frako PQC 1202401-0 User manual

Power Quality Controller – PQC
Reactive Power Control Relay
Operating Manual
FRAKO Kondensatoren- und Anlagenbau
www.frako.com

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Inhalt
1 Safety 6
1.1 Objective 6
1.2 Safety instructions 6
1.3 Intended use 7
1.4 Improper use 8
1.5 Repair 8
1.6 Symbols used 8
2 Technical data 9
3 Instrument description 12
3.1 Function 12
3.2 Regeneration 12
4 Mounting the instrument 13
4.1 Suitable location 13
4.2 Installing the instrument 13
5 Installation 15
5.1 Electrical connections 15
5.2 Earth connection 17
5.3 Supply voltage 17
5.4 Voltage measurement 18
5.5 Current measurement 19
5.6 Output relays (control outputs) 21
5.7 Connection diagrams of all PQC instrument types 22
5.7.1 Connection diagram: version PQC 1202401-XX 22
5.7.2 Connection diagram: version PQC 1202403-XX 23
5.7.3 Connection diagram: version PQC 0602401-XX 24
5.7.4 Connection diagram: version PQC 1204801-XX 25
5.7.5 Connection diagram: version PQC 1204803-XX 26
5.7.6 Connection diagram: version PQC 0614801-XX 27
5.7.7 Options for connecting the AUX power supply for PQC XXX480X-XX versions 27
5.7.7.1 Connection diagram for 400/415 V networks with no neutral conductor 28
5.7.7.2 Connection diagram for 690 V networks with a neutral conductor 28
6 Commissioning (Initial start-up) 29
6.1 Alarm function 29
6.1.1 List of alarms and messages 29
6.2 Safety precautions before start-up 30
6.3 Functional checkout 30
6.4 Configuration 30
6.5 Automatic commissioning 30
6.5.1 Automatic connection identification 30
6.5.2 Automatic identification of the connected capacitor stages 31
6.5.3 Calculation of c/k 32
7 Description of the menu 33
7.1 Menu overview 34

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8 Main menu 36
8.1 PQC initial start-up 37
8.1.1 Language selection on start-up 37
8.1.2 Start-up 39
8.2 PQC overview 39
8.2.1 Displayed parameters 40
8.3 Control diagram 41
8.3.1 Scale 41
8.4 Manual control 42
8.4.1 Stages menu 43
8.5 Settings 44
8.5.1 Settable control profiles 44
8.5.2 Typical control profile applications 45
8.5.2.1 Setting target cos φ46
8.5.2.2 Parallel shift 47
8.5.2.3 Limitation L 48
8.5.2.4 Switching delay 50
8.5.2.5 Selecting the control phase 50
8.5.3 General settings 50
8.5.3.1 Capacitor stages menu 51
8.5.3.2 Setting alarm limits 52
8.5.3.2.1 Overcurrent 53
8.5.3.2.2 Detection of voltage blackout (sag) 53
8.5.3.3 Alarm management 54
8.5.3.4 Optional Modbus RTU interface 55
8.5.3.5 Factory settings 56
8.5.3.6 Password protection 56
8.6 Info / status 57
8.6.1 PQC status 58
8.6.2 Corrective power 58
8.6.3 Capacitor stages table 59
8.6.4 Capacitor stages rating diagram 59
8.6.5 Switch cycle diagram 59
8.6.6 Voltage and current harmonics diagram 60
8.6.7 Voltage and current harmonics table 60
8.6.8 Manual frequency analysis 61
8.7 About PQC submenu 61
8.8 Factory default settings 62
8.9 Update 64
9 Instrument versions 65
10 Maintenance 66
10.1 Cleaning 66
11 Decommissioning and removal, storage and disposal 67
11.1 Decommissioning and removal 67
11.2 Storage 69
11.3 Disposal 69
12 General operation 69
12.1 Troubleshooting 70
13 Scope of supply 71

