Eltroplan REVCON SVCS Series Operating Instructions Manual
ELTROPLAN-REVCON
Operating instructions
Power feedback unit
REVCON
SVCS
Power range 7 ... 33kW
Rated voltage 400V
V 2.0 As of 03/10
Contents
1 Preface and general information .......................................................................................... 3
1.1 About these Operating Instructions ..................................................................................... 3
1.1.1 Terminology used .......................................................................................................... 3
1.1.2 Type determinator ......................................................................................................... 4
1.2 Scope of delivery ................................................................................................................. 4
1.3 Legal regulations.................................................................................................................. 5
1.4 EC-Directives / Declaration of conformity .......................................................................... 6
1.4.1 What is the purpose of EC-Directives? ......................................................................... 6
1.4.2 What is the meaning of the CE-mark? .......................................................................... 6
1.4.3 EC-Low-Voltage Directive ........................................................................................... 6
1.4.4 EC-Directive Machinery ............................................................................................... 8
2 Safety information ............................................................................................................. 10
2.1 General safety information ................................................................................................ 11
2.2 Safety-responsible persons ................................................................................................ 15
2.3 Usage as directed ............................................................................................................... 15
2.4 Layout of the safety information ....................................................................................... 16
2.5 Residual hazards ................................................................................................................ 16
2.6 General instructions ........................................................................................................... 17
3 Technical data .................................................................................................................... 27
3.1 Characteristics .................................................................................................................... 27
3.2 General data / application conditions................................................................................. 28
3.3 Rated data .......................................................................................................................... 29
3.3.1 Power feedback unit .................................................................................................... 29
3.3.2 Current load ................................................................................................................. 30
3.3.4 Fuses and wire cross sections ...................................................................................... 34
3.3.4.1 Series fuses .............................................................................................................. 34
3.3.4.2 Internal fuses ............................................................................................................ 35
3.3.5 RFI-filter ..................................................................................................................... 36
3.3.6 SKS-module ................................................................................................................ 36
4 Installation ......................................................................................................................... 37
4.1 Mechanical installation ..................................................................................................... 37
4.1.1 Important hints ........................................................................................................... 37
4.2 Dimensions ........................................................................................................................ 38
4.2.1 Power feedback unit .................................................................................................... 38
4.2.2 RFI-filters .................................................................................................................... 41
ELTROPLAN-REVCON page 1
Contents
4.3 Electrical installation ......................................................................................................... 43
4.3.1 Operator’s safety ......................................................................................................... 43
4.3.2 Protection of the power feedback unit ........................................................................ 43
4.3.3 Mains types / Mains characteristics ............................................................................ 44
4.3.4 Specifications of the used wires ................................................................................. 44
4.4 Connection ........................................................................................................................ 45
4.4.1 Power connection ....................................................................................................... 45
4.4.1.1 Wiring schematic ..................................................................................................... 47
4.4.2 Fan supply ................................................................................................................... 49
4.4.3 Control wires .............................................................................................................. 49
4.4.4 Control functions ........................................................................................................ 49
4.5 Application example ......................................................................................................... 53
4.6 Installation of a power feedback unit in a CE-typical drive system .................................. 54
4.6.1 Installation .................................................................................................................. 55
4.6.2 Connection of a RFI-filter .......................................................................................... 56
4.6.3 Design of an EMC-conformal cabinet ........................................................................ 57
4.6.4 Remarks ...................................................................................................................... 58
4.6.5 Installation of control wires ........................................................................................ 59
5 Commissioning .................................................................................................................. 60
5.1 First powering up .............................................................................................................. 60
6 Configuration .................................................................................................................... 61
7 Troubleshooting and fault elimination .............................................................................. 64
7.1 LED-messages ................................................................................................................... 65
8 Service ............................................................................................................................... 66
9 Appendix ........................................................................................................................... 67
9.1 Options .............................................................................................................................. 67
9.2 REVCON Product overview ............................................................................................. 69
9.3 Contact .............................................................................................................................. 70
Seite 2 ELTROPLAN-REVCON
Preface and general information
1 Preface and general information
1.1 About these Operating Instructions
• These Operating Instructions help you to work properly on and with the
power feedback units REVCON SVCS. They contain safety information
which must be observed and information which are necessary for an undisturbed operation of the units together with the exploitation of all the advantages of the system.
