This design guide is intended for project and systems
engineers, design consultants, and application and product
specialists. Technical information is provided to understand
the capabilities of the frequency converter for integration
into motor control and monitoring systems. Details
concerning operation, requirements, and recommendations
for system integration are described. Information is proved
for input power characteristics, output for motor control,
and ambient operating conditions for the frequency
converter.
Also included are:
Safety features.
•
Fault condition monitoring.
•
Operational status reporting.
•
Serial communication capabilities.
•
Programmable options and features.
•
Also provided are design details such as:
Site requirements.
•
Cables.
•
Fuses.
•
Control wiring.
•
Unit sizes and weights.
•
Other critical information necessary to plan for
•
system integration.
Reviewing the detailed product information in the design
stage enables developing a well-conceived system with
optimal functionality and
eciency.
with regards to backwards compatibility for H1–H5 and I2–
I4 enclosure sizes. Refer to Table 1.2 for the limitations.
Software
compatibility
Old software
(OSS-le version 3.xx
and below)
New software
(OSS-le version 4.xx
or higher)
Hardware
compatibility
Old power card
(production week 33
2017 or before)
New power card
(production week 34
2017 or after)
Table 1.2 Software and Hardware Compatibility
Safety Symbols
1.3
The following symbols are used in this guide:
Old control card
(production week
33 2017 or before)
YesNo
NoYes
Old control card
(production week
33 2017 or before)
Yes (only software
version 3.xx or
below)
Yes (MUST update
software to version
3.xx or below, the
fan continuously
runs at full speed)
New control card
(production week
34 2017 or after)
New control card
(production week
34 2017 or after)
Yes (MUST update
software to version
4.xx or higher)
Yes (only software
version 4.xx or
higher)
WARNING
Indicates a potentially hazardous situation that could
result in death or serious injury.
VLT® is a registered trademark.
Document and Software Version
1.2
This manual is regularly reviewed and updated. All
suggestions for improvement are welcome.
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
EditionRemarksSoftware version
MG18C8xx Update to new SW & HW version.4.2x
Table 1.1 Document and Software Version
From software version 4.0x and later (production week 33
2017 and after), the variable speed heat sink cooling fan
function is implemented in the frequency converter for
power sizes 22 kW (30 hp) 400 V IP20 and below, and 18.5
kW (25 hp) 400 V IP54 and below. This function requires
software and hardware updates and introduces restrictions
Indicates important information, including situations that
can result in damage to equipment or property.
IntroductionDesign Guide
1.4 Abbreviations
°C
°F
AAmpere/AMP
ACAlternating current
AMAAutomatic motor adaptation
AWGAmerican wire gauge
DCDirect current
EMCElectro magnetic compatibility
ETRElectronic thermal relay
FCFrequency converter
f
M,N
kgKilogram
HzHertz
I
INV
I
LIM
I
M,N
I
VLT,MAX
I
VLT,N
kHzKilohertz
LCPLocal control panel
mMeter
mAMilliampere
MCTMotion control tool
mHMillihenry inductance
minMinute
msMillisecond
nFNanofarad
NmNewton meters
n
s
P
M,N
PCBPrinted circuit board
PELVProtective extra low voltage
RegenRegenerative terminals
RPMRevolutions per minute
sSecond
T
LIM
U
M,N
VVolts
Table 1.3 Abbreviations
Additional Resources
1.5
VLT® HVAC Basic Drive FC 101 Quick Guide provides
•
basic information on mechanical dimensions,
installation, and programming.
VLT® HVAC Basic Drive FC 101 Programming Guide
•
provides information on how to program, and
includes complete parameter descriptions.
Danfoss VLT® Energy Box software. Select PC
•
Software Download at www.danfoss.com/en/
service-and-support/downloads/dds/vlt-energy-box/.
Degrees Celsius
Degrees Fahrenheit
Nominal motor frequency
Rated inverter output current
Current limit
Nominal motor current
The maximum output current
The rated output current supplied by the
frequency converter
Synchronous motor speed
Nominal motor power
Torque limit
Nominal motor voltage
®
Energy Box software allows energy
VLT
consumption comparisons of HVAC fans and
pumps driven by Danfoss frequency converters
and alternative methods of ow control. Use this
tool to accurately project the costs, savings, and
payback of using Danfoss frequency converters
on HVAC fans, pumps, and cooling towers.
Danfoss technical literature is available in electronic form
on the documentation CD that is shipped with the
product, or in print from your local Danfoss sales oce.
MCT 10 Set-up Software support
Download the software from www.danfoss.com/en/serviceand-support/downloads/dds/vlt-motion-control-tool-mct-10/.
During the installation process of the software, enter
access code 81463800 to activate the FC 101 functionality.
A license key is not required for using the FC 101
functionality.
The latest software does not always contain the latest
updates for frequency converters. Contact the local sales
oce for the latest frequency converter updates (in the
form of *.upd les), or download the frequency converter
updates from www.danfoss.com/en/service-and-support/downloads/dds/vlt-motion-control-tool-mct-10/#Overview.
Denitions
1.6
Frequency converter
I
VLT, MAX
The maximum output current.
I
VLT,N
The rated output current supplied by the frequency
converter.
U
VLT, MAX
The maximum output voltage.
Input
The connected motor can start and stop via LCP and
digital inputs. Functions are divided into 2 groups, as
described in Table 1.4. Functions in group 1 have higher
priority than functions in group 2.
A dened preset reference to be set from -100% to +100%
of the reference range. Selection of 8 preset references via
the digital terminals.
Ref
MAX
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
parameter 3-03 Maximum Reference.
Ref
MIN
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 is set in
parameter 3-02 Minimum Reference.
Analog inputs
The analog inputs are used for controlling various
functions of the frequency converter.
There are 2 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
The AMA algorithm determines the electrical parameters
for the connected motor at standstill and compensates for
the resistance based on the length of the motor cable.
Digital inputs
The digital inputs can be used for controlling various
functions of the frequency converter.
Digital outputs
Illustration 1.1 Break-away Torque
The frequency converter provides 2 solid-state outputs that
can supply a 24 V DC (maximum 40 mA) signal.
Relay outputs
η
VLT
The eciency of the frequency converter is dened 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 Table 1.4.
Stop command
See Table 1.4.
Analog reference
A signal transmitted to the analog inputs 53 or 54. It can
be voltage or current.
•
•
Current input: 0–20 mA and 4–20 mA
Voltage input: 0–10 V DC
Bus reference
A signal transmitted to the serial communication port (FC
port).
The frequency converter provides 2 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 and prevent overheating of the motor.
Initializing
If initializing is carried out (parameter 14-22 Operation
Mode), the programmable parameters of the frequency
converter return to their default settings.
Parameter 14-22 Operation Mode does not initialize
communication parameters, fault log, or re mode log.
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 noneperiodic duty.
The local control panel (LCP) makes up a complete
interface for control and programming of the frequency
converter. The control panel is detachable on IP20 units
and xed on IP54 units. It can be installed up to 3 m
(9.8 ft) from the frequency converter, that is, in a front
panel with the installation kit option.
Lsb
Least signicant bit.
MCM
Short for mille circular mil, an American measuring unit for
cable cross-section. 1 MCM = 0.5067 mm2.
Msb
Most signicant bit.
On-line/O-line parameters
Changes to on-line parameters are activated immediately
after the data value is changed. Press [OK] to activate o-line parameters.
PI controller
The PI controller maintains the desired speed, pressure,
temperature, and so on, by adjusting the output frequency
to match the varying load.
RCD
Residual current device.
Set-up
Parameter settings in 2 set-ups can be saved. Change
between the 2 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-dened actions executed
when the associated user-dened events are evaluated as
true by the SLC.
Thermistor
A temperature-dependent resistor placed where the
temperature is to be monitored (frequency converter or
motor).
Trip
A state entered in fault situations, for example, if the
frequency converter is subject to an overtemperature or
when the frequency converter is protecting the motor,
process, or mechanism. Restart is prevented until the cause
of the fault does not exist and the trip state is canceled by
activating reset or, sometimes, by being programmed to
reset automatically. Do not use trip for personal safety.
Trip lock
A state entered in fault situations when the frequency
converter is protecting itself and requiring physical
intervention, for example, if the frequency converter is
subject to a short circuit on the output. A locked trip can
only be canceled by cutting o mains, removing the cause
of the fault, and reconnecting the frequency converter.
Restart is prevented until the trip state is canceled by
activating reset or, sometimes, by being programmed to
reset automatically. Do not use trip lock for personal safety.
VT characteristics
Variable torque characteristics used for pumps and fans.
+
VVC
If compared with standard voltage/frequency ratio control,
voltage vector control (VVC+) improves the dynamics and
the stability, both when the speed reference is changed
and in relation to the load torque.
Power Factor
1.7
The power factor indicates to which extent the frequency
converter imposes a load on the mains supply. The power
factor is the ratio between I1 and I
fundamental current, and I
RMS
, where I1 is the
RMS
is the total RMS current
including harmonic currents. The lower the power factor,
the higher the I
Powerfactor =
for the same kW performance.
RMS
3 × U × I1× cosϕ
3 × U × I
RMS
The power factor for 3-phase control:
Power factor =
= I
2
+ I
1
I
RMS
I1 × cosϕ1
I
RMS
2
2
+ I
+ . . + I
5
7
I
1
=
sincecosϕ1 = 1
I
RMS
2
n
A high-power factor indicates that the dierent harmonic
currents are low.
The frequency converters built-in DC coils produce a highpower factor, which minimizes the imposed load on the
mains supply.
Frequency converters are designed in compliance with the
directives described in this section.
1.8.1 CE Mark
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 1.5.
NOTICE
The CE mark does not regulate the quality of the
product. Technical specications cannot be deduced from
the CE mark.
CE mark, but must comply with the basic protection
requirements of the EMC directive.
1.8.1.3 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 directive aims at increasing
energy eciency 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 UL Compliance
UL-listed
NOTICE
Frequency converters with an integrated safety function
must comply with the machinery directive.
EU directiveVersion
Low Voltage Directive2014/35/EU
EMC Directive2014/30/EU
ErP Directive
Illustration 1.2 UL
NOTICE
IP54 units are not certied for UL.
Table 1.5 EU Directives Applicable to Frequency Converters
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 and maintained correctly in its
intended application.
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 installations. The basic protection requirement of the EMC
Directive 2014/30/EU states that devices that generate
electromagnetic interference (EMI), or whose operation
could be aected by EMI, must be designed to limit the
generation of electromagnetic interference and shall have
a suitable degree of immunity to EMI when properly
installed, maintained, and used as intended.
Electrical equipment devices used alone or as part of a
system must bear the CE mark. Systems do not require the
The frequency converter complies with UL 508C thermal
memory retention requirements. For more information,
refer to the section Motor Thermal Protection in the
product-specicdesign guide.
1.8.3 RCM Mark Compliance
Illustration 1.3 RCM Mark
The RCM Mark label indicates compliance with the
applicable technical standards for Electromagnetic Compatibility (EMC). An RCM Mark label is required for placing
electrical and electronic devices on the market in Australia
and New Zealand. The RCM Mark regulatory arrangements
only deal with conducted and radiated emission. For
frequency converters, the emission limits specied in
EN/IEC 61800-3 apply. A declaration of conformity can be
provided on request.
The EurAsian Conformity (EAC) mark indicates that the
product conforms to all requirements and technical
regulations applicable to the product per the EurAsian
Customs Union, which is composed of the member states
of the EurAsian Economic Union.
The EAC logo must be both on the product label and on
the packaging label. All products used within the EAC area,
must be bought at Danfoss inside the EAC area.
1.8.5 UkrSEPRO
Illustration 1.5 UkrSEPRO
11
UKrSEPRO certicate ensures quality and safety of both
products and services, in addition to manufacturing
stability according to Ukrainian regulatory standards. The
UkrSepro certicate is a required document to clear
customs for any products coming into and out of the
territory of Ukraine.
Correct and reliable transport, storage, installation,
operation, and maintenance are required for the troublefree and safe operation of the frequency converter. Only
qualied personnel are allowed to install or operate this
equipment.
Qualied personnel are dened as trained sta, who are
authorized to install, commission, and maintain equipment,
systems, and circuits in accordance with pertinent laws and
regulations. Also, the personnel must be familiar with the
instructions and safety measures described in this guide.
2.2 Safety Precautions
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 qualied personnel can result in death or serious
injury.
Only qualied personnel must perform instal-
•
lation, start-up, and maintenance.
Before performing any service or repair work,
•
use an appropriate voltage measuring device to
make sure that there is no remaining voltage on
the frequency converter.
WARNING
UNINTENDED START
When the drive is connected to AC mains, DC supply, or
load sharing, the motor can 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 with an external switch, a
eldbus command, an input reference signal from the
LCP or LOP, via remote operation using MCT 10 Set-up
Software, or after a cleared fault condition.