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Figures
Figure 1 PQC dimensions in mm 13
Figure 2 Connection diagram for PQC 1202401-XX 22
Figure 3 Connection diagram for PQC 1202403-XX 23
Figure 4 Connection diagram for PQC 0602401-XX 24
Figure 5 Connection diagram for PQC 1204801-XX 25
Figure 6 Connection diagram for PQC 1204803-XX 26
Figure 7 Connection diagram for PQC 0614801-XX 27
Figure 8 Part of the connection diagram for 400/415 V networks with no neutral
conductor 28
Figure 9 Part of the connection diagram for 690 V networks with a neutral conductor 28
Figure 10 PQC Start screen (firmware version number may be different) 30
Figure 11 Menu structure 1 34
Figure 12 Menu structure 2 35
Figure 13 Menu structure 3 35
Figure 14 Main menu 1/3 36
Figure 15 Main menu 2/3 36
Figure 16 Main menu 3/3 36
Figure 17 Changing the working language 37
Figure 18 Identification: Stage + Connection 38
Figure 19 Identification: Connection 38
Figure 20 Identification: Connection submenu 38
Figure 21 Identification: Stage 38
Figure 22 Identification: Stage submenu 38
Figure 23 Identification: Manual 38
Figure 24 Identification: Manual submenu 38
Figure 25 Connection identification started 39
Figure 26 Capacitor stage identification started 39
Figure 27 Start-up completed 39
Figure 28 PQC overview L1 (1-phase) 40
Figure 29 PQC overview L1 (3-phase) 40
Figure 30 Capacitor stage statuses (1-phase, 6 stages) 40
Figure 31 Capacitor stage statuses (3-phase, 12 stages) 40
Figure 32 Control diagram 41
Figure 33 Control diagram with additional information 41
Figure 34 Zoomed in on control diagram 41
Figure 35 Manual control 42
Figure 36 Manual control enabled 42
Figure 37 Manual control: Switch out stages 42
Figure 38 Manual control: Stages menu 43
Figure 39 Example of a selected stage 43
Figure 40 Message on failed attempt to switch in a stage 44
Figure 41 Settings 44
Figure 42 Control profiles 45
Figure 43 Control profile parameters 45
Figure 44 Control response after setting target cos φ= 1, limitation = 0, parallel shift = 0 46
Figure 45 Control response after setting target cos φ= 0.92 ind, limitation = 0,
parallel shift = 0 47
Figure 46 Control response after setting target cos φ= 1, limitation = 0,
parallel shift = +1.0 47
Figure 47 Control response after setting target cos φ= 0.92 ind, limitation = OFF,
parallel shift = -1.0 48

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Figure 48 Control response after setting target cos φ= 0.92 ind, limitation = +1.0 48
Figure 49 Control response after setting target cos φ= 0.92 ind, limitation = +1.0,
parallel shift = -1.0 49
Figure 50 Control response after setting target cos φ= 0.95 cap, limitation = -1.0,
parallel shift = 0 49
Figure 51 Phase L1 is the control phase 50
Figure 52 General settings menu 51
Figure 53 Capacitor stages 52
Figure 54 Set limits 1/2 52
Figure 55 Set limits 2/2 52
Figure 56 Change set limit for switching cycle counter 53
Figure 57 Alarm management 54
Figure 58 Alarm management; here the Display alarm option 54
Figure 59 Extensions menu 55
Figure 60 Modbus configuration 55
Figure 61 Factory default settings 56
Figure 62 Password prompt 57
Figure 63 Info / status 1/3 57
Figure 64 Info / status 2/3 57
Figure 65 Info / status 3/3 58
Figure 66 PQC status overview 58
Figure 67 Total corrective power Q 58
Figure 68 Capacitor stages table 59
Figure 69 Diagram showing all stages at 100% 59
Figure 70 Diagram showing corrective power of all stages 59
Figure 71 Switch cycle diagram 60
Figure 72 Current harmonics diagram, y-axis 100% 60
Figure 73 Current harmonics zoomed in, y-axis 25% 60
Figure 74 Voltage harmonics table 60
Figure 75 Manual frequency analysis 61
Figure 76 About PQC 61
Tables
Table 1 Connection types for current transformers in L1, L2 and L3 31
Table 2 c/k settings at 400 V AC and 50 Hz 32
Table 3 Key functions 33
Table 4 Factory default settings 62
Table 5 Instrument versions 65
Formulas
Formula 1 Calculation of c/k 32

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1 Safety
1.1 Objective
This operating manual has been prepared for persons who install, connect, commission and
operate the PQC Power Quality Controller.
1.2 Safety instructions
No claims under guarantee shall be valid in the event of damages caused by
failure to observe the instructions in this operating manual. We shall not be held
liable for consequential damages!
Incorrect operation or failure to observe the safety instructions will invalidate
all claims under the guarantee, and no liability is accepted for any injuries to
persons or damages to assets arising therefrom or occasioned thereby!
DANGER!
The following instructions must be observed to prevent danger to life and limb
or damage to equipment and other assets:
Installation and commissioning of the instrument in industrial plant must be car-
ried out in strict compliance with the standards IEC 61508 and DIN VDE 0801.
Any other laws, standards, regulations and safety rules (IEC, EN, VDE, etc.)
relevant to this product and the protection of persons and assets must be
observed. In Germany, it is essential to comply with the Equipment Safety Act
(GSG) and the regulations of the German Social Accident Insurance Institutions.
In other countries, the equivalent local regulations must be followed.
Installation, commissioning, modifications and retrofitting may only be carried
out by appropriately qualified personnel.
In Germany, it is essential to comply with the regulations of the Social Accident
Insurance Institution covering electrical installations. In other countries, the
equivalent local regulations must be followed.
The instrument contains live components at the AC supply voltage and must
therefore not be opened.
If the instrument is visibly damaged, it must not be installed, connected or
commissioned.
Only approved installation cables must be used.
If the instrument does not work after commissioning, it must again be isolated
from the power supply.
The instrument must only be employed on duties up to the specified maximum
power. Overloading the instrument can result in its destruction, create a fire
hazard or cause an electrical accident. The load ratings for the various connec-
tions must not be exceeded.
Do not expose the instrument to direct sunlight or high temperatures, as these
could damage it or shorten its service life.
Do not install the instrument near to sources of heat such as radiators or other
devices that generate heat.
Do not expose the instrument to rain, water, dampness or high levels of humi-
dity. Avoid direct contact with water at all cost.