• All persons who work on and with the power feedback units REVCON
SVCS, must have the Operation instructions available and observe all
relevant notes and instruction.
• The Operating Instructions must always be in a complete and perfectly
readable state.
1.1.1 Terminology used
Power feedback unit
For „Power feedback unit REVCON SVCS“ in the following the term
„Power feedback unit“ is used.
Controller
For the frequency inverter which is used together with the power feedback unit
in the following the term „Controller“ is used.
Drive system
For a drive system with power feedback units, controller and other components
of the drive system in the following the term „Drive system“ is used.
ELTROPLAN-REVCON page 3
Preface and general information
1.1.2 Type determinator
SVCS 33 - XXX - 1 - 230 V AC
for up to 50% duty cycle
Auxiliary voltage e. g. 230V
Number of fans
Mains voltage e. g. 400 (3 x 400V AC)
max. feedback power e. g.33 (33 kW)
Including SKS-R
SVCS = Power feedback unit
1.2 Scope of delivery
• 1 Power feedback unit REVCON
• 1 Operating Instructions
After receipt of delivery, check immediately whether the scope of supply
matches with the accompanying papers. We do not accept any liability for deficiencies claimed subsequently.
Claim
• visible transport damage immediately to the forwarder .
• visible deficiencies/incompleteness immediately to ELTROPLAN
REVCON.
page 4 ELTROPLAN-REVCON
Preface and general information
•
•
1.3 Legal regulations
Labelling Nameplate CE-mark Manufacturer
Power feedback units REVCON SVC are
unequivocally marked by the contents of
Conforms the EC Low
Voltage Directive
the nameplate.
Patent rights
The power feedback unit REVCON
is protected in Germany and Europe by patents :
Patent-No.: DE 3938654C1 and Patent-Nr.: 90123584.6-2207.
Patent infringements become prosecute.
Application
as directed
Power feedback unit REVCON
SVC
• Must only be operated under the conditions prescribed in these instructions.
• Are components
– to feedback electrical energy.
– used for installation into a machine.
– used for assembly together with other components to from a machine.
• Are electric units for the installation into control cabinets or similar enclosed operating hous-
ing.
• Comply with the requirements of he Low-Voltage Directive
• Are not machines for the purpose of the Machinery Directive
• Are not to be used as domestic appliances, but only for industrial purpose.
Drive systems with power feedback unit REVCON
SVC
• Comply with the EMC-Directive if they are installed according to the guidelines of CE-typical
drive systems.
• Can be used
– on public and non-public mains.
– in industrial as well as residential and commercial premises.
• The user is responsible for the compliance of this application with the EC directives .
Liability
The information, data and notes in these Operating Instructions met the state of the art at the
time of printing. Claims referring to power feedback units which have already been supplied
cannot be derived from information, illustrations and descriptions given in these Operation Instructions.
• The specifications, processes and circuitry described in these Operating Instructions are for
guidance only and must be adapted to your own specific application. ELTROPLAN-REVCON
does not take responsibility for the suitability of the process and circuit proposals.
• The indications given in these Operating Instructions describe the features of the product with-
out warranting them.
• ELTROPLAN-REVCON does not accept any liability for damage and operating interference
caused by:
– disregarding these instructions
– unauthorized modifications to the power feedback unit
– operating errors
– improper working on and with the power feedback unit
Warranty
Warranty conditions: see sales and delivery conditions of ELTROPLAN-REVCON GmbH.
• Warranty claims must be made immediately after detecting defects or faults.
• The warranty is void in all cases where liability claims cannot be made.
Disposal Material recycle disposal
Metal
Plastic
l
l
Printed-board assemblies -
ELTROPLAN-
REVCON
Edisonstraße 3
D-59199 Bönen
-
-
l
ELTROPLAN-REVCON page 5
Preface and general information
1.4 EC-Directives / Declaration of conformity
1.4.1 What is the purpose of EC-Directives?
The EC-Directives have been drawn up by the European council to define
common technical standards and certification procedures within the European
Community. At the moment there are 21 EC-Directives for product sectors.
