frako RM 2106/12 User manual

Operating Instructions
Reactive Power Control Relay RM 2106/12

2

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Safety and warning notices
!!! Important !!!
Read this before commissioning!!!
• The operating instructions should be read carefully before the
device is assembled, installed and put into operation.
• Installation and commissioning should only be carried out by
appropriate specialists in accordance with existing regula-
tions and provisions.
• The operator must ensure that all operatives are familiar with
these operating instructions and proceed accordingly.
• The device conducts mains voltage and should not be
opened.
• If the device is obviously damaged, it should not be installed,
connected or commissioned.
• If the device does not work after commissioning, it should be
disconnected from the mains again.
• Any other laws, standards, guidelines, etc. regarding this
product must be observed.
The commissioning and safety information for the power factor
correction system should also be observed.

4
Figure 1: Front view
a Display for active capacitor stages
b Display for inductive or capacitive
operating status
c Digital display
d LED indicates regenerative power
e Display for current or historical
alarms
f LED lights up in setup mode
g LED lights up in manual mode
h Multifunctional button
(see operating instructions)
i Selection key for manual mode,
setup mode or automatic mode

5
Figure 2: Rear view
j Connection for the current trans-
former
k Optional connector for improved
measurement of harmonic wave
l Connector for power supply to the
control relay
m Connectors for the control contacts
that switch the contactors. The
shared pole is connected to terminal
´L´.
n Typical connection

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Contents Page Page
1. Introduction .................................7
1.1 How to use
these operating instructions...........7
1.2 Scope of functions.........................7
2. Installation and connection.........8
2.1 Installation.....................................8
2.2 Voltage connection........................8
2.3 Current transformer connection .....8
2.4 ”Meas” measuring
voltage connection.........................9
2.5 Switching contacts.........................9
2.6 Alarm contact ................................9
2.7 Standard connection....................10
2.8 Extended connection...................11
2.9 Connection with
voltage transformer......................12
2.10 Connection in special cases ........13
3. Start-up ......................................14
3.1 Initial start-up...............................14
3.2 Subsequent start-up ....................15
4. Control relay setup....................16
4.1 Target power factor setting ..-1-...17
4.2 Overcurrent switch off..........-2-...19
4.3 Relay 6 as alarm relay.........-3-...19
4.4 Automatic response
current identification.............-4-...20
4.5 Response current ................-5-...20
4.6 Relative value
of the switch outputs............-6-...22
4.7 Service................................-7-...22
5. Functioning and operation....... 23
5.1 Automatic control mode .............. 23
5.2 Displaying the
total harmonic distortion factor .... 23
5.3 Check System ............................ 23
5.4 Manual mode.............................. 24
6. Alarms and troubleshooting .... 25
6.1 Connection errors....................... 25
6.1.1 E3 - No capacitors ................. 25
6.1.2 E1 - Defect capacitor stages.. 25
6.1.3 E2 - Incorrect connection....... 25
6.1.4 I = 0 - No current in current path25
6.2 Connection messages ................ 26
6.2.1 A2 - Incorrect connection
that can be corrected
internally......................... 26
6.2.2 A1 - Relative value of the
switch output.................. 26
6.3 Alarms in automatic control
operation .................................... 26
6.3.1 E4 - Harmonic overcurrent
in the capacitor............... 26
6.3.2 E5 - Target power factor
not reached.................... 27
6.3.3 E1 - Defect capacitor stages.. 27
6.3.4U = 0 - No measuring voltage..... 27
6.3.5 I = 0 - No measuring current..... 27
6.4 Other errors ................................ 27
6.5 Troubleshooting.......................... 28
7. Technical data........................... 29

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1. Introduction
The reactive power control relay RM
2112 and RM 2106 respectively is capa-
ble of measuring the reactive power and
active power of the connected mains
network. Working in conjunction with a
power factor correction system, the de-
vice controls the programmed target
power factor by activating or deactivating
capacitors.
1.1 How to use these operating in-
structions
Important:
It is essential that you read section 2
“Installation and connection” and
section 3 „Start-up“ before installing
the control relay.
The functions of the control relay are also
described in brief in section 1.2 „Scope
of functions“.
The setting options for the control relay
are described in section 4 „Control re-
lay setup”.
Section 5 „Functioning and operation“
explains how the control relay works and
how to operate it.
Section 6 „Alarms and troubleshoot-
ing“ describes alarms and error mes-
sages of the control relay. Troubleshooting
information is also provided there.
1.2 Scope of functions
Below is a brief overview of the various
functions of the device:
• 12 switching contacts at RM 2112 and
6 switching contacts at RM 2106
• Power factor display
• Total harmonic distortion factor display
(voltage thd)
• Semi-automatic connection detection
• Automatic detection of the capacitor
stages
• Comprehensive connection analysis
• Patented characteristic avoiding over-
compensation for low active power
• Four-quadrant regulation
• Cyclic switching of all capacitor stages
of the same capacity
• Reactive power requirement-
dependent switching delay time
• Optional monitoring of the harmonic
overcurrent in the capacitor
• Deactivation at zero voltage or zero
current
• Alarm signals for:
- failure to reach the target power fac-
tor
- overcurrent in the capacitor
- defects at capacitor stages