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Failure to observe the safety instructions can result in death, serious injury or
severe damage to equipment and other assets.
In commercial premises, the local accident prevention regulations must be
complied with (e.g. in Germany, the regulations of the German Social Accident
Insurance Institutions for electrical installations and equipment).
The safety of the system in which the PQC is incorporated is the responsibility
of the persons installing and operating the system.
For safety reasons and to retain conformity with product approval requirements
(CE marking), the user is not permitted to convert or otherwise modify the inst-
rument.
The instrument must always be handled with due care; if it is jolted, knocked or
dropped from even a low height, it will be damaged.
This operating manual may be changed without notification. Please consult our
website www.frako.com for the up-to-date version.
When work is carried out on the instrument terminals and connecting cables,
there is a risk of live components being touched inadvertently. The working
voltage may present a hazard to health or may even be life-threatening.
The risk to life and limb can be significantly reduced by observing the above
safety precautions.
The user must ensure that all operators are familiarized with this operating manual and follow it·
at all times.
This operating manual must be read through carefully and completely before the instrument is·
installed, connected, commissioned and operated. All actions taken must be in accordance
with this operating manual.
The operating manual must be held for future reference.·
· ⚠ Wherever this symbol is shown, the documentation must be referred to.
1.3 Intended use
The PQC Power Quality Controller is intended for the following applications within the scope of
the technical data [see Section 2, Technical data]:
Control of reactive power in stages. Output relays (switched outputs, stages) are provided for·
this purpose. Capacitors can be connected to these via current-amplifying electromechanical
devices (relays, contactors).
Measurement of data relevant to network power quality, such as voltage, current and fre-·
quency, either in any desired phase L1 or in all three phases L1,L2 and L3, depending on the
instrument version [see Section 2, Technical data]; connection of an alarm contact rated within
the allowable limits for the electrical parameters [see Section 2, Technical data].
The PQC is intended for installation in stationary, weather-protected control cabinets and enclo-
sures located indoors. Exposure to dampness is not permitted. The instrument is installed verti-
cally, usually on the outside of the control cabinet or enclosure, so that the controls and display
are accessible to the operator.
The USB port is a service interface provided solely for updating the PQC firmware. Users are not
permitted to use this USB port for any other purpose, and therefore must not connect any cable
or device to it. When the PQC is in operation, the USB port must not be touched. It is intended
for connecting a battery-powered notebook.

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1.4 Improper use
Any use of the instrument that deviates from its intended use is considered improper and
therefore not permitted. If the PQC is used in a way not specified in this operating manual, the
protection supported by the instrument may be adversely affected.
1.5 Repair
Repairs may not be carried out by the customer or user. Should repair work be necessary, the
customer or user must contact the manufacturer:
FRAKO Kondensatoren und Anlagenbau GmbH,
Tscheulinstrasse 21A, D-79331 Teningen, Germany, www.frako.com.
1.6 Symbols used
Special instructions in this operating manual are marked by symbols.
The corresponding word that expresses the extent of the danger is also printed above the inst-
ructions.
In order to avoid accidents, death or injury and damage to assets, these instructions must be
complied with at all times.
Warning signs
DANGER!
Indicates an immediate danger that if not avoided can result in death or serious
injury.
DANGER!
Indicates an immediate danger of electric shock that if not avoided can result in
death or serious injury.
Notes for the correct functioning of the instrument
CAUTION!
These instructions indicate dangers that could result in damage to equipment if
the instructions are not followed.
They can also cover aspects of environmental protection.
NOTE!
These instructions, when followed, serve to ensure the correct functioning and
fault-free operation of the instrument.

