.7.3 High and Low Feedback Warning 31
2.7.4 Phase Imbalance or Phase Loss 31
2.7.5 High Frequency Warning 31
2.7.6 Low Frequency Warning 31
2.7.7 High Current Warning 31
Contents VLT®Refrigeration Drive FC 103
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2.7.8 Low Current Warning 31
2.7.9 No Load/Broken Belt Warning 31
2.7.10 Lost Serial Interface 32
2.8 User Interfaces and Programming 32
2.8.1 Local Control Panel 32
2.8.2 PC Software 33
2.8.2.1 MCT 10 Set-up Software 33
2.8.2.2 VLT®Harmonics Calculation Software MCT 31 33
2.8.2.3 Harmonic Calculation Software (HCS) 33
2.9 Maintenance 34
2.9.1 Storage 34
3 System Integration 35
3.1 Ambient Operating Conditions 35
3.1.1 Humidity 35
3.1.2 Temperature 36
3.1.3 Cooling 36
3.1.4 Motor-generated Overvoltage 37
3.1.5 Acoustic Noise 37
3.1.6 Vibration and Shock 37
3.1.7 Aggressive Atmospheres 37
3.1.8 IP Rating Denitions 38
3.1.9 Radio Frequency Interference 39
3.1.10 PELV and Galvanic Isolation Compliance 39
3.2 EMC, Harmonics, and Ground Leakage Protection 40
3.2.1 General Aspects of EMC Emissions 40
3.2.2 EMC Test Results (Emission) 42
3.2.3 Emission Requirements 43
3.2.4 Immunity Requirements 43
3.2.5 Motor Insulation 44
3.2.6 Motor Bearing Currents 44
3.2.7 Harmonics 45
3.2.8 Ground Leakage Current 47
3.3 Energy Eciency 49
3.3.1 IE and IES Classes 50
3.3.2 Power Loss Data and Eciency Data 50
3.3.3 Losses and Eciency of a Motor 51
3.3.4 Losses and Eciency of a Power Drive System 51
3.4 Mains Integration 51
3.4.1 Mains Congurations and EMC Eects 51
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3.4.2 Low-frequency Mains Interference 52
3.4.3 Analysing Mains Interference 53
3.4.4 Options for Reducing Mains Interference 53
3.4.5 Radio Frequency Interference 53
3.4.6 Classication of the Operating Site 53
3.4.7 Use with Isolated Input Source 54
3.4.8 Power Factor Correction 54
3.4.9 Input Power Delay 54
3.4.10 Mains Transients 54
3.4.11 Operation with a Standby Generator 54
3.5 Motor Integration 55
3.5.1 Motor Selection Considerations 55
3.5.2 Sine-wave and dU/dt Filters 55
3.5.3 Proper Motor Grounding 55
3.5.4 Motor Cables 55
3.5.5 Motor Cable Shielding 56
3.5.6 Connection of Multiple Motors 56
3.5.7 Motor Thermal Protection 57
3.5.8 Output Contactor 58
3.5.9 Energy Eciency 58
3.6 Additional Inputs and Outputs 59
3.6.1 Wiring Schematic 59
3.6.2 Relay Connections 60
3.6.3 EMC-compliant Electrical Connection 61
3.7 Mechanical Planning 62
3.7.1 Clearance 62
3.7.2 Wall Mounting 63
3.7.3 Access 63
3.8 Options and Accessories 63
3.8.1 Communication Options 66
3.8.2 Input/Output, Feedback, and Safety Options 66
3.8.3 Sine-wave Filters 66
3.8.4 dU/dt Filters 66
3.8.5 Harmonic Filters 66
3.8.6 IP21/NEMA Type 1 Enclosure Kit 67
3.8.7 Common-mode Filters 69
3.8.8 Remote Mounting Kit for LCP 69
3.8.9 Mounting Bracket for Enclosure Sizes A5, B1, B2, C1, and C2 70
3.9 Serial Interface RS485 71
3.9.1 Overview 71
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3.9.2 Network Connection 72
3.9.3 RS485 Bus Termination 72
3.9.4 EMC Precautions 73
3.9.5 FC Protocol Overview 73
3.9.6 Network Conguration 73
3.9.7 FC Protocol Message Framing Structure 73
3.9.8 FC Protocol Examples 77
3.9.9 Modbus RTU Protocol 78
3.9.10 Modbus RTU Message Framing Structure 79
3.9.11 Access to Parameters 82
3.9.12 FC Drive Control Prole 83
3.10 System Design Checklist 89
4 Application Examples 91
4.1 Application Examples 91
4.2 Selected Application Features 91
