6.0–10 kW (8–15 hp): Version 2.0
18–30 kW (25–40 hp): Version 61.20
Description
Conformity mark
EU/EC Declaration of Conformity (EC/CE - European Conformity/Conformité Européenne)
Low Voltage Directive/Electromagnetic compatibility (EMC)/Restriction of Hazardous Substances
(RoHS)
Countries of use: Europe
ACMA Declaration of Conformity (RCM - Regulatory Compliance Mark)
Australian Communications Media Authority (ACMA)
Low Voltage Directive/Electromagnetic compatibility (EMC)
Countries of use: Australia and New Zealand
VLT® Compressor Drive CDS 803
Design Guide
Introduction
1 Introduction
1.1 Purpose of this Design Guide
This Design Guide is intended for qualified personnel, such as:
•
Project and systems engineers.
•
Design consultants.
•
Application and product specialists.
The Design Guide provides technical information to understand the capabilities of the VLT® Compressor Drive CDS 803 for integration into motor control and monitoring systems. Its purpose is to provide design considerations and planning data for integration of
the drive into a system. It caters for selection of drives 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 efficiency.
This manual is targeted at a worldwide audience. Therefore, wherever occurring, both SI and imperial units are shown.
VLT® is a registered trademark for Danfoss A/S.
1.2 Additional Resources
1.2.1 Supplementary Documentation
Various resources are available to understand advanced drive operation, programming, and directives compliance.
•
The Programming Guide provides information on how to program and includes complete parameter descriptions.
•
The Operating Guide provides detailed information about installation and commissioning of the drive.
See www.danfoss.com for supplementary documentation.
1.2.2 VLT® Motion Control Tool MCT 10 Software Support
Download the software from the Service and Support download page on www.danfoss.com.
During the installation process of the software, enter CD-key 34544400 to activate the CDS 803 functionality. An activation key is not
required for using the CDS 803 functionality.
The latest software does not always contain the latest updates for the drive. Contact the local sales office for the latest drive updates
(in the form of *.upd files), or download the drive updates from the Service and Support download page on www.danfoss.com.
1.3 Manual and Software Version
This manual is regularly reviewed and updated. All suggestions for improvement are welcome.
Indicates a hazardous situation which, if not avoided, will result in death or serious injury.
W A R N I N G
Indicates a hazardous situation which, if not avoided, could result in death or serious injury.
C A U T I O N
Indicates a hazardous situation which, if not avoided, could result in minor or moderate injury.
N O T I C E
Indicates information considered important, but not hazard-related (for example, messages relating to property damage).
Safety
2.2 Qualified Personnel
To allow trouble-free and safe operation of the unit, only qualified personnel with proven skills are allowed to transport, store, assemble, install, program, commission, maintain, and decommission this equipment.
Persons with proven skills:
•
Are qualified electrical engineers, or persons who have received training from qualified electrical engineers and are suitably
experienced to operate devices, systems, plant, and machinery in accordance with pertinent laws and regulations.
•
Are familiar with the basic regulations concerning health and safety/accident prevention.
•
Have read and understood the safety guidelines given in all manuals provided with the unit, especially the instructions given in
the Operating Guide.
•
Have good knowledge of the generic and specialist standards applicable to the specific application.
2.3 Safety Precautions
W A R N I N G
HAZARDOUS VOLTAGE
AC drives contain hazardous voltage when connected to the AC mains or connected on the DC terminals. Failure to perform
installation, start-up, and maintenance by skilled personnel can result in death or serious injury.
Only skilled personnel must perform installation, start-up, and maintenance.
-
W A R N I N G
UNINTENDED START
When the drive 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. Start the motor with an external
switch, a fieldbus command, an input reference signal from the local control panel (LCP), via remote operation using MCT 10
software, or after a cleared fault condition.
Disconnect the drive from the mains.
-
Press [Off/Reset] on the LCP before programming parameters.
-
Ensure that the drive is fully wired and assembled when it is connected to AC mains, DC supply, or load sharing.
