National Instruments NI 9242 User manual

NI-9242

GETTING STARTED GUIDE
NI 9242
3 AI/1 Neutral, 250 Vrms L-N/400 Vrms L-L,
24 Bit, 50 kS/s/ch Simultaneous

This document explains how to connect to the NI 9242.
Note Before you begin, complete the software and
hardware installation procedures in your chassis
documentation.
Note The guidelines in this document are specific to
the NI 9242. The other components in the system might
not meet the same safety ratings. Refer to the
documentation for each component in the system to
determine the safety and EMC ratings for the entire
system.
Safety Guidelines
Operate the NI 9242 only as described in this document.
Caution Do not operate the NI 9242 in a manner not
specified in this document. Product misuse can result in
a hazard. You can compromise the safety protection
built into the product if the product is damaged in any
way. If the product is damaged, return it to NI for
repair.
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Hazardous Voltage This icon denotes a warning
advising you to take precautions to avoid electrical
shock.
Safety Voltages
Connect only voltages that are within the following limits.
Maximum working voltage, channel-to earth ground
Continuous 250 Vrms,
Measurement Category III
Division 2 and Zone 2 hazardous locations applications
Channel-to-earth
ground
250 Vrms,
Measurement Category III
Measurement Category III is for measurements performed in the
building installation at the distribution level. This category refers
to measurements on hard-wired hardware such as hardware in
fixed installations, distribution boards, and circuit breakers. Other
examples are wiring, including cables, bus bars, junction boxes,
switches, socket outlets in the fixed installation, and stationary
motors with permanent connections to fixed installations.
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Caution Do not connect the NI 9242 to signals or use
for measurements within Measurement Category IV.
Safety Guidelines for Hazardous Voltages
If hazardous voltages are connected to the device, take the
following precautions. A hazardous voltage is a voltage greater
than 42.4 Vpk voltage or 60 VDC to earth ground.
Caution Ensure that hazardous voltage wiring is
performed only by qualified personnel adhering to local
electrical standards.
Caution Do not mix hazardous voltage circuits and
human-accessible circuits on the same module.
Caution Ensure that devices and circuits connected to
the module are properly insulated from human contact.
Caution When module terminals are hazardous
voltage LIVE (>42.4 Vpk/60 VDC), you must ensure
that devices and circuits connected to the module are
properly insulated from human contact. You must use
the NI 9967 connector backshell kit to ensure that the
terminals are not accessible.
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Safety Guidelines for Hazardous Locations
The NI 9242 is suitable for use in Class I, Division 2, Groups A,
B, C, D, T4 hazardous locations; Class I, Zone 2, AEx nA IIC T4
and Ex nA IIC T4 hazardous locations; and nonhazardous
locations only. Follow these guidelines if you are installing the
NI 9242 in a potentially explosive environment. Not following
these guidelines may result in serious injury or death.
Caution Do not disconnect I/O-side wires or
connectors unless power has been switched off or the
area is known to be nonhazardous.
Caution Do not remove modules unless power has
been switched off or the area is known to be
nonhazardous.
Caution Substitution of components may impair
suitability for Class I, Division 2.
Caution For Division 2 and Zone 2 applications,
install the system in an enclosure rated to at least IP54
as defined by IEC/EN 60079-15.
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Special Conditions for Hazardous Locations Use in
Europe and Internationally
The NI 9242 has been evaluated as Ex nA IIC T4 Gc equipment
under DEMKO Certificate No. 12 ATEX 1202658X and is
IECEx UL 14.0089X certified. Each NI 9242 is marked II 3G
and is suitable for use in Zone 2 hazardous locations, in ambient
temperatures of -40 °C ≤ Ta ≤ 70 °C. If you are using the NI 9242
in Gas Group IIC hazardous locations, you must use the device in
an NI chassis that has been evaluated as Ex nC IIC T4, Ex IIC
T4, Ex nA IIC T4, or Ex nL IIC T4 equipment.
Caution The system shall only be used in an area of
not more than Pollution Degree 2, as defined in
IEC 60664-1.
Caution The system shall be mounted in an
ATEX/IECEx-certified enclosure with a minimum
ingress protection rating of at least IP54 as defined in
IEC/EN 60079-15.
Caution The enclosure must have a door or cover
accessible only by the use of a tool.
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Electromagnetic Compatibility Guidelines
This product was tested and complies with the regulatory
requirements and limits for electromagnetic compatibility (EMC)
stated in the product specifications. These requirements and
limits provide reasonable protection against harmful interference
when the product is operated in the intended operational
electromagnetic environment.
This product is intended for use in industrial locations. However,
harmful interference may occur in some installations, when the
product is connected to a peripheral device or test object, or if the
product is used in residential or commercial areas. To minimize
interference with radio and television reception and prevent
unacceptable performance degradation, install and use this
product in strict accordance with the instructions in the product
documentation.
Furthermore, any changes or modifications to the product not
expressly approved by National Instruments could void your
authority to operate it under your local regulatory rules.
NI 9242 Getting Started Guide | © National Instruments | 7