4.2.1 SmartStart 91
4.2.2 Start/Stop 92
4.2.3 Pulse Start/Stop 92
4.2.4 Potentiometer Reference 93
4.3 Application Set-up Examples 93
5 Special Conditions 99
5.1 Derating 99
5.2 Manual Derating 99
5.3 Derating for Long Motor Cables or Cables with Larger Cross-section 99
5.4 Derating for Ambient Temperature 100
6 Type Code and Selection 104
6.1 Ordering 104
6.1.1 Introduction 104
6.1.2 Type Code 104
6.2 Options, Accessories, and Spare Parts 105
6.2.1 Ordering Numbers: Options and Accessories 105
6.2.2 Ordering Numbers: Harmonic Filters 107
6.2.3 Ordering Numbers: Sine-wave Filter Modules, 200–480 V AC 107
6.2.4 Ordering Numbers: Sine-wave Filter Modules, 525-600/690 V AC 108
6.2.5 Harmonic Filters 109
6.2.6 Sine-wave Filters 111
6.2.7 dU/dt Filters 113
6.2.8 Common Mode Filters 114
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7 Specications 115
7.1 Electrical Data 115
7.1.1 Mains Supply 3x200–240 V AC 115
7.1.2 Mains Supply 3x380–480 V AC 117
7.1.3 Mains Supply 3x525–600 V AC 119
7.2 Mains Supply 121
7.3 Motor Output and Motor Data 121
7.4 Ambient Conditions 122
7.5 Cable Specications 122
7.6 Control Input/Output and Control Data 123
7.7 Connection Tightening Torque 126
7.8 Fuses and Circuit Breakers 127
7.9 Power Ratings, Weight, and Dimensions 132
7.10 dU/dt Testing 133
7.11 Acoustic Noise Ratings 135
7.12 Selected Options 135
7.12.1 VLT®General Purpose I/O Module MCB 101 135
7.12.2 VLT®Relay Card MCB 105 136
7.12.3 VLT®Extended Relay Card MCB 113 138
8 Appendix - Selected Drawings 140
8.1 Mains Connection Drawings 140
8.2 Motor Connection Drawings 143
8.3 Relay Terminal Drawings 145
8.4 Cable Entry Holes 146
Index 151
Contents VLT®Refrigeration Drive FC 103
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1 Introduction
1.1 Purpose of the Design Guide
This design guide for VLT®Refrigeration Drive FC 103
frequency converters is intended for:
•Project and systems engineers.
•Design consultants.
•Application and product specialists.
The design guide provides technical information to
understand the capabilities of the frequency converter for
integration into motor control and monitoring systems.
The purpose of the design guide is to provide design
considerations and planning data for integration of the
frequency converter into a system. The design guide caters
for selection of frequency converters and options for a
diversity of applications and installations.
Reviewing the detailed product information in the design
stage enables developing a well-conceived system with
optimal functionality and eciency.
VLT®is a registered trademark.
1.2 Organisation
Chapter 1 Introduction: The general purpose of the design
guide and compliance with international directives.
Chapter 2 Product Overview: The internal structure and
functionality of the frequency converter and operational
features.
Chapter 3 System Integration: Environmental conditions;
EMC, harmonics, and ground leakage; mains input; motors
and motor connections; other connections; mechanical
planning; and descriptions of options and accessories
available.
Chapter 4 Application Examples: Samples of product
applications and guidelines for use.
Chapter 5 Special Conditions: Details on unusual operational
environments.
Chapter 6 Type Code and Selection: Procedures for ordering
equipment and options to meet the intended use of the
system.
Chapter 7 Specications: A compilation of technical data in
table and graphics format.
