Current and Energy Measurement Technology

Current and Energy Measurement Technology
Current and Energy
Measurement Technology
Current Measurement and Evaluation
WAGO's Solution for Energy Monitoring and Conservation
Rogowski Coils, 855 Series
•Conversion of AC currents up to
500 A/2000 A
Rogowski Current Transducer, 789 Series
•Measures AC currents up to 500 A or 2,000 A via
three Rogowski coils
•Provides in-phase conversion to 100 mA AC current
signals for connection to the WAGO-I/O-SYSTEM 750
WAGO-I/O-SYSTEM 750
3-Phase Power Measurement Modules
•Measure voltages and currents, as well as power
and energy consumption in three-phase networks
Contents
2
Energy Management System
6
System Implementation
7
Power and Energy Measurement via 3-Phase Power Measurement Modules
8
Comprehensive Network Analysis via WAGO-I/O-CHECK
12
Plug-in Current Transformers, 855 Series
14
Plug-In Current Transformers, 855 Series … with picoMAX® Pluggable Connector
20
Split-Core Current Transformers, 855 Series
22
Rogowski Current Transducer
26
Rogowski Coils, 855 Series
28
JUMPFLEX®, 857 and 2857 Series
30
Intelligent Current Sensors
36
Measuring Methods
38
Glossary
40
JUMPFLEX® Current Transducers,
857 and 2857 Series
•DC/AC current measurement and conversion
into analog standard signals
(e.g., 0 ... 10 V, 4 ... 20 mA)
Intelligent Current Sensors,
789 Series
•Monitor DC and AC currents up to 140 A
•Data transmission is performed via
MODBUS communication (RS-485)
Current Transformers, 855 Series
•Convert AC currents
- Plug-In Current Transformers with CAGE CLAMP®
- Plug-In Current Transformers with picoMAX®
Pluggable Connector
- Split-Core Current Transformers
3
Energy Management System
DIN EN ISO 50001
For certification, energy management systems must
meet standardized requirements. The individual actions
required may vary greatly and are an ongoing process.
Goal: Reducing energy costs, greenhouse gases and
other environmental impacts.
System illustration as PDCA cycle acc. to ISO 50001:
The three following pillars are required:
Energy team
Energy management representative + team
established by the top management
(defining responsibilities)
Energy Policy and
Energy Planning
Corrective and Preventive
Measures,
Management Review
Continuous
Improvement
Implementation and
Operation
Reviewing, Measuring,
Analysing, Auditing
Certification
Certification according to DIN 50001 requires that a
company/organization …
… establish and document an energy management
system according to DIN 50001,
… define and document, as well as implement and
maintain the application area and limits of its energy
management system,
… define and document how it will meet DIN 50001
requirements, while continuously improving its energy
efficiency.
Energy policy
Appropriate to the nature and extent of the energy
used by an organization
•Commitment to continuous improvement
•Availability of required information and
resources
•Compliance with legal and other requirements
(defining objectives)
Energy planning
•Determination and evaluation of both past and current
energy use/consumption
•Estimation of future energy use/consumption
•Identification of the major energy consumption,
prioritization of improvement possibilities
(from rough to detail)
In other words, such a system is all about establishing responsibilities, determining current states,
continuously defining objectives and actions,
while verifying that they are met.
4
System Implementation
WAGO's Energy Management System
Energy management is not just an empty word at
WAGO; instead, we live it by conserving resources and
protecting the environment.
All organizational and technical measures serve
the goal of using as little energy as possible in the
production and operation of the buildings. Here,
careful handling of resources has been a cornerstone of our company policy for many years.
In 2012, WAGO successfully passed the DIN EN ISO
50001 energy management certification, which forms
the basis for our systematic worldwide actions.
“In 2012, WAGO was one of the very first
companies to be certified!”
Here we rely especially on the following pillars:
•Systematic installation and evaluation of energy
meters
•Expansion of software-supported power data management
•Formation of figures and comparative values
(consideration of dependencies, e.g. production
performance or weather influences on heating and
ventilation)
•Department-spanning cooperation between Facility
Management and other areas, especially Production, Maintenance – Purchasing and Controlling
•Systematic energetic evaluation when
perchasing machines, systems or
new and upgrade facilities
•Implementation of internal audits
•Awareness-raising and staff training regarding
energy issues
A certification according to DIN EN ISO 50001 is
provided from various agencies. Since the idea of sustainability and resource conservation has always been part
of our company mission, WAGO was one of the first companies to be certified in 2012, only 6 months after the
internal process was started.
Energy management always pays off:
•The reduction of electricity and eco taxes as revenue
peak adjustment will become effective by 2013 for
companies operating in the production industry.
