Danfoss vlt aqua Guide

Contents
1 How to Read this Design Guide
1-1
Copyright, Limitation of Liability and Revision Rights 1-1
Symbols 1-2
Abbreviations 1-3
Definitions 1-3
2 Introduction to the VLT AQUA Drive 2-1
CE labeling 2-3
Vibration and shock 2-6
Control Structures 2-11
General aspects of EMC 2-20
Immunity Requirements 2-24
Galvanic isolation (PELV) 2-25
PELV - Protective Extra Low Voltage 2-25
Ground leakage current 2-26
Control with brake function 2-27
Control with Brake Function 2-28
Mechanical brake control 2-28
Extreme running conditions 2-28
Safe Stop Operation (optional) 2-32
3 VLT AQUA Selection 3-1
General Specifications 3-1
Efficiency 3-19
Special Conditions 3-25
Options and Accessories 3-31
General Description 3-40
High Power Options 3-47
Installation of Duct Cooling Kit in Rittal Enclosures 3-47
Outside Installation/ NEMA 3R Kit for Rittal enclosures 3-49
Installation on Pedestal 3-51
Input Plate Option 3-53
Installation of Line Power Shield for Adjustable Frequency Drives 3-54
Frame size F Panel Options 3-55
4 How to Order 4-1
Ordering form 4-1
Type Code String 4-2
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®
AQUA Drive Design Guide Contents
MG.20.N5.22 - VLT®is a registered Danfoss trademark

Ordering Numbers 4-6
5 How to Install 5-1
Mechanical Installation 5-1
Pre-installation 5-7
Planning the Installation Site 5-7
Receiving the Adjustable Frequency Drive 5-7
Transportation and Unpacking 5-7
Lifting 5-8
Cooling and Airflow 5-11
Electrical Installation 5-15
Connections - Frame sizes D, E and F 5-32
Power Connections 5-32
Disconnectors, circuit breakers and contactors 5-44
Final Set-Up and Test 5-46
Safe Stop Installation 5-47
Safe Stop Commissioning Test 5-48
Additional Connections 5-49
Installation of misc. connections 5-51
Safety 5-54
EMC-correct Installation 5-54
Residual Current Device 5-58
6 Application Examples 6-1
Potentiometer Reference 6-2
Automatic Motor Adaptation (AMA) 6-2
SLC Application Example 6-4
System Status and Operation 6-6
Cascade Controller Wiring Diagram 6-7
Fixed Variable Speed Pump Wiring Diagram 6-7
Lead Pump Alternation Wiring Diagram 6-8
7 RS-485 Installation and Set-up 7-1
RS-485 Installation and Set-up 7-1
FC Protocol Overview 7-4
Network Configuration 7-5
FC Protocol Message Framing Structure 7-5
Examples 7-12
Modbus RTU Overview 7-13
Contents VLT
®
AQUA Drive Design Guide
MG.20.N5.22 - VLT®is a registered Danfoss trademark

VLT AQUA with Modbus RTU 7-13
Modbus RTU Message Framing Structure 7-14
How to Access Parameters 7-19
Examples 7-20
Danfoss FC Control Profile 7-25
8 Troubleshooting 8-1
9 Index 9-1
VLT
®
AQUA Drive Design Guide Contents
MG.20.N5.22 - VLT®is a registered Danfoss trademark

Contents VLT
®
AQUA Drive Design Guide
MG.20.N5.22 - VLT®is a registered Danfoss trademark

1 How to Read this Design Guide
1.1.1 Copyright, Limitation of Liability and Revision Rights
This publication contains information proprietary to Danfoss. By accepting and using this manual, the user agrees that the information contained herein
will be used solely for operating equipment from Danfoss or equipment from other vendors provided that such equipment is intended for communication
with Danfoss equipment over a serial communication link. This publication is protected under the copyright laws of Denmark and most other countries.