Chapter 8 Appendix - Selected Drawings: A compilation of
graphics illustrating:
•Mains and motor connections
•Relay terminals
•Cable entries
1.3 Additional Resources
Resources available to understand advanced operation of
the frequency converter, programming, and directives
compliance:
•The VLT
®
Refrigeration Drive FC 103 Operating
Instructions (referenced as operating instructions in
this manual) provide detailed information for the
installation and start-up of the frequency
converter.
•The VLT
®
Refrigeration Drive FC 103 Design Guide
provides information required for design and
planning for integration of the frequency
converter into a system.
•The VLT
®
Refrigeration Drive FC 103 Programming
Guide (referenced as programming guide in this
manual) provides greater detail about how to
work with parameters and many application
examples.
•The VLT
®
Safe Torque O Operating Instructions
describe how to use Danfoss frequency
converters in functional safety applications. This
manual is supplied with the frequency converter
when the STO option is present.
Supplemental publications and manuals are available for
download from vlt-drives.danfoss.com/Products/Detail/
Technical-Documents.
NOTICE
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
specic requirements.
Contact a Danfoss supplier or visit www.danfoss.com for
more information.
Introduction Design Guide
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1.4 Abbreviations, Symbols and
Conventions
60°AVM 60°asynchronous vector modulation
A Ampere/AMP
AC Alternating current
AD Air discharge
AEO Automatic energy optimisation
AI Analog input
AMA Automatic motor adaptation
AWG American wire gauge
°CDegrees celsius
CD Constant discharge
CDM Complete drive module: the frequency converter,
feeding section and auxiliaries
CM Common mode
CT Constant torque
DC Direct current
DI Digital input
DM Dierential mode
D-TYPE Drive dependent
EMC Electromagnetic compatibility
EMF Electromotive force
ETR Electronic thermal relay
fJOG Motor frequency when jog function is activated.
fMMotor frequency
fMAX Maximum output frequency, the frequency
converter applies on its output.
fMIN Minimum motor frequency from the frequency
converter
fM,N Nominal motor frequency
FC Frequency converter
g Gramme
Hiperface®Hiperface®is a registered trademark by Stegmann
HO High overload
hp Horse power
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 Maximum output current
IVLT,N Rated output current supplied by the frequency
converter
kHz Kilohertz
LCP Local control panel
lsb Least signicant bit
m Meter
mA Milliampere
MCM Mille circular mil
MCT Motion control tool
mH Inductance in milli Henry
mm Millimeter
ms Millisecond
msb Most signicant bit
ηVLT Eciency of the frequency converter dened as
ratio between power output and power input.
nF Capacitance in nano Farad
NLCP Numerical local control panel
Nm Newton meter
NO Normal overload
nsSynchronous motor speed
Online/
Oine
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
PDS Power drive system: a CDM and a motor
PELV Protective extra low voltage
PmFrequency converter nominal output power as
high overload (HO).
PM,N Nominal motor power
PM motor Permanent magnet motor
Process PID PID (Proportional Integrated Dierential) regulator
that maintains the speed, pressure, temperature,
and so on.
Rbr,nom Nominal resistor value that ensures a brake power
on the motor shaft of 150/160% for 1 minute
RCD Residual current device
Regen Regenerative terminals
Rmin Minimum permissible brake resistor value by
frequency converter
RMS Root mean square
RPM Revolutions per minute
Rrec Recommended brake resistor resistance of
Danfoss brake resistors
s Second
SFAVM Stator ux-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
VVC+Voltage vector control plus
Table 1.1 Abbreviations
Introduction VLT®Refrigeration Drive FC 103
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Conventions
Numbered lists indicate procedures.
Bullet lists indicate other information and description of
illustrations.
Italicised text indicates:
•Cross reference.
•Link.
•Footnote.
•Parameter name, parameter group name,
parameter option.
All dimensions are in mm (inch).
* indicates a default setting of a parameter.
1.5 Safety Symbols
The following symbols are used in this manual:
WARNING
Indicates a potentially hazardous situation that could
result in death or serious injury.
CAUTION
Indicates a potentially hazardous situation that could
result in minor or moderate injury. It can also be used to
alert against unsafe practices.
NOTICE
Indicates important information, including situations that
can result in damage to equipment or property.
1.6 Denitions
Coast
The motor shaft is in free mode. No torque on the motor.
CT characteristics
Constant torque characteristics used for all applications
such as:
•Conveyor belts.