To prevent unintended motor start:
Press [O/Reset] on the LCP before
•
programming parameters.
Disconnect the drive from the mains.
•
Completely wire and assemble the drive, motor,
•
and any driven equipment before connecting
the drive 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 can be present
even when the warning LED indicator lights are o.
Failure to wait the specied time after power has been
removed before performing service or repair work can
result in death or serious injury.
Stop the motor.
•
Disconnect AC mains and remote DC-link power
•
supplies, including battery back-ups, UPS, and
DC-link connections to other frequency
converters.
Disconnect or lock PM motor.
•
Wait for the capacitors to discharge fully. The
•
minimum duration of waiting time is specied
in Table 2.1.
Before performing any service or repair work,
•
use an appropriate voltage measuring device to
make sure that the capacitors are fully
discharged.
Voltage [V]Power range [kW (hp)] Minimum waiting time
(minutes)
3x2000.25–3.7 (0.33–5)4
3x2005.5–11 (7–15)15
3x4000.37–7.5 (0.5–10)4
3x40011–90 (15–125)15
3x6002.2–7.5 (3–10)4
3x60011–90 (15–125)15
Table 2.1 Discharge Time
WARNING
LEAKAGE CURRENT HAZARD
Leakage currents exceed 3.5 mA. Failure to ground the
frequency converter properly can result in death or
serious injury.
3.1.1 Why use a Frequency Converter for
Controlling Fans and Pumps?
A frequency converter takes advantage of the fact that
centrifugal fans and pumps follow the laws of proportionality for such fans and pumps. For further information,
see chapter 3.1.3 Example of Energy Savings.
3.1.2 The Clear Advantage - Energy Savings
The clear advantage of using a frequency converter for
controlling the speed of fans or pumps lies in the
electricity savings.
When comparing with alternative control systems and
technologies, a frequency converter is the optimum energy
control system for controlling fan and pump systems.
Illustration 3.1 Fan Curves (A, B, and C) for Reduced Fan
Illustration 3.2 Energy Savings with Frequency Converter
Solution
When using a frequency converter to reduce fan capacity
to 60% - more than 50% energy savings may be obtained
in typical applications.
3.1.3 Example of Energy Savings
As shown in Illustration 3.3, the ow is controlled by
changing the RPM. By reducing the speed by only 20%
from the rated speed, the ow is also reduced by 20%.
This is because the ow 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
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 amount of energy saved is even
more than 50%.
n
100%
50%
25%
12,5%
50%100%
80%
80%
175HA208.10
Power ~n
3
Pressure ~n
2
Flow ~n
130BA782.10
Discharge
damper
Less energy savings
IGV
Costlier installation
Maximum energy savings
130BA779.12
060060060
0
20
40
60
80
100
Discharge Damper Solution
IGV Solution
VLT Solution
Energy consumed
Energy consumed
Energy consumed
Input power %
Volume %
Product OverviewDesign Guide
Illustration 3.3 describes the dependence of ow, pressure,
and power consumption on RPM.
Illustration 3.3 Laws of Proportionally
33
Q
n
1
Flow:
Q
Pressure:
Power:
2
P
P
=
H
H
1
=
2
1
2
1
n
2
=
2
n
1
n
2
3
n
1
n
2
Q = FlowP = Power
Q1 = Rated owP1 = Rated power
Q2 = Reduced owP2 = Reduced power
H = Pressuren = Speed control
H1 = Rated pressuren1 = Rated speed
H2 = Reduced pressuren2 = Reduced speed
Table 3.1 The Laws of Proportionality
3.1.4 Comparison of Energy Savings
The Danfoss frequency converter solution oers major
savings compared with traditional energy saving solutions
such as discharge damper solution and inlet guide vanes
(IGV) solution. This is because the frequency converter is
able to control fan speed according to thermal load on the
system, and the frequency converter has a built-in facility
that enables the frequency converter to function as a
building management system, BMS.
Illustration 3.3 shows typical energy savings obtainable
with 3 well-known solutions when fan volume is reduced
to 60%.
As the graph shows, more than 50% energy savings can be
achieved in typical applications.
Illustration 3.4 The 3 Common Energy Saving Systems
Illustration 3.5 Energy Savings
Discharge dampers reduce power consumption. Inlet guide
vanes oer a 40% reduction, but are expensive to install.
The Danfoss frequency converter solution reduces energy
consumption with more than 50% and is easy to install. It
also reduces noise, mechanical stress, and wear-and-tear,
and extends the life span of the entire application.
500
[h]
t
1000
1500
2000
200100300
[m
3
/h]
400
Q
175HA210.11
175HA209.11
60
50
40
30
20
10
H
s
0100200300400
(mwg)
B
C
A
750rpm
1050rpm
1350rpm
1650rpm
0
10
20
30
(kW)
40
50
60
200100300
(
m3 /h
)
(
m3 /h
)
400
750rpm
1050rpm
1350rpm
1650rpm
P
shaft
C
1
B
1
A
1
Product Overview
VLT® HVAC Basic Drive FC 101
3.1.5 Example with Varying Flow over 1
Year
This example is calculated based on pump characteristics
obtained from a pump datasheet.
33
The result obtained shows energy savings of more than
50% at the given ow distribution over a year. The
payback period depends on the price per kWh and the
price of frequency converter. In this example, it is less than
a year when compared with valves and constant speed.
Energy savings
P
= P
shaft
shaft output
Illustration 3.6 Flow Distribution over 1 Year
Illustration 3.7 Energy
Distri-
m3/
bution
h
% Hours Power
A1 - B
Valve regulation
Consump-
tion
kWhA1 - C
1
Frequency converter
control
Power
Consump-
1
tion
kWh
350543842.518.61542.518.615
300 15 131438.550.58929.038.106
250 20 175235.061.32018.532.412
200 20 175231.555.18811.520.148
150 20 175228.049.0566.511.388
100 20 175223.040.2963.56.132
100 8760–275.064–26.801
Σ
Table 3.2 Result
3.1.6 Better Control
If a frequency converter is used for controlling the ow or
pressure of a system, improved control is obtained.
A frequency converter can vary the speed of the fan or
pump, obtaining variable control of ow and pressure.
Furthermore, a frequency converter can quickly adapt the
speed of the fan or pump to new ow or pressure
conditions in the system.
Simple control of process (ow, level, or pressure) utilizing
the built-in PI control.
3.1.7 Star/Delta Starter or Soft Starter not
Required
When larger 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. Such motor starters are not required
if a frequency converter is used.
As illustrated in Illustration 3.8, a frequency converter does
not consume more than rated current.
3.1.8 Using a Frequency Converter Saves
Money
The example in chapter 3.1.9 Without a Frequency Converter
shows that a frequency converter replaces other
equipment. It is possible to calculate the cost of installing
the 2 dierent systems. In the example, the 2 systems can
be established at roughly the same price.
Use the VLT® Energy Box software that is introduced in
chapter 1.5 Additional Resources to calculate the cost
savings that can be achieved by using a frequency
converter.
Illustration 3.10 Fan System Controlled by Frequency Converters
3.1.11 Application Examples
The following sections give typical examples of
applications within HVAC.
3.1.12 Variable Air Volume
VAV or variable air volume systems, control both the
ventilation and temperature to fulll the requirements of a
building. Central VAV systems are considered to be the
most energy-ecient method to air condition buildings. By
designing central systems instead of distributed systems, a
greater eciency can be obtained.
The eciency comes from utilizing larger fans and larger
chillers which have much higher eciencies than small
motors and distributed air-cooled chillers. Savings are also
seen from the decreased maintenance requirements.
Centrifugal devices such as fans behave according to the
centrifugal laws. This means that the fans decrease the
While dampers and IGVs work to maintain a constant
pressure in the ductwork, a frequency converter solution
saves much more energy and reduces the complexity of
the installation. Instead of creating an articial pressure
33
drop or causing a decrease in fan eciency, the frequency
pressure and ow they produce as their speed is reduced.
Their power consumption is thereby signicantly reduced.
The PI controller of the VLT® HVAC Basic Drive FC 101 can
be used to eliminate the need for additional controllers.
converter decreases the speed of the fan to provide the
ow and pressure required by the system.
CAV, or constant air volume systems, are central ventilation
systems usually used to supply large common zones with
the minimum amounts of fresh tempered air. They
preceded VAV systems and are therefore found in older
multi-zoned commercial buildings as well. These systems
preheat amounts of fresh air utilizing air handling units
(AHUs) with a heating coil, and many are also used to air
condition buildings and have a cooling coil. Fan coil units
are frequently used to assist in the heating and cooling
requirements in the individual zones.
3.1.15 The VLT Solution
With a frequency converter, signicant energy savings can
be obtained while maintaining decent control of the
building. Temperature sensors or CO2 sensors can be used
as feedback signals to frequency converters. Whether
controlling temperature, air quality, or both, a CAV system
can be controlled to operate based on actual building
conditions. As the number of people in the controlled area
decreases, the need for fresh air decreases. The CO2 sensor
detects lower levels and decreases the supply fans speed.
The return fan modulates to maintain a static pressure
setpoint or
airows.
xed dierence between the supply and return
With temperature control, especially used in air
conditioning systems, as the outside temperature varies as
well as the number of people in the controlled zone
changes, dierent cooling requirements exist. As the
temperature decreases below the setpoint, the supply fan
can decrease its speed. The return fan modulates to
maintain a static pressure setpoint. By decreasing the air
ow, energy used to heat or cool the fresh air is also
reduced, adding further savings.
Several features of the Danfoss HVAC dedicated frequency
converter can be utilized to improve the performance of
the CAV system. One concern of controlling a ventilation
system is poor air quality. The programmable minimum
frequency can be set to maintain a minimum amount of
supply air regardless of the feedback or reference signal.
The frequency converter also includes a PI controller, which
allows monitoring both temperature and air quality. Even if
the temperature requirement is fullled, the frequency
converter maintains enough supply air to satisfy the air
quality sensor. The controller is capable of monitoring and
comparing 2 feedback signals to control the return fan by
maintaining a xeddierentialairow between the supply
and return ducts as well.
Several features of the Danfoss HVAC dedicated frequency
converter can be utilized to improve the performance of
Cooling tower fans cool condenser-water in water-cooled
chiller systems. Water-cooled chillers provide the most
ecient means of creating chilled water. They are as much
as 20% more ecient than air cooled chillers. Depending
33
on climate, cooling towers are often the most energy
ecient method of cooling the condenser-water from
chillers.
They cool the condenser water by evaporation.
cooling tower fans applications. As the cooling tower fans
drop below a certain speed, the eect the fan has on
cooling the water becomes small. Also, when utilizing a
gearbox to frequency control the tower fan, a minimum
speed of 40–50% is required.
The customer programmable minimum frequency setting is
available to maintain this minimum frequency even as the
feedback or speed reference calls for lower speeds.
The condenser water is sprayed into the cooling tower
until the cooling towers ll to increase its surface area. The
tower fan blows air through the ll and sprayed water to
aid in the evaporation. Evaporation removes energy from
the water dropping its temperature. The cooled water
collects in the cooling towers basin where it is pumped
back into the chillers condenser and the cycle is repeated.
Also as a standard feature, the frequency converter can be
programmed to enter a sleep mode and stop the fan until
a higher speed is required. Additionally, some cooling
tower fans have undesirable frequencies that may cause
vibrations. These frequencies can easily be avoided by
programming the bypass frequency ranges in the
frequency converter.
3.1.17 The VLT Solution
With a frequency converter, the cooling tower fans can be
controlled to the required speed to maintain the
condenser-water temperature. The frequency converters
can also be used to turn the fan on and o as needed.
Condenser water pumps are primarily used to circulate
water through the condenser section of water cooled
chillers and their associated cooling tower. The condenser
water absorbs the heat from the chiller's condenser section
and releases it into the atmosphere in the cooling tower.
These systems are used to provide the most ecient
means of creating chilled water, they are as much as 20%
more ecient than air cooled chillers.
3.1.19 The VLT Solution
Frequency converters can be added to condenser water
pumps instead of balancing the pumps with a throttling
valve or trimming the pump impeller.
Using a frequency converter instead of a throttling valve
simply saves the energy that would have been absorbed
by the valve. This can amount to savings of 15–20% or
more. Trimming the pump impeller is irreversible, thus if
the conditions change and higher ow is required the
impeller must be replaced.
Primary pumps in a primary/secondary pumping system
can be used to maintain a constant ow through devices
that encounter operation or control diculties when
33
exposed to variable ow. The primary/secondary pumping
technique decouples the primary production loop from the
secondary distribution loop. This allows devices such as
chillers to obtain constant design ow and operate
properly while allowing the rest of the system to vary in
ow.