Danfoss does not warrant that a software program produced according to the guidelines provided in this manual will function properly in every physical,
hardware and software environment.
Although Danfoss has tested and reviewed the documentation within this manual, Danfoss makes no warranty or representation, neither expressed nor
implied, with respect to this documentation, including its quality, performance, or fitness for a particular purpose.
In no event shall Danfoss be liable for direct, indirect, special, incidental, or consequential damages arising out of the use, or the inability to use information
contained in this manual, even if advised of the possibility of such damages. In particular, Danfoss is not responsible for any costs, including but not
limited to those incurred as a result of lost profits or revenue, loss or damage of equipment, loss of computer programs, loss of data, the costs to substitute
these, or any claims by third parties.
Danfoss reserves the right to revise this publication at any time and to make changes to its contents without prior notice or any obligation to notify former
or present users of such revisions or changes.
VLT
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AQUA Drive Design Guide 1 How to Read this Design Guide
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1.1.2 Available Literature for VLT
®
AQUA DriveFC 200
-VLT®AQUA Drive Instruction Manual MG.20.Mx.yy provides the neccessary information for getting the drive up and running.
-VLT® AQUA Drive High Power Instruction Manual MG.20.Px.yy provides the neccessary information for getting the HP drive up and running.
-VLT®AQUA Drive Design Guide MG.20.Nx.yy contains all the technical information about the drive and customer design and applications.
-VLT® AQUA Drive Programming Guide MN.20.Ox.yy provides information on how to program and includes complete parameter descriptions.
-VLT® AQUA Drive FC 200 Profibus MG.33.Cx.yy
-VLT® AQUA Drive FC 200 DeviceNet MG.33.Dx.yy
-Output Filters Design Guide MG.90.Nx.yy
-VLT®AQUA Drive FC 200 Cascade Controller MI.38.Cx.yy
-Application Note MN20A102: Submersible Pump Application
-Application Note MN20B102: Master/Follower Operation Application
-Application Note MN20F102: Drive Closed-loop and Sleep Mode
-Instruction MI.38.Bx.yy: Installation Instruction for Mounting Brackets Enclosure type A5, B1, B2, C1 and C2 IP21, IP55 or IP66
-Instruction MI.90.Lx.yy: Analog I/O Option MCB109
-Instruction MI.33.Hx.yy: Panel through mount kit
x = Revision number
yy = Language code
Danfoss technical literature is also available online at
www.danfoss.com/BusinessAreas/DrivesSolutions/Documentations/Technical+Documentation.htm .
1.1.3 Symbols
Symbols used in this guide.
NOTE!
Indicates something to be noted by the reader.
Indicates a general warning.
Indicates a high-voltage warning.
*Indicates a default setting
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1.1.4 Abbreviations
Alternating current AC
American wire gauge AWG
Ampere/AMP A
Automatic Motor Adaptation AMA
Current limit ILIM
Degrees Celsius °C
Direct current DC
Drive Dependent D-TYPE
Electro Magnetic Compatibility EMC
Electronic Thermal Relay ETR
Drive Adjustable frequency drive
Gram g
Hertz Hz
Kilohertz kHz
Local Control Panel LCP
Meter m
Millihenry Inductance mH
Milliampere mA
Millisecond ms
Minute min
Motion Control Tool MCT
Nanofarad nF
Newton Meters Nm
Nominal motor current IM,N
Nominal motor frequency fM,N
Nominal motor power PM,N
Nominal motor voltage UM,N
Parameter par.
Protective Extra Low Voltage PELV
Printed Circuit Board PCB
Rated Inverter Output Current IINV
Revolutions Per Minute RPM
Regenerative terminals Regen
Second s
Synchronous Motor Speed ns
Torque limit TLIM
Volt V
1.1.5 Definitions
Drive:
IVLT,MAX
The maximum output current.
IVLT,N
The rated output current supplied by the adjustable frequency drive.
UVLT, MAX
The maximum output voltage.