•Exemption from the “German Renewable Energy
Act” levy (EEG apportionment) for energy-intensive
companies that invest more than 14% of their gross
value in energy
•Transparency
•Energy cost reduction
•Reduction of your company's greenhouse gas
emissions and carbon footprint
5
•Measuring energy consumption values of machines and systems
•Measuring and processing all relevant measured variables
•Comprehensive network analysis
•Connection to the WAGO-I/O-SYSTEM: fieldbus-independent,
compact and flexible
6
Power and Energy Measurement
via 3-Phase Power Measurement Modules
The WAGO-I/O-SYSTEM 750 offers a comprehensive
range of perfectly tuned solutions for your energy measurement applications. WAGO's 3-Phase Power Measurement Modules measure and process all relevant variables
in a three-phase supply network. They provide system
operators with increased insight into energy consumption
by specific machines and systems, as well as ability to
perform comprehensive network analysis.
Additionally, metrics allow the operator to optimize the
supply to a drive or machine, thus protecting the system
from damage and failure. For this purpose, WAGO's
3-Phase Power Measurement Modules can be integrated
into existing systems.
Energy consumption
Voltage
Current
uce
We red
tect
We pro
gy c
r
e
n
e
r
you
osts!
es!
chin
a
m
r
u
yo
750-493
750-494
750-495



3~ 480 V
3~ 480 V
3~ 480 V/ 690 V
1 A (750-493)
5 A (750-493/000-001)
1 A (750-494)
5 A (750-494/000-001)
1 A (750-495)
5 A (750-495/000-001)
Rogowski coil (750-495/000-002)
Active energy/power



Phase position



Reactive power/energy
via function block


Apparent power/energy
via function block






Four-quadrant operation (inductive,
capacitive, consumer, generator)


Harmonic analysis (up to the 41st
harmonic)


Rotary field detection
Power factor
()
Frequency measurement

N-conductor measurement

Extended temperature range
Housing width

12 mm
12 mm
24 mm
7
Power and Energy Measurement
via 3-Phase Power Measurement Modules
General Configurations
Power and energy measurement on a machine in a 480
VAC mains network via 750-493, 750-494 modules
Power, energy and N-conductor measurement on a machine
in a 480/690 VAC mains network via 750-495 module
L1
L2
L3
N
L1
IL1
L2
IL2
L3
IL3
N
IN
L1
L2
L3
N
L1
L2
L3
L1
IL1
L2
IL2
L3
IL3
N
IN
Machine
N L3 L2 L1
Machine
Applications
Connecting current transformers
to the 3-Phase Power Measurement Modules
k-S1
I-S2
k-S1
I-S2
k-S1
8
I-S2
2007-8873
Terminal block assembly for current transformers
L1
L2
L3
N
PE
1
171
1
Connecting Rogowski coils with electronic ballast
to the 750-494 3-Phase Power Measurement Module
IL1
IL2
IL3
IN
OUT
789-652
Rogowski - Current Transducer
US
POWER
24 V OV
L1
L1
L2
IN
U1 GND U2 GND U3 GND
L3
L3
L2
ON
ON
1
MS
A
C
B
D
24V 0V
A
C
B
D
C
B
D
AI1 AI2
L1 IL1
A
SD
1
171
C
D
B
1
I/O
USR
+US +US
-US -US -US
13 14
A
NS
750-880
0: WBM
255: DHCP
13 14
01 02
LINK 1
ACT
LINK 2
ACT
ETHERNET
W
8
1 2 3 4 5 6 7 8
+US
+
+
UV1 UV2
L2 IL2
—
—
0V 0V
L3 IL3
S
N N
X1
S
X2
750-470
750-494
750-600
Connecting Rogowski coils directly
to the 750-495/000-002 3-Phase Power Measurement Module
L1
L2
ON
1
750-880
0: WBM
255: DHCP
L3
LINK 1
ACT
LINK 2
ACT
MS
A
C
B
D
24V 0V
N
13 14
01 02
ETHERNET
W
8
ON
L3
L2
1 2 3 4 5 6 7 8
L1
A
C
B
D
13 14
A
B
C
D
E
F
G
H
15 16
A
B
C
D
E
F
G
H
AI1 AI2
L1 IL1
I1+ I1-
A
B
C
D
NS
I/O
USR
SD
+
+
UV1 UV2
L2 IL2
I2+ I2-
—
—
0V 0V
L3 IL3
I3+ I3-
S
N N
IN+ IN-
X1
S
X2
750-470
750-495/000-002
750-600
9
Comprehensive Network Analysis
via WAGO-I/O-CHECK
Configuration and visualization of measured values
• Graphical bus node representation
• Displaying, recording and exporting process data (measured values)
• Application settings
• Settings for measuring each of the three phases
• I/O module settings
• Energy value storage settings
Three phases' measured value overview:
Measured value configuration is also possible via function block:
10
Harmonic diagram:
Measured value chart:
11
Everywhere that high currents have to be measured and
processed, WAGO's Plug-In Current Transformers are the
means of first choice.