As the evaporator ow rate decreases in a chiller, the
chilled water begins to become overchilled. As this
happens, the chiller attempts to decrease its cooling
capacity. If the ow rate drops far enough, or too quickly,
the chiller cannot shed its load suciently and the chiller’s
safety trips the chiller requiring a manual reset. This
situation is common in large installations especially when 2
or more chillers in parallel are installed if primary/
secondary pumping is not utilized.
3.1.21 The VLT Solution
Depending on the size of the system and the size of the
primary loop, the energy consumption of the primary loop
can become substantial.
A frequency converter can be added to the primary system
to replace the throttling valve and/or trimming of the
impellers, leading to reduced operating expenses. 2 control
methods are common:
Flow meter
Because the desired
ow meter installed at the discharge of each chiller, can be
used to control the pump directly. Using the built-in PI
controller, the frequency converter always maintains the
appropriate ow rate, even compensating for the changing
resistance in the primary piping loop as chillers and their
pumps are staged on and o.
Local speed determination
The operator simply decreases the output frequency until
the design ow rate is achieved.
Using a frequency converter to decrease the pump speed
is very similar to trimming the pump impeller, except it
does not require any labor, and the pump eciency
remains higher. The balancing contractor simply decreases
the speed of the pump until the proper ow rate is
achieved and leaves the speed xed. The pump operates
at this speed any time the chiller is staged on. Because the
primary loop does not have control valves or other devices
that can cause the system curve to change, and the
variance due to staging pumps and chillers on and o is
usually small, this xed speed remains appropriate. If the
ow rate needs to be increased later in the system’s life,
the frequency converter can simply increase the pump
speed instead of requiring a new pump impeller.
With the proper sensor location, the addition of frequency
converters allows the pumps to vary their speed to follow
Secondary pumps in a primary/secondary chilled water
pumping system distribute the chilled water to the loads
from the primary production loop. The primary/secondary
pumping system is used to hydronically de-couple 1 piping
33
loop from another. In this case, the primary pump is used
to maintain a constant ow through the chillers while
allowing the secondary pumps to vary in ow, increase
control and save energy.
If the primary/secondary concept is not used in the design
of a variable volume system when the ow rate drops far
enough or too quickly, the chiller cannot shed its load
the system curve instead of the pump curve.
This results in the elimination of wasted energy and
eliminates most of the overpressurization that 2-way valves
can be subjected to.
As the monitored loads are reached, the 2-way valves close
down. This increases the dierential pressure measured
across the load and the 2-way valve. As this dierential
pressure starts to rise, the pump is slowed to maintain the
control head also called setpoint value. This setpoint value
is calculated by summing the pressure drop of the load
and the 2-way valve together under design conditions.
properly. The chiller’s low evaporator temperature safety
then trips the chiller requiring a manual reset. This
situation is common in large installations especially when 2
or more chillers in parallel are installed.
NOTICE
When running multiple pumps in parallel, they must run
at the same speed to maximize energy savings, either
with individual dedicated frequency converters or 1
3.1.23 The VLT Solution
frequency converter running multiple pumps in parallel.
While the primary-secondary system with 2-way valves
improves energy savings and eases system control
problems, the true energy savings and control potential is
realized by adding frequency converters.
Select [0] Open loop or [1] Closed loop in parameter 1-00 Conguration Mode.
3.2.1 Control Structure Open Loop
Illustration 3.17 Open-loop Structure
33
In the conguration shown in Illustration 3.17,
parameter 1-00 Conguration Mode is set to [0] Open loop.
The resulting reference from the reference handling system
or the local reference is received and fed through the ramp
limitation and speed limitation before being sent to the
motor control. The output from the motor control is then
limited by the maximum frequency limit.
Current limitations for PM motors:
induction motors and 0.37–22 kW (0.5–30 hp)
(400 V) for PM motors.
Currently only supported up to 22 kW (30 hp).
•
LC lters are not supported with PM motors.
•
Kinetic back-up algorithm is not supported with
•
PM motors.
3.2.2 PM/EC+ Motor Control
Support only complete AMA of the stator
•
resistance Rs in the system.
The Danfoss EC+ concept provides the possibility for using
high-ecient PM motors (permanent magnet motors) in
IEC standard enclosure sizes operated by Danfoss
No stall detection (supported from software
•
version 2.80).
frequency converters.
The commissioning procedure is comparable to the
existing one for asynchronous (induction) motors by
3.2.3 Local (Hand On) and Remote (Auto
On) Control
utilizing the Danfoss VVC+ PM control strategy.
The frequency converter can be operated manually via the
local control panel (LCP) or remotely via analog/digital
inputs or serial bus. If allowed in parameter 0-40 [Hand on]
Key on LCP, parameter 0-44 [O/Reset] Key on LCP, and
parameter 0-42 [Auto on] Key on LCP, it is possible to start
and stop the frequency converter via LCP by pressing
[Hand On] and [O/Reset]. Alarms can be reset via the
[O/Reset] key.
Illustration 3.18 LCP Keys
7-30 PI
Normal/Inverse
Control
PI
Reference
Feedback
Scale to
speed
P 4-10
Motor speed
direction
To motor
control
130BB894.11
S
100%
0%
-100%
100%
*[-1]
_
+
130BB895.10
+
-
PI
P
P
P
Ref.
signal
Desired
ow
FB conversion
Ref.
FB
Flow
FB
signal
Flow
P 20-01
Product Overview
VLT® HVAC Basic Drive FC 101
Local reference forces the conguration mode to openloop, independent on the setting of
parameter 1-00 Conguration Mode.
For example, consider a pump application where the speed
of a pump is to be controlled to ensure a constant static
pressure in a pipe. The static pressure value is supplied to
the frequency converter as the setpoint reference. A static
Local reference is restored at power-down.
pressure sensor measures the actual static pressure in the
pipe and supplies this data to the frequency converter as a
33
3.2.4 Control Structure Closed Loop
The internal controller allows the frequency converter to
become a part of the controlled system. The frequency
converter receives a feedback signal from a sensor in the
system. It then compares this feedback to a setpoint
feedback signal. If the feedback signal is greater than the
setpoint reference, the frequency converter slows the
pump down to reduce the pressure. In a similar way, if the
pipe pressure is lower than the setpoint reference, the
frequency converter automatically speeds the pump up to
increase the pressure provided by the pump.
reference value and determines the error, if any, between
these 2 signals. It then adjusts the speed of the motor to
correct this error.
Illustration 3.19 Control Structure Closed-loop
While the default values for the closed-loop controller of
3.2.5 Feedback Conversion
the frequency converter often provide satisfactory
performance, the control of the system can often be
optimized by adjusting parameters.
In some applications, it may be useful to convert the
feedback signal. One example of this is using a pressure
signal to provide ow feedback. Since the square root of
pressure is proportional to ow, the square root of the
pressure signal yields a value proportional to the ow. See
Illustration 3.20.
Up to 8 preset references can be programmed in the
frequency converter. The active preset reference can be
selected using digital inputs or the serial communications
bus. The reference can also be supplied externally, most
commonly from an analog input. This external source is
selected by 1 of the 3 reference source parameters
(parameter 3-15 Reference 1 Source,
parameter 3-16 Reference 2 Source, and
parameter 3-17 Reference 3 Source). All reference resources
and the bus reference are added to produce the total
external reference. The external reference, the preset
reference, or the sum of the 2 can be selected to be the
active reference. Finally, this reference can by be scaled
using parameter 3-14 Preset Relative Reference.
External references (analog inputs and serial
communication bus references).
The preset relative reference.
Feedback-controlled setpoint.
The scaled reference is calculated as follows:
Reference = X + X ×
Where X is the external reference, the preset reference or
the sum of these and Y is parameter 3-14 Preset RelativeReference in [%].
Y
100
If Y, parameter 3-14 Preset Relative Reference, is set to 0%,
the reference is not aected by the scaling.
110%
100%
90 %
80
%
70 %
60 %
50 %
40 %
30 %
20 %
10 %
0
I
out
[%]
0
2
5
10
16
40
o
C
50
o
C
45
o
C
fsw[kHz]
130BC217.10
fsw[kHz]
2010
0
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
110%
I
out
[%]
16
40
45
50
5
o
C
o
C
o
C
104 oF
113 oF
122
o
F
fsw[kHz]
2010
0
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
110%
I
out
[%]
16
40
45
50
5
o
C
o
C
o
C
130BC219.10
Product Overview
VLT® HVAC Basic Drive FC 101
3.2.7 Tuning the Drive Closed-loop
Controller
Once the frequency converter's closed-loop controller has
been set up, test the performance of the controller. Often,
its performance may be acceptable using the default
33
values of parameter 20-93 PI Proportional Gain and
parameter 20-94 PI Integral Time. However, sometimes it
may be helpful to optimize these parameter values to
provide faster system response while still controlling speed
overshoot.
2.Set parameter 20-93 PI Proportional Gain to 0.3
and increase it until the feedback signal begins to
oscillate. If necessary, start and stop the
frequency converter or make step changes in the
setpoint reference to attempt to cause oscillation.
3.Reduce the PI proportional gain until the
feedback signal stabilizes.
4.Reduce the proportional gain by 40–60%.
5.Set parameter 20-94 PI Integral Time to 20 s and
reduce it until the feedback signal begins to
oscillate. If necessary, start and stop the
frequency converter or make step changes in the
setpoint reference to attempt to cause oscillation.
6.Increase the PI integral time until the feedback
signal stabilizes.
The frequency converter has been designed to meet the
IEC/EN 60068-2-3 standard, EN 50178 9.4.2.2 at 50 °C
(122 °F).
The ambient temperature measured over 24 hours should
be at least 5 °C (41 °F) lower than the maximum ambient
temperature. If the frequency converter is operated at high
ambient temperature, decrease the continuous output
current.
If the motor or the equipment driven by the motor - for
example, a fan - makes noise or vibrations at certain
frequencies, congure the following parameters or
parameter groups to reduce or eliminate the noise or
vibrations:
Parameter group 4-6* Speed Bypass.
•
Set parameter 14-03 Overmodulation to [0] O.
•
Switching pattern and switching frequency
•
parameter group 14-0* Inverter Switching.
Parameter 1-64 Resonance Dampening.
•
The acoustic noise from the frequency converter comes
from 3 sources:
DC-link coils.
•
Integral fan.
•
RFI lter choke.
•
Enclosure size
Level [dBA]
H143.6
H250.2
H353.8
H464
H563.7
H671.5
H767.5 (75 kW (100 hp) 71.5 dB)
H873.5
H960
H1062.9
I250.2
I354
I467.4
I670
I762
I865.6
1)
33
Table 3.3 Typical Values Measured at a Distance of 1 m (3.28 ft)
from the Unit
1) The values are measured under the background of 35 dBA noise
and the fan running with full speed.
The frequency converter has been tested according to the
procedure based on the shown standards, Table 3.4.
The frequency converter complies with the requirements
A frequency converter contains many mechanical and
electronic components. All are to some extent vulnerable
to environmental eects.
Product Overview
CAUTION
INSTALLATION ENVIRONMENTS
Do not install the frequency converter in environments
with airborne liquids, particles, or gases that may aect
or damage the electronic components. Failure to take
33
necessary protective measures increases the risk of
stoppages, potentially causing equipment damage and
personnel injury.
VLT® HVAC Basic Drive FC 101
General Aspects of EMC
3.4
3.4.1 Overview of EMC Emissions
Frequency converters (and other electrical devices)
generate electronic or magnetic
with their environment. The electromagnetic compatibility
(EMC) of these eects depends on the power and the
harmonic characteristics of the devices.
elds that may interfere
Liquids can be carried through the air and condense in the
frequency converter 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
IP54. As an extra protection, coated printed circuit boards
can be ordered as an option (standard on some power
sizes).
Airborne particles such as dust may cause mechanical,
electrical, or thermal failure in the frequency converter. A
typical indicator of excessive levels of airborne particles is
dust particles around the frequency converter fan. In dusty
environments, use equipment with enclosure rating IP54 or
a cabinet for IP20/TYPE 1 equipment.
In environments with high temperatures and humidity,
corrosive gases such as sulphur, nitrogen, and chlorine
compounds cause chemical processes on the frequency
converter components.
Such chemical reactions rapidly
electronic components. In such environments, mount the
equipment in a cabinet with fresh air ventilation, keeping
aggressive gases away from the frequency converter.
An extra protection in such areas is a coating of the
printed circuit boards, which can be ordered as an option.
Before installing the frequency converter, 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 blackening of
copper rails and cable ends on existing installations.
aect and damage the
Uncontrolled interaction between electrical devices in a
system can degrade compatibility and impair reliable
operation. Interference may take the form of mains
harmonics distortion, electrostatic discharges, rapid voltage
uctuations, or high-frequency interference. Electrical
devices generate interference along with being aected by
interference from other generated sources.
Electrical interference usually arises at frequencies in the
range 150 kHz to 30 MHz. Airborne interference from the
frequency converter system in the range 30 MHz to 1 GHz
is generated from the inverter, the motor cable, and the
motor.