•Displacement pumps.
•Cranes.
Initialising
If initialising is carried out (parameter 14-22 Operation
Mode), the frequency converter 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 o-load
period. The operation can be either periodic duty or non-
periodic duty.
Power factor
The true power factor (lambda) considers all the
harmonics. The true power factor is always smaller than
the power factor (cosphi) that only considers the 1st
harmonics of current and voltage.
cosϕ=  P kW
P kVA =UλxIλxcosϕ UλxIλ
Cosphi is also known as displacement power factor.
Both lambda and cosphi are stated for Danfoss VLT®
frequency converters in chapter 7.2 Mains Supply.
The power factor indicates to which extent the frequency
converter imposes a load on the mains supply.
The lower the power factor, the higher the IRMS for the
same kW performance.
In addition, a high power factor indicates that the
harmonic currents are low.
All Danfoss frequency converters have built-in DC coils in
the DC link. The coils ensure a high power factor and
reduce the THDi on the main supply.
Set-up
Save parameter settings in 4 set-ups. Change between the
4 parameter set-ups and edit 1 set-up while another set-up
is active.
Slip compensation
The frequency converter 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-dened actions executed
when the associated user-dened events are evaluated as
true by the SLC. (Parameter group 13-** Smart Logic).
FC standard bus
Includes RS485 bus with FC protocol or MC protocol. See
parameter 8-30 Protocol.
Thermistor
A temperature-dependent resistor placed where the
temperature is to be monitored (frequency converter or
motor).
Trip
A state entered in fault situations, such as when the
frequency converter is subject to an overtemperature or
when it protects the motor, process, or mechanism. Restart
is prevented until the cause of the fault has disappeared
and the trip state is cancelled. Cancel the trip state by:
•Activating reset, or
•Programming the frequency converter to reset
automatically
Do not use trip for personal safety.
Introduction Design Guide
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11

Trip lock
A state entered in fault situations when the frequency
converter is protecting itself and requires physical
intervention, for example if the frequency converter is
subject to a short circuit on the output. A locked trip can
only be cancelled by cutting o mains, removing the cause
of the fault, and reconnecting the frequency converter.
Restart is prevented until the trip state is cancelled by
activating reset or, in some cases, by being programmed to
reset automatically. Do not use trip for personal safety.
VT characteristics
Variable torque characteristics for pumps and fans.
1.7 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
MG16G2xx Replaces MG16G1xx 1.4x
Table 1.2 Document and Software Version
1.8 Approvals and Certications
Frequency converters are designed in compliance with the
directives described in this section.
For more information on approvals and certicates, go to
the download area at vlt-marine.danfoss.com/support/type-
approval-certicates/.
1.8.1 CE Mark
Illustration 1.1 CE
The CE mark (Communauté Européenne) indicates that the
product manufacturer conforms to all applicable EU
directives. The EU directives applicable to the design and
manufacture of frequency converters are listed in Table 1.3.
NOTICE
The CE mark does not regulate the quality of the
product. Technical specications cannot be deduced from
the CE mark.
NOTICE
Frequency converters with an integrated safety function
must comply with the machinery directive.
EU Directive Version
Low Voltage Directive 2014/35/EU
EMC Directive 2014/30/EU
Machinery Directive1) 2014/32/EU
ErP Directive 2009/125/EC
ATEX Directive 2014/34/EU
RoHS Directive 2002/95/EC
Table 1.3 EU Directives Applicable to Frequency Converters
1) Machinery Directive conformance is only required for frequency
converters with an integrated safety function.
Declarations of conformity are available on request.
1.8.1.1 Low Voltage Directive
The Low Voltage Directive applies to all electrical
equipment in the 50–1000 V AC and the 75–1600 V DC
voltage ranges.
The aim of the directive is to ensure personal safety and
avoid property damage, when operating electrical
equipment that is installed, maintained, and used as
intended.
1.8.1.2 EMC Directive
The purpose of the EMC (electromagnetic compatibility)
Directive is to reduce electromagnetic interference and
enhance immunity of electrical equipment and instal-
lations. The basic protection requirement of the EMC
Directive is that devices that generate electromagnetic
interference (EMI), or whose operation could be aected
by EMI, must be designed to limit the generation of
electromagnetic interference. The devices must have a
suitable degree of immunity to EMI when properly
installed, maintained, and used as intended.