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2 Technical data
Power supply
Supply voltage PQC version: PQC xxx240x-xx:·
85 – 267 V AC (absolute limits), frequency 45 – 65 Hz or
100 – 377 V DC (absolute limits)
PQC version: PQC xxx480x-xx:
85 – 530 V AC (absolute limits), frequency 45 – 65 Hz or
100 – 750 V DC (absolute limits)
Power draw maximum 5 VA·
Overcurrent protection External, maximum 2 A (slow-blow) specified·
Inputs
Voltage path measurement PQC version: PQC xxxxxx1-xx: single phase·
PQC version: PQC xxxxxx3-xx: 3-phase
3-phase 80 V AC – maximum 760 V AC (phase–phase, absolute
limits), this corresponds to 115–690VAC networks, electrically
interconnected via high resistance, medium voltage measure-
ment via ../100 V transformer possible
Power failure detection after duration of a half-wave
Current path measurement PQC version: PQC xxxxxx1-xx: single phase·
PQC version: PQC xxxxxx3-xx: 3-phase
x/5 A AC or x/1 A AC (transformer secondary current ≥ 15mA),
electrically isolated, power draw maximum 1 VA per trans-
former connection, continuous overload rating up to 6 A AC,
transient overload maximum 10 A AC for 10 seconds
Digital inputs and outputs PQC version: PQC xxxxxxx-x1:·
Up to 5 × 5 – 24 V DC inputs, alternatively usable as up to
5 × 24 V DC, 100 mA outputs, electrically interconnected with
each other and the temperature input
Temperature inputs PQC version: PQC xxxxxxx-x1:·
1 × PT-100 or PT-1000 RTD, 4-wire or 2-wire configuration,
automatic detector type identification
2 × NTC thermistor type TDK/Epcos-B57861S0502F040,
FRAKO Article No. 29-20094
Measurement range -50 – 200 °C
Electrically connected with the digital outputs
Outputs
Output relays (control outputs, Normally open with common pole P·
PQC version: PQC 120xxxx-xx: 12 output relays and
PQC version: PQC 060xxxx-xx: 6 output relays,
AC -14 250 V AC, maximum 3 A or DC -13 30 V DC, maximum
3 A, mechanical service life 2 × 107switching cycles,
electrical service life AC -14 at 3 A 1 × 105switching cycles,
AC -14 at 0.5 A 2 × 106switching cycles
PQC version: PQC 061xxxx-xx: 6 output relays
AC-14 440 V AC, maximum 3 A or DC-13 125 V DC,
maximum 3 A, mechanical service life 1 × 107switching cycles,
capacitor stages)
inputs
inputs

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electrical service life AC -14 at 3 A 1 × 105switching cycles,
AC -14 at 0.5 A 2 × 106switching cycles
Common supply conductor P to the output relays maximum
10 A
Note: utilization category AC / DC as per IEC 60947-5-1
For all PQC versions in areas where UL / CSA standards apply:
3 A 250 V AC cos φ= 1 at 85 °C
3 A 30 V DC L/R = 0 ms at 85 °C
Alarm contact Volt-free, normally open,·
AC -14 250 V AC, maximum 3 A or DC -13 30 V DC, maximum
3 A, mechanical service life 2 × 107switching cycles,
electrical service life AC -14 at 3 A 1.5 × 105switching cycles,
AC -14 at 0.5 A 2 × 106switching cycles
Note: utilization category AC / DC as per IEC 60947-5-1
In areas where UL / CSA standards apply:
3 A 250 V AC cos φ= 1 at 85 °C
3 A 30 V DC L/R = 0 ms at 85 °C
Digital outputs PQC version: PQC xxxxxxx-x1:·
Up to 5 × 24 V DC, 100 mA outputs, electrically interconnected
with each other and the temperature input, alternatively usable
as up to 5 × 5 – 24 V DC inputs.
Interfaces
Modbus RTU connection PQC version: PQC xxxxxxx-2x:·
120 Ω terminating resistor required at the end of the bus
system
Connections Via pluggable screw terminals
Instrument power AUX Conductor cross section max. 2.5mm², min. 0.2mm²·
PQC version: PQC xxx240x-xx:
Insulation rating: min. 250 V AC, 80 °C
PQC version: PQC xxx480x-xx:
Insulation rating: min. 500 V AC, 80 °C
Protective earth PE Via 6.3 mm female slide connector·
Conductor cross section at least equal to the largest
conductor cross section of the AUX phases, the voltage
measurement connections, the output relays and the alarm
connections; insulation colour yellow/green
Voltage measurement inputs Conductor cross section max. 2.5mm², min. 0.2mm²·
Insulation rating:
Example 1: 230 V AC, select at least 250 V AC, 80 °C
Example 2: 690 V AC, select at least 750 V AC, 80 °C
Current measurement inputs Conductor cross section max. 2.5mm², min. 0.2mm²·
Insulation rating: min. 250 V AC, 80 °C
Output relays (control outputs, Conductor cross section max. 2.5 mm², min. 0.2 mm²·
PQC version: PQC xx0xxxx-xx: 250 V relays
Insulation rating: min. 250 V AC, 80 °C
PQC version: PQC xx1xxxx-xx: 440 V relays
Insulation rating: min. 500 V AC, 80 °C
L1, L2, L3, N
capacitor stages)
L1, L2, L3, terminals S1 and
S2 in each case