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2. Installation and connection
The reactive power control relay
RM 2112 and RM 2106 respectively can
be connected in a number of different
ways. The main connection methods are
described below.
Important information:
The control relay should be discon-
nected from the mains during
installation.
2.1 Installation
The reactive power control relay is in-
stalled from the front in a control panel
space measuring 138 x 138mm and is
fixed in place using the mounting screws
of the front panel.
As accessories (protection kit; see
section 8) insulated fixing screws are
available. These can be used to install
the control relay into switchgear cabinets
and cubicles of protective class II. Also a
sealing ring is part of the protection kit,
which must be used when installing the
control relay in switchgear cabinets and
cubicles of protection class IP 54.
The pre-assembled fixing clamps ensure
speedy and secure assembly. The elec-
trical connection is created by means of
plug-in connectors which are also in-
cluded in the delivery.
2.2 Voltage connection
Reactive power control relay obtains its
voltage supply via terminals ”L” and ”N”
(see figure 2, item ’l’).
A phase conductor is to be connected to
terminal ”L” and neutral conductor to ter-
minal ”N”. For advanced connection
variations see sections 2.7 to 2.10.
Important information:
The reactive power control relay is
designed for voltage supplies of up to
240VAC.
The connections for the supply volt-
age are to be fused externally with 4A
max.
In the case of mains networks that do not
facilitate voltage tapping in the 220VAC
to 240VAC range (either phase/phase or
phase/neutral), a voltage transformer
must be used for the power supply for the
control relay. (See section 2.9 )
2.3 Current transformer connection
Outputs S1 and S2 of the current trans-
former are connected to terminals S1 and
S2 (Figure 2, item ’j’) of the control relay.
To keep the load of the current trans-
former as low as possible, the feed lines
should have a adequate cross section.

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It is permissible for connector S1 or S2 of
the current transformer to be grounded.
Caution:
The nominal current in the current
transformer path may not exceed 5 A.
Note:
After connection it is necessary to re-
move the short-circuit jumper on the cur-
rent transformer, if present.
2.4 ”Meas” measuring voltage con-
nection
This connection can be used to switch
the control relay to a different measuring
procedure for monitoring overcurrent
(see section 2.8 ).
This terminal ”Meas” (Figure 2, item ’k’)
is not used in the standard connection.
Important information:
The nominal voltage between the
”Meas” and ”N” connectors may not
exceed 240 VAC. The voltage between
the ”Meas” and ”L” connectors may
not exceed 420 VAC.
If ”Meas” is connected directly to a
phase conductor, then this is to be
secured externally with a maximum
of 4 A.
2.5 Switching contacts
The shared pole of all switching contacts
(Figure 2, item ’m’) is connected to ter-
minal ”L” of the voltage supply.
Important information:
The outputs of the switching contacts
do not have floating potential.
When the switching contacts are
switched, the same voltage is applied as
is used to supply voltage to the control
relay (connection ”L”).
The contactor relays of the capacitor
stages are operated (supplied) via the
switching contacts of the control relay.
2.6 Alarm contact
Switching contact 12 at RM 2112 (switch-
ing contact 6 at RM 2106) can be used
either as a control output for a capacitor
stage or as an alarm contact. The rele-
vant selection is made in setup mode
under -3-.
In the event of an alarm, switching con-
tact 6 is closed.
It should be noted that, even when oper-
ating as an alarm contact, this switching
contact continues to have potential bind-
ing to the supply voltage of the control
relay. If a floating potential contact is re-
quired, use an additional contactor relay.