Capacitive currents in the motor cable coupled with a high
dU/dt from the motor voltage generate leakage currents,
as shown in Illustration 3.52.
The use of a shielded motor cable increases the leakage
current (see Illustration 3.52) because shielded cables have
higher capacitance to ground than unshielded cables. If
the leakage current is not ltered, it causes greater
interference on the mains in the radio frequency range
below approximately 5 MHz. Since the leakage current (I1)
is carried back to the unit through the shield (I3), there is
only a small electro-magnetic eld (I4) from the shielded
motor cable according to Illustration 3.52.
The shield reduces the radiated interference, but increases
the low-frequency interference on the mains. Connect the
motor cable shield to the frequency converter enclosure as
well as on the motor enclosure. This is best done by using
integrated shield clamps to avoid twisted shield ends
(pigtails). Pigtails increase the shield impedance at higher
frequencies, which reduces the shield
the leakage current (I4).
If a shielded cable is used for relay, control cable, signal
interface, and brake, mount the shield on the enclosure at
both ends. In some situations, however, it is necessary to
break the shield to avoid current loops.
eect and increases
If the shield is to be placed on a mounting plate for the
frequency converter, the mounting plate must be made of
metal, to convey the shield currents back to the unit.
Moreover, ensure good electrical contact from the
mounting plate through the mounting screws to the
frequency converter chassis.
When using unshielded cables, some emission
requirements are not complied with, although most
immunity requirements are observed.
as possible. Avoid placing cables with a sensitive signal
level alongside motor and brake cables. Radio interference
higher than 50 MHz (airborne) is especially generated by
the control electronics.
To reduce the interference level from the entire system
(unit+installation), make motor and brake cables as short
The EMC product standard for frequency converters
denes 4 categories (C1, C2, C3, and C4) with specied
requirements for emission and immunity. Table 3.5 states
33
the denition of the 4 categories and the equivalent classi-
cation from EN 55011.
EN/IEC
61800-3
Category
C1
C2
C3
C4
Denition
Frequency converters installed in
the 1st environment (home and
oce) with a supply voltage less
than 1000 V.
Frequency converters installed in
the 1st environment (home and
oce) with a supply voltage less
than 1000 V, which are neither
plug-in nor movable and are
intended to be installed and
commissioned by a professional.
Frequency converters installed in
the 2nd environment (industrial)
with a supply voltage lower than
1000 V.
Frequency converters installed in
the 2nd environment with a supply
voltage equal to or above 1000 V
or rated current equal to or above
400 A or intended for use in
complex systems.
Equivalent
emission class
in EN 55011
Class B
Class A Group 1
Class A Group 2
No limit line.
Make an EMC
plan.
Table 3.5 Correlation between IEC 61800-3 and
EN 55011
When the generic (conducted) emission standards are
used, the frequency converters are required to comply with
the limits in Table 3.6.
Environment
First
environment
(home and
oce)
Second
environment
(industrial
environment)
Table 3.6 Correlation between Generic Emission Standards and EN 55011
The following test results have been obtained using a system with a frequency converter, a shielded control cable, a control
box with potentiometer, and a shielded motor cable.
RFI lter
type
Industrial environment
EN 55011
EN/IEC
61800-3
H4 RFI lter (EN55011 A1, EN/IEC61800-3 C2)
0.25–11 kW
(0.34–15 hp)
3x200–240 V
IP20
0.37–22 kW
(0.5–30 hp)
3x380–480 V
IP20
H2 RFI lter (EN 55011 A2, EN/IEC 61800-3 C3)
15–45 kW
(20–60 hp)
3x200–240 V
IP20
30–90 kW
(40–120 hp)
3x380–480 V
IP20
0.75–18.5 kW
(1–25 hp)
3x380–480 V
IP54
22–90 kW
(30–120 hp)
3x380–480 V
IP54
H3 RFI lter (EN55011 A1/B, EN/IEC 61800-3 C2/C1)
15–45 kW
(20–60 hp)
3x200–240 V
IP20
30–90 kW
(40–120 hp)
3x380–480 V
IP20
0.75–18.5 kW
(1–25 hp)
3x380–480 V
IP54
Conduct emission. Maximum shielded cable length [m (ft)]Radiated emission
A frequency converter takes up a non-sinusoidal current
from mains, which increases the input current I
RMS
. A nonsinusoidal current is transformed with a Fourier analysis
and split into sine-wave currents with dierent frequencies,
that is, dierent harmonic currents In with 50 Hz basic
frequency:
I
Hz50250350
Table 3.8 Harmonic Currents
1
I
5
I
7
The harmonics do not aect the power consumption
directly, but increase the heat losses in the installation
(transformer, cables). So, in plants with a high percentage
of rectier load, maintain harmonic currents at a low level
to avoid overload of the transformer and high temperature
in the cables.
Illustration 3.53 DC-link Coils
NOTICE
Some of the harmonic currents might disturb communication equipment connected to the same transformer or
cause resonance with power factor correction batteries.
To ensure low harmonic currents, the frequency converter
is equipped with DC-link coils as standard. This normally
reduces the input current I
The voltage distortion on the mains supply voltage
depends on the size of the harmonic currents multiplied
by the mains impedance for the frequency in question. The
total voltage distortion THDv is calculated based on the
individual voltage harmonics using this formula:
2
THD
% = U
5
+ U
2
+ ... + U
7
(UN% of U)
RMS
by 40%.
2
N
3.4.5 Harmonics Emission Requirements
Equipment connected to the public supply network
OptionsDenition
IEC/EN 61000-3-2 Class A for 3-phase balanced
1
equipment (for professional equipment only up to
1 kW (1.3 hp) total power).
IEC/EN 61000-3-12 Equipment 16–75 A and profes-
2
sional equipment as from 1 kW (1.3 hp) up to 16 A
phase current.
Table 3.9 Connected Equipment
3.4.6 Harmonics Test Results (Emission)
Power sizes up to PK75 in T4 and P3K7 in T2 complies with
IEC/EN 61000-3-2 Class A. Power sizes from P1K1 and up to
P18K in T2 and up to P90K in T4 complies with IEC/EN
61000-3-12, Table 4.
Actual 0.25–11
kW (0.34–15 hp),
IP20, 200 V
(typical)
Limit for R
Actual 0.25–11
kW (0.34–15 hp),
200 V (typical)
Limit for R
Table 3.10 Harmonic Current 0.25–11 kW (0.34–15 hp), 200 V
Actual 0.37–22
kW (0.5–30 hp),
IP20, 380–480 V
(typical)
Limit for R
Actual 0.37–22
kW (0.5–30 hp),
380–480 V
(typical)
Limit for R
≥120
sce
≥120
sce
≥120
sce
≥120
sce
Individual harmonic current In/I1 (%)
I
5
32.616.68.06.0
40251510
Harmonic current distortion factor (%)
Individual harmonic current In/I1 (%)
I
5
36.720.87.66.4
40251510
Harmonic current distortion factor (%)
I
7
THDiPWHD
3941.4
4846
I
7
THDiPWHD
44.440.8
4846
I
11
I
11
I
13
I
13
33
Table 3.11 Harmonic Current 0.37–22 kW (0.5–30 hp), 380-480 V
It is the responsibility of the installer or user of the
equipment to ensure, by consultation with the distribution
network operator if necessary, that the equipment is
connected only to a supply with a short-circuit power S
sc
greater than or equal to specied above.
Other power sizes can be connected to the public supply
network by consultation with the distribution network
operator.
Compliance with various system level guidelines:
The harmonic current data in Table 3.10 to Table 3.17 are
given in accordance with IEC/EN 61000-3-12 with reference
to the Power Drive Systems product standard. They may be
used as the basis for calculation of the harmonic currents'
inuence on the power supply system and for the
documentation of compliance with relevant regional
guidelines: IEEE 519 -1992; G5/4.
3.4.7 Immunity Requirements
The immunity requirements for frequency converters
depend on the environment where they are installed. The
requirements for the industrial environment are higher
than the requirements for the home and
environment. All Danfoss frequency converters comply
with the requirements for the industrial environment and
therefore comply also with the lower requirements for
home and oce environment with a large safety margin.
oce
0.25–22 kW (0.34–30 hp)
33
1 Supply (SMPS)
2 Optocouplers, communication between AOC and BOC
3 Custom relays
a Control card terminals
Illustration 3.54 Galvanic Isolation
30–90 kW (40–120 hp)
Galvanic Isolation (PELV)
3.5
PELV oers protection through extra low voltage.
Protection against electric shock is ensured when the
electrical supply is of the PELV type and the installation is
made as described in local/national regulations on PELV
supplies.
All control terminals and relay terminals 01-03/04-06
comply with PELV (protective extra low voltage) (does not
apply to grounded delta leg above 440 V).
Galvanic (ensured) isolation is obtained by
fullling
requirements for higher isolation and by providing the
relevant creepage/clearance distances. These requirements
1 Supply (SMPS) including signal isolation of UDC, indicating
the intermediate current voltage
2 Gate drive that runs the IGBTs (trigger transformers/opto-
couplers)
3 Current transducers
4 Internal soft-charge, RFI, and temperature measurement
circuits
5 Custom relays
a Control card terminals
are described in the EN 61800-5-1 standard.
Illustration 3.55 Galvanic Isolation
The components that make up the electrical isolation, as
described, also comply with the requirements for higher
isolation and the relevant test as described in EN
61800-5-1.
The functional galvanic isolation (see Illustration 3.54) is for
the RS485 standard bus interface.
The PELV galvanic isolation can be shown in
Illustration 3.55.
To maintain PELV, all connections made to the control
terminals must be PELV, for example, thermistors must be
reinforced/double insulated.
At altitudes above 2000 m (6500 ft), contact Danfoss
regarding PELV.
1.21.01.4
30
10
20
100
60
40
50
1.81.62.0
2000
500
200
400
300
1000
600
t [s]
175ZA052.12
f
OUT
= 2 x f
M,N
f
OUT
= 0.2 x f
M,N
f
OUT
= 1 x f
M,N
(par. 1-23)
IMN(par. 1-24)
I
M
Product Overview
VLT® HVAC Basic Drive FC 101
3.6 Earth Leakage Current
WARNING
DISCHARGE TIME
Touching the electrical parts could be fatal - even after
33
the equipment has been disconnected from mains.
Also make sure that other voltage inputs have been
disconnected, such as load sharing (linkage of DC-link),
and the motor connection for kinetic back-up.
Before touching any electrical parts, wait at least the
amount of time indicated in Table 2.1.
Shorter time is allowed only if indicated on the
nameplate for the specic unit.
WARNING
LEAKAGE CURRENT HAZARD
Leakage currents exceed 3.5 mA. Failure to ground the
frequency converter properly can result in death or
serious injury.
Ensure the correct grounding of the equipment
•
by a certied electrical installer.
WARNING
RESIDUAL CURRENT DEVICE PROTECTION
This product can cause a DC current in the protective
conductor. Where a residual current device (RCD) is used
for protection in case of direct or indirect contact, only
an RCD of Type B is allowed on the supply side of this
product. Otherwise, apply another protective measure,
such as separation from the environment by double or
reinforced insulation, or isolation from the supply system
by a transformer. See also application note Protectionagainst Electrical Hazards.
Protective grounding of the frequency converter and the
use of RCDs must always follow national and local
regulations.
Motor-generated overvoltage
The voltage in the DC link is increased when the motor
acts as a generator. This occurs in following cases:
The load drives the motor (at constant output
•
frequency from the frequency converter), that is
the load generates energy.
During deceleration (ramp-down) if the inertia
•
moment is high, the friction is low, and the rampdown time is too short for the energy to be
dissipated as a loss in the frequency converter,
the motor, and the installation.
Incorrect slip compensation setting
•
(parameter 1-62 Slip Compensation) may cause
higher DC-link voltage.
The control unit may attempt to correct the ramp if
parameter 2-17 Over-voltage Control is enabled.
The frequency converter turns o to protect the transistors
and the DC-link capacitors when a certain voltage level is
reached.
Mains drop-out
During a mains dropout, the frequency converter keeps
running until the DC-link voltage drops below the
minimum stop level, which is typically 15% below the
frequency converter's lowest rated supply voltage. The
mains voltage before the drop-out and the motor load
determines how long it takes for the frequency converter
to coast.
3.7.1 Motor Thermal Protection (ETR)
Danfoss uses ETR to protect the motor from being
overheated. It is an electronic feature that simulates a
bimetal relay based on internal measurements. The characteristic is shown in Illustration 3.56.
3.7 Extreme Running Conditions
Short circuit (motor phase-phase)
Current measurement in each of the 3 motor phases or in
the DC-link, protects the frequency converter against short
circuits. A short circuit between 2 output phases causes an
overcurrent in the inverter. The inverter is turned o
individually when the short circuit current exceeds the
allowed value (alarm 16, Trip Lock).