Danfoss offers CDS drives in different-sized enclosures with power ratings from 6.0–30 kW (8.0–40 hp). Common for all drives are
the following:
•
I/Os
-
4 digital inputs (PNP or NPN)
-
2 digital outputs
-
2 analog inputs (voltage or current)
-
2 analog outputs
-
2 relay outputs
•
RS485 serial communication
-
Danfoss FC protocol and VLT® Motion Control Tool MCT 10 support
-
Modbus RTU
The drive is a free-standing, wall-mountable, or cabinet-mountable drive available in different ratings to fit various applications. The
complete overview is listed in Table 3.
Illustration 1: VLT® Compressor Drive CDS 803 Family
Table 3: Overview of VLT® Compressor Drive CDS 803 Family
Product Overview
1
All CDS 803 drives can be upgraded to IP21/NEMA Type 1 with an IP21/NEMA Type 1 Conversion Kit.
3.2 VLT® Compressor Drive CDS 803 Features
Various application functions are programmed in the drive for enhanced system performance. The functions require minimum programming or setup. For activation of the functions, refer to the VLT® Compressor Drive CDS 803 Programming Guide listed in 1.2
Additional Resources.
3.2.1 Compressor Features
The VLT® Compressor Drive CDS 803 offers various specialized functions for use in combination with compressor systems.
3.2.1.1 Secure Start-up
To ensure that the compressor ramps fast to the defined start speed, the VLT® Compressor Drive CDS 803 always runs a start-up
sequence. The compressor runs at the start speed for a defined fixed time.
•
If a locked rotor or flooded compressor occurs, it is detected during start-up.
•
If the drive fails to start the compressor, it trips on Alarm 18, Start failed.
To avoid a malfunction inside the compressor due to missing or low lubrication the VLT® Compressor Drive CDS 803 protects the
compressor if the speed drops below the minimum speed detection limit for too long.
•
In case of excessive low speed the drive issues Alarm 49, Speed limit.
The VLT® Compressor Drive CDS 803 includes a compressor short-cycling protection that prevents mechanical wear to the compressor and reduces the risk of oil shortage caused by starting and stopping too often. The short-cycle protection consists of 2 timers:
•
The interval between starts ensures that a new start first becomes active when the start time has expired.
•
The minimum run time ensures that the compressor always runs for a defined minimum time before stopping the compressor.
•
Warning 96, Start Delay is shown in the display if there is a start signal and the INTERVAL BETWEEN STARTS has not expired.
•
Warning 97, Stop Delay is shown in the display if there is a stop signal and the MINIMUM RUNTIME has not expired.
Illustration 4: Short Cycle Protection, Start Delay
Illustration 5: Short Cycle Protection, Stop Delay
3.2.1.4 Anti-reverse Protection
The anti-reverse protection function prevents the compressor scroll set from running in the wrong direction during stop.
The oil return management (ORM) function helps retrieve oil trapped in the cooling system by ramping up periodically (oil boost
speed).
•
The ORM becomes active when the compressor has run below the ORM minimum speed limit for a given time defined by ORM
running time.
•
When ORM is active, the speed increases to a predefined ORM boost speed for a given time defined by ORM boost time
•
Additional a fixed boost interval timer shall trigger the ORM function in case no ORM has run within the defined ORM interval.
Illustration 7: Oil Return Management
3.2.1.6 Data Readouts and Commissioning
The VLT® Motion Control Tool MCT 10 supports the VLT® Compressor Drive CDS 803. The MCT is an efficient tool, for example for
readouts and commissioning.
VLT® Motion Control Tool MCT 10 supports the following readouts:
•
Readouts of alarms, warnings, and fault log in 1 view.
•
Compare a saved project with an online drive.
•
Scope & logging: Easy problem analysis.
•
Offline commissioning.
•
Save/send/mail projects anywhere.
•
Multiple drives in project file. Enables the service organization to be more efficient.
Programmable compressor choices allow downscaling of a drive to operate with an undersized compressor or running an oversized
drive under extreme conditions. This functionality is useful in applications which are outside the specified appliance area:
•
High ambient temperature installations.
•
High altitude installations.
N O T I C E
UL 60730-1 certification restricts for only allowing 1 dedicated compressor combination and does not offer the ability to run an
undersized compressor.