Electrical equipment devices used alone or as part of a
system must bear the CE mark. Systems do not require the
CE mark, but must comply with the basic protection
requirements of the EMC Directive.
Introduction VLT®Refrigeration Drive FC 103
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11

1.8.1.3 Machinery Directive
The aim of the Machinery Directive is to ensure personal
safety and avoid property damage for mechanical
equipment used in its intended application. The Machinery
Directive applies to a machine consisting of an aggregate
of interconnected components or devices of which at least
1 is capable of mechanical movement.
Frequency converters with an integrated safety function
must comply with the Machinery Directive. Frequency
converters without a safety function do not fall under the
Machinery Directive. If a frequency converter is integrated
into a machinery system, Danfoss can provide information
on safety aspects relating to the frequency converter.
When frequency converters are used in machines with at
least 1 moving part, the machine manufacturer must
provide a declaration stating compliance with all relevant
statutes and safety measures.
1.8.1.4 ErP Directive
The ErP Directive is the European Ecodesign Directive for
energy-related products. The directive sets ecodesign
requirements for energy-related products, including
frequency converters. The aim of the directive is to
increase energy eciency and the level of protection of
the environment, while increasing the security of the
energy supply. Environmental impact of energy-related
products includes energy consumption throughout the
entire product life cycle.
1.8.2 C-tick Compliance
Illustration 1.2 C-tick
The C-tick label indicates compliance with the applicable
technical standards for Electromagnetic Compatibility
(EMC). C-tick compliance is required for placing electrical
and electronic devices on the market in Australia and New
Zealand.
The C-tick regulatory is about conducted and radiated
emission. For frequency converters, apply the emission
limits specied in EN/IEC 61800-3.
A declaration of conformity can be provided on request.
1.8.3 UL Compliance
UL Listed
Illustration 1.3 UL
NOTICE
525–690 V frequency converters are not certied for UL.
The frequency converter complies with UL 508C thermal
memory retention requirements. For more information,
refer to chapter 2.6.2 Motor Thermal Protection.
1.8.4 Marine Compliance (ADN)
Units with ingress protection rating IP55 (NEMA 12) or
higher prevent spark formation, and are classied as
limited explosion risk electrical apparatus in accordance
with the European Agreement concerning International
Carriage of Dangerous Goods by Inland Waterways (ADN).
For units with ingress protection rating IP20/Chassis, IP21/
NEMA 1, or IP54, prevent risk of spark formation as follows:
•Do not install a mains switch.
•Ensure that parameter 14-50 RFI Filter is set to [1]
On.
•Remove all relay plugs marked RELAY. See
Illustration 1.4.
•Check which relay options are installed, if any.
The only permitted relay option is VLT®Extended
Relay Card MCB 113.
Go to vlt-marine.danfoss.com/support/type-approval-certif-
icates/ for additional marine approvals information.
Introduction Design Guide
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11

1
2
130BD832.10
1, 2 Relay plugs
Illustration 1.4 Location of Relay Plugs
Manufacturer declaration is available on request.
1.8.5 Export Control Regulations
Frequency converters can be subject to regional and/or
national export control regulations.
The frequency converters that are subject to export control
regulations are classied by an ECCN number.
The ECCN number is provided in the documents
accompanying the frequency converter.
In case of re-export, it is the responsibility of the exporter
to ensure compliance with the relevant export control
regulations.
1.9 Safety
1.9.1 General Safety Principles
If handled improperly, frequency converters have the
potential for fatal injury as they contain high-voltage
components. Only qualied personnel should install and
operate the equipment. Do not attempt repair work
without rst removing power from the frequency converter
and waiting the designated amount of time for stored
electrical energy to dissipate.
Strict adherence to safety precautions and notices is
mandatory for safe operation of the frequency converter.
Correct and reliable transport, storage, installation,
operation, and maintenance are required for the trouble-
free and safe operation of the frequency converter. Only
qualied personnel are allowed to install and operate this
equipment.