For information about protecting the frequency converter
against a short circuit at the load sharing and brake
outputs, see chapter 8.3.1 Fuses and Circuit Breakers.
Switching on the output
Switching on the output between the motor and the
frequency converter is allowed. The frequency converter is
not damaged in any way by switching on the output.
However, fault messages may appear.
Illustration 3.56 Motor Thermal Protection Characteristic
1330
550
250
-20 °C
175HA183.11
4000
3000
R
(Ω)
nominal
nominal -5 °C nominal +5 °C
[°C]
R
OFF
ON
<800 Ω >2.9 kΩ
18
19
12 20 55
27 29 42 45 50 53 54
DIGI IN
DIGI IN
DIGI IN
DIGI IN
61 68 69
N
P
COMM. GND
+24V
0/4-20mA A OUT / DIG OUT0/4-20mA A OUT / DIG OUT
COM A IN
COM DIG IN
10V/20mA IN
10V/20mA IN
10V OUT
BUS TER.
OFFON
130BB898.10
Product OverviewDesign Guide
The X-axis shows the ratio between I
motor
and I
motor
nominal. The Y-axis shows the time in seconds before the
ETR cuts o and trips the frequency converter. The curves
show the characteristic nominal speed at twice the
nominal speed and at 0.2x the nominal speed.
It is clear that at lower speed the ETR cuts o 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.
3.7.2 Thermistor Inputs
The thermistor cutout value is >3 kΩ.
Integrate a thermistor (PTC sensor) in the motor for
winding protection.
Motor protection can be implemented using a range of
techniques:
PTC sensor in motor windings.
•
Mechanical thermal switch (Klixon type).
•
Electronic thermal relay (ETR).
•
Example with digital input and 10 V power supply
The frequency converter trips when the motor temperature
is too high.
Parameter set-up:
Set parameter 1-90 Motor Thermal Protection to [2]Thermistor Trip.
Set parameter 1-93 Thermistor Source to [6] Digital Input 29.
33
Illustration 3.57 Trip due to High Motor Temperature
Illustration 3.58 Digital Input/10 V Power Supply
Example with analog input and 10 V power supply
The frequency converter trips when the motor temperature
is too high.
Parameter set-up:
Set parameter 1-90 Motor Thermal Protection to [2]Thermistor Trip.
Set parameter 1-93 Thermistor Source to [1] Analog Input 53.
A type code denes a specicconguration of the VLT® HVAC Basic Drive FC 101 frequency converter. Use Illustration 4.1 to
create a type code string for the desired conguration.
Illustration 4.1 Type Code
DescriptionPositionPossible choice
Product group & FC series1–6FC 101
Power rating7–100.25–90 kW (0.34–120 hp) (PK25-P90K)
Number of phases113 phases (T)
T2: 200-240 V AC
Mains voltage11–12
Enclosure13–15
RFI lter16–17
Brake18X: No brake chopper included
Display19
Coating PCB20
Mains option21X: No mains option
Adaptation22X: No adaptation
Adaptation23X: No adaptation
Software release24–27SXXXX: Latest release - standard software
1Panel cut out. Panel thickness 1–3 mm (0.04–0.12 in)
2Panel
3Gasket
4LCP
Illustration 4.3 Place LCP on Panel (Front-mounted)
130BB777.10
130BB778.10
130BB902.12
A
B
C
OK
Alarm
Warn.
On
B
a
c
k
Hand
On
Reset
Auto
On
Status
Quick
Menu
Main
Menu
Selection and OrderingDesign Guide
Step 3
Place bracket on back of the LCP, then slide down.
Tighten screws and connect cable female side to LCP.
Illustration 4.4 Place Bracket on LCP
Step 4
Connect cable to frequency converter.
4.2.3 IP21/NEMA Type 1 Enclosure Kit
IP21/NEMA Type 1 is an optional enclosure element
available for IP20 units.
If the enclosure kit is used, an IP20 unit is upgraded to
comply with enclosure IP21/NEMA Type 1.
44
Illustration 4.5 Connect Cable
NOTICE
Illustration 4.6 H1–H5 (See Data in Table 4.4)
Use the provided thread-cutting screws to fasten the
connector to the frequency converter. The tightening
torque is 1.3 Nm (11.5 in-lb).
With external lters listed in Table 4.11, the maximum shielded cable length of 50 m (164 ft) according to EN/IEC 61800-3 C2
(EN 55011 A1), or 20 m (65.6 ft) according to EN/IEC 61800-3 C1(EN 55011 B) can be achieved.
All cabling must comply with national and local regulations on cable cross-sections and ambient temperature. Copper
conductors are required. 75 °C (167 °F) is recommended.
The frequency converter is designed to operate all
standard 3-phase asynchronous motors. For maximum
cross-section on cables, see chapter 8.4 General TechnicalData.
Use a shielded/armored motor cable to comply
•
with EMC emission
this cable to both the decoupling plate and the
motor.
Keep the motor cable as short as possible to
•
reduce the noise level and leakage currents.
For further details on mounting the decoupling
•
plate, see FC 101 Decoupling Plate Mounting
Instruction.
Make sure that the mains cables for enclosure size H9 is
connected correctly, for details, see chapter Connecting to
Mains and Motor in the VLT® HVAC Basic Drive FC 101 Quick
Guide. Use the tightening torques described in
chapter 5.1.1 Electrical Installation in General.
Relays and terminals on enclosure size H10
55
Illustration 5.5 Enclosure Size H8
IP20, 380–480 V, 90 kW (125 hp)
IP20, 200–240 V, 37–45 kW (50–60 hp)
IP20, 525–600 V, 75–90 kW (100–125 hp)
Mains and motor connection for enclosure size H9
Illustration 5.7 Enclosure Size H10
IP20, 600 V, 11–15 kW (15–20 hp)
Illustration 5.6 Motor Connection for Enclosure Size H9
Refer to VLT® HVAC Basic Drive FC 101 Quick Guide and
make sure that the terminal cover is removed correctly.
Illustration 5.17 shows all the frequency converter control
terminals. Applying start (terminal 18), connection between
terminals 12-27, and an analog reference (terminal 53 or
54, and 55) make the frequency converter run.
The digital input mode of terminal 18, 19, and 27 is set in
55
parameter 5-00 Digital Input Mode (PNP is default value).
Digital input 29 mode is set in parameter 5-03 Digital Input29 Mode (PNP is default value).
The frequency converter can be programmed from the LCP
or from a PC via the RS485 COM port by installing the MCT
10 Set-up Software. Refer to chapter 1.5 AdditionalResources for more details about the software.
6.2 Local Control Panel (LCP)
The LCP is divided into 4 functional sections.
A. Display
B. Menu key
C. Navigation keys and indicator lights
D. Operation keys and indicator lights
1 Parameter number and name.
2 Parameter value.
Set-up number shows the active set-up and the edit set-up.
If the same set-up acts as both active and edit set-up, only
that set-up number is shown (factory setting). When active
3
and edit set-up dier, both numbers are shown in the
display (set-up 12). The number ashing indicates the edit
set-up.
Motor direction is shown to the bottom left of the display –
4
indicated by a small arrow pointing either clockwise or
counterclockwise.
The triangle indicates if the LCP is in Status, Quick Menu, or
5
Main Menu.
Table 6.1 Legend to Illustration 6.1, Part I
B. Menu key
Press [Menu] to select among Status, Quick Menu, or Main
Menu.
C. Navigation keys and indicator lights
6 Com. LED: Flashes during bus communication.
7 Green LED/On: Control section is working correctly.
8 Yellow LED/Warn.: Indicates a warning.
9 Flashing Red LED/Alarm: Indicates an alarm.
[Back]: For moving to the previous step or layer in the
10
navigation structure.
[▲] [▼] [►]: For navigating among parameter groups and
11
parameters, and within parameters. They can also be used
for setting local reference.
[OK]: For selecting a parameter and for accepting changes
12
to parameter settings.
6
6
Table 6.2 Legend to Illustration 6.1, Part II
Illustration 6.1 Local Control Panel (LCP)
A. Display
The LCD display is illuminated with 2 alphanumeric lines.
All data is shown on the LCP.
Illustration 6.1 describes the information that can be read
from the display.
[Hand On]: Starts the motor and enables control of the
frequency converter via the LCP.
NOTICE
[2] Coast inverse is the default option for
13
parameter 5-12 Terminal 27 Digital Input. If there is
no 24 V supply to terminal 27, [Hand On] does not
start the motor. Connect terminal 12 to terminal 27.
[O/Reset]: Stops the motor (O). If in alarm mode, the
14
alarm is reset.
[Auto On]: The frequency converter is controlled either via
15
control terminals or serial communication.
Table 6.3 Legend to Illustration 6.1, Part III
FC
+24 V (OUT)
DIG IN
DIG IN
DIG IN
DIG IN
COM DIG IN
A OUT / D OUT
A OUT / D OUT
18
19
27
29
42
55
50
53
54
20
12
01
02
03
04
05
06
R2
R1
+
0–10 V
Start
+10 V (OUT)
A IN
A IN
COM IN/OUT
130BB674.11
45
Reference
130BB629.10
Press OK to start Wizard
Push Back to skip it
Setup 1
Programming
VLT® HVAC Basic Drive FC 101
6
6.3 Menus
6.3.1 Status Menu
In the Status menu, the selection options are:
Motor frequency [Hz], parameter 16-13 Frequency.
•
Motor current [A], parameter 16-14 Motor current.
•
Motor speed reference in percentage [%],
•
parameter 16-02 Reference [%].
Feedback, parameter 16-52 Feedback[Unit].
•
Motor power, parameter 16-10 Power [kW] for kW,
•
parameter 16-11 Power [hp] for hp. If
parameter 0-03 Regional Settings is set to [1] North
America, motor power is shown in hp instead of
kW.
Custom readout, parameter 16-09 Custom Readout.
•
Motor Speed [RPM], parameter 16-17 Speed [RPM].
•
6.3.2 Quick Menu
Use the Quick Menu to program the most common
functions. The Quick Menu consists of:
Wizard for open loop applications. See
•
Illustration 6.4 for details.
Wizard for closed loop applications. See
•
Illustration 6.5 for details.
Motor set-up. See Table 6.6 for details.
•
Changes made.
•
The built-in wizard menu guides the installer through the
set-up of the frequency converter in a clear and structured
manner for open-loop applications, closed-loop
applications, and quick motor settings.
The wizard is shown after power-up until any parameter
has been changed. The wizard can always be accessed
again through the quick menu. Press [OK] to start the
wizard. Press [Back] to return to the status view.
0.0–400.0 Hz0.0 HzEnter the minimum limit for low speed.
0.0–400.0 Hz100.0 HzEnter the maximum limit for high speed.
0.0–400.0 Hz100.0 HzEnter the maximum output frequency value. If
[0] O
[1] On
0.05–1.00 s0.10 s
VLT® HVAC Basic Drive FC 101
parameter 4-19 Max Output Frequency is set lower than
parameter 4-14 Motor Speed High Limit [Hz],
parameter 4-14 Motor Speed High Limit [Hz] is set equal to
parameter 4-19 Max Output Frequency automatically.
[0] O
–
–
6
Table 6.6 Motor Set-up Wizard Settings
Changes made
The changes made function lists all parameters changed
from default settings.
The list shows only parameters that have been
•
changed in the current edit set-up.
Parameters that have been reset to default values
•
are not listed.
The message Empty indicates that no parameters
•
have been changed.
Changing parameter settings
1.To enter the Quick Menu, press the [Menu] key
until the indicator in the display is placed above
Quick Menu.
2.
Press [▲] [▼] to select the wizard, closed-loop setup, motor set-up, or changes made.
3.Press [OK].
4.
Press [▲] [▼] to browse through the parameters in
the Quick Menu.
5.Press [OK] to select a parameter.
6.
Press [▲] [▼] to change the value of a parameter
setting.
7.Press [OK] to accept the change.
8.Press either [Back] twice to enter Status, or press
[Menu] once to enter the Main Menu.
The main menu accesses all parameters
1.Press the [Menu] key until the indicator in the
display is placed above Main Menu.
2.
Press [▲] [▼] to browse through the parameter
groups.
3.Press [OK] to select a parameter group.
4.
Press [▲] [▼] to browse through the parameters in
the specic group.
5.Press [OK] to select the parameter.
6.
Press [▲] [▼] to set/change the parameter value.
7.Press [OK] to accept the change.
6.3.3 Main Menu
Press [Menu] to access the main menu and program all
parameters. The main menu parameters can be accessed
readily unless a password has been created via
parameter 0-60 Main Menu Password.
For most applications, it is not necessary to access the
main menu parameters. The quick menu provides the
simplest and quickest access to the typically required
parameters.
Quick Transfer of Parameter Settings
6.4
between Multiple Frequency Converters
When the set-up of a frequency converter is completed,
store the data in the LCP or on a PC via MCT 10 Set-up
Software.