3.2.2 Application Features
The VLT® Compressor Drive CDS 803 offers custom application functions for enhanced performance.
3.2.2.1 Automatic Motor Adaptation (AMA)
Automatic motor adaptation (AMA) is an automated test procedure used to measure the electrical characteristics of the motor. AMA
provides an accurate electronic model of the motor, allowing the drive to calculate optimal performance and efficiency. Running
the AMA procedure also maximizes the automatic energy optimization feature of the drive.
AMA is performed without the motor rotating and without uncoupling the load from the motor.
N O T I C E
Automatic motor adaptation (AMA) is not required when used with a VZH Danfoss compressor.
Electronic thermal protection (ETR) is used in combination with a VZH Danfoss compressor.
ETR calculates motor temperature by measuring current, frequency, and operating time. The drive shows the thermal load on the
motor in percentage and can issue a warning at a programmable overload setpoint. Programmable options at the overload allow
the drive to stop the motor, reduce output, or ignore the condition. Even at low speeds, the drive meets I2t Class 20 electronic
motor overload standards.
Illustration 8: ETR Characteristics
The X-axis shows the ratio between I
motor
and I
nominal. The Y-axis shows the time in seconds before the ETR cuts off and trips
motor
the drive. The curves show the characteristic nominal speed at twice the nominal speed and at 0.2 x the nominal speed. At lower
speed, the ETR cuts off at lower heat due to less cooling of the motor. In that way, the motor is protected from being overheated
even at low speed. The ETR feature calculates the motor temperature based on actual current and speed. The calculated temperature is visible as a readout parameter in parameter 16-18 Motor Thermal.
3.2.2.3 Built-in PID Controller
The built-in proportional, integral, derivative (PID) controller eliminates the need for auxiliary control devices. The PID controller
maintains constant control of closed-loop systems where regulated pressure, flow, temperature, or other system requirements must
be maintained.
The drive can use 2 feedback signals from 2 different devices, allowing the system to be regulated with different feedback requirements. The drive makes control decisions by comparing the 2 signals to optimize system performance.
3.2.2.4 Automatic Restart
The drive can be programmed to restart the motor automatically after a minor trip, such as momentary power loss or fluctuation.
This feature eliminates the need for manual resetting and enhances automated operation for remotely controlled systems. The
number of restart attempts and the duration between attempts can be limited.
3.2.2.5 Flying Start
Flying start allows the drive to synchronize with an operating motor rotating at up to full speed in either direction. This prevents
trips due to overcurrent draw. It minimizes mechanical stress to the system since the motor receives no abrupt change in speed
when the drive starts.
3.2.2.6 Frequency Bypass
In some applications, the system can have operational speeds that create a mechanical resonance. This mechanical resonance can
generate excessive noise and possibly damage mechanical components in the system. The drive has 4 programmable bypass-frequency bandwidths (parameters 4-60 to 4-63). The bandwidths allow the motor to step over speeds that induce system resonance.
3.2.2.7 Motor Preheat
Instead of using a space heater, Danfoss provides motor preheat functionality. To preheat a motor in a cold or damp environment, a
small amount of DC current can be trickled continuously into the motor to protect it from condensation and cold starts.
Coast
Start timer
Set Do X low
Select set-up 2
. . .
Running
Warning
Torque limit
Digital input X 30/2
. . .
=
TRUE longer than..
. . .
. . .
VLT® Compressor Drive CDS 803
Design Guide
Product Overview
3.2.2.8 Programmable Set-ups
The drive has 2 setups that can be independently programmed. Using multi-setup, it is possible to switch between independently
programmed functions activated by digital inputs or a serial command. Independent set-ups are used, for example, to change references, or for day/night or summer/winter operation, or to control multiple motors. The LCP shows the active setup.
Setup data can be copied from drive to drive by downloading the information from the removable LCP or by using VLT® Motion
Control Tool MCT 10.
3.2.2.9 Smart Logic Control (SLC)
Smart logic control (SLC) is a sequence of user-defined actions (see parameter 13-52 SL Controller Action [x]) executed by the SLC
when the associated user-defined event (see parameter 13-51 SL Controller Event [x]) is evaluated as TRUE by the SLC.