The 855 Series units transform primary rated currents
into electrically isolated secondary currents of 1 A or
5 A, with a measuring accuracy of one percent (accuracy class 1). They can be used in temperatures ranging from -5 to +50 °C and may be permanently loaded with up to 120% of the nominal current. The 855
Series' UL-recognized components are suitable for
230 V, 400 V and 690 V low-voltage applications.
The plug-in current transformers are inductive, single-conductor current transformers. The special feature is the
screwless, shock- and vibration-resistant CAGE CLAMP®
connection technology. CAGE CLAMP® provides screwless termination of conductors ranging from 0.08 to 4 mm2
(AWG 28–12). Conductors can be terminated from both
the front side and the rear side of the transformers. The
855 Series plastic housing is extremely robust and can
be mounted in four different ways on: round cables, copper current bars, mounting plates and – depending on
the version – carrier rails.
• Screwless CAGE-CLAMP® connection technology
• Continuous overload of 120% the nominal primary current
• Low-voltage current transformer for max. operating voltages up to 1.2 kV
• UL Recognized Components
12
Plug-in Current Transformers, 855 Series
Mounting on round cable
Mounting on carrier rail
with carrier rail adapter
Quick-mount kit
Mounting on copper
current bar
Mounting on mounting
plate
Conductor termination
WAGO Plug-in Current Transformers – Time-Saving Installation
CAGE CLAMP® connection
Quick-mount kit
3
1
1
3
2
2
13
Plug-in Current Transformers, 855 Series
03
855-03xx/xxxx-xxxx
Rail 1: 30 x 10 mm
Rail 2: 25 x 12 mm
Rail 3: 20 x 20 mm
Round cable: 26 mm
04
855-04xx/xxxx-xxxx
Rail 1: 40 x 10 mm
Rail 2: 30 x 15 mm
Round cable: 32 mm
05
855-05xx/xxxx-xxxx
Rail 1: 50 x 12 mm
Rail 2: 40 x 30 mm
Round cable: 44 mm
14
Item Number
855-0301/0050-0103
855-0305/0050-0103
855-0301/0060-0101
855-0305/0060-0101
855-0301/0075-0201
855-0305/0075-0201
855-0301/0100-0201
855-0305/0100-0201
03
855-0301/0150-0501
855-0305/0150-0501
855-0301/0200-0501
855-0305/0200-0501
855-0301/0250-0501
855-0305/0250-0501
855-0301/0400-1001
855-0305/0400-1001
855-0301/0600-1001
05
04
855-0305/0600-1001
855-0401/0400-0501
855-0405/0400-0501
855-0501/1000-1001
855-0505/1000-1001
Primary
Rated Current
50 A
60 A
75 A
100 A
150 A
200 A
250 A
400 A
600 A
400 A
1000 A
Secondary
Rated Current
1A
5A
1A
5A
1A
5A
1A
5A
1A
5A
1A
5A
1A
5A
1A
5A
1A
5A
1A
5A
1A
5A
Rated
Power
Accuracy
Class
1.25 VA
3
1.25 VA
1
2.5 VA
1
2.5 VA
1
5 VA
1
5 VA
1
5 VA
1
10 VA
1
10 VA
1
5 VA
1
10 VA
1
Accessories
855-9900
Carrier Rail Adapter for Plug-In Current Transformers
(for 855-3xx/xxxx-xxxx and 855-4xx/xxxx-xxxx)
855-9910
Quick-mount kit
(2 pieces including cable tie)
15
Current transformers, which are not directly connected to a consumer, must be short-circuited on
the secondary side for safety reasons! If there is no
low-resistance load on the secondary side, then significant increases in voltages can occur. These present a danger for people and may possibly impair the
Implementation of the primary winding
is designated with "K-P1" and "L-P2."
Connections of the secondary winding
are designated with the corresponding
lower case letters "k-S1" and "I-S2."
I-S2
k-S1
functional safety of the current transformer. WAGO's
terminal block assembly for current transformers
(2007-8873) provide the required safety and functionality. Simple actuation of the lever automatically
short-circuits the current transformer via inserted circuit jumper.
L
L2
I-S2
(K)
P2
L3
k-S1
(K)
P1
L3
L1
16
L2
I-S2
L3
PE
k-S1
2007-8873
Terminal block assembly for current
transformers
S1
(k)
S2
(l)
Terminal Block Assembly for Current Transformers
Current transformer power requirements:
Both power losses from the measuring conductors and
from connected devices must be considered when determining actual power requirements. It is therefore necessary to calibrate the power supply of the current transformer (nominal apparent power) to the actual power
requirement of the measuring device. To determine actual power requirements, both the power requirements of
the connected measuring devices and the power losses
from the measuring conductors connected to the transformer's secondary circuit must be taken into account.