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Input:
Control command
You can start and stop the connected motor by means of LCP and the
digital inputs.
Functions are divided into two groups.
Functions in group 1 have higher priority than functions in group 2.
Group 1 Reset, Coasting stop, Reset and Coasting stop, Quick-stop, DC
braking, Stop and the "Off" key.
Group 2 Start, Pulse start, Reversing, Start reversing, Jog and Freeze
output
Motor:
fJOG
The motor frequency when the jog function is activated (via digital terminals).
fM
The motor frequency.
fMAX
The maximum motor frequency.
fMIN
The minimum motor frequency.
fM,N
The rated motor frequency (nameplate data).
IM
The motor current.
IM,N
The rated motor current (nameplate data).
nM,N
The rated motor speed (nameplate data).
PM,N
The rated motor power (nameplate data).
TM,N
The rated torque (motor).
UM
The instantaneous motor voltage.
UM,N
The rated motor voltage (nameplate data).
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ηVLT
The efficiency of the adjustable frequency drive is defined as the ratio between the power output and the power input.
Start-disable command
A stop command belonging to the group 1 control commands - see this group.
Stop command
See Control commands.
References:
Analog Reference
A signal transmitted to the analog inputs 53 or 54, can be voltage or current.
Bus Reference
A signal transmitted to the serial communication port (FC port).
Preset Reference
A defined preset reference to be set from -100% to +100% of the reference range. Selection of eight preset references via the digital terminals.
Pulse Reference
A pulse frequency signal transmitted to the digital inputs (terminal 29 or 33).
RefMAX
Determines the relationship between the reference input at 100% full scale value (typically 10 V, 20 mA) and the resulting reference. The maximum
reference value set in par. 3-03.
RefMIN
Determines the relationship between the reference input at 0% value (typically 0 V, 0 mA, 4 mA) and the resulting reference. The minimum reference
value set in par. 3-02.
Miscellaneous:
Analog Inputs
The analog inputs are used for controlling various functions of the adjustable frequency drive.
There are two types of analog inputs:
Current input, 0–20 mA and 4–20 mA
Voltage input, 0–10 V DC.
Analog Outputs
The analog outputs can supply a signal of 0–20 mA, 4–20 mA, or a digital signal.
Automatic Motor Adaptation, AMA
AMA algorithm determines the electrical parameters for the connected motor at standstill.
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 positive displacement pumps and blowers.
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Digital Inputs
The digital inputs can be used for controlling various adjustable frequency drive functions.
Digital Outputs
The drive features two solid state outputs that can supply a 24 V DC (max. 40 mA) signal.
DSP
Digital Signal Processor.
Relay Outputs:
The adjustable frequency drive features two programmable relay outputs.
ETR
Electronic Thermal Relay is a thermal load calculation based on present load and time. Its purpose is to estimate the motor temperature.
GLCP:
Graphical Local Control Panel (LCP102)
Initializing
If initializing is carried out (par. 14-22), the programmable parameters of the adjustable frequency drive return to their default settings.
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.
LCP
The Local Control Panel (LCP) makes up a complete interface for control and programming of the adjustable frequency drive. The control panel is
detachable and can be installed up to 9.8 ft [3 m] from the adjustable frequency drive, i.e., in a front panel by means of the installation kit option.
The local control panel is available in two versions:
-Numerical LCP101 (NLCP)
-Graphical LCP102 (GLCP)
lsb
Least significant bit.
MCM
Short for Mille Circular Mil, an American measuring unit for cable cross-section. 1 MCM ≡0.00079 in2(0.5067 mm2).
msb
Most significant bit.
NLCP
Numerical Local Control Panel LCP101
On-line/Off-line Parameters
Changes to on-line parameters are activated immediately after the data value is changed. Changes to offline parameters are not activated until you enter
[OK] on the LCP.
PID Controller
The PID controller maintains the desired speed, pressure, temperature, etc., by adjusting the output frequency to match the varying load.