The condition for an event can be a particular status, or that the output from a logic rule or a comparator operand becomes TRUE.
The condition leads to an associated action as shown in
Illustration 9.
Illustration 9: SLC Event and Action
Events and actions are each numbered and linked in pairs (states), which means that when event [0] is fulfilled (attains the value
TRUE), action [0] is executed. After the 1st action is executed, the conditions of the next event are evaluated. If this event is evaluated
as true, then the corresponding action is executed. Only 1 event is evaluated at any time. If an event is evaluated as false, nothing
happens in the SLC during the current scan interval and no other events are evaluated. When the SLC starts, it only evaluates event
[0] during each scan interval. Only when event [0] is evaluated as true, the SLC executes action [0] and starts evaluating the next
event. It is possible to program 1–20 events and actions.
When the last event/action has been executed, the sequence starts over again from event [0]/action [0]. An example with 4 events/
actions is shown in Illustration 10:
Illustration 10: Order of Execution when 4 Events/Actions are Programmed
3.2.2.9.1 Comparators
Comparators are used for comparing continuous variables (output frequency, output current, analog input, and so on) to fixed preset values.
Illustration 11: Comparators
3.2.2.9.2 Logic Rules
Combine up to 3 boolean inputs (TRUE/FALSE inputs) from timers, comparators, digital inputs, status bits, and events using the
logical operators AND, OR, and NOT.
Illustration 12: Logic Rules
3.3 VLT® Compressor Drive CDS 803 Protections
The drive has a range of built-in protection functions to protect itself and the compressor during operation. For details of any required setup, in particular compressor parameters, refer to the VLT® Compressor Drive CDS 803 Programming Guide listed in 1.2
Additional Resources for parameter details and programming.
3.3.1 Mains Input Protection
The VLT® Compressor Drive CDS 803 offers various built-in input protections for the 3-phase power terminals L1, L2, and L3.
3.3.1.1 Mains Supply Failure, Momentary Dropouts, and Surges
During a mains dropout, the drive keeps running until the internal DC-link voltage drops below the minimum stop level, which is
typically around 15% or more below the lowest rated supply voltage of the drive. The mains voltage before the dropout and the
motor load determine how long it takes for the drive to coast.
The drive automatically compensates for input voltages ±10% from the mains nominal to provide full rated output current. With
auto restart selected, the drive automatically powers up after a voltage trip. With flying start parameterization, the drive can synchronize to a motor spinning freely after a mains dropout and bring it back to normal operation.
Product Overview
3.3.1.2 Missing Mains Phase Detection
The drive monitors the mains input and reacts according to the programmed configuration if improper conditions, such as missing
or detecting too high imbalance between the input phases.
Operation under severe mains imbalance conditions reduces the lifetime of the drive. Conditions are considered severe if the motor
is operated continously near nominal load. The default setting issues a warning, but automated derating of the load can also be
parameterized among multiple choices.
3.3.2 Output Protection
The VLT® Compressor Drive CDS 803 offers various built-in protection features for the compressor terminals U, V, and W.
3.3.2.1 Short-circuit Protection (Phase-to-phase)
The drive is protected against short circuits on the output side by current measurements. A short circuit between 2 output phases
causes an overcurrent internally and turns off all outputs once the short-circuit current exceeds the maximum limit. A drive that
works correctly limits the current it can draw from the supply. Still, it is recommended to use fuses and/or circuit breakers on the
supply side as protection if there is a component breakdown inside the drive (1st fault). Mains side fuses are mandatory for UL compliance.
N O T I C E
To ensure compliance with IEC 60364 for CE or NEC 2017 for UL, it is mandatory to use fuses and/or circuit breakers.
The drive is protected against ground faults on all output terminals, U, V, and W.
3.3.2.3 Locked Rotor Detection
Sometimes the rotor is locked because of excessive load or other factors preventing the compressor from rotating.
The drive detects the locked rotor situation and trips accordingly to prevent overheating the compressor and the drive.
N O T I C E
In regulation with UL 60730-1 certified products, the locked rotor detection cannot be disabled.