Qualied personnel are dened as trained sta, who are
authorised to install, commission, and maintain equipment,
systems, and circuits in accordance with pertinent laws and
regulations. Additionally, the qualied personnel must be
familiar with the instructions and safety measures
described in these operating instructions.
WARNING
HIGH VOLTAGE
Frequency converters contain high voltage when
connected to AC mains input, DC supply, or load sharing.
Failure to perform installation, start-up, and maintenance
by qualied personnel can result in death or serious
injury.
•Only qualied personnel must perform instal-
lation, start-up, and maintenance.
Introduction VLT®Refrigeration Drive FC 103
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WARNING
UNINTENDED START
When the frequency converter is connected to AC mains,
DC supply, or load sharing, the motor may start at any
time. Unintended start during programming, service, or
repair work can result in death, serious injury, or
property damage. The motor can start via an external
switch, a eldbus command, an input reference signal
from the LCP, or after a cleared fault condition.
To prevent unintended motor start:
•Disconnect the frequency converter from the
mains.
•Press [O/Reset] on the LCP before
programming parameters.
•Completely wire and assemble the frequency
converter, motor, and any driven equipment
before connecting the frequency converter to
AC mains, DC supply, or load sharing.
WARNING
DISCHARGE TIME
The frequency converter contains DC-link capacitors,
which can remain charged even when the frequency
converter is not powered. High voltage may be present
even when the warning LED indicator lights are o.
Failure to wait the specied time after power has been
removed before performing service or repair work, could
result in death or serious injury.
1. Stop the motor.
2. Disconnect AC mains, permanent magnet type
motors, and remote DC-link supplies, including
battery back-ups, UPS, and DC-link connections
to other frequency converters.
3. Wait for the capacitors to discharge fully, before
performing any service or repair work. The
duration of waiting time is specied in Table 1.4.
Voltage [V] Minimum waiting time (minutes)
4 15
200–240 1.1–3.7 kW 5.5–45 kW
380–480 1.1–7.5 kW 11–90 kW
525–600 1.1–7.5 kW 11–90 kW
Table 1.4 Discharge Time
WARNING
LEAKAGE CURRENT HAZARD
Leakage currents exceed 3.5 mA. Failure to ground
frequency converter properly can result in death or
serious injury.
•Ensure the correct grounding of the equipment
by a certied electrical installer.
WARNING
EQUIPMENT HAZARD
Contact with rotating shafts and electrical equipment
can result in death or serious injury.
•Ensure that only trained and qualied personnel
perform installation, start-up, and maintenance.
•Ensure that electrical work conforms to national
and local electrical codes.
•Follow the procedures in this manual.
WARNING
UNINTENDED MOTOR ROTATION
WINDMILLING
Unintended rotation of permanent magnet motors
creates voltage and can charge the unit, resulting in
death, serious injury, or equipment damage.
•Ensure that permanent magnet motors are
blocked to prevent unintended rotation.
CAUTION
INTERNAL FAILURE HAZARD
An internal failure in the frequency converter can result
in serious injury, when the frequency converter is not
properly closed.
•Ensure that all safety covers are in place and
securely fastened before applying power.
Introduction Design Guide
MG16G202 Danfoss A/S © 08/2015 All rights reserved. 13
11

2 Product Overview
2.1 Introduction
This chapter provides an overview of the frequency
converter’s primary assemblies and circuitry. It describes
the internal electrical and signal processing functions. A
description of the internal control structure is also
included.
Also described are automated and optional frequency
converter functions available for designing robust
operating systems with sophisticated control and status
reporting performance.
2.1.1 Product Dedication to Refrigeration
Applications
The VLT®Refrigeration Drive FC 103 is designed for refrig-
eration applications. The integrated application wizard
guides the user through the commissioning process. The
range of standard and optional features includes:
•Multi-zone cascade control
•Neutral zone control.
•Floating condensing temperature control.
•Oil return management.
•Multi-feedback evaporator control.
•Cascade control.
•Dry-run detection.
•End of curve detection.
•Motor alternation.
•STO.
•Sleep mode.
•Password protection.
•Overload protection.
•Smart logic control.
•Minimum speed monitor.
•Free programmable texts for information,
warnings, and alerts.
2.1.2 Energy Savings
When comparing with alternative control systems and
technologies, a frequency converter is the optimum energy
control system for controlling fan and pump systems.