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Alarm contact Conductor cross section max. 2.5mm², min. 0.2mm²·
Insulation rating: min. 250 V AC, 80 °C
USB for updates USB Micro-A and Micro-B ports·
Digital inputs and PQC version: PQC xxxxxxx-1x:·
Conductor cross section max. 1.5mm², min. 0.14mm²
Insulation rating: 50 V DC, 80 °C
Temperature inputs PQC version: PQC xxxxxxx-1x:·
Conductor cross section max. 1.5mm², min. 0.14mm²
Insulation rating: min. 50 V DC, 80 °C
Modbus RTU connection PQC version: PQC xxxxxxx-2x:·
Conductor cross section max. 1.5mm², min. 0.14mm²
Insulation rating: min. 50 V DC, 80 °C
Note: 0.14 mm² = AWG 26; 0.2 mm² ≈ AWG 25;·
1.4 mm² ≈ AWG 16; 2.5 mm² = AWG 14
Design data
Dimensions (W × H × D) 144 mm × 144 mm × 70 mm casing·
144 mm × 165 mm × 70 mm including connectors
Mounting Front of panel in 138mm×138mm cutout to IEC 61554, held·
by four retaining lugs at the corners of the casing
Maximum screw tightening torque 0.4 Nm
Weight approx. 770g without packaging·
Ingress protection Front of instrument when mounted in cabinet IP40, when·
mounted in cabinet with upgrade kit (Item No. 20-50015) IP54;
rear of instrument and terminals IP20; all as per EN 60529
Pollution degree 2 as per EN 61010-1:2011-07
Electrical design Casing protection class I as per EN 61140·
Working voltage up to max. 760VAC absolute value at voltage
measurement inputs.
TNV1 circuits, some of which interconnected:
digital inputs and outputs, optional temperature inputs,
optional Modbus connection.
Casing design Flammability rating UL 94 V-0 according to casing manufacturer·
Impact resistance IK06 as per EN 61010-1:2011-07, 8.2.2
Service life At +25 °C ambient temperature 15 years·
EMC EMC as per EN 61326-1·
EN 61000-4-2, electrostatic discharge: air 8kV and contact
6 kV with horizontal and vertical coupling plane
EN 61000-4-3, radiated immunity (EMS) 80 MHz – 1 GHz,
horizontal and vertical, level 10 V/m = industrial environment
radiation, Class A
Hardware version V1.0: EN 55022A EMI 30 MHz – 1 GHz =
industrial environment, Class A
From hardware version V1.1: EN 55022A EMI 30 MHz – 1 GHz
= office and residential area, Class B
(service interface)

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EN 61000-4-6, immunity to conducted disturbances, level
10 V RMS, 150 kHz – 80 MHz1
EN 61000-4-4, burst immunity, 1kV capacitive coupling, 2 kV
injection into power supply cable and voltage measurement
inputs
EN 61000-4-5 surge immunity, 2 kV injection into power supply
cable and voltage measurement inputs
Ambient conditions
Temperature range -20° C to +65° C, noncondensing·
Installation altitude Maximum height above sea level 2000 m·
Measuring system
Accuracy Voltage and current measurement ±1% of full scale reading at·
50/60 Hz and 25 °C ambient temperature
Averaging function Over 1 second, updated every 100 ms·
Harmonics Measured via Lx – N·
All even and uneven harmonics up to the 19th
3 Instrument description
3.1 Function
The PQC Power Quality Controller is a reactive power control relay. It continuously calculates the
reactive and active power components of the supply network using the measurement data from
the current path (current transformer) and the voltage path (voltage measurement connection).
If the reactive power component exceeds certain thresholds, which the PQC has determined
during the calibration procedure or which have been set as described, switching commands are
given via the instrument outputs. If the inductive reactive power is greater than the value preset
during instrument configuration (target cos φ), after an adjustable time delay one or more of the
PQC control contacts are closed. The PQC thus switches capacitor stages in as required in order
to restore the target power factor. If the inductive reactive power component of the loads reduces
again, this causes capacitor stages to be switched out. The PQC makes a variety of options pos-
sible for customizing the control settings to suit the individual application. The clear overview in
the display provides effective monitoring of power factor correction. So-called ‘cyclic switching’ is
a useful feature for prolonging the service life of the installation, since it ensures that all capacitor
stages of the same power rating are on average switched in equally frequently.
3.2 Regeneration
The PQC has a four-quadrant control function. If active power is fed back into the supply net-
work, for example by combined heat and power systems, the PQC continues to correct for the
reactive power drawn from the supply network. When this regeneration occurs, the active power
P is displayed with a minus sign before it. Regeneration mode is also indicated by a symbol
appearing on the display screen.
¹ The standard radio-frequency field test as per EN 61000-4-6 (EMC immunity) calls for amplitude modu-
lation at a modulation frequency of 1 kHz. However, this frequency lies within the measurement range of
the instrument in its intended use (20th harmonic of 50 Hz = 1 kHz). It is therefore to be expected that the
measuring circuit clearly responds to this. For this reason, the radio-frequency field test can only be carried
out without amplitude modulation.