Power calculation of copper conductors between measuring device and current transformer:
IS2 x 2 x l
VA
PV=
ACU x 56
IS
I
ACU
PV
= Secondary rated measuring current strength [A]
= Simple conductor length in m
= Conductor cross-section in mm²
= Conductor power loss
Note: When using a common three-phase current return conductor, the values for PV are halved.
Example:
A 1 amp or 5 amp current transformer is
used, with an ammeter on the secondary
circuit, at a distance of 10 m between the
transformer and the measuring device.
Current transformer 1 A
Current transformer 5 A
12 x 2 x 10
VA
PV=
1.5 x 56
PV=
= 0.24 VA
52 x 2 x 10
VA
1.5 x 56
= 5.95 VA
2007-8873 includes:
Quantity Item Number
Description
2x
249-117
Screwless end stop, 10 mm wide
3x
282-882
Locking cover, mechanically locks multiple links, 2-pole
1x
282-884
Locking cover, mechanically locks multiple links, 4-pole
3x
2007-8442
Adjacent jumper for switch lever, insulated, 2-way
1x
2007-8807
2-conductor ground terminal block with touch-proof test socket for 4 mm Ø test plug
4x
2007-8811
2-conductor disconnect/test terminal block with touch-proof test sockets for 4 mm Ø test plugs
6x
2007-8821
2-conductor disconnect/test terminal block with touch-proof test sockets for 4 mm Ø test plugs
2x
2007-8892
End and separator plate, 1.5 mm thick, without lock-out seal
2x
2009-135
WMB Inline, plain
1x
282-435/011-000
Jumper, insulated, 1-3-5
17
Today, extensive current measurements are required in
many systems. The space available for measurement is usually very limited, while relatively low values are being measured. At the same time, measurements must be performed
with sufficient accuracy (at least class 1). A single solution
unites all these requirements. WAGO's extremely compact
current transformer is specially designed for connection to
digital measurement systems. Its compact design makes it
ideally suited for use in a 3-phase power circuit breaker
featuring 17.5 mm phase spacing. The current transformer
features a connector equipped with spring-clamp technology, permitting easy wiring of the secondary conductors.
The optional carrier rail adapter is another advantage of
the current transformer.
•First current transformer with picoMAX® pluggable connector
•Also suitable for space-restricted applications
•Simple assembly permits 17.5 mm phase spacing, allowing perfect adjustment
to any circuit breaker
•Mounting on DIN rails or panels via carrier rail adapter
•Converts currents from 64 A or 35 A to 1 A
•Accuracy class 1
18
Plug-In Current Transformers, 855 Series
… with picoMAX® Pluggable Connector
Termination made easy!
Quick and easy mounting!
<_____________________ 54 ________________________>
<_________ 25 _________>
5 _
7, __
Ø ____
_
__
__
_
__
__
__
__
__
__
__
_
_
__
_<
__
__
__
>
_
_
__
<_____ 19 _____>
<______________ 38 _______________>
<____17,5 ____><____17,5 ____>
<_______17,5_______>
<_____ 19 _____>
5 __
7, __
Ø ____
<___________ 30 ___________>
__
_
_
__
__
__
__
_
_
__
__
__
__
_
_
__
__
<
__
_
__
__
>
__
_
_
<____ 17,5 ____>
Industry's most compact design!
<_________________ 46,3 _________________>
<_________ 27 ________>
Primary
Rated Current
Secondary
Rated Current
Rated Power
Accuracy Class
855-2701/0035-0001
35 A
1A
0.2 VA
1
855-2701/0064-0001
64 A
1A
0.2 VA
1
Item No.
855-9927
Carrier rail adapter
19
20
WAGO's compact split-core current transformers are
ideal for retrofit applications in existing systems. Splitcore current transformers are particularly suited for
applications requiring no current path interruption. The
transformer's accuracy permits extremely precise current
measurements. The split-core current transformers are
capable of supplying the specified rated power at the
end of the secondary cable. All transformers are supplied with color-coded cables. Two UV-resistant cable
ties for reliable and easy mounting are also included.
Termination made easy!
Quick and easy mounting!