Data transfer from the frequency converter to the LCP
1.Go to parameter 0-50 LCP Copy.
2.Press [OK].
3.Select [1] All to LCP.
4.Press [OK].
Connect the LCP to another frequency converter and copy
the parameter settings to this frequency converter as well.
Data transfer from the LCP to the frequency converter
1.Go to parameter 0-50 LCP Copy.
2.Press [OK].
3.Select [2] All from LCP.
4.Press [OK].
6.5 Readout and Programming of Indexed
Parameters
Select the parameter, press [OK], and press [
through the indexed values. To change the parameter
value, select the indexed value and press [OK]. Change the
value by pressing [▲]/[▼]. Press [OK] to accept the new
setting. Press [Cancel] to abort. Press [Back] to leave the
parameter.
]/[▼] to scroll
▲
6.6 Initialization to Default Settings
There are 2 ways to initialize the frequency converter to
the default settings.
Recommended initialization
1.Select parameter 14-22 Operation Mode.
2.Press [OK].
3.Select [2] Initialisation and Press [OK].
4.Power
5.Reconnect the mains supply. The frequency
o the frequency converter and wait until
the display turns o.
converter is now reset, except for the following
parameters:
Parameter 1-06 Clockwise Direction
•
Parameter 8-30 Protocol
•
Parameter 8-31 Address
•
Parameter 8-32 Baud Rate
•
Parameter 8-33 Parity / Stop Bits
•
Parameter 8-35 Minimum Response Delay
•
Parameter 8-36 Maximum Response Delay
•
Parameter 8-37 Maximum Inter-char delay
•
Parameter 8-70 BACnet Device Instance
•
Parameter 8-72 MS/TP Max Masters
•
Parameter 8-73 MS/TP Max Info Frames
•
Parameter 8-74 "I am" Service
•
Parameter 8-75 Intialisation Password
•
Parameter 15-00 Operating hours to
•
parameter 15-05 Over Volt's
Parameter 15-03 Power Up's
•
Parameter 15-04 Over Temp's
•
Parameter 15-05 Over Volt's
•
Parameter 15-30 Alarm Log: Error Code
•
Parameter group 15-4* Drive identication
•
Parameter 18-10 FireMode Log:Event
•
2-nger initialization
The other way to initialize the frequency converter to
default settings is through 2-nger initialization:
1.Power o the frequency converter.
2.Press [OK] and [Menu].
3.Power up the frequency converter while still
pressing the keys for 10 s.
4.The frequency converter is now reset, except for
the following parameters:
Parameter 1-06 Clockwise Direction
•
Parameter 15-00 Operating hours
•
Parameter 15-03 Power Up's
•
Parameter 15-04 Over Temp's
•
Parameter 15-05 Over Volt's
•
Parameter group 15-4* Drive identication
•
Parameter 18-10 FireMode Log:Event
•
Initialization of parameters is conrmed by alarm 80, Drive
initialised in the display after the power cycle.
RS485 is a 2-wire bus interface compatible with multi-drop
network topology, that is, nodes can be connected as a
bus, or via drop cables from a common trunk line. A total
of 32 nodes can be connected to 1 network segment.
Repeaters divide network segments.
NOTICE
Each repeater functions as a node within the segment in
which it is installed. Each node connected within a given
network must have a unique node address across all
77
segments.
Terminate each segment at both ends, using either the
termination switch (S801) of the frequency converters or a
biased termination resistor network. Always use shielded
twisted pair (STP) cable for bus cabling, and follow good
common installation practice.
Low-impedance ground connection of the shield at every
node is important. Connect a large surface of the shield to
ground, for example with a cable clamp or a conductive
cable gland. Apply potential-equalizing cables to maintain
the same ground potential throughout the network particularly in installations with long cables.
To prevent impedance mismatch, always use the same
type of cable throughout the entire network. When
connecting a motor to the frequency converter, always use
shielded motor cable.
7.1.2 Network Connection
Connect the frequency converter to the RS485 network as
follows (see also Illustration 7.1):
1.Connect signal wires to terminal 68 (P+) and
terminal 69 (N-) on the main control board of the
frequency converter.
2.Connect the cable shield to the cable clamps.
NOTICE
To reduce noise between conductors, use shielded,
twisted-pair cables.
Illustration 7.1 Network Connection
7.1.3 Frequency Converter Hardware Set-up
Use the terminator dip switch on the main control board
of the frequency converter to terminate the RS485 bus.
The address range depends on the
protocol selected in
parameter 8-30 Protocol.
Set the baud rate.
NOTICE
The default baud rate depends on the
protocol selected in
parameter 8-30 Protocol.
Set the parity and number of stop bits.
NOTICE
The default selection depends on the
protocol selected in
parameter 8-30 Protocol.
7.1.5 EMC Precautions
NOTICE
Observe relevant national and local regulations
regarding protective ground connection. Failure to
ground the cables properly can result in communication
degradation and equipment damage. To avoid coupling
of high frequency noise between the cables, keep the
RS485 communication cable away from motor and brake
resistor cables. Normally, a distance of 200 mm (8 in) is
sucient. Maintain the greatest possible distance
between the cables, especially where cables run in
parallel over long distances. When crossing is
unavoidable, the RS485 cable must cross motor and
brake resistor cables at an angle of 90°.
77
Parameter 8-35 Min
imum Response
Delay
Parameter 8-36 Ma
ximum Response
Delay
Parameter 8-37 Ma
ximum Inter-char
delay
Specify a minimum delay time between
receiving a request and transmitting a
response. This function is for overcoming
modem turnaround delays.
Specify a maximum delay time between
transmitting a request and receiving a
response.
If transmission is interrupted, specify a
maximum delay time between 2 received
bytes to ensure timeout.
NOTICE
The default selection depends on the
protocol selected in
parameter 8-30 Protocol.
1Fieldbus cable
Table 7.2 Modbus Communication Parameter Settings
2Minimum 200 mm (8 in) distance
Illustration 7.3 Minimum Distance between Communication
The FC protocol, also referred to as FC bus or standard bus,
is the Danfoss standard
technique according to the master-slave principle for
communications via a serial bus.
One master and a maximum of 126 slaves can be
connected to the bus. The master selects the individual
slaves via an address character in the telegram. A slave
itself can never transmit without rst being requested to
do so, and direct message transfer between the individual
slaves is not possible. Communications occur in the halfduplex mode.
The master function cannot be transferred to another node
(single-master system).
eldbus. It denes an access
Parameter Settings to Enable the
7.3
Protocol
To enable the FC protocol for the frequency converter, set
the following parameters.
ParameterSetting
Parameter 8-30 ProtocolFC
Parameter 8-31 Address1–126
Parameter 8-32 Baud Rate2400–115200
Parameter 8-33 Parity / Stop Bits
Table 7.3 Parameters to Enable the Protocol
Even parity, 1 stop bit
(default)
7.4 FC Protocol Message Framing Structure
7.4.1 Content of a Character (Byte)
77
The physical layer is RS485, thus utilizing the RS485 port
built into the frequency converter. The FC protocol
supports
dierent telegram formats:
A short format of 8 bytes for process data.
•
A long format of 16 bytes that also includes a
•
parameter channel.
A format used for texts.
•
Each character transferred begins with a start bit. Then 8
data bits are transferred, corresponding to a byte. Each
character is secured via a parity bit. This bit is set at 1
when it reaches parity. Parity is when there is an equal
number of 1s in the 8 data bits and the parity bit in total.
A stop bit completes a character, thus consisting of 11 bits
in all.
7.2.2 FC with Modbus RTU
The FC protocol provides access to the control word and
bus reference of the frequency converter.
The control word allows the Modbus master to control
several important functions of the frequency converter:
Start.
•
Stop of the frequency converter in various ways:
•
-Coast stop.
-Quick stop.
-DC brake stop.
-Normal (ramp) stop.
Reset after a fault trip.
•
Run at various preset speeds.
•
Run in reverse.
•
Change of the active set-up.
•
Control of the 2 relays built into the frequency
•
converter.
The bus reference is commonly used for speed control. It is
also possible to access the parameters, read their values,
and where possible, write values to them. Accessing the
parameters oers a range of control options, including
controlling the setpoint of the frequency converter when
its internal PI controller is used.
Illustration 7.4 Content of a Character
7.4.2 Telegram Structure
Each telegram has the following structure:
Start character (STX) = 02 hex.
•
A byte denoting the telegram length (LGE).
•
A byte denoting the frequency converter address
•
(ADR).
Several data bytes (variable, depending on the type of
telegram) follow.
The telegram length is the number of data bytes plus the
address byte ADR and the data control byte BCC.
4 data bytesLGE = 4+1+1 = 6 bytes
12 data bytesLGE = 12+1+1 = 14 bytes
Telegrams containing texts
Table 7.4 Length of Telegrams
1) The 10 represents the
(depending on the length of the text).
xed characters, while the n is variable
101)+n bytes
7.4.4 Frequency Converter Address (ADR)
Address format 1–126
Bit 7 = 1 (address format 1–126 active).
•
Bit 0–6 = frequency converter address 1–126.
•
Bit 0–6 = 0 broadcast.
•
The slave returns the address byte unchanged to the
master in the response telegram.
Parameter block
The parameter block is used to transfer parameters
between master and slave. The data block is made up of
12 bytes (6 words) and also contains the process block.
Illustration 7.7 Parameter Block
Text block
The text block is used to read or write texts via the data
block.
Illustration 7.8 Text Block
7.4.7 The PKE Field
The PKE eld contains 2 subelds:
Parameter command and response (AK)
•
Parameter number (PNU)
•
77
7.4.5 Data Control Byte (BCC)
The checksum is calculated as an XOR-function. Before the
rst byte in the telegram is received, the calculated
checksum is 0.
7.4.6 The Data Field
The structure of data blocks depends on the type of
telegram. There are 3 telegram types, and the type applies
for both control telegrams (master⇒slave) and response
telegrams (slave⇒master).
The 3 types of telegram are:
Process block (PCD)
The PCD is made up of a data block of 4 bytes (2 words)
and contains:
Control word and reference value (from master to
•
slave).
Status word and present output frequency (from
•
slave to master).
Illustration 7.9 PKE Field
Bits 12–15 transfer parameter commands from master to
slave and return processed slave responses to the master.
If the command cannot be performed, the slave sends
0111 Command cannot be performed response and issues
the following fault reports in Table 7.7.
Bit numbers 0–11 transfer parameter numbers. The
function of the relevant parameter is dened in the
parameter description in chapter 6 Programming.
7.4.9 Index (IND)
The index is used with the parameter number to read/
write access parameters with an index, for example,
parameter 15-30 Alarm Log: Error Code. The index consists
of 2 bytes: a low byte and a high byte.
Only the low byte is used as an index.
7.4.10 Parameter Value (PWE)
The parameter value block consists of 2 words (4 bytes),
and the value depends on the dened command (AK). The
master prompts for a parameter value when the PWE block
contains no value. To change a parameter value (write),
write the new value in the PWE block and send from the
master to the slave.
When a slave responds to a parameter request (read
command), the present parameter value in the PWE block
is transferred and returned to the master. If a parameter
contains several data options, for example
parameter 0-01 Language, select the data value by entering
the value in the PWE block. Serial communication is only
capable of reading parameters containing data type 9 (text
string).
Parameter 15-40 FC Type to parameter 15-53 Power Card
Serial Number contain data type 9.
For example, read the unit size and mains voltage range in
parameter 15-40 FC Type. When a text string is transferred
(read), the length of the telegram is variable, and the texts
are of dierent lengths. The telegram length is dened in
the 2nd byte of the telegram (LGE). When using text
transfer, the index character indicates whether it is a read
or a write command.
To read a text via the PWE block, set the parameter
command (AK) to F hex. The index character high-byte
must be 4.
7.4.11 Data Types Supported by the
Frequency Converter
Unsigned means that there is no operational sign in the
telegram.
Data typesDescription
3Integer 16
4Integer 32
5Unsigned 8
6Unsigned 16
7Unsigned 32
9Text string
Table 7.8 Data Types
7.4.12 Conversion
The programming guide contains the descriptions of
attributes of each parameter. Parameter values are
transferred as whole numbers only. Conversion factors are
used to transfer decimals.
Conversion indexConversion factor
743600
2100
110
01
-10.1
-20.01
-30.001
-40.0001
-50.00001
Table 7.9 Conversion
7.4.13 Process Words (PCD)
The block of process words is divided into 2 blocks of 16
bits, which always occur in the dened sequence.
PCD 1PCD 2
Control telegram (master⇒slave control
word)
Control telegram (slave⇒master) status
word
Table 7.10 Process Words (PCD)
Examples
7.5
Reference value
Present output
frequency
7.5.1 Writing a Parameter Value
Change parameter 4-14 Motor Speed High Limit [Hz] to 100
Hz.