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RCD
Residual Current Device.
Set-up
You can 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.
SFAVM
Switching pattern called S tator F lux oriented A synchronous V ector M odulation (par. 14-00).
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 SLC.
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. The trip-lock function may not be used as a personal safety measure.
VT Characteristics
Variable torque characteristics used for pumps and fans.
VVCplus
If compared with standard voltage/frequency ratio control, Voltage Vector Control (VVCplus) improves the dynamics and the stability, both when the speed
reference is changed and in relation to the load torque.
60° AVM
Switching pattern called 60° A synchronous V ector M odulation (par. 14-00).
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1.1.6 Power Factor
The power factor is the relation between I1and IRMS.
Power factor =
3 × U × I
1 × COS ϕ
3 × U × IRMS
The power factor for 3-phase control:
=
I
1×
cos ϕ1
IRMS
=
I
1
IRMS
since cos ϕ1=1
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 per-
formance.
IRMS = I
1
2+
I
5
2+
I
7
2+ . . +
In
2
In addition, a high power factor indicates that the different harmonic currents are low.
The built-in DC coils in the adjustable frequency drive produce a high power factor, which minimizes the imposed load on the line power supply.
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2 Introduction to the VLT AQUA Drive
2.1 Safety
2.1.1 Safety note
The voltage of the adjustable frequency drive is dangerous whenever connected to line power. Incorrect installation of the motor,
adjustable frequency drive or serial communication bus may cause damage to the equipment, serious personal injury or death. Con-
sequently, the instructions in this manual, as well as national and local rules and safety regulations, must be complied with.
Safety Regulations
1. The adjustable frequency drive must be disconnected from line power if repair work is to be carried out. Make sure that the line power supply has
been disconnected and that the necessary time has passed before removing motor and line plugs.
2. The [STOP/RESET] key on the control panel of the adjustable frequency drive does not disconnect the equipment from line power and is thus not to
be used as a safety switch.
3. Correct protective grounding of the equipment must be established, the user must be protected against supply voltage, and the motor must be protected
against overload in accordance with applicable national and local regulations.
4. The ground leakage currents are higher than 3.5 mA.
5. Protection against motor overload is set by par. 1-90
Motor Thermal Protection . If this function is desired, set par. 1-90 to data value [ETR trip] (default
value) or data value [ETR warning]. Note: The function is initialized at 1.16 x rated motor current and rated motor frequency. For the North American
market: The ETR functions provide class 20 motor overload protection in accordance with NEC.
6. Do not remove the plugs for the motor and line power supply while the adjustable frequency drive is connected to line power. Make sure that the line
power supply has been disconnected and that the necessary time has passed before removing motor and line plugs.
7. Please note that the adjustable frequency drive has more voltage inputs than L1, L2 and L3 when load sharing (linking of DC intermediate circuit) and
external 24 V DC have been installed. Make sure that all voltage inputs have been disconnected and that the necessary time has passed before commencing
repair work.
Installation at High Altitudes
At altitudes higher than 6,600 feet [2 km], please contact Danfoss regarding PELV.
Warning against Unintended Start
1. The motor can be brought to a stop by means of digital commands, bus commands, references or a local stop while the adjustable frequency drive is
connected to line power. If personal safety considerations make it necessary to ensure that no unintended start occurs, these stop functions are not
sufficient. 2. While parameters are being changed, the motor may start. Consequently, the stop key [STOP/RESET] must always be activated; following
which data can be modified. 3. A motor that has been stopped may start if faults occur in the electronics of the adjustable frequency drive, or if a temporary
overload or a fault in the supply line power or the motor connection ceases.
Warning:
Touching the electrical parts may be fatal - even after the equipment has been disconnected from line power.
Also make sure that other voltage inputs have been disconnected, such as external 24 V DC, load sharing (linkage of DC intermediate circuit), as well as
the motor connection for kinetic back-up.
Refer to
VLT
®
AQUA Drive Instruction Manual MG.20.MX.YY for further safety guidelines.