Split-Core Current Transformers, 855 Series
Item Number
Primary
Rated Current
Secondary
Rated Current
Rated Power
Accuracy
Class
Cable
Length
855-3001/0060-0003
60 A
1A
0.2 VA
3
5m
855-3001/0100-0003
100 A
1A
0.2 VA
3
5m
855-3001/0200-0001
200 A
1A
0.2 VA
1
3m
855-3001/0250-0001
250 A
1A
0.2 VA
1
3m
855-4001/0100-0001
100 A
1A
0.2 VA
1
3m
855-4001/0150-0001
150 A
1A
0.2 VA
1
3m
855-4001/0200-0001
200 A
1A
0.2 VA
1
3m
855-4101/0200-0001
200 A
1A
0.5 VA
1
3m
855-4101/0250-0001
250 A
1A
0.5 VA
1
3m
855-4101/0400-0001
400 A
1A
0.5 VA
1
3m
855-5001/0400-0000
400 A
1A
0.5 VA
0.5
3m
855-5001/0600-0000
600 A
1A
0.5 VA
0.5
3m
855-5001/1000-0000
1000 A
1A
0.5 VA
0.5
3m
855-5101/1000-0000
1000 A
1A
0.5 VA
0.5
3m
21
The Rogowski Current Transducer records 5–2000 A
alternating currents in a three-phase system. The magnetic field generated around each conductor is detected via three non-contact Rogowski coils and provided
as a proportional voltage signal to the transducer. The
current transducer adjusts the phase of each of the
three voltage signals, converting them into 100 mA alternating current signals, which are then transmitted to
the 3-Phase Power Measurement Modules. Within the
22
WAGO-I/O-SYSTEM, the 3-Phase Power Measurement Module measures electrical data (e.g., voltage,
current, effective power and energy consumption) in a
three-phase supply network. Thus, the user is always
able to determine the load condition (imbalance, reactive components), to optimize consumption and protect
machines or systems from damage and breakdowns.
Easy installation of Rogowski coils also allows existing
systems to be retrofitted without process interruption.
Rogowski Current Transducer
IL1
IL2
IL3
IN
OUT
789-652
Rogowski - Current Transducer
US
POWER
IN
24 V OV
L1
L1
L2
L2
U1 GND U2 GND U3 GND
L3
L3
ON
1
750-880
0: WBM
255: DHCP
ETHERNET
W
8
ON
1 2 3 4 5 6 7 8
+US
13 14
01 02
LINK 1
ACT
LINK 2
ACT
MS
A
C
B
D
24V 0V
A
C
B
D
+US +US
-US -US -US
13 14
A
C
B
D
AI1 AI2
L1 IL1
A
B
C
D
(conductor length < 30 m)
NS
I/O
USR
SD
+
+
UV1 UV2
L2 IL2
—
—
0V 0V
L3 IL3
S
N N
X1
S
X2
750-470
Item Number
789-652
750-494
750-600
Input signal
Output Signal
Overcurrent
Sensitivity
750 A
10.05 mV;
50 Hz, sinusoidal
3000 A
10.05 mV;
50 Hz, sinusoidal
3 x RT 500
(500 A)
3 x 100 mA AC
789-654
750-494
3 x RT 2000
(2,000 A)
see page 7
855-9100/500-000
855-9300/500-000
see pages 24–25
855-9100/2000-000
855-9300/2000-000
23
Rogowski Coils, 855 Series
Slim, Light-Weight, Flexible, Hinged Current Sensor
The Rogowski coil is a closed-air coil with non-magnetic split core. The coil is placed around a conductor
or current bar. The magnetic field produced by the
AC current flowing through the conductor induces an
output voltage in the coil. This measurement proce-
dure provides galvanic isolation between the primary
circuit (power) and secondary circuit (measurement).
Easy installation of the Rogowski coils allows existing
systems to be retrofitted without time-consuming installation or process interruption.
• Easy installation of Rogowski coils for retrofitting existing machines and
systems without process interruption
• Broad measuring range: only two types of Rogowski coils instead of several different current transformers
• Reduced footprint: ideal for measuring high currents
• Connection to the WAGO-I/O-SYSTEM links measurement results with
controls (e.g., for optimizing consumption or preventing damage), unlike
a system that only provides measurements.
• Existing CODESYS function blocks can be used, minimizing
engineering time.
24
27,4
Ø5
Rogowski Coils – Time-Saving Installation
34,4
1500
3000
RT 500:
1.5 m/long
cable
RT 2000: 3 m long cable
black
-Us
Ø max 55
IpIp
RT 500: Ø max 55
RT 2000: Ø max 125
Ø5
15,7
white
+Us
Item Number
Input
Output
Description
RT 500,
1.5 m long cable
855-9100/500-000
500 A
10.05 mV
855-9300/500-000
RT 500,
3 m long cable
855-9100/2000-000
RT 2000,
1.5 m long cable
2000 A
855-9300/2000-000
40.2 mV
RT 2000,
3 m long cable
25
The 857-550 Current Transducer measures both 0–1 A
and 0–5 A AC/DC currents, converting the input
signal to an analog standard signal at the output
(e.g., 4–20 mA).