Write the data in EEPROM.
PKE = E19E hex - Write single word in
parameter 4-14 Motor Speed High Limit [Hz]:
IND = 0000 hex.
•
PWEHIGH = 0000 hex.
•
PWELOW = 03E8 hex.
•
Data value 1000, corresponding to 100 Hz, see
chapter 7.4.12 Conversion.
77
Parameter 4-12 Motor Speed Low Limit [Hz] has a conversion
factor of 0.1. To preset the minimum frequency to 10 Hz,
transfer the value 100. A conversion factor of 0.1 means
that the value transferred is multiplied by 0.1. The value
100 is thus perceived as 10.0.
Parameter 4-14 Motor Speed High Limit [Hz] is a single
word, and the parameter command for write in EEPROM
is E. Parameter 4-14 Motor Speed High Limit [Hz] is 19E in
hexadecimal.
The response from the slave to the master is shown in
Illustration 7.11.
Illustration 7.11 Response from Master
VLT® HVAC Basic Drive FC 101
Modbus RTU Overview
7.6
7.6.1 Introduction
Danfoss assumes that the installed controller supports the
interfaces in this document, and strictly observes all
requirements and limitations stipulated in the controller
and frequency converter.
The built-in Modbus RTU (remote terminal unit) is
designed to communicate with any controller that
supports the interfaces dened in this document. It is
assumed that the user has full knowledge of the
capabilities and limitations of the controller.
7.6.2 Overview
7.5.2 Reading a Parameter Value
77
Read the value in parameter 3-41 Ramp 1 Ramp Up Time.
PKE = 1155 hex - Read parameter value in
parameter 3-41 Ramp 1 Ramp Up Time:
IND = 0000 hex.
•
PWE
•
PWE
•
Illustration 7.12 Telegram
If the value in parameter 3-41 Ramp 1 Ramp Up Time is
10 s, the response from the slave to the master is shown in
Illustration 7.13.
Illustration 7.13 Response
3E8 hex corresponds to 1000 decimal. The conversion
index for parameter 3-41 Ramp 1 Ramp Up Time is -2, that
is, 0.01.
Parameter 3-41 Ramp 1 Ramp Up Time is of the type
Unsigned 32.
= 0000 hex.
HIGH
= 0000 hex.
LOW
Regardless of the type of physical communication
networks, this section describes the process that a
controller uses to request access to another device. This
process includes how the Modbus RTU responds to
requests from another device, and how errors are detected
and reported. It also establishes a common format for the
layout and contents of telegram elds.
During communications over a Modbus RTU network, the
protocol:
Determines how each controller learns its device
•
address.
Recognizes a telegram addressed to it.
•
Determines which actions to take.
•
Extracts any data or other information contained
•
in the telegram.
If a reply is required, the controller constructs the reply
telegram and sends it.
Controllers communicate using a master/slave technique in
which only the master can initiate transactions (called
queries). Slaves respond by supplying the requested data
to the master, or by acting as requested in the query.
The master can address individual slaves, or initiate a
broadcast telegram to all slaves. Slaves return a response
to queries that are addressed to them individually. No
responses are returned to broadcast queries from the
master.
The Modbus RTU protocol establishes the format for the
master query by providing the following information:
The device (or broadcast) address.
•
A function code dening the requested action.
•
Any data to be sent.
•
An error-checking eld.
•
The response telegram of the slave device is also
constructed using Modbus protocol. It contains eldsconrming the action taken, any data to be returned, and
an error-checking eld. If an error occurs in receipt of the
telegram, or if the slave is unable to perform the requested
action, the slave constructs and sends an error message.
Alternatively, a timeout occurs.
7.6.3 Frequency Converter with Modbus
RTU
The frequency converter communicates in Modbus RTU
format over the built-in RS485 interface. Modbus RTU
provides access to the control word and bus reference of
the frequency converter.
The control word allows the Modbus master to control
several important functions of the frequency converter:
Start.
•
Various stops:
•
-Coast stop.
-Quick stop.
-DC brake stop.
-Normal (ramp) stop.
Reset after a fault trip.
•
Run at various preset speeds.
•
Run in reverse.
•
Change the active set-up.
•
Control built-in relay of the frequency converter.
•
The bus reference is commonly used for speed control. It is
also possible to access the parameters, read their values,
and, where possible, write values to them. Accessing the
parameters
controlling the setpoint of the frequency converter when
its internal PI controller is used.
7.7
To enable Modbus RTU on the frequency converter, set the
following parameters:
Parameter 8-30 ProtocolModbus RTU
Parameter 8-31 Address1–247
Parameter 8-32 Baud Rate2400–115200
Parameter 8-33 Parity / Stop Bits
Table 7.11 Network Conguration
oers a range of control options, including
Network Conguration
ParameterSetting
Even parity, 1 stop bit
(default)
Modbus RTU Message Framing
7.8
Structure
7.8.1 Introduction
The controllers are set up to communicate on the Modbus
network using RTU (remote terminal unit) mode, with each
byte in a telegram containing 2 4-bit hexadecimal
characters. The format for each byte is shown in Table 7.12.
Start
bit
Table 7.12 Format for Each Byte
Coding system8-bit binary, hexadecimal 0–9, A–F.
Bits per byte
Error check eldCyclic redundancy check (CRC).
Table 7.13 Byte Details
Data byteStop/
parity
2 hexadecimal characters contained in each
8-bit eld of the telegram.
1 start bit.
•
8 data bits, least signicant bit sent rst.
•
1 bit for even/odd parity; no bit for no
•
parity.
1 stop bit if parity is used; 2 bits if no
•
parity.
Stop
7.8.2 Modbus RTU Telegram Structure
The transmitting device places a Modbus RTU telegram
into a frame with a known beginning and ending point.
This allows receiving devices to begin at the start of the
telegram, read the address portion, determine which
device is addressed (or all devices, if the telegram is
broadcast), and to recognize when the telegram is
completed. Partial telegrams are detected and errors set as
a result. Characters for transmission must be in
hexadecimal 00–FF format in each eld. The frequency
converter continuously monitors the network bus, also
during silent intervals. When the rsteld (the address
eld) is received, each frequency converter or device
decodes it to determine which device is being addressed.
Modbus RTU telegrams addressed to 0 are broadcast
telegrams. No response is permitted for broadcast
telegrams. A typical telegram frame is shown in Table 7.14.
Telegrams start with a silent period of at least 3.5 character
intervals. The silent period is implemented as a multiple of
character intervals at the selected network baud rate
(shown as Start T1-T2-T3-T4). The rsteld to be
transmitted is the device address. Following the last
transmitted character, a similar period of at least 3.5
character intervals marks the end of the telegram. A new
telegram can begin after this period.
Transmit the entire telegram frame as a continuous stream.
If a silent period of more than 1.5 character intervals
occurs before completion of the frame, the receiving
device
ushes the incomplete telegram and assumes that
the next byte is the address eld of a new telegram.
Similarly, if a new telegram begins before 3.5 character
intervals after a previous telegram, the receiving device
77
considers it a continuation of the previous telegram. This
behavior causes a timeout (no response from the slave),
since the value in the nal CRC eld is not valid for the
combined telegrams.
7.8.4 Address Field
The address eld of a telegram frame contains 8 bits. Valid
slave device addresses are in the range of 0–247 decimal.
The individual slave devices are assigned addresses in the
range of 1–247. 0 is reserved for broadcast mode, which all
slaves recognize. A master addresses a slave by placing the
slave address in the address eld of the telegram. When
the slave sends its response, it places its own address in
this address eld to let the master know which slave is
responding.
7.8.6 Data Field
The data eld is constructed using sets of 2 hexadecimal
digits, in the range of 00–FF hexadecimal. These digits are
made up of 1 RTU character. The data eld of telegrams
sent from a master to a slave device contains additional
information which the slave must use to perform
accordingly.
The information can include items such as:
Coil or register addresses.
•
The quantity of items to be handled.
•
The count of actual data bytes in the
•
eld.
7.8.7 CRC Check Field
Telegrams include an error-checking eld, operating based
on a cyclic redundancy check (CRC) method. The CRC eld
checks the contents of the entire telegram. It is applied
regardless of any parity check method used for the
individual characters of the telegram. The transmitting
device calculates the CRC value and appends the CRC as
the last eld in the telegram. The receiving device
recalculates a CRC during receipt of the telegram and
compares the calculated value to the actual value received
in the CRC eld. 2 unequal values result in bus timeout.
The error-checking eld contains a 16-bit binary value
implemented as 2 8-bit bytes. After the implementation,
the low-order byte of the eld is appended rst, followed
by the high-order byte. The CRC high-order byte is the last
byte sent in the telegram.
7.8.8 Coil Register Addressing
7.8.5 Function Field
The function eld of a telegram frame contains 8 bits. Valid
codes are in the range of 1–FF. Function elds are used to
send telegrams between master and slave. When a
telegram is sent from a master to a slave device, the
function code eld tells the slave what kind of action to
perform. When the slave responds to the master, it uses
the function code eld to indicate either a normal (errorfree) response, or that some kind of error occurred (called
an exception response).
For a normal response, the slave simply echoes the original
function code. For an exception response, the slave returns
a code that is equivalent to the original function code with
its most
places a unique code into the data eld of the response
telegram. This code tells the master what kind of error
occurred, or the reason for the exception. Also refer to
chapter 7.8.11 Function Codes Supported by Modbus RTU and
chapter 7.8.12 Modbus Exception Codes.
signicant bit set to logic 1. In addition, the slave
In Modbus, all data is organized in coils and holding
registers. Coils hold a single bit, whereas holding registers
hold a 2 byte word (that is 16 bits). All data addresses in
Modbus telegrams are referenced to 0. The 1st occurrence
of a data item is addressed as item number 0. For example:
The coil known as coil 1 in a programmable controller is
addressed as coil 0000 in the data address eld of a
Modbus telegram. Coil 127 decimal is addressed as coil
007Ehex (126 decimal).
Holding register 40001 is addressed as register 0000 in the
data address eld of the telegram. The function code eld
already species a holding register operation. Therefore,
the 4XXXX reference is implicit. Holding register 40108 is
addressed as register 006Bhex (107 decimal).
RS485 Installation and Set-...Design Guide
Coil
number
1–16
17–32
33–48
49–64
66–65536 Reserved.–
Table 7.15 Coil Register
Coil01
01Preset reference lsb
02Preset reference msb
03DC brakeNo DC brake
04Coast stopNo coast stop
05Quick stopNo quick stop
06Freeze frequencyNo freeze frequency
07Ramp stopStart
08No resetReset
09No jogJog
10Ramp 1Ramp 2
11Data not validData valid
12Relay 1 oRelay 1 on
13Relay 2 oRelay 2 on
14Set up lsb
15–
16No reversingReversing
Frequency converter control word
(see Table 7.16).
Frequency converter speed or
setpoint reference range 0x0–
0xFFFF (-200% ... ~200%).
Frequency converter status word
(see Table 7.17).
Open-loop mode: Frequency
converter output frequency.
Closed-loop mode: Frequency
converter feedback signal.
Parameter write control (master to
slave).
0 = Parameter changes are written
to the RAM of the frequency
65
converter.
1 = Parameter changes are written
to the RAM and EEPROM of the
frequency converter.
Description
Signal
direction
Master to slave
Master to slave
Slave to master
Slave to master
Master to slave
Coil01
33Control not readyControl ready
Frequency converter not
34
ready
35Coast stopSafety closed
36No alarmAlarm
37Not usedNot used
38Not usedNot used
39Not usedNot used
40No warningWarning
41Not at referenceAt reference
42Hand modeAuto mode
43Out of frequency rangeIn frequency range
44StoppedRunning
45Not usedNot used
46No voltage warningVoltage exceeds
47Not in current limitCurrent limit
48Thermal level is OKThermal level exceeds
Table 7.17 Frequency Converter Status Word (FC Prole)
Frequency converter ready
77
Table 7.16 Frequency Converter Control Word (FC Prole)
Reserved for legacy frequency converters VLT® 5000 and
VLT® 2800.
Reserved for legacy frequency converters VLT® 5000 and
VLT® 2800.
Reserved for legacy frequency converters VLT® 5000 and
VLT® 2800.
TCP only. Reserved for Modbus TCP
(parameter 12-28 Store Data Values and
parameter 12-29 Store Always - stored in, for example,
EEPROM).
Fault code received from parameter database, refer to
WHAT 38295 for details.
Address of register with which last error occurred, refer
to WHAT 38296 for details.
Subindex of parameter to be accessed. Refer to WHAT
38297 for details.
Parameter 0-03 Regional
Settings
Dependent on
parameter
access
Dependent on
parameter
access
Parameter 0-01 Language (Modbus register = 10
parameter number)
20 bytes space reserved for parameter in Modbus map.