VLT
®
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2.1.2 Caution
The adjustable frequency drive DC link capacitors remain charged after power has been disconnected. To avoid an electrical shock
hazard, disconnect the adjustable frequency drive from line power before carrying out maintenance. Wait at least as follows before
doing service on the adjustable frequency drive:
Voltage (V) Min. Waiting Time (Minutes)
415 20 30 40
200 - 240 0.34–5 hp [0.25–3.7
kW]
7.5–60 hp [5.5–45 kW]
380 - 480 0.5–10 hp [0.37–7.5
kW]
15–125 hp [11–90 kW] 150–350 hp [110–250
kW]
450–1350 hp [315–
1000 kW]
525-600 1–10 hp [0.75 kW–7.5
kW]
15–125 hp [11–90 kW] 450–1600 hp [315–
1200 kW]
525-690 15–125 hp [11–90 kW] 60–550 hp [45–400 kW] 600–1600 hp [450–
1200 kW]
Be aware that there may be high voltage on the DC link even when the LEDs are turned off.
2.1.3 Disposal Instructions
Equipment containing electrical components may not be disposed of together with domestic
waste.
It must be separately collected with electrical and electronic waste according to local and cur-
rently valid legislation.
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2.2 Software Version
2.2.1 Software Version and Approvals
VLT AQUA Drive
Software version: 1.33
This manual can be used with all VLT AQUA Drive adjustable frequency drives with software version 1.33.
The software version number can be found in parameter 15-43.
2.3 CE labeling
2.3.1 CE Conformity and Labeling
What is CE Conformity and Labeling?
The purpose of CE labeling is to avoid technical trade obstacles within the EFTA and the EU. The EU has introduced the CE label as a simple way of
showing whether a product complies with the relevant EU directives. The CE label says nothing about the specifications or quality of the product. Adjustable
frequency drives are regulated by three EU directives:
The machinery directive (98/37/EEC)
All machines with critical moving parts are covered by the Machinery Directive of January 1, 1995. Since an adjustable frequency drive is largely electrical,
it does not fall under the Machinery Directive. However, if an adjustable frequency drive is supplied for use in a machine, we provide information on its
safety aspects in the manufacturer's declaration.
The low-voltage directive (73/23/EEC)
Adjustable frequency drives must be CE-labeled in accordance with the Low-voltage Directive of January 1, 1997. The directive applies to all electrical
equipment and appliances used in the 50–1,000 V AC and the 75 –1,500 V DC voltage ranges. Danfoss CE labels in accordance with the directive and
issues a declaration of conformity upon request.
The EMC directive (89/336/EEC)
EMC is short for electromagnetic compatibility. The presence of electromagnetic compatibility means that the mutual interference between different
components/appliances does not affect the way the appliances work.
The EMC directive came into effect on January 1, 1996. Danfoss CE labels in accordance with the directive and issues a declaration of conformity upon
request. To carry out EMC-correct installation, see the instructions in this Design Guide. In addition, we specify the standards with which our products
comply. We offer the filters presented in the specifications and provide other types of assistance to ensure the optimum EMC result.
The adjustable frequency drive is most often used by professionals of the trade as a complex component forming part of a larger appliance, system or
installation. It must be noted that the responsibility for the final EMC properties of the appliance, system or installation rests with the installer.
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2.3.2 What Is Covered
The EU " Guidelines on the Application of Council Directive 89/336/EEC " outline three typical situations of using an adjustable frequency drive. See below
for EMC coverage and CE labeling.
1. The adjustable frequency drive is sold directly to the end-consumer. For example, it may be sold to a DIY market. The end-consumer is a layman.
He installs the adjustable frequency drive himself for use with a hobby machine, a kitchen appliance, etc. For such applications, the adjustable
frequency drive must be CE-labeled in accordance with the EMC directive.