Special Conditions for Marine Applications
Some products are Lloyd’s Register (LR) Type Approved for
marine (shipboard) applications. To verify Lloyd’s Register
certification for a product, visit ni.com/certification and search
for the LR certificate, or look for the Lloyd’s Register mark on
the product.
Caution In order to meet the EMC requirements for
marine applications, install the product in a shielded
enclosure with shielded and/or filtered power and
input/output ports. In addition, take precautions when
designing, selecting, and installing measurement probes
and cables to ensure that the desired EMC performance
is attained.
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Preparing the Environment
Ensure that the environment in which you are using the NI 9242
meets the following specifications.
Operating temperature
(IEC 60068-2-1, IEC 60068-2-2)
-40 °C to 70 °C
Operating humidity
(IEC 60068-2-78)
10% RH to 90% RH,
noncondensing
Pollution Degree 2
Maximum altitude 5,000 m
Indoor use only.
Note Refer to the device datasheet on ni.com/manuals
for complete specifications.
NI 9242 Getting Started Guide | © National Instruments | 9

NI 9242 Pinout
AI0
AI1
AI2
Neutral
0
1
2
3
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Table 1. Signal Descriptions
Signal Description
AI Analog input signal connection referenced to the Neutral
signal
Neutral Referenced, single-ended analog input connection
Connecting Phase Measurements
The NI 9242 accepts three-phase and single-phase measurement
configuration.
Three-Phase Measurement Configurations
NI recommends the following three-phase connection types.
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4-Wire WYE Measurement Configuration
NI 9242
AI0
Phase A
Phase B
Phase C
Neutral Neutral
AI2
AI1
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High-Leg Delta Measurement Configuration
NI 9242
AI0
Phase A
Phase B
Phase C
Neutral
AI2
AI1
Neutral
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3-Wire Delta Measurement Configuration
NI 9242
AI0
Phase A
Phase B
Phase C AI2
AI1
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Corner Grounded 2-Wire Delta Measurement
Configuration
NI 9242
AI0
Phase A
Phase B
Phase C AI2
AI1
Corner grounded 2-wire delta measurement configurations
support only standard service levels up to 240 Vrms L-L.
Connecting Single-Phase Measurement
Configurations
NI recommends the following single-phase connection types.
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3-Wire Measurement (Split Phase) Configuration
NI 9242
AI0
Neutral
AI1
2-Wire Measurement
NI 9242
AI0
Neutral
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Potential Transformer Connections
The NI 9242 accepts the following potential transformer
connections.
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4-Wire WYE-to-WYE (Full)
AI0
AI1
AI2
N
Phase A
Phase B
Phase C
Neutral
NI 9242
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In a 4-wire WYE-to-WYE (full) configuration, the Neutral
terminal on the NI 9242 measures the neutral-to-ground voltage
through the bottom transformer. You can use a lower ratio
transformer due to the typically low voltages on the Neutral
terminal. Ensure that you scale each NI 9242 channel reading
with the corresponding transformer ratio.
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