Current Transducer
857-550
857-552
Input signal
0 … 1 A AC/DC
0 … 5 A AC/DC
Rogowski coils
500 A/2000 A
Frequency range
16 Hz … 400 Hz
16 Hz ... 1000 Hz
Output signal
Voltage: 0 … 5 V, 1 … 5 V, 0 … 10 V, 2 … 10 V
Current: 0 … 10 mA, 2 … 10 mA, 0 … 20 mA, 4 … 20 mA
Digital output DO
Load impedance
Supply voltage
26
The 857-552 Rogowski Transducer records RMS values from alternating currents via a Rogowski coil, converting the input signal into an analog standard signal
at the output (e.g., 4–20 mA).
24 VDC/100 mA
Current ≤ 600 Ω,
Voltage ≥ 2000 Ω
Current ≤ 600 Ω,
Voltage ≥ 1000 Ω
24 VDC
JUMPFLEX® Current Transducers
Current Transducer/Rogowski Transducer
0 … 20 mA
Current Transducer
857-550
A
C
B
Current transformer
250 A/1 A
A
C
B
D
A
C
B
D
A
C
D
B
PLC
DO/Alarm indication
24 V/100 mA
L1
D
Power
• Configuration via DIP switch/PC configuration tool/smartphone app
• Digital switching output (configurable switching thresholds)
• Configurable output signal
• True RMS measurement or arithmetic mean value
• Calibrated measurement range switching
• Measuring range overflow indication
• Safe 3-way isolation with 2.5 kV test voltage acc. to EN 61140
Rogowski Transducer
857-552
RT 500 (500 A)
+US
0 … 20 mA
A
B
C
D
A
B
C
D
A
B
C
D
A
B
C
D
-US
PLC
Rogowski coil
L1
DO/Alarm indication
24 V/100 mA
Power
• Configuration via DIP switch/PC configuration tool/smartphone app
• Digital switching output (configurable switching thresholds)
• Configurable output signal
• Supports different types of Rogowski coils
• True RMS measurement (TRMS)
• No current bar interruption required during installation
• Calibrated measurement range switching
• Indication of measuring range overflow/wire break in the measuring equipment
• Safe 3-way isolation with 2.5 kV test voltage acc. to EN 61140
27
WAGO's 2857-0550 Current Transducer is used for
measuring, isolating and converting AC/DC currents
into standard signals in various industries (e.g., processing, sewage, power technology or machinery and plant
engineering). Transducers protect installations, systems
and persons via electrical isolation of measurement signals (immunity to external interferences, such as differen-
tial signals or floating grounds, rise in potential) or via
overcurrent monitoring. WAGO's transducer is ideal for
current measurement and overcurrent detection, while simultaneously isolating field signals to the central control
system for further signal processing. Measured values
visualization or settings are performed via WAGO's
2857-0900 Display.
• Configuration via DIP switch/PC configuration tool/smartphone app
• Digital switching output (configurable switching thresholds)
• Changeover contact relay output with 6 A
• Configurable output signal
• True RMS measurement (TRMS)
• Calibrated measurement range switching
• Measuring range overflow indication
• Safe 3-way isolation with 2.5 kV test voltage acc. to EN 61140
28
JUMPFLEX® Current Transducer
2857 Series
Application example:
0 … 20 mA
DO/Alarm indication
24 V/100 mA
A
B
C
D
A
B
C
D
A
B
C
D
A
B
C
D
Power supply
L1
PLC
Emergency power
Power
Lighting monitoring
Current Transducer
2857-550
Input signal
AC/DC 100 A
Frequency range
15 … 2000 Hz
Output signal
Current: ± 10 mA; 0 … 10 mA; 2 … 10 mA;
± 20 mA; 0 … 20 mA; 4 … 20 mA
Voltage: ± 5 V; 0 … 5 V; 1 … 5 V;
± 10 V; 0 … 10 V; 2 … 10 V
Digital output
24 VDC/100 mA
Relay output
1 changeover contact (1u)
250 VAC/6 A
Load impedance
Nominal supply voltage
Current < 600 Ω
Voltage > 1000 Ω
24 VDC
29
JUMPFLEX® Configuration, 857 and 2857 Series
Interface Configuration Software
The following devices are already supported:
857-401: Isolation Amplifier
857-500: Frequency Transducer
857-531: Threshold Value Switch
857-550: Current Transducer
857-552: Rogowski Transducer
857-801: Temperature Transducer for
Pt Sensors
857-809: Potentiometer Position Transducer
857-811: Temperature Transducer for
TC Sensors
857-819: Millivolt Transducer
2857-0401: Universal Isolation Amplifier
2857-0533: RTD Threshold Value Switch
2857-0534: TC Threshold Value Switch
2857-0550: Current Transducer
100 AC/DC
The interface configuration software – DIP switch alternative
Software features:
• Easy EXE application
• Automatic module detection
• Visualization of process values
• Parameterization of the digital switch output (threshold functionality)
• Communication via 750-923 WAGO USB Service Cable or
WAGO 750-921 Bluetooth® Adapter
30
Interface Configuration App
Android-Based
JUMPFLEX®-ToGo
JUMPFLEX®-ToGo Configuration App – DIP Switch Alternative
The "JUMPFLEX®-ToGo" free app brings the power
of a PC-based configuration software to your mobile device. Configure 857 Series Transducers' input
and output parameters via finger swipe on your An-
Device information
Input parameter
droid-based smartphone or tablet. You can also easily
view both configuration data and actual measured
value. WAGO's 750-921 Bluetooth® Adapter communicates between your smartphone and the transducer.