The directives are or will be converted in national laws by the member states.
If a certificate is conferred in one member state, it is valid in all other member
states automatically.
The directives only describe the basic standards. The technical details are or
will be described in harmonized European standards.
1.4.2 What is the meaning of the CE-mark?
After an conformity-assessment-procedure the harmony with the standards of
the EC-Directives certified by fixing the CE-mark. Within the EC there are no
trading obstacles for a CE-marked product.
Power feedback units with CE-mark themselves are compliant with the LowVoltage Directive only. . For observing the EMC Directive recommendations
are made.
1.4.3 EC-Low-Voltage Directive
(73/23/EEC)
Modified by: CE – Marking Directive (93/68/EEC)
General:
• The Low-Voltage Directive is valid for all electrical equipment which is
used at a nominal voltage between 50V and 1000V AC and between 75V
and 1500V DC together with customary environment conditions. Excluded
is e.g. the use of electrical equipment in explosive areas and electrical
components of lifts for persons or material.
• Aim of the Low-Voltage Directive is to put only those products into com-
merce which don’t endanger the safety of persons and animals as well as
the preservation of material assets.
page 6 ELTROPLAN-REVCON
Preface and general information
EC-declaration of conformity
According to the EC-Low Voltage Directive /73/23/EEC)
Modified by: CE – Marking Directive (93/68/EEC)
The power feedback units REVCON SVC have been developed, designed and
manufactured in accordance with the above mentioned EC-Directive and in
sole responsibility of
ELTROPLAN-REVCON Elektrotechnische Anlagen GmbH,
Edisonstraße 3, D-59199 Bönen
Considered standards:
Standard
DIN VDE 0160 5.88 +A1 / 4.89 +A2 / 10.88
PRDIN EN 50178
Class VDE 0160 / 11.94
DIN VDE 0100 Guidelines for the desing of
EN 50529 IP type of protection
DIN EN 50081 Part 2 3.94 Basic standard noise emission
DIN EN 50082 Part 2 3.85 Basic standard noise emission
Equipement of power installations with
electronic components
power installations
ELTROPLAN-REVCON page 7
Preface and general information
1.4.4 EC-Directive Machinery
(89/392/EEC)
Modified by: 1. modification guideline (91/368/EEC)
2. modification guideline (93/44/EEC)
CE – marking guideline (93/68/EEC)
General:
As defined by the machinery guideline a „machine“ is a unit of combined
components or devices, from which at least one has moving parts, and of handling devices, control and energy circuits and so on, which have been combined for a specific application (like treating, moving, processing of a material).
page 8 ELTROPLAN-REVCON
Preface and general information
EC-declaration of the manufacturer
In the sense of the EC-Directive Machinery (89/392/EEC)
modified by: 1. Modifying Directive (91/368/EEC)
2. Modifying Directive (93/44/EEC)
CE – Labelling Directive (93/68/EEC)
The power feedback units REVCON SVC have been developed, designed and
manufactured in accordance with the above mentioned EC Directive in exclu-
sive responsibility of
ELTROPLAN-REVCON Elektrotechnische Anlagen GmbH,
Edisonstraße 3, D-59199 Bönen
When installing the machines, commissioning (i.e. the staring of operation as
directed) the power feedback units is prohibited until it is proven that the ma-
chine corresponds to the regulations of the EC Directive 89/392/EEC (Machin-
ery Directive).
ELTROPLAN-REVCON page 9
Safety information
2 Safety information
Safety and application notes
for controller
1. General
During operation, power feedback unit may have, according to
their type of protection, live, bare, in some cases also movable or
rotating parts as well as hot surfaces.
Non –authorized removal of required cover, inappropriate use, incorrect installation or operation, creates the risk of severe injury to
persons or damage to material assets.
Further information can be obtained from the documentation.
All operations concerning transport, installation and commissioning as well as maintenance must be carried out by qualified,
skilled personnel (IEC 364 and CENELEC HD 384 or DIN VDE
0100 and IEC-Report 664 or DIN VDE 0110 and national regulations for the preventions of accidents must be observed).