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4 Mounting the instrument
4.1 Suitable location
[see Section 1.3, Intended use]
The PQC is intended for installation in stationary, weather-protected control cabinets and enclo-
sures located indoors. Exposure to dampness is not permitted. The instrument is installed verti-
cally, usually on the outside of the control cabinet or enclosure, so that the controls and display
are accessible to the operator.
Hardware version V1.0: This is a Class A device. In office and residential areas, it can cause
interference to radio reception. In this case, it may be necessary to take appropriate precautions
with the installation.
4.2 Installing the instrument
Figure 1 PQC dimensions in mm
Upgrade kit for IP54:
In the optional upgrade kit (Article No. 20-50015) a gasket is available that must be used when
mounting the PQC in control cabinets with IP54 ingress protection. It is fitted in the groove at the
rear of the instrument’s front panel (moulded polymer) before the PQC is mounted in the cutout.
The gasket seals the gap between the PQC front panel and the wall of the control cabinet.
7
70
63
37
12
12
168 144
135.5
earthing tab
6.3 mm × 0.8 mm

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DANGER!
The rear of the panel-mounting PQC inside the control cabinet or enclosure only
has IP20 ingress protection. Adequate protection against inadvertently touching
live components must be provided, and the ingress of dust and water must be
prevented by ensuring that the instrument is installed in a suitable enclosure
(e.g. control cabinet or distribution panel).
DANGER!
The PQC must not be installed in a hazardous zone, as its switching operations
generate sparks that could ignite flammable gases.
Only install the instrument in areas where there is no danger of a gas or dust
explosion.
The PQC is designed for mounting in a 138 mm × 138 mm cutout to IEC 61554 in the front of a
control cabinet.
It is held in place by four retaining lugs in the corners of the instrument.
Fitting:
Preparation: the four retaining lugs at the corners of the instrument are swivelled to lie flat·
behind its front panel by turning the retaining screws (accessible from the front) anticlockwise.
Insert the sheet-metal rear of the PQC through the cutout provided in the control cabinet until·
fully home (having first fitted the IP54 gasket in the groove behind the PQC front panel when
appropriate).
Press the PQC front panel gently against the control cabinet exterior and tighten the four·
retaining screws at the corners by turning them clockwise, applying a torque of no more than
0.4 Nm. This causes the retaining lugs to swivel outwards and be drawn toward the inner side
of the cabinet wall until they are held tightly up against it.
DANGER!
To avoid accidents, the following must be observed:
- The PQC must be installed in accordance with its intended use before power
is switched on.
- All the connectors supplied with the instrument must be plugged in.
If the above precautions are taken, the danger to life and limb can be signifi-
cantly reduced.
DANGER!
To prevent the PQC overheating, the following must be observed:
- The PQC must be installed in an adequately ventilated space, and its rear and
sidewalls must not be covered.
- No sources of heat must be located in the vicinity.
- The PQC must not be exposed to direct sunlight.
If the above safety precautions are taken, the risk of damaging equipment and
assets or endangering life and limb can be significantly reduced.

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IMPORTANT SAFETY NOTICE!
To avoid accidents, the following must be observed:
When the FRAKO panel-mounting instrument is fitted in the front of a control
cabinet for its intended use, there is a danger that its four retaining screws
could become live and therefore a safety hazard if there is a fault in the wiring
adjacent to the instrument. If a wire at a dangerous voltage works loose, it
could make electrical contact with one of the four retaining screws. This means
that it cannot be excluded that the head of the screw, which can be touched
from outside the cabinet, could become live. In rare cases this could constitute
a danger to life and limb.
At the location where the FRAKO panel-mounting instrument is installed (e.g.
control cabinet, enclosure), all wires and cables must be securely fastened or
grouped in harnesses to ensure that any stray wire or strand cannot contact
one or more of the instrument's retaining screws, thus making it or them live
and therefore dangerous.
If the above safety precautions are taken, the risk of damaging equipment and
assets or endangering life and limb can be significantly reduced.
5 Installation
5.1 Electrical connections
The instrument is connected as shown in the diagrams in [Section 5.4].
DANGER!
The following instructions must be observed to avoid danger to life and limb:
- When the instrument is being installed or serviced, the instrument and the
electrical system must be isolated from the power supply.
- The isolated electrical system must be locked out to prevent its being
inadvertently switched on again.
- It must be verified that none of the terminals are live!
- The earthing tab must always be the first connection that is made
(see Section 5.2, Earth connection).
- The power supply and voltage measurement terminals are live and must not
be touched (risk of electric shock)!
- The measurement terminals L1, L2, L3 and N, the AUX power supply terminals
and both alarm contacts must be short-circuited during any work carried out
on the instrument.
- All live components in the vicinity must be covered to prevent inadvertent
contact.
- If the power supply voltage and the voltage measured exceed the values
specified in this operating manual and stated on the instrument, this may
cause damage to the PQC. Consequential damage to other parts of the
installation is also possible.
- The instrument power supply circuit AUX must be protected externally by
a 2 A slow-blow 250 V AC fuse. One such fuse is required when the power is
from an L–N connection, but two fuses must be installed if an L–L connection
is used.
- A disconnecting device must be installed so that the connections of the PQC
can be isolated from the electrical system and building electrical installations.