2. The adjustable frequency drive is sold for installation in a plant. The plant is built up by professionals of the trade. It could be a production plant
or a heating/ventilation plant designed and installed by professionals of the trade. Neither the adjustable frequency drive nor the finished plant
must be CE-labeled under the EMC directive. However, the unit must comply with the basic EMC requirements of the directive. This is ensured
by using components, appliances and systems that are CE-labeled under the EMC directive.
3. The adjustable frequency drive is sold as part of a complete system. The system is being marketed as complete and could, for example, be an
air-conditioning system. The complete system must be CE-labeled in accordance with the EMC directive. The manufacturer can ensure CE-
labeling under the EMC directive either by using CE-labeled components or by testing the EMC of the system. If he chooses to use only CE-
labeled components, he does not have to test the entire system.
2.3.3 Danfoss Adjustable frequency drive and CE Labeling
CE labeling is a positive feature when used for its original purpose, i.e., to facilitate trade within the EU and EFTA.
However, CE labeling may cover many different specifications. Thus, you have to check what a given CE label specifically covers.
The covered specifications can be very different and a CE label may therefore give the installer a false feeling of security when using an adjustable
frequency drive as a component in a system or an appliance.
Danfoss CE labels the adjustable frequency drives in accordance with the low-voltage directive. This means that if the adjustable frequency drive is
installed correctly, we guarantee compliance with the low-voltage directive. Danfoss issues a declaration of conformity that confirms our CE labeling in
accordance with the low-voltage directive.
The CE label also applies to the EMC directive provided that the instructions for EMC-correct installation and filtering are followed. On this basis, a
declaration of conformity in accordance with the EMC directive is issued.
The Design Guide offers detailed instructions for installation to ensure EMC-correct installation. Furthermore, Danfoss specifies which our different prod-
ucts comply with.
Danfoss gladly provides other types of assistance that can help you obtain the best EMC result.
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2.3.4 Compliance with EMC Directive 89/336/EEC
As mentioned, the adjustable frequency drive is mostly used by professionals of the trade as a complex component forming part of a larger appliance,
system or installation. It must be noted that the responsibility for the final EMC properties of the appliance, system or installation rests with the installer.
As an aid to the installer, Danfoss has prepared EMC installation guidelines for the Power Drive system. The standards and test levels stated for power
drive systems are complied with, provided that the EMC-correct instructions for installation are followed; see the section
EMC Immunity .
The adjustable frequency drive has been designed to meet the IEC/EN 60068-2-3 standard, EN 50178 pkt. 9.4.2.2 at 122°F [50°C].
An adjustable frequency drive contains a large number of mechanical and electronic components. All are to some extent vulnerable to environmental
effects.
The adjustable frequency drive should not be installed in environments with airborne liquids, particles or gases capable of affecting
and damaging the electronic components. Failure to take the necessary protective measures increases the risk of stoppages, thus
reducing the life of the adjustable frequency drive.
Liquids can be carried through the air and condense in the adjustable frequency drive and may cause corrosion of components and metal parts. Steam,
oil, and salt water may cause corrosion of components and metal parts. In such environments, use equipment with enclosure rating IP 54/55. As an extra
protection, coated printed circuit boards can be ordered as an option.
Airborne particles such as dust may cause mechanical, electrical or thermal failure in the adjustable frequency drive. A typical indicator of excessive levels
of airborne particles is the presence of dust particles around the adjustable frequency drive fan. In very dusty environments, use equipment with enclosure
rating IP 54/55 or a cabinet for IP 00/IP 20/TYPE 1 equipment.
In environments with high temperatures and humidity, corrosive gases such as sulfur, nitrogen and chlorine compounds will cause chemical reactions on
the adjustable frequency drive components.
Such chemical reactions will rapidly affect and damage the electronic components. In such environments, mount the equipment in a cabinet with fresh
air ventilation, keeping aggressive gases away from the adjustable frequency drive.
An extra protection in such areas is a coating of the printed circuit boards, which can be ordered as an option.