According to this basic safety information qualified skilled personnel are persons who are familiar with the erection, assembly,
commissioning and operation of the product and who have the
qualifications necessary for their occupation .
2. Application as directed
Power feedback units are components which are designed for installation in electrical systems or machinery.
When installing in machines, commissioning of the power feedback unit (i.e. the starting of operation as directed) is prohibited
until it is proven, that the machine corresponds to the regulations
of the EC Directive 83/392/EEC (Machinery Directive); EN
60204 must be observed.
Commissioning (i.e. starting operation as directed) is only allowed
when there is compliance with the EMC-Directive89/336/EEC.
The power feedback units meet the requirements of the LowVoltage Directive 73/23/EEC. The harmonized standards of the
prEN 50178/DIN VDE 0160 series together with EN 604391/DIN VDE 0660 part 500 and EN 60146/DIN VDE 0558 are applicable for the power feedback unit. The technical data and information on the connection conditions must be obtained from the
nameplate and the documentation and must be observed in all
cases.
3. Transport, Storage
Notes on transport, storage and appropriate handling must be observed
The power feedback unit has to protected from inadmissible
stress. In particular during transport and handling no components
are allowed to be bend and / or isolating distances may not be altered. The units are equipped with electrostatic sensitive devices,
which may be damaged by improper handling. Therefore it has to
be avoid to get in contact with electronic components. If electronic components are damaged mechanically the unit must not be
put into operation, as it cannot be ensured, that all relevant standards are observed. Climatic conditions must be observed according to prEN 50178
(to : Low-Voltage Directive 73/23/EEC)
4. Erection
The devices must be erected and cooled according to the regulations of the corresponding documentation.
The power feedback units must be protected from inappropriate
loads. Particularly during transport and handling, components
must not be bent and / or isolating distances must not be changed.
Touching of electronic components and contacts must be avoided.
Power feedback units contain electro-statically sensitive components which can easily be damaged by inappropriate handling.
Electrical components must not be damaged or destroyed mechanically (health risk are possible!).
5. Electrical Connection
When working on live power feedback units, the valid national
regulations for the prevention of accidents (e.g. VBG 4) must be
observed. Before any installation or connection works, the pant
has to be switched off and to be secured properly.
The electrical installation must be carried out according to the appropriate regulations (e.g. cable cross-sections, fuses, PEconnection). More detailed information is included in the documentation. When using the power feedback unit with controllers
without safe separation from the supply line (to VDE 0100) all
control wiring has to be include in further protective measures
(e.g. double insulated or shielded, grounded and insulated) .
Notes concerning the installation in compliance with EMC – such
as screening, grounding, arrangement of filters and laying of cables – are included in the chapter installation of this documentation. These notes must be also observed in all cases for power
feedback units with the CE-mark. The compliance with the required limit values demanded by the EMC legislation is the responsibility of the manufacturer of the system or machine.
6. Operation
Systems where power feedback units are installed, if applicable,
have to be equipped with additional monitoring and protective devices according to the valid safety regulations e.g. law on technical tools, regulations for the prevention of accidents, etc. .
After disconnecting the power feedback unit from the supply voltage, live parts of the power feedback unit and power connections
must not be touched immediately, because of possibly charged
capacitors. For this, observe the corresponding labels on the drive
controllers.
During operation, all covers and doors must be closed.
7. Maintenance and service
The manufacturer’s documentation must be observed.
This safety information must be kept!
The product-specific safety and application notes in
these Operating Instructions must also be observed!
page 10 ELTROPLAN-REVCON
Safety information
2.1 General safety information
• These safety regulations are not entitled to completeness. In case of ques-
tions please contact our technicians.
• When commissioning the power feedback units is compliant with the state
of the art. The power feedback unit generally allows safe operation.
• The statements of this manual describe the attributes of the products with-
out guaranteeing them.
• The power feedback unit may expose persons, the power feedback units it-
self and other material to danger, if
– non qualified personal works at and with the power feedback unit.
– The power feedback units is used in opposite to its purpose.