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Figure 3: Single phase connection
2.7 Single phase connection
The connection diagram above shows
the same connection as the one printed
on the back of the control relay.
The voltage signal for power factor meas-
urement is received in parallel with the
voltage supply. The terminal ”Meas” is
not in use.
In this connection variant, only the 5th,
7th, 11th and 13th harmonics of the volt-
age are used to calculate the harmonic
overcurrent in the capacitor.
This connection variant can be chosen if
the above-mentioned harmonics are suf-
ficient for monitoring overcurrent or if
overcurrent monitoring has been com-
pletely switched off (setup code -2-).
(see section 4.2)
Current transformer and terminal ”L”
should be attached to the same phase
conductor: Either L1, L2 or L3.
RM2112 / 06

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Figure 4: Extended connection
2.8 Extended connection
This type of connection offers a more
precise measuring procedure for the
overcurrent in the capacitor.
In this case, the terminal ”Meas” is at-
tached to another phase conductor of the
AC mains network. The voltage signal for
the internal measurements is tapped be-
tween terminal ”L” and terminal ”Meas”.
Because the voltage signal is recorded
between two phase conductors to which
the capacitors are also connected, the
dU/dt measuring procedure can be used
for calculating the overcurrent.
This means that all frequencies up to the
31st harmonic are taken into account
calculating harmonic overcurrent in the
capacitor(see also section 4.2).
The total harmonic distortion factor of the
voltage (thd) is also measured between
the phase conductors in this type of con-
nection.
RM2112 / 06

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Figure 5: Connection with control transformer
2.9 Connection with voltage
transformer
The connection diagram above shows
how the control relay is connected
together with a control transformer.
Important information:
The control voltage of the transformer
may not exceed 240VAC.
If the voltage signal is tapped by the con-
trol transformer between two phase
conductors, connection must be as
shown in the diagram. The measuring
procedure then is similar to that for the
extended connection (see section 2.8).
If the control transformer taps the voltage
signal between a phase conductor and
neutral, the terminal ”Meas” must remain
unused.
RM2112 / 06

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Figure 6: Connection in special cases
2.10 Connection in special cases
The type of connection shown above
should be used if the voltage between
the phase conductors does not exceed
240VAC.
The following general principles apply:
If the terminal ”Meas” remains unused,
the voltage for terminals ”L” and ”N” must
be connected to a phase conductor and
to the neutral conductor.
If the terminal ”Meas” is used, the voltage
for terminals ”Meas” and ”L” must be
connected each to a phase conductor.
For all types of connections (figure 3 to 6)
it is also possible to connect the current
transformer in phase conductors L2 or
L3. In this case, the voltage connections
to the phase conductors should be ex-
changed accordingly.
If the control relay operates with auto-
matic response current recognition, con-
nection errors would be reported.
If response current recognition is deacti-
vated, then an error in the connection will
lead to functional errors during subse-
quent operation.
RM2112 / 06

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3. Start-up
After installation has been carried out as
described in section 2, the control relay
can be started.
Important information:
Make sure that the connector termi-
nals of the control relay are no longer
accessible (e.g. by means of a locked
door or a cover hood).
3.1 Initial start-up
During initial start-up the control relay
attempts to determine the type of con-
nection and the size of the stages. After
about 5 seconds, ”---” appears on the
display (figure 1, item ’c’). The stages are
switched on and off in succession. This
can take up to 15 minutes.
Important:
If the control relay does not behave as
described above, the device should be
switched off and the installation
should be checked.
It may be that the device has already
been used and behaves as described in
section 3.2.
If the measuring process is not complete
after 15 minutes, then an error has
probably occurred.
Important information:
The device should always be switched
off before carrying out wiring or
installation activities.
(For help in troubleshooting see
section 6.)
Note:
The control relay needs to be con-
nected to at least one capacitor stage
to switch in order to determine the
type of connection.
Make sure that both the control circuit
and at least one capacitor stage are
fully functional.
It is also possible to abort the measuring
procedure by switching off the automatic
connection and responce current identifi-
cation. This takes place in setup mode
-4- and simultaneously requires the man-
ual programming of the stage parameters
(see section 4.4)
After measurement the control relay indi-
cates the results it has determined on the
display (c).
Flashing messages that begin with E
(e.g. E2), indicate an error. Message
”I=0” also indicates an error after initial
start-up.