By using a frequency converter to control the ow, a pump
speed reduction of 20% leads to energy savings of about
50% in typical applications.
Illustration 2.1 shows an example of the achievable energy
reduction.
130BD889.10
60
50
40
30
20
10
Hs
0 100 200 300 400
(mwg)
1350rpm
1650rpm
0
10
20
30
(kW)
40
50
60
200100 300 (m
3
/h)
(m
3
/h)
400
1350rpm
1650rpm
Pshaft
1
1 Energy saving
Illustration 2.1 Example: Energy Saving
Product Overview VLT®Refrigeration Drive FC 103
14 Danfoss A/S © 08/2015 All rights reserved. MG16G202
22

2.1.3 Example of Energy Savings
As shown in Illustration 2.2, the ow is controlled by
changing the pump speed, measured in RPM. By reducing
the speed only 20% from the rated speed, the ow is also
reduced by 20%. The ow is directly proportional to the
speed. The consumption of electricity is reduced by up to
50%.
If the system only has to supply a ow that corresponds to
100% a few days in a year, while the average is below 80%
of the rated ow for the remainder of the year, the energy
savings are even greater than 50%.
Illustration 2.2 describes the dependence of ow, pressure,
and power consumption on pump speed in RPM for
centrifugal pumps.
n
100%
50%
25%
12,5%
50% 100%
80%
80%
175HA208.10
Power ~n
3
Pressure ~n
2
Flow ~n
Illustration 2.2 Anity Laws for Centrifugal Pumps
Flow:Q1
Q2
=n1
n2
Pressure: H1
H2
 =  n1
n2
2
Power: P1
P2
= n1
n2
3
Assuming an equal eciency in the speed range.
Q=Flow P=Power
Q1=Flow 1 P1=Power 1
Q2=Reduced ow P2=Reduced power
H=Pressure n=Speed regulation
H1=Pressure 1 n1=Speed 1
H2=Reduced pressure n2=Reduced speed
Table 2.1 Anity Laws
2.1.4 Example with Varying Flow over 1
Year
This example is calculated based on pump characteristics
obtained from a pump datasheet, shown in Illustration 2.4.
The result obtained shows energy savings in excess of 50%
at the given ow distribution over a year,
see Illustration 2.3. The payback period depends on the
price of electricity and the price of the frequency
converter. In this example, payback is less than a year,
when compared with valves and constant speed.
500
[h] t
1000
1500
2000
200100 300 [m
3
/h]
400 Q
175HA210.11
t [h] Duration of ow. See also Table 2.2.
Q [m3/h] Flowrate
Illustration 2.3 Flow Distribution over 1 Year (Duration versus
Flowrate)
Product Overview Design Guide
MG16G202 Danfoss A/S © 08/2015 All rights reserved. 15
22

175HA209.11
60
50
40
30
20
10
Hs
0 100 200 300 400
(mwg)
B
C
A
750rpm
1050rpm
1350rpm
1650rpm
0
10
20
30
(kW)
40
50
60
200100 300 (m
3
/h)
(m
3
/h)
400
750rpm
1050rpm
1350rpm
1650rpm
Pshaft
C
1
B
1
A
1
Illustration 2.4 Energy Consumption at Dierent Speeds
Flow
rate
Distribution Valve regulation Frequency
converter
control
% Duration Power Consump-
tion
Power Consump-
tion
[m3/h] [h] [kW] [kWh] [kW] [kWh]
350 5 438 42.51) 18.615 42.51) 18.615
300 15 1314 38.5 50.589 29.0 38.106
250 20 1752 35.0 61.320 18.5 32.412
200 20 1752 31.5 55.188 11.5 20.148
150 20 1752 28.0 49.056 6.5 11.388
100 20 1752 23.02) 40.296 3.53) 6.132
Σ10
0
8760 – 275.064 – 26.801
Table 2.2 Result
1) Power reading at point A1.
2) Power reading at point B1.
3) Power reading at point C1.
2.1.5 Improved Control
Use a frequency converter to improve control of the ow
or pressure of a system.
Use a frequency converter to vary the speed of the
compressor, fan, or pump, obtaining variable control of
ow and pressure.