• Power feedback units have to be projected in a way, that they fulfil their
function and don’t expose persons to danger, if they are mounted correctly
and are used in accordance with their purpose. This applies also for the in-
terplay with the whole plant.
• The units, operational data and circuit details described in this manual
have to be understood analogously and have to be checked for transferabil-
ity to each application.
• For the reasons of personal safety, the observance of the EMC-regulations
and for the regular cooling the operation of the device is only allowed
with a closed cover of the housing and with mounted flanges!
•
• Use the drive system only in flawless condition.
•
Modifications of the power feedback units without consultation of a
REVCON-technician are not allowed generally.
ELTROPLAN-REVCON page 11
Safety information
•
The warranty given by us expires, if the unit is modified or (even partially)
dismantled or if it is used in contradiction to our instructions.
•
The constructor of the plant, who has to know the technical guidelines,
bears the responsibility for the correct selection and arrangement of the
electrical components.
•
Putting into operation of the power feedback unit is only admissible at
VDE-conform nets of electrical power supply. Non observance may dam-
age the device!
•
In accordance with the corresponding standards and guidelines the opera-
tion on even for a short time over-compensated networks (cosϕ≤1) respec-
tively on un-choked compensation-units is not admissible. If this is done
nevertheless, overvoltages will occur (caused by oscillating currents),
which may damage all connected components, especially electronic units
like controllers and power feedback units.
•
To low powered or unloaded generators and to regulating transformers it is
never allowed to feed back power without a previous consultation of our
application department. Otherwise unintended voltage rises / excess volt-
ages are generated, which may damage or destroy REVCON and com-
bined units!
• Before operating at nets without reference to neutral ground additional
safety measures (e.g. installation of over voltage suppressors like MOV’s)
have to be done. If necessary, please ask for technical support by our tech-
nicians.
• An undisturbed operation of the power feedback unit is only probable, if
the following instructions are observed. If these instructions are not ob-
served, tripping of the unit and damages may occur.
♦ Pay attention to the correct values of mains and DC-bus voltage.
♦ Separate power and control wires (> 15cm)
♦ Use shielded or twisted control wires. Connect both ends of the
shield to ground!
page 12 ELTROPLAN-REVCON
Safety information
♦ When using the digital input devices, only use suitable switching de-
vices, whose contacts are able to switch the connected voltages.
♦ Connect the housings of drive, controller and power feedback unit to
ground carefully. Connect shields of power cables to ground at both
ends with as big surface as possible (remove lacquer)!
♦ Connect the cabinet or the plant by a star-shaped network to ground
(ground loops have to be avoided!)
• The power feedback unit has been designed for a fixed connection to
mains only. Especially when using RFI-filter leakage current values>
3,5mA may occur. The cross section of the earthing conductor must be al
least 10mm² copper, or a second conductor has to be connected in parallel
(star shaped grounding network).
• If components are used, which have no electrical separated inputs / outputs
it is necessary to equalize the potentials (e.g. by a equalizing wire). If this
is not observed, these components may be damaged by equalizing currents.
• When carrying out an insulations test in accordance with VDE0100/part
620 the device has to be disconnected to avoid damage to the power semi-
conductors. This procedure corresponds with the standard, as each device
performs a high voltage test in accordance with VDE 0160 (EN 50178) in
the course of final testing after manufacturing.
ELTROPLAN-REVCON page 13
Safety information
• A standard fault-current circuit breaker (sensitive on peak currents) is not
allowed to be used as the only protective measure when using controller
and power feedback unit Caused by a DC-component in the mains current
a controller with 3-phase input voltage may prevent a fault-current circuit
breaker from tripping in case of a earth fault. In accordance with VDE
0160 a fault-current circuit breaker is not allowed to be used as the only
protective measure. In dependence on the kind of network (TN, IT, TT)
further protective measures in accordance with VDE 0100 part 410 are
necessary. For a TN-network this may be an over current protection, for a
IT-network a insulation supervision with pulscode-measurment. For all
kind of networks protective insulation (-transformer) may be used, if re-
quired power and length of wires allow that. When selecting a fault current
circuit breaker the following measures have to be considered:
♦ The fault current circuit breaker has to be compliant with the VDE
0664 standard.