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In such cases the entire control system is
to be switched off and the error must be
eliminated.
(For troubleshooting see section 6.)
In some circumstances the control relay
displays the message ”A2” after identifi-
cation of the connection type. This
means that there are deviations from the
types of connection shown that do not
restrict the control process.
This message is acknowledged auto-
matically after about 30 seconds or can
be acknowledged by pressing any key.
The control relay always displays ”A1”
after identification of the connection type.
A stage indicator (a) also flashes. The
value displayed alternately with ”A1” in
the display is the determined value for
the indicated stage (switching contact).
This message is acknowledged auto-
matically for each stage after about 15
seconds or can be acknowledged earlier
by pressing any key.
When all messages have been acknow-
ledged, the control relay begins the auto-
matic regulating process. The current
power factor appears on the display.
If the power factor displayed does not
correspond to the actual power factor,
the identification of the connection must
be repeated. This is activated by press-
ing the ”Select” and ”Voltage thd” keys
simultaneously for at least 3 seconds
(check system).
3.2 Subsequent start-up
The control relay begins with its normal
regulatory program immediately after a
power failure.
If the ”Select” and ”Voltage thd” keys
are pressed simultaneously for at least 3
seconds (check system), then the control
relay carries out connection identification
again. It then behaves in the same way
as in the initial start-up (see section 3.1).
This requires that automatic connection
identification should be activated.
( setup mode -4-; see section 4.4)
The programmed control parameters are
stored in a non-volatile memory and can
be altered as necessary. (see chapter 4)
3.3 Maintenance
With maintenance of the power factor
correction system, also the function of
the control relay should be checked.
The control relay may be cleaned only
with a dry cloth.
Important information:
The control relay should be discon-
nected from the mains while cleaning
the back of the control relay.

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4. Control relay setup
A wide range of setting options are pro-
vided to enable the reactive power con-
trol relay to be used in the widest possi-
ble way. To simplify matters the control
relay is set to standard values in the fac-
tory (see table 1 below).
This means that the user mostly only
needs to change the target power factor.
The setup mode can be reached from
any of the control relay’s operating
modes.
Setup
code Significance Standard values Setting range
-1- Target power factor ind 1.00 From inductive o,85 to o,99 and
from inductive 0.85 to 1.00
in steps of 0.01
-2- Maximum harmonic over- current until the alarm is
activated 1.30 From 1.05 times to 1.95 times the
fundamental wave current or OFF
in steps of 0.05
-3- -Alarm output on contact 6
and contact 12 respectively
-switch on or off alarm E5
OFF
no alarm
E5
OFF or On
with or without alarm E5
(see section 4.3)
-4- Automatic determination of
response current On OFF or On
-5- Manual setting of
response current 2.00 from 0.02 to 2 in steps of 0.01
-6- Relative value of the stage 1.0 for each switch
output
Optional for each switch
output the value 0 to 16
in steps of 1.0
-7- Service: ---
Measuring (only the fundamental
frequency components):
- Active current
- Reactive current
- Apparent current
Table 1: Programmable values

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The procedure for checking or repro-
gramming the setting values is as fol-
lows:
• Press the ”Select”(i) key to switch to
setup mode (approx. 6 seconds) until
the ”Setup Mode”LED (f) lights up.
”-1-” then appears on the display. This
number (setup code) shows which vari-
able is displayed and/or changed (see
Table 1).
• The current setting alternates with the
setup code on the display.
• By pressing ”Voltage thd” key (h) it is
possible to switch to the next highest
setting value. The highest setting value
is followed by the lowest setting value
again.
• Pressing the ”Select” key briefly
switches to the next setup code (see
Table 1). the setting value displayed
can also be changed as described
above.
• The control relay returns to automatic
regulatory mode if the ”Select” key is
held down (approx. 3 seconds).
Note:
During ”setup mode”, no controlling
activities are carried out by the control
relay.
If no key is pressed for about 15 minutes,
setup mode is quit automatically.
4.1 Target power factor setting -1-
The required target power factor can be
set between 1.00 and ind. 0.85 in steps
of 0.01.
This for example results in the following
control characteristic for a target power
factor of 1.00:
Active power
Reactive power
2
3
-2
-3
ind
cap
Regenerative power
Activation
Deactivation
The scale spacing corresponds to
0,65 * smallest stage power
Figure 7: Target power factor 1.00
In this setting the control relay attempts
to minimize reactive power irrespective of
active power.
The control relay creates a tolerance
band (or control band) around its target
(in this case the target is to permit no
reactive power). If the operating point is
within the control band, then the control