NOTE!
Mounting adjustable frequency drives in aggressive environments increases the risk of stoppages and considerably reduces the life of
the drive.
Before installing the adjustable frequency drive, check the ambient air for liquids, particles and gases. This is done by observing existing installations in
this environment. Typical indicators of harmful airborne liquids are water or oil on metal parts, or corrosion of metal parts.
Excessive dust particle levels are often found on installation cabinets and existing electrical installations. One indicator of aggressive airborne gases is
the blackening of copper rails and cable ends on existing installations.
NOTE!
D and E enclosures have a stainless steel backchannel option to provide additional protection in aggressive environments. Proper ventilation is still
required for the internal components of the drive. Contact Danfoss for additional information.
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2.6 Vibration and shock
The adjustable frequency drive has been tested according to the procedure based on the shown standards:
The adjustable frequency drive complies with requirements that exist for units mounted on the walls and floors of production premises, as well as in
panels bolted to walls or floors.
IEC/EN 60068-2-6: Vibration (sinusoidal) - 1970
IEC/EN 60068-2-64: Vibration, broad-band random
2.7 Advantages
2.7.1 Why use an adjustable frequency drive for controlling fans and pumps?
An adjustable frequency drive takes advantage of the fact that centrifugal fans and pumps follow the laws of proportionality for such fans and pumps.
For further information, see the text
The Laws of Proportionality .
2.7.2 The Clear Advantage - Energy Savings
The very clear advantage of using an adjustable frequency drive for controlling the speed of fans or pumps lies in the electricity savings.
Compared to alternative control systems and technologies, an adjustable frequency drive is the optimum energy control system for controlling fan and
pump systems.
Figure 2.1: The graph is showing fan curves (A, B and C) for
reduced fan volumes.
Figure 2.2: When using a adjustable frequency drive to re-
duce fan capacity to 60%, more than 50% energy savings
may be obtained in typical applications.
2 Introduction to the VLT AQUA Drive VLT
®
AQUA Drive Design Guide
2-6 MG.20.N5.22 - VLT®is a registered Danfoss trademark
2

2.7.3 Example of Energy Savings
As can be seen from the figure (the laws of proportionality), the flow is controlled by changing the RPM. By reducing the rated speed by only 20%, the
flow is also reduced by 20%. This is because the flow is directly proportional to the RPM. The consumption of electricity, however, is reduced by 50%.
If the system in question only needs to be able to supply a flow corresponding to 100% a few days each year, while the average is below 80% of the
rated flow for the remainder of the year, the amount of energy saved is even greater than 50%.
The laws of proportionality
The figure below describes the dependence of flow, pressure and power consumption on RPM.
Q = Flow P = Power
Q1= Rated flow P1= Rated power
Q2= Reduced flow P2= Reduced power
H = Pressure n = Speed regulation
H1= Rated pressure n1= Rated speed
H2= Reduced pressure n2= Reduced speed
Flow :
Q
1
Q
2
=
n
1
n
2
Pressure :
H
1
H
2
=
(
n
1
n
2
)
2
Power :
P
1
P
2
=
(
n
1
n
2
)
3
2.7.4 Example with Varying Flow over 1 Year
The example below is calculated on the basis of pump characteristics ob-
tained from a pump datasheet.
The result obtained shows energy savings in excess of 50% at the given
flow distribution over a year. The pay back period depends on the price
per kwh and the price of the adjustable frequency drive. In this example,
it is less than a year when compared with valves and constant speed.
VLT
®
AQUA Drive Design Guide 2 Introduction to the VLT AQUA Drive
MG.20.N5.22 - VLT®is a registered Danfoss trademark 2-7
2

Energy savings
Pshaft=Pshaft output
Flow distribution over 1 year
2 Introduction to the VLT AQUA Drive VLT
®
AQUA Drive Design Guide
2-8 MG.20.N5.22 - VLT®is a registered Danfoss trademark
2