Output parameter
Digital output
Actual value
750-921
QR Code
31
Addressing
1…
32
s
e ns
ors
Status indicator
Intelligent current sensors monitor solar plants
or inverters for DC measurements within a large
current measurement range.
32
289-965
RJ-45 Interface Module for
Current Sensor Modules
Intelligent Current Sensors
… Monitor Solar Array Performance via MODBUS Communication
Measuring range
789-620
789-621
789-622
DC 0 … 80 A
DC 0 … 140 A
AC 0 … 50 A rms
Transmission error
≤ 0.5% of upper range value
Power supply
12 V … 34 V (via RJ-45)
Feedthrough
15 mm (for electrical lines)
Interface
RS-485
Protocol
MODBUS over serial line
1 … 32
Addressing
Max. bus length
≤ 1200 m
Connection to a WAGO PERSPECTO®
Control Panel
Serial Interface RS-485
Supply voltage
E.g., 787-1002
EPSITRON® COMPACT Power
33
Measuring Methods
Shunt Measurement (AC/DC)
Current measurement is performed using a low-ohm resistor (shunt), which is connected in parallel to a voltmeter. The current is proportional to the current measured
at the shunt resistor, I = V/R.
Iin
Measuring device
Ushunt
V
Rshunt
Vin
The shunt can be located upstream or downstream of
the load (high-side/low-side method). WAGO products
are equipped for both methods, giving users the freedom to decide where the conductor section should be
disconnected. In addition to DC and AC currents, shunt
measurements are also suitable for measuring superimposed signals (DC + AC). Accuracies of 0.1% and
better can be achieved. WAGO's 855 Series Plug-In
Current Transformers with predefined division ratio can
be used to expand the measurement range for pure AC
measurements.
Rmeas
Iin= Vshunt / Rshunt
High-Side Method
Iin
Rmeas
Measuring device
Vin
Ushunt
Rshunt
V
Iin= Vshunt / Rshunt
Low-Side Method
Shunt Measurement in Combination with
Plug-In Current Transformer (AC)
Plug-In Current Transformers are used at higher measurement currents. They function according to the transformer principle and expand the range of an existing
measurement system (usually a shunt transformer). The
number of secondary windings mirrors the fixed setting
of the division ratio. The electrically isolated output AC
is proportional and in phase with the input AC. The
measuring error typically lies below 1%.
B
A
I
I
Transformer Principle
34
Hall Effect Sensors (AC/DC)
A soft-magnetic core is applied around the conductor.
The core has a small air gap in which the Hall effect
sensor is located. A magnetic flux is generated in the
ring-shaped core by the current flowing through the conductor. The magnetic flux also flows through the Hall
effect sensor, which outputs a voltage signal proportional to the current measured. This signal is prepared
and forwarded for processing. Using the Hall method,
different signals (AC/DC) and measuring ranges can
be mapped, depending on the design. Measurement
accuracy lies between 0.5% and 1%.
Hall Effect Sensor
Vout
I meas
Hall Effect Sensor
Rogowski Coil (AC)
U
V, I
A closed-air coil (i.e., coil without iron core) is applied
around the conductor to be measured. The AC current
flowing through the conductor induces a proportional
voltage in the Rogowski coil. The output voltage is amplified and conditioned. A measurement error of less
than 2% and a response threshold of only a few amps
guarantee a straightforward measurement of high to
very high AC currents.
Measuring Method:
Advantages:
Application Areas:
Shunt
• Very high accuracy
• Suitable for DC and AC currents
• Integration into control and regulation systems
• Process and energy technology
Shunt +
Current transformer
• Suitable for higher AC currents
• Potential-free measurement
• Installations and systems technology
• Network monitoring and analysis
Hall effect
• Potential-free measurement
• For higher currents
• DC and AC versions
• PV systems and general energy technology
• Control processing of several individual systems
35
Glossary
Apparent Power
Apparent power (S) is the total power of a transmission network. It is composed of active power (P) and
reactive power (Q).
A positive apparent power, which is in the interest of
the consumer, means that the power is drawn from the
grid. A negative apparent power, however, means that
power is fed back into the grid.
S=U*I
+
-
S
+
I
-
Active Power
U
-
P=UR*IR
S
U
Active power (P) is the power actually consumed. It has
no phase shift between current and voltage and relates
to a resistive load. For an alternating voltage, the active
power results from the multiplication of the RMS values
for current and voltage.