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relay will not carry out any further
switching.
For a target power factor of 1.00 this
means that the permitted reactive power
may not exceed 0.65 times the lowest
capacitor stage.
If, on the other hand, the work point is
outside of the control band, the control
relay will attempt to reach the control
band with the smallest possible number
of switchings by means of specific activa-
tion and deactivation procedures.
3
Reactive power
4
-1
ind
cap
Regenerative power
Activation
Deactivation
The scale spacing corresponds to
0,65 * smallest stage power
Active power
-2
-3
Figure 8: Target power factor 0.92
In addition to the target power factor set-
ting 1.00, the control relay can also be
set to a target power factor between 0.85
and 0.99. A distinction is made here be-
tween two different control bands. The
control bands are distinguished by a
large or small zero preceding the decimal
point in the target power factor input.
The type of control band shown in figure
8 can be achieved by means of a large
zero preceding the decimal point of the
target power factor setting.
The target power factor forms the upper
limit of the control band. The control relay
always attempts to obtain a better power
factor.
However, the control band levels off at
low values of active power in order to
avoid overcompensation.
For regenerative power (active power
supplied to the mains) the control band
stays leveled off for regenerative power.
1
Reactive power
2
-2-3
ind
cap
Regenerative power
Activation
Deactivation
The scale spacing corresponds to
0,65 * smallest stage power
Active power
Figure 9: Target power factor o.92

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If generators are active in mains parallel
mode, even small amounts of inductive
reactive powers are unwanted in the
mode of regenerative power.
In such cases the target power factor
should be set with a small zero preceding
the decimal point (see Figure 9).
The target power factor always forms the
upper limit of the control band. However,
a capacitive power factor in this case is
prefered to even small amounts of induc-
tive reactive power. So the control band
is completely within the capacitive range
for the mode of regenerative power.
4.2 Overcurrent switch off -2-
The control relay is capable of calculating
the ratio between the rms current and the
fundamental wave current (50 - 60 Hz) in
the capacitor. This is achieved using the
curve of the voltage signal.
If the set value of this ratio is exceeded
for at least one minute due to harmonic
oscillations and resulting resonance-
related amplifications, then the control
relay switches off all activated stages. An
alarm signal is emitted at the same time.
After the overcurrent falls below the limit-
ing value, the control relay begins to acti-
vate the stages again after waiting about
5 minutes.
Note:
This function should be set to OFF
when choked capacitor stages are
used.
4.3 Switching contact as
alarm contact -3-
Contact 6 of the RM 2106 device or con-
tact 12 of the RM 2112 device can be
used to issue alarm signals.
If this menu item is set to On, then every
alarm displayed by the alarm LED will
also cause contact 6 or 12 to close.
Important information:
All contact outputs don’t have floating
potential.
If a floating potential contact is
required, use an additional contactor
relay.
Historical alarms (alarms that are not
pending at present) are not reported at
the alarm contact.
In addition, at setup code -3- the alarm
"Target power factor not reached" E5 can
be permitted or suppressed. If the ind
LED lights up the alarm is permitted. Oth-
erwise the alarm is suppressed.

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4.4 Automatic response current
identification -4-
If set to On the control relay operates
with the response current determined at
initial start-up and the values determined
for the switch outputs. These values can
be read under points -5- and -6- .
If set to Off the response current (setup
code -5-) and the value of the switch
outputs (-6-) must be programmed manu-
ally.
This setting is to be selected if the low
voltage network is fed by several trans-
formers switched in parallel.
Important:
If ”OFF” is set, connection must be as
shown in connection diagrams 3, 4, 5
or 6. Deviations are not signalled and
are not corrected automatically.
4.5 Response current -5-
The response current describes the width
of the control band (see figures 7 to 9).
The greater the value, the broader the
control band.
When automatic response current identi-
fication is switched on (-4-), the response
current is adapted to the connected
power factor correction system to opti-
mum effect. The response current
determined can be read under setup
code -5- but cannot be altered.
When automatic response current identi-
fication is switched off (-4-), the response
current can be set between 0.02 and 2 A
in steps of 0.01 A.
The correct setting for 400 VAC mains
voltage and current transformer with 5 A∼
secondary voltage can be found in
Table 2.
For other mains currents or current
transformers with unlisted primary or
secondary current, the response current
can be calculated according to the
following formula:
Formula 1:
IQ V k
U k VQ k
U k
Au
i
u
i
=⋅
⋅
⋅
⋅ ⋅ ≈ ⋅
⋅
⋅
0 65 400
3150
22
,
IA= Response current to be set in A
Q= Capacitor stage rating of the lowest
stage in var
(not the overall power of the system)
U= Mains voltage in V (phase to phase)
ki= Current transformer ratio
(primary/ secondary current)
ku= Voltage transformer ratio
(primary/ secondary voltage)
(if any)