16
- Only the specified and appropriate voltages and signals may be connected to
the respective terminals and ports provided for them.
- The cross-sectional areas of all cables used must be adequate for the
purpose.
- Suitable measures must be taken to prevent cables operating at the power
supply voltage being inadvertently pulled out and twisted.
- A disconnecting device, such as an isolator or circuit breaker, must be fitted in
the building electrical installation in a suitable location, accessible by the user
and appropriately labelled as a disconnecting device for the PQC. It must be
able to isolate all cables operating at the power supply voltage from the
instrument.
- If flexible stranded cables with their total cross-sectional area assembled from
several fine filaments are used for the connections, ferrules must be crimped
onto their ends. It must be ensured that no individual filament has been left
out of the ferrule.
When work is carried out on the connecting cables and the instrument termi-
nals, it is possible that live components may be touched inadvertently. If this
occurs, the voltage present may be injurious to health or may even have fatal
consequences.
The risk to life and limb can be significantly reduced by observing the above
safety precautions.
NOTE!
The instrument can be damaged by incorrect operation.
- Only the specified and appropriate voltages and signals may be connected to
the respective terminals and ports provided for them.
- The cross-sectional areas of all cables used must be adequate for the
purpose.
- The required cable types are specified in [Section 2, Technical Data].
If any incorrect cables, voltages or signals are applied to the terminals, this can
result in damage to the PQC and the electrical installation.
DANGER!
To avoid accidents, the following must be observed:
At the PQC installation site (e.g. control cabinet, enclosure), all wires and stran-
ded cables must be adequately secured or grouped in harnesses to ensure that
no conductor can work free and touch one or more of the instrument retaining
screws so as to make them live and a source of danger.
If the above safety precautions are taken, the risk of damaging equipment and
assets or endangering life and limb can be significantly reduced.
NOTE!
If flexible stranded cables used for the connections, insulated ‘short’ ferrules
6 mm in length must be crimped onto their ends.

17
5.2 Earth connection
DANGER!
To avoid accidents, the following must be observed:
- The earthing conductor PE must always be connected to the PQC instrument
casing before any other connections are made.
- The PE conductor cross section must be at least equal to that of the largest
conductor of the AUX phases, the voltage measurement connections, the
output relays or the alarm connections. Its insulation colour is yellow/green.
Earthing connections for network power circuits must have at least the same
current-carrying capacity rating as the circuits themselves.
- If the earthing tab has broken off, the PQC must not be started up.
The instrument must either be repaired or replaced.
- The PQC may only be put into service when the earthing conductor is
connected to it.
If the above safety precautions are taken, the risk of damaging equipment and
assets or endangering life and limb can be significantly reduced.
The earthing conductor PE must always be connected to the PQC instrument casing.
An earthing tab is provided for this in the rear wall of the casing. It is marked with the
earthing symbol as per EN 60617-2 shown at left.
5.3 Supply voltage
The instrument power supply circuit AUX must be protected externally by a fuse, either
2 A slow-blow, 250 V AC (PQC version: PQC xxx240x-xx), or·
2 A 500 V AC time delay (PQC version: PQC xxx480x-xx).·
One such fuse is required when the power is from an L–N connection, but two fuses must be
installed if an L–L connection is used.
A disconnecting device must be installed so that the connections of the PQC can be isolated
from the electrical system and building electrical installations.
The connection diagrams [see Section 5.7] show instruments with 6 or 12 output relays.
DANGER!
To avoid accidents, the following must be observed:
- The safety instructions in [Section 5.1, Electrical connections].
- Connection of the instrument power supply as specified in this manual
- Not exceeding the specified maximum operating voltage at the AUX power
supply terminals [see Section 2, Technical data]
When work is carried out on the instrument terminals and connecting cables,
there is a risk of live components being touched inadvertently. The working
voltage may present a hazard to health or may even be life-threatening.
If the above instructions are followed, and the precautions specified in [Sec-
tion1.2, Safety instructions], are taken, the risk of damaging equipment and assets
or endangering life and limb can be significantly reduced.

18
With these instrument types [see Section 9, Instrument versions], provided that the specified
voltage limits are not exceeded, it is possible to use phase–phase or phase–neutral connections.
For typical examples, [see Figures 8 and 9].
CAUTION!
- The cables and the earthing conductor leading to the instrument must be
permanently connected. It is not permitted for these to have plug-in
connections, except for those connectors supplied with the instrument.
- An external disconnecting device, such as an isolator or circuit breaker,
must be fitted in the power supply line to the instrument. This must be located
in the vicinity of the PQC and must be able to isolate all cables connected
to the AUX terminals. It must be suitable for this application, comply with the
requirements of IEC 60947-1 and IEC 60947-3, and be appropriately labelled
as a disconnecting device for the PQC. This device must not disconnect the
earthing conductor.
5.4 Voltage measurement
Depending on the instrument type [see Section 9, Instrument versions], the PQC can measure
one, two or three AC voltages. The voltage measurement inputs are electrically interconnected
via high resistances. [See Section 2, Technical data], for the measurement ranges. DC voltages
cannot be measured.
The PQC voltage measurement inputs are designed for 100 – 690 V AC networks.
It is possible to measure medium voltages using an x/100V transformer.
It is not necessary to provide external overcurrent protection in the voltage measurement circuits
since these are safety impedance-protected. In this case, a short-circuit-proof cable (double
insulated stranded wire) must be used to connect the voltage measurement inputs.
DANGER!
To avoid accidents, the following must be observed:
- The safety instructions in [Section 5.1, Electrical connections].
When work is carried out on the instrument terminals and connecting cables,
there is a risk of live components being touched inadvertently. The working
voltage may present a hazard to health or may even be life-threatening.
If the above instructions are followed, and the precautions specified in [Section
1.2, Safety instructions], are taken, the risk of damaging equipment and assets or
endangering life and limb can be significantly reduced.
Instrument types with single-phase measurement [see Section 9, Instrument versions]:
For single-phase measurement, the terminals L1 and N are connected as shown in the connec-
tion diagrams in Section 5.7. The voltage can be measured between any two phases or between
any phase and neutral.
Instrument types with 3-phase measurement [see Section 9, Instrument versions]:
For 3-phase measurement, the terminals L1, L2, L3 and Nare connected as shown in the
connection diagrams in [Section 5.7]. Phases L1, L2 and L3 must be connected in correct phase
sequence.
If an instrument of the 3-phase type is used for single-phase measurement, only the terminals L1
and Nare to be used. In this case, it is necessary to connect the terminals L2 and L3 to terminal
Nin order to avoid false readings being obtained.