I
Reactive Power
Reactive power (Q) refers to a load on the power grid,
which acts against the power flowing from the producer
to the consumer. Reactive power is the product of voltage and current flowing through a reactance. Reactive
power is generated by any device that is connected
to an AC grid. Any electrical equipment generates an
electromagnetic field when a voltage is applied. The
magnetic field is constantly being built up and then dismantled again by the alternating voltage. The energy
created when the field is being dismantled is fed back
into the power grid, which increases the resistance to
the current flow.
36
Q=UL*IL
+ +
-
-
U
+
-
I
S
Harmonics
Harmonics are currents having frequencies that are
multiples of the 50 Hz fundamental frequency. The harmonic degree is defined as the relationship between
harmonic and fundamental frequency.
Harmonics are created by devices with non-linear characteristic curve (e.g., transformers, rectifiers, televisions,
computers, halogen lighting). The non-sinusoidal currents of these devices result in a voltage drop in the
network impedance, which distorts the network nominal
voltage and affects the proper operation of the device.
The impacts of harmonics contamination include: failures of protective devices, thermal overload and premature ageing of electrical equipment, loss of mechanical
stability, performance loss, measurement errors, higher
noise level, hard drive failures, system crashes, operational breakdowns, etc.
If many devices are operated within a network generating the third harmonic, a very high current load of the
neutral conductor might be the consequence. Neutral
conductor currents caused by harmonics in TN-C power
networks travel within the entire equipotential bonding
system via water/heating pipes, grounding systems,
shields of data lines, video lines as well as communication systems, and can lead to increased corrosion or
pitting on piping systems.
Therefore, a continuous harmonics and neutral conductor analysis is required for guaranteeing both power
supply and overvoltage protection, as well as fire safety.
Fundamental frequency (50 Hz)
Third harmonic (150 Hz)
Addition gives a non-sinusoidal wave form.
37
Arithmetic Mean Value
The arithmetic mean value (also average) is the quotient of the sum of all measured values detected and the
number of measured values.
For periodic variables (e.g., sine waves) the arithmetic mean is zero. For this reason, it is not meaningful
for use with periodic variables, or it only provides information about a possibly present constant. For DC
variables, the arithmetic mean value corresponds to
the average measured value viewed over time.
Sine current
400
300
200
A
100
0
-100
3/2T
1/2T
2T
-200
-300
-400
Period
Sine
Arithmetic mean value
Mean Square Value
The mean square value — RMS (root-mean-square), also
the TRMS (true root-mean-square) — is the square root
of the quotient of the sum of squares of the measured
values and number of measured values (square root of
the average of the measured value).
In electrical engineering, the effective value of an
periodic quantity corresponds to the effective value
of the DC variable. It is characteristic of the power
transformed in the consumer.
Irms ≈
1
n
n
∑x
2
i
i=1
Mean square current
400
350
300
250
A differentiation is frequently made between the terms
RMS and TRMS. This is merely historical conditioning,
so that newer measuring procedures are preferred over
form factor based methods. In principle, WAGO measures according to the TRMS method. However, no special differentiation is made, as both terms describe the
same mathematical equation, and one merely indicates
the specific accuracy of the measurement.
38
200
A 150
100
50
0
1/2T
T
Period
Absolute value of the sine curve
3/2T
RMS
2T
Digital Processing
During digital processing, the signal is sampled in defined, very short time intervals (digitized). The sampled
values are processed and, e.g., converted into an analog standard signal.
Input signal
400
300
200
100
Digital processes are becoming increasingly common,
since high reproducibility and signal-authentic mapping
can be guaranteed due to the high sampling rates. In
addition, further processing or transmission of the digitized information is easier, less susceptible to interference and more flexible, due to the software.
0
-100
1/2T
-200
-300
-400
Sampling
80000
70000
60000
50000
40000
30000
20000
10000
0
Sampled signal
Analog Processing
During analog processing, the input signal is fed directly to a processing unit and prepared according to a
fixed transfer function. The processing takes place using
an operational amplifier (OpAmp) and a few passive
components.
39
IM-PE-US-DE-BA-130815_002 · 0888-0595/0200-6901 · Current and Energy Measurement 2.0 US · 11/2013-00 · Printed in Germany · Subject to design changes
WAGO Kontakttechnik GmbH & Co. KG
Postfach 2880 · 32385 Minden
Hansastraße 27 · D-32423 Minden
Phone: Headquarters +49 (0)571/887 - 0
Sales
+49 (0)571/887 - 222
Order Service
+49 (0)571/887 - 333
Technical Support +49 (0)571/887 - 555
Fax: +49 (0)571/887 - 169
Email:
info@wago.com
Online:
www.wago.com
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