♦ The tripping current should be 300mA or more, to prevent a prema-
ture tripping caused by the leakage current of the controller. In de-
pendence on the load, the length of the motor cables and the usage of
a RFI-filter the leakage current may even be much higher.
Faults current circuit breaker, which are sensitive to all kinds of leakage
currents, grant a good protection and are suitable as the only protection
measurement for one ore three phase controllers. The connection instruc-
tions of the manufacturer has to be observed.
page 14 ELTROPLAN-REVCON
2.2 Safety-responsible persons
User
• User is any natural or legal entity, who uses the drive system or by whom
order the drive system is used.
• The user respectively his security officer have to grant
– that all relevant regulations, instructions and laws have to be observed
– that only qualified personnel works with or at he drive system
– that the relevant manual is available for the personnel during any works.
– that non-qualified personnel is prohibited to work on the drive system.
Qualified personnel
Qualified personnel are persons who are, based on their education, experience,
instruction and knowledge about standards and guidelines, regulations for the
Safety information
prevention of accidents and the situation in the plant, authorized by the safety
officer of the plant to execute the necessary works and are able to recognize
possible dangers and to avoid them.
(Definition of qualified personnel in accordance with IEC 364)
2.3 Usage as directed
Power feedback units are electrical drive components, which are directed to be
installed in electrical plants or machines. They have to be used only for drive
systems with infinity variable speed controls of 3-phase asynchronous or per-
manent magnet motors. The usage with other electrical loads is not permitted
and may damage the devices. The power feedback unit may only be connected
to symmetrical networks. Non-observance may damage the devices.
ELTROPLAN-REVCON page 15
Warning of hazardous
FFFF
STOP
STOP
Safety information
2.4 Layout of the safety information
• All safety notes have a uniform layout:
- The icon characterizes the type of danger.
- The signal word characterizes the severity of danger.
- The note describes the danger and suggests how to avoid the danger.
Signal word
Note
Icons used Signal words
Warning of
danger to
persons
Warning of
danger to material
electrical voltage
Warning of a general
danger
Danger!
Warning!
Caution!
Stop!
Warns of impending danger.
Consequences if disregarded:
Death or very severe injuries.
Warns of potential, very hazardous situation.
Possible consequences if disregarded:
Death or very severe injuries.
Warns of potential, hazardous situation.
Possible consequences if disregarded:
Light or minor injuries.
Warns of potential damage to material.
Possible consequences if disregarded:
Damage of the drive system or its environment.
Other notes
2.5 Residual hazards
Operator’s safety
After mains disconnections, the power terminals + and – remain live for
several minutes.
Protection of the device
Cyclic connection and disconnection of the supply voltage at terminals L1, L2
und L3, may overload the internal input current limitation:
Allow at least 1 minute between disconnection and reconnection.
Note!
This note designates general, useful notes.
If you observe it, handling of the power feedback
unit / drive system is made easier.
page 16 ELTROPLAN-REVCON
2.6 General instructions
By these information to erectors and users of a plant hints on properties and
directions concerning the power feedback unit are given. These hints are not
entitled to completeness.
Special features in comparison towards a chopper
Unlike a braking resistor a power feedback device isn't a constant sink, but it's
dependent on the momentary characteristics of the supplying net. Commutation
brake downs and voltage-flicker in the net have an considerable effect to the
backward current of the device. In case of a short time voltage brake down the
Safety information
backward current has to rise correspondingly to feedback the demanded power-
amount. Does the level of the supply voltage sink for a longer time, the maxi-
mum feedback power is reduced.
If only one phase fails, the device is able to work on, but the current in the two
remaining conductors will rise up to 150% of the normal level.