3.3.2.4 Output Phase Loss Detection
The drive monitors all outputs to detect any missing or interrupted connections. If no currents are drawn on any output, it is assumed that no motor is connected and will cause this event to be triggered. If a single phase is lost, an output phase missing event
is triggered. In both scenarios all outputs are turned off. The missing output phase function is enabled by default to avoid motor
damage. Disabling this protection is possible via parameterization.
N O T I C E
In regulation with UL 60730-1 certified products, the output phase loss detection cannot be disabled.
3.3.2.5 Overload Protection
If excessive current outputs or high temperatures are observed for an unwanted period, the protections trip the drive and turn all
the outputs off. The time before the drive trips is controlled by parameterization of the monitored protections.
Voltage limit
The inverter turns off to self-protect the internal components when the maximum voltage limits are reached.
The inverter turns off to self-protect the internal components when the maximum current limits are reached.
Overtemperature
The inverter turns off to self-protect the internal components when the maximum temperature limits are reached.
Electronic thermal relay (ETR)
ETR is an electronic feature that simulates a bimetal relay based on internal measurements. See also 3.2.2.2 Motor Thermal Protec-
tion.
Product Overview
N O T I C E
In regulation wih UL 60730-1 certified products, the output overload conditions, such as motor overload (ETR), cannot be disa-
bled.
3.3.3 Temperature Protection
The VLT® Compressor Drive CDS 803 offers various built-in temperature protection features for monitoring the operation environment.
3.3.3.1 Minimum and Maximum Temperature Protection
The drive has built-in temperature sensors and reacts immediately to critical temperature limits. At low temperature, a warning will
be triggered. If high temperature limits are exceeded, the drive trips on an alarm and turns off all outputs.
3.3.3.2 Automatic Temperature Derating
Automatic temperature derating can be enabled via parameterization to allow continued operation during high temperatures.
3.3.3.3 Temperature-controlled Fans
Sensors in the drive regulate the operation of the internal cooling fans. Often, the cooling fans do not run during low-load operation, when in sleep mode, or in standby. The sensors reduce noise, increase efficiency, and extend the operating life of the fan.
3.3.4 Internal Protection
The VLT® Compressor Drive CDS 803 offers various built-in internal protection features ensuring that the drive is fully operational.
3.3.4.1 DC Overvoltage Protection
The internal DC-link voltage is increased when the motor acts as a generator. This occurs in the following situations:
•
The load drives the motor (at constant output frequency from the drive), that is, the load generates energy.
•
During deceleration (ramp-down) if the moment inertia is high, the friction is low, and the ramp-down time is too short for the
energy to be dissipated as a loss in the drive, the motor, and the installation.
•
Incorrect slip compensation setting may cause higher DC-link voltage.
•
Back EMF from PM motor operation. If coasted at high RPM, the PM motor back EMF may potentially exceed the maximum
voltage tolerance of the drive and cause damage. To prevent this, the maximum output frequency is automatically limited
based on an internal calculation. This calculation is based on motor parameterizations.
Monitoring of the internal voltage ensures that the drive trips when the DC-link voltage is too high. The drive turns off the output to
protect itself when a certain voltage level is reached. Enabling overvoltage control (OVC) reduces the risk of the drive tripping due
to an overvoltage on the DC link. This is controlled by automatically extending the ramp-down time.
3.3.4.2 Internal Faults
The drive has various internal self-monitoring functions which ensure that the drive is fully operational. For warning and alarm details, refer to VLT® Compressor Drive CDS 803 Programming Guide listed in 1.2 Additional Resources.
3.4 Ecodesign for Power Drive Systems
The Ecodesign Directive is the legislative framework that sets requirements on all energy-related products in the domestic, commercial, and industrial sectors throughout Europe.
The Ecodesign requirements are only mandatory within the European Union. These requirements are like the legislative requirements for energy-related products which apply in North America and Australia.
Terms like Complete Drive Module (CDM) and Power Drive Systems (PDS) are used to define the elements in the design. The objective is to make more efficient and fewer energy consuming designs.
The CDM contains the drive controller as well as auxiliary devices and input components.
Illustration 13: Drive System Design
The efficiency classes IE0 to IE2 of the drive controller as specified in IEC 61800-9-2 (EN 50598-2) refer to the 90/100 operating point,
i.e. 90 % motor stator frequency and 100% torque current (see Illustration 14).