19
For 3-phase measurement, it is advisable to connect the Nterminal as well. This enables the high
measurement accuracy of the PQC to be achieved when measuring phase–neutral voltages and
the parameters derived from these. If no neutral conductor is present, the Nterminal can be left
unconnected. However, this is only advisable when the phases are symmetrically loaded.
NOTE!
With instrument types designed for three-phase measuring, the voltage mea-
surement inputs not in use must be commoned with the terminal N. This is
necessary, for example, with single-or two-phase connections.
If this is not done, phantom measurement readings may be displayed for the
inputs that are not in use.
With three-phase measurement, automatic connection identification is not
possible.
5.5 Current measurement
The PQC is designed for connection to x / 1 A and x / 5 A current transformers. Only AC currents
can be measured; DC currents cannot be measured. Depending on the instrument type [see
Section 9, Instrument versions], the PQC can measure one, two or three AC currents. [See Sec-
tion 2, Technical data], for the measurement ranges.
DANGER!
If live current transformer circuits are interrupted, there is the danger that arcing
may occur, which would cause electric shock, burns or eye injuries. In addition,
red-hot metal particles could be spattered, which apart from the health hazard
also constitute a fire risk.
To avoid accidents, the following must be observed:
- The safety instructions in [Section 5.1, Electrical connections].
- The current measurement inputs must be connected as specified.
- The retaining screws on the connectors must be tightened to prevent the
connectors accidently working loose.
- The secondary-side connections of the current transformers must be short-
circuited before the circuits to the PQC are interrupted or the connector
removed!
When work is carried out on the instrument terminals and connecting cables,
there is a risk of live components being touched inadvertently. The working
voltage may present a hazard to health or may even be life-threatening.
If the above instructions are followed, and the precautions specified in [Section
1.2, Safety instructions], are taken, the risk of damaging equipment and assets or
endangering life and limb can be significantly reduced.
DANGER!
The retaining screws on the sides of the connectors for the current transformer
circuits must always be tightened before the instrument is put into service.
Tightening these retaining screws prevents the connectors from accidentally
working loose and therefore reduces the risk of arcing.

20
DANGER!
If an earth terminal is provided at the secondary side of the current transformer,
this must be connected to an earthing conductor!
In general, it is recommended that all current transformer circuits be earthed.
CAUTION!
The following must be observed to ensure safe and reliable operation:
- The connection of the current measurement inputs must be via an external,
electrically isolating current transformer.
- Overloading of the current transformers incorporated in the instrument must
be avoided. The maximum allowable continuous current is 6AAC; transient
peaks 10 A.
These measures must be taken to ensure that the instrument is not damaged.
CAUTION!
The instrument terminals can become hot during operation.
- After the PQC has been operating, sufficient time must be allowed for the
instrument and its terminals to cool down before work is carried out on the
terminals.
Compliance with this stipulation will avoid the risk of burns.
Instrument types with single-phase measurement [see Section 9, Instrument versions]:
The current in any desired phase L is measured via an external, electrically isolating current
transformer.
[See Section 2, Technical data], for the measurement range.
The terminals L1 – S1-S2 are connected as shown in the connection diagram in
[Figure 2].
Instrument types with 3-phase measurement [see Section 9, Instrument versions]:
The currents in phases L1, L2 and L3 are measured via external, electrically isolating current
transformers.
See Section 2, Technical data, for the measurement range.
The terminals L1 – S1-S2, L2 – S1-S2 and L3 – S1-S2 must be connected as shown in the con-
nection diagram in [Figure 3], in correct phase sequence.
Unassigned current measurement inputs can be left unconnected.
NOTE!
In networks with a nominal voltage of 1000V and more, the regulations call for
the current transformer circuits to be earthed.
Note: In general, it is recommended that all current transformer circuits be
earthed.
If networks with a nominal voltage of 1000 V or over are left unearthed, damage
may occur to the instrument.
With three-phase measurement, automatic connection identification is not
possible.