Furthermore, a frequency converter can quickly adapt the
speed of the compressor, fan, or pump to new ow or
pressure conditions in the system.
Obtain simple control of process (ow, level, or pressure)
utilising the built-in PI control.
2.1.6 Star/Delta Starter or Soft Starter
When large motors are started, it is necessary in many
countries to use equipment that limits the start-up current.
In more traditional systems, a star/delta starter or soft
starter is widely used. If a frequency converter is used,
such motor starters are not required.
As illustrated in Illustration 2.5, a frequency converter does
not consume more than rated current.
Full load
% Full-load current
& speed
500
100
0
0 12,5 25 37,5 50Hz
200
300
400
600
700
800
4
3
2
1
175HA227.10
1VLT®Refrigeration Drive FC 103
2 Star/delta starter
3 Soft starter
4 Start directly on mains
Illustration 2.5 Start-up Current
Product Overview VLT®Refrigeration Drive FC 103
16 Danfoss A/S © 08/2015 All rights reserved. MG16G202
22

2.2 Description of Operation
The frequency converter supplies a regulated amount of
mains AC power to the motor to control its speed. The
frequency converter supplies variable frequency and
voltage to the motor.
The frequency converter is divided into 4 main modules:
•Rectier
•Intermediate DC bus circuit
•Inverter
•Control and regulation
Illustration 2.6 is a block diagram of the internal
components of the frequency converter.
Area Title Functions
1 Mains input •3-phase AC mains supply to the
frequency converter.
2Rectier
•The rectier bridge converts the
AC input to DC current to supply
inverter power.
3 DC bus •Intermediate DC bus circuit
handles the DC current.
4 DC reactors
•Filter the intermediate DC circuit
voltage.
•Prove mains transient protection.
•Reduce RMS current.
•Raise the power factor reected
back to the line.
•Reduce harmonics on the AC
input.
5 Capacitor bank
•Stores the DC power.
•Provides ride-through protection
for short power losses.
6 Inverter
•Converts the DC into a controlled
PWM AC waveform for a
controlled variable output to the
motor.
7 Output to motor •Regulated 3-phase output power
to the motor.
Area Title Functions
8 Control circuitry
•Input power, internal processing,
output, and motor current are
monitored to provide ecient
operation and control.
•User interface and external
commands are monitored and
performed.
•Status output and control can be
provided.
Illustration 2.6 Frequency Converter Block Diagram
Product Overview Design Guide
MG16G202 Danfoss A/S © 08/2015 All rights reserved. 17
22

2.2.1 Control Structure Principle
•The frequency converter recties AC voltage from
mains into DC voltage.
•The DC voltage is converted into an AC current
with a variable amplitude and frequency.
The frequency converter supplies the motor with variable
voltage/current and frequency, which enables variable
speed control of 3-phased, standard asynchronous motors
and non-salient PM motors.
The frequency converter manages various motor control
principles such as U/f special motor mode and VVC+. Short-
circuit behaviour of the frequency converter depends on
the 3 current transducers in the motor phases.
Inrush
R inr
Load sharing -
Load sharing +
LC Filter -
(5A)
LC Filter +
(5A) Brake
Resistor
130BA193.14
M
L2 92
L1 91
L3 93
89(+)
88(-)
R+
82
R-
81
U 96
V 97
W 98
P 14-50 R Filter
Illustration 2.7 Frequency Converter Structure
2.3 Sequence of Operation
2.3.1 Rectier Section
When power is applied to the frequency converter, it
enters through the mains terminals (L1, L2, and L3).
Depending on the unit conguration, the power moves on
to the disconnect and/or RFI lter option.
2.3.2 Intermediate Section
Following the rectier section, voltage passes to the
intermediate section. A lter circuit consisting of the DC
bus inductor and the DC bus capacitor bank smoothes the
rectied voltage.
The DC bus inductor provides series impedance to
changing current. This aids the ltering process while
reducing harmonic distortion to the input AC current
waveform normally inherent in rectier circuits.
2.3.3 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 VVC+PWM principle at the control card, provides
optimal performance and minimal losses in the motor.
Product Overview VLT®Refrigeration Drive FC 103
18 Danfoss A/S © 08/2015 All rights reserved. MG16G202
22