Illustration 14: Operating Point according to IEC 61800-9-2 (EN 50598)
Since in the future all component manufacturers will disclose their loss data according to this new standard, optimized applications
can be designed with a wide range of different components. The new Standard allows an accurate preliminary calculation of the
power losses, so that the ROI (Return of Investment) can be reliably determined. Up to now the overall efficiency of speed-regulated
electric motors was estimated with the aid of approximate energy consumption calculations.
It is now possible to determine the total losses of a system for the 8 operating points defined in the standard, including the part
load operation, via a simple addition of power losses. Danfoss helps its customers to avoid having to rely on system solution providers, to ensure that their systems will retain a competitive advantage also in the future.
EC 61800-9-2 (EN 50598-2) shifts the focus from the individual component to the efficiency of the whole drive system. The new
efficiency classes (International Efficiency for Systems, IES)
allow a simple determination of the total losses for a whole drive system (PDS).
Danfoss offers the MyDrive® ecoSmart™ tool, which is available online or as a Smartphone app to assist with the efficiency calcula-
tion. Use MyDrive® ecoSmart™ to:
Look up part load data as defined in IEC 61800-9-2, for VLT® and VACON® drives
•
Calculate efficiency class and part load efficiency for drives and power drive systems
•
Create a report documenting part load loss data and IE or IES efficiency class.
•
For more information, refer to
Refer to Illustration 15 to see the components in the PDS which contribute to losses in the design. Mains cables and the load ma-
chine are not a part of the PDS, even though their losses can be significant and could be a part of the evaluation of the overall
energy efficiency of the installation.
The cabling from the supply must be considered, as the selection of suitable cables is often a problem, especially when dedicated
feeding transformers are installed. From the impedance of the cables, the energy losses are created in the ohmic part. Calculate the
active power losses for a 3-phase system with a star point groundingas follows:
P
= 3 x R x I
L,mains
Because the load, when using drives and motors, also include reactive power and harmonic currents, these parameters also contribute to losses. The ratio between active and apparent power is normally called the power factor. Having a PDS with a power factor
close to 1 result in the lowest losses in the mains. Using filters on the input side of the drive can lower the power factor.
2
L1
3.4.2 Input Filters: Line Reactors and Harmonic Filters
Line reactor
A line reactor is an inductor which is wired in series between a power source and a load. Line reactors, also called input AC reactors,
are typically used in motor drive applications.
The main function of the line reactor lies into its current limiting characteristics. Line reactors also reduce the main harmonics, limit
the inrush currents, and protect drives and motors. An overall improvement of the true power factor and the quality of the input
current waveform can be achieved.
Line reactors are classified by their percent impedance (denoted as percent IZ or %IZ), which is the voltage drop due to impedance,
at the rated current, expressed as a percent of rated voltage. The most common line reactors have either 3% or 5% impedance.
When to use line reactors
It is important to consider the installation environment for the drives. In some situations, distortion from the grid can damage the
drive and precautions must be taken.
A simple menas of prevention is to ensure a minimum of impedance in front of the drive.
When calculating the impedance, the contribution from the supply transformer and the supply cables is also a part of the circuit. In
specific cases, an additional transformer or reactor is recommended. If the conditions listed exist, consider adding impedance (line
reactor or transformer) in front of the drive:
•
The installation site has switched power factor correction capacitors.
•
The installation site has lightening strikes or voltage spikes.
•
The installation site has power interruptions or voltage dips.
Danfoss offers the line reactor program VLT® Line Reactor MCC 103, see
Harmonic filters
The purpose of using harmonic filters is to reduce the distortion on the mains. The distortion is generated by the drives when
switching the voltage to generate a frequency on the output. The harmonics should be limited both seen from energy consumption
perspective and disturbance of other users in the grid.
There are 2 categories of harmonic solutions:
•
Passive.
•
Active.
Passive solutions consist of capacitors, inductors, or a combination of both in different arrangements. The simplest solution is to add
inductors/reactors of typically 3–5% in front of the drive. This added inductance reduces the number of harmonic currents pro-