Parameter 0-03 Regional Settings
20 bytes space reserved for parameter in Modbus map.
Table 7.18 Address/Registers
1) Value written in the Modbus RTU telegram must be 1 or less than the register number. For example, Read Modbus Register 1 by writing value 0
in the telegram.
7.8.9 Access via PCD write/read
The PCD read list is data sent from the frequency converter
to the controller like status word, main actual value, and
The advantage of using the PCD write/read conguration is
that the controller can write or read more data in 1
application dependent data like running hours, motor
current, and alarm word.
telegram. Up to 63 registers can be read or written to via
the function code read holding register or write multiple
registers in 1 telegram. The structure is also exible so that
only 2 registers can be written to and 10 registers can be
NOTICE
The status word and main actual value is always sent in
the list from the frequency converter to the controller.
read from the controller.
The PCD write list is data sent from the controller to the
frequency converter, the data includes control word,
reference, and application dependent data like minimum
reference and ramp times, and so on.
NOTICE
The control word and reference is always sent in the list
from the controller to the frequency converter.
The PCD write list is set up in parameter 8-42 PCD WriteConguration.
Modbus RTU supports use of the following function codes
in the function eld of a telegram.
FunctionFunction code (hex)
Read coils1
Read holding registers3
Write single coil5
Write single register6
Write multiple coilsF
Write multiple registers10
Get comm. event counterB
Report slave ID11
Read write multiple registers17
Illustration 7.14 Accessing via PCD write/read
NOTICE
The boxes marked in grey are not changeable, they are
default values.
NOTICE
The 32 bit parameters must be mapped inside the 32 bit
boundaries (PCD2 & PCD3 or PCD4 & PCD5, and so on.),
where the parameter number is mapped twice to
Some parameters in the frequency converter are array
parameters, for example parameter 3-10 Preset Reference.
Since the Modbus does not support arrays in the holding
registers, the frequency converter has reserved the holding
register 9 as pointer to the array. Before reading or writing
an array parameter, set the holding register 9. Setting
holding register to the value of 2 causes all following read/
write to array parameters to be to the index 2.
7.9.4 Text Blocks
Parameters stored as text strings are accessed in the same
way as the other parameters. The maximum text block size
is 20 characters. If a read request for a parameter is for
more characters than the parameter stores, the response is
truncated. If the read request for a parameter is for fewer
characters than the parameter stores, the response is space
lled.
7.9.5 Conversion Factor
A parameter value can only be transferred as a whole
number. To transfer decimals, use a conversion factor.
7.9.6 Parameter Values
7.9.1 Parameter Handling
The PNU (parameter number) is translated from the
register address contained in the Modbus read or write
message. The parameter number is translated to Modbus
as (10 x parameter number) decimal. Example: Reading
parameter 3-12 Catch up/slow Down Value (16 bit): The
holding register 3120 holds the parameters value. A value
of 1352 (decimal) means that the parameter is set to
12.52%.
Reading parameter 3-14 Preset Relative Reference (32 bit):
The holding registers 3410 and 3411 hold the parameters
values. A value of 11300 (decimal), means that the
parameter is set to 1113.00.
For information on the parameters, size, and conversion
index, see chapter 6 Programming.
Standard data types
Standard data types are int 16, int 32, uint 8, uint 16, and
uint 32. They are stored as 4x registers (40001–4FFFF). The
parameters are read using function 03 hex read holding
registers. Parameters are written using the function 6 hex
preset single register for 1 register (16 bits), and the
function 10 hex preset multiple registers for 2 registers (32
bits). Readable sizes range from 1 register (16 bits) up to
10 registers (20 characters).
Non-standard data types
Non-standard data types are text strings and are stored as
4x registers (40001–4FFFF). The parameters are read using
function 03 hex read holding registers and written using
function 10 hex preset multiple registers. Readable sizes
range from 1 register (2 characters) up to 10 registers (20
characters).
Examples
7.10
7.9.2 Storage of Data
The coil 65 decimal determines whether data written to
the frequency converter is stored in EEPROM and RAM (coil
65 = 1), or only in RAM (coil 65 = 0).
The following examples show various Modbus RTU
commands.
7.10.1 Read Coil Status (01 hex)
Description
This function reads the ON/OFF status of discrete outputs
(coils) in the frequency converter. Broadcast is never
supported for reads.
RS485 Installation and Set-...Design Guide
Query
The query telegram species the starting coil and quantity
of coils to be read. Coil addresses start at 0, that is, coil 33
is addressed as 32.
Example of a request to read coils 33–48 (status word)
from slave device 01.
Field nameExample (hex)
Slave address01 (frequency converter address)
Function01 (read coils)
Starting address HI00
Starting address LO20 (32 decimals) coil 33
Number of points HI00
Number of points LO10 (16 decimals)
Error check (CRC)–
Table 7.22 Query
Response
The coil status in the response telegram is packed as 1 coil
per bit of the data
eld. Status is indicated as: 1 = ON; 0 =
OFF. The lsb of the rst data byte contains the coil
addressed in the query. The other coils follow toward the
high-order end of this byte, and from low order to high
order in subsequent bytes.
If the returned coil quantity is not a multiple of 8, the
remaining bits in the nal data byte are padded with
values 0 (toward the high-order end of the byte). The byte
count eldspecies the number of complete bytes of data.
Field nameExample (hex)
Slave address01 (frequency converter address)
Function01 (read coils)
Byte count02 (2 bytes of data)
Data (coils 40–33)07
Data (coils 48–41)06 (STW = 0607hex)
Error check (CRC)–
Table 7.23 Response
Field nameExample (hex)
Slave address01 (Frequency converter address)
Function05 (write single coil)
Coil address HI00
Coil address LO40 (64 decimal) Coil 65
Force data HIFF
Force data LO00 (FF 00 = ON)
Error check (CRC)–
Table 7.24 Query
Response
The normal response is an echo of the query, returned
after the coil state has been forced.
Field nameExample (hex)
Slave address01
Function05
Force data HIFF
Force data LO00
Quantity of coils HI00
Quantity of coils LO01
Error check (CRC)–
Table 7.25 Response
7.10.3 Force/Write Multiple Coils (0F hex)
Description
This function forces each coil in a sequence of coils to
either on or o. When broadcasting, the function forces
the same coil references in all attached slaves.
Query
The query telegram species the coils 17–32 (speed
setpoint) to be forced.
NOTICE
Coil addresses start at 0, that is, coil 17 is addressed as
16.
77
NOTICE
Coils and registers are addressed explicitly with an oset of -1 in Modbus.
For example, coil 33 is addressed as coil 32.
7.10.2 Force/Write Single Coil (05 hex)
Description
This function forces the coil to either ON or OFF. When
broadcast, the function forces the same coil references in
all attached slaves.
Query
The query telegram species the coil 65 (parameter write
control) to be forced. Coil addresses start at 0, that is, coil
65 is addressed as 64. Force data = 00 00 hex (OFF) or FF
The normal response returns the slave address, function
code, starting address, and quantity of coils forced.
Field nameExample (hex)
Slave address01 (frequency converter address)
Function0F (write multiple coils)
Coil address HI00
Coil address LO10 (coil address 17)
Quantity of coils HI00
Quantity of coils LO10 (16 coils)
Error check (CRC)–
Table 7.27 Response
7.10.4 Read Holding Registers (03 hex)
Description
77
This function reads the contents of holding registers in the
slave.
Slave address01
Function03
Byte count04
Data HI (register 3030)00
Data LO (register 3030)16
Data HI (register 3031)E3
Data LO (register 3031)60
Error check (CRC)–
Table 7.29 Response
7.10.5 Preset Single Register (06 hex)
Description
This function presets a value into a single holding register.
Query
The query telegram species the register reference to be
preset. Register addresses start at 0, that is, register 1 is
Field nameExample (hex)
addressed as 0.
Query
The query telegram species the starting register and
quantity of registers to be read. Register addresses start at
0, that is, registers 1–4 are addressed as 0–3.
Example: Read parameter 3-03 Maximum Reference, register
03030.
Field nameExample (hex)
Slave address01
Function03 (Read holding registers)
Starting address HI0B (Register address 3029)
Starting address LOD5 (Register address 3029)
Number of points HI00
02 – (parameter 3-03 Maximum
Number of points LO
Error check (CRC)–
Table 7.28 Query
Reference is 32 bits long, that is, 2
registers)
Response
The register data in the response telegram is packed as 2
bytes per register, with the binary contents right justied
within each byte. For each register, the 1st byte contains
the high-order bits, and the 2nd contains the low-order
bits.
Example: hex 000088B8 = 35.000 = 35 Hz.
Example: Write to parameter 1-00 Conguration Mode,
register 1000.
Field nameExample (hex)
Slave address01
Function06
Register address HI03 (register address 999)
Register address LOE7 (register address 999)
Preset data HI00
Preset data LO01
Error check (CRC)–
Table 7.30 Query
Response
The normal response is an echo of the query, returned
after the register contents have been passed.
This function presets values into a sequence of holding
registers.
Query
The query telegram species the register references to be
preset. Register addresses start at 0, that is, register 1 is
addressed as 0. Example of a request to preset 2 registers
(set parameter 1-24 Motor Current to 738 (7.38 A)):
Field nameExample (hex)
Slave address01
Function10
Starting address HI04
Starting address LO07
Number of registers HI00
Number of registers LO02
Byte count04
Write data HI (Register 4: 1049)00
Write data LO (Register 4: 1049)00
Write data HI (Register 4: 1050)02
Write data LO (Register 4: 1050)E2
Error check (CRC)–
Table 7.32 Query
Response
The normal response returns the slave address, function
code, starting address, and quantity of registers preset.
Field nameExample (hex)
Slave address01
Function10
Starting address HI04
Starting address LO19
Number of registers HI00
Number of registers LO02
Error check (CRC)–
Table 7.33 Response
7.10.7 Read/Write Multiple Registers (17
hex)
Description
This function code performs a combination of 1 read
operation and 1 write operation in a single MODBUS
transaction. The write operation is performed before read.
Query
The query message species the starting address and
number of holding registers to be read as well as the
starting address, number of holding registers, and the data
to be written. Holding registers are addressed starting at
zero. Example of a request to set parameter 1-24 Motor
Current to 738 (7.38 A) and read parameter 3-03 Maximum
Reference which has value 50000 (50,000 Hz):
The normal response contains the data from the group of
registers that were read. The byte count eldspecies the
quantity of bytes to follow in the read data eld.
Bit 02 = 0: Leads to DC braking and stop. Set braking
current and duration in parameter 2-01 DC Brake Current
and parameter 2-02 DC Braking Time.
Bit 02 = 1: Leads to ramping.
Bit 03, Coasting
Bit 03 = 0: The frequency converter immediately releases
the motor (the output transistors are shut o), and it
coasts to a standstill.
Bit 03 = 1: If the other starting conditions are met, the
frequency converter starts the motor.
In parameter 8-50 Coasting Select, dene how bit 03 gates
with the corresponding function on a digital input.
Bit 04, Quick stop
Bit 04 = 0: Makes the motor speed ramp down to stop (set
in parameter 3-81 Quick Stop Ramp Time).
Bit 05, Hold output frequency
Bit 05 = 0: The present output frequency (in Hz) freezes.
Change the frozen output frequency only with the digital
inputs programmed to [21] Speed up and [22] Speed down
(parameter 5-10 Terminal 18 Digital Input toparameter 5-13 Terminal 29 Digital Input).
NOTICE
If freeze output is active, the frequency converter can
only be stopped in 1 of the following ways:
Bit 03 coast stop.
•
Bit 02 DC brake.
•
Digital input programmed to [5] DC brake
•
inverse, [2] Coast inverse, or [3] Coast and reset
inv (parameter 5-10 Terminal 18 Digital Input to
parameter 5-13 Terminal 29 Digital Input).
Bit 06, Ramp stop/start
Bit 06 = 0: Causes a stop and makes the motor speed
ramp down to stop via the selected ramp-down parameter.
Bit 06 = 1: If the other starting conditions are met, bit 06
allows the frequency converter to start the motor.
In parameter 8-53 Start Select, dene how bit 06 ramp stop/
start gates with the corresponding function on a digital
input.
Bit 07, Reset
Bit 07 = 0: No reset.
Bit 07 = 1: Resets a trip. Reset is activated on the leading
signal edge, that is, when changing from logic 0 to logic 1.
Bit 08, Jog
Bit 08 = 1: Parameter 3-11 Jog Speed [Hz] determines the
output frequency.
Bit 09, Selection of ramp 1/2
Bit 09 = 0: Ramp 1 is active (parameter 3-41 Ramp 1 Ramp
Up Time to parameter 3-42 Ramp 1 Ramp Down Time).
Bit 09 = 1: Ramp 2 (parameter 3-51 Ramp 2 Ramp Up Time
to parameter 3-52 Ramp 2 Ramp Down Time) is active.
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