ELTROPLAN-REVCON page 17
(
)
i
REVCON
®
-
type
Power
DC-
capacitance
SVC
7-
45kW
100µF
70-
135kW
200µF
160-200kW
420µF
Safety information
Length of the DC-connection
The maximum inductivity of the DC-connection between output B6 bridge of
the inverter and the power feedback device mustn't exceed a certain level, as
this inductivity inducts an additional voltage to the DC-bus, when the IGBT’s
are switched off . To avoid an overload to the components of the power feed-
back unit, this additional voltage must not exceed 100V. Resulting from this
and other relevant characteristics of the power feedback unit (DC-capacity and
absolute maximum value of the grid current) the maximum inductivity
L
=
max
or equal than the sum of the DC-bus inductivity of the frequency inverter and
the conductor inductivity of the DC connection. The DC-bus inductivity of the
2
UC
∆⋅
GL
2
ˆ
can be calculated. This inductivity always has to be higher
frequency inverter has only to be considered, if it is placed between the inverter
B6 bridge and the power feed-back unit. The cables, which are normally used
for power applications, have an inductance per unit length of about 0,6µ H/m. If
the values of the input capacitance C, the during power backfeeding maximum
allowed rise of the DC-voltage ∆UGL =100V, the top level of the AC-current of
the device (=2xI
DC-bus ´choke L
be calculated with the following equation:
), the inductance per unit length L´ and the inductance of the
eff
are known the maximum longitude of the conductors can
ZKD
2
UC
l
max
∆⋅
=
2
ˆ
Li
⋅
L
ZKDGL
−
′
′
L
Typical capacitance of the DC-connection inside the power feedback unit :
Table 2.6.1
Example:
C=200µF, ∆UGL=100V, i=271A, a=80mm, r=8,5mm, µ0=1,257.10-6 H/m ⇒
l
=26m
max
For longer DC-Bus-wires additional capacitors have to be installed (please get
in contact with our application-department if the occasion arrises).
page 18 ELTROPLAN-REVCON
Safety information
REVCON
0,4kV
G
STOP
Operation on a generator
The usage of a power feedback unit within an island network (e.g. with an
diesel generator) is possible, but there are restrictive regulations concerning the
power limits.
100kVA
R
20kW
M
20kW
FU
M
Figure 2.6.1
Within a network, that is assembled like in figure 2.6.1, there are two addi-
tional restrictions: First the power of the motor connected to the inverter must
be lower than half of the nominal power of the generator. Second the total
amount of the power of the two other loads must be more than double of the
backfeed-power.
If these conditions aren't checked up a change from motory to generatory op-
eration may result in load shocks. These shocks are too dynamic for the voltage
regulator of the generator. The regulator reacts with an overshoot and as a re-
sult of this with an over voltage within the island network.
STOP!
Over voltages may cause serious damages to the connected frequency in-
verter and /or to the power feedback unit and to the other loads.
ELTROPLAN-REVCON page 19
REVCON
Safety information
Operation on a transformer
If only a few loads operate within a network section the connected transformer
must be able to transport the in this section not used power back to the next
voltage level without producing a not allowed voltage increase inside the sec-
tion. Therefore the nominal power of the transformer has to be one and a half
higher than the backfed power out of the section, so that also the harmonic and
reactive components of the current can be transmitted. In the network section
displayed in figure 2.6.2 these conditions are checked up, even if the other
loads are switched off.
Is the backfed power in the order of the nominal power of the transformer, it's
impedance voltage has to be small enough (max. 6%) to limit the voltage in-
crease in the section.
The operation of the power feedback unit in combination with an adjusting
transformer (e.g. in the case of a braked slip-ring induction motor) is only al-
lowed, if the quotient ratio of feedback-power and nominal power is much
smaller than one
10kV
100kVA
Tr
0,4kV
20kW
R
M
20kW
M
FU
60kW
Figure 2.6.2
page 20 ELTROPLAN-REVCON
Safety information
REVCON
Not allowed!
STOP
Placing of the commutation choke
If the frequency converter is connected to an external commutation choke, the
connection of the power feedback unit has to be done at it's network terminals
(figure 2.6.3). Is the connection done at the load terminals of the commutation
choke it's inductivity prevents the synchronising to the supplying net and the
induction voltage of the choke when it is switched of under load may result in
damages to the power feedback device.
STOP!
Over voltages may cause serious damages to the connected frequency in-
verter and /or to the power feedback unit and to the other loads.
Figure 2.6.3
FU
M
60kW
The same things apply to the also non-admissible pre-connection of further
commutation chokes.
ELTROPLAN-REVCON page 21
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