National Instruments NI 9481 User manual

OPERATING INSTRUCTIONS AND SPECIFICATIONS
NI 9481
4-Channel SPST Electromechanical Relay Module
ni.com/manuals
DeutschFrançais

NI 9481 Operating Instructions and Specifications 2 ni.com
This document describes how to use the National Instruments 9481
and includes specifications and terminal assignments for the NI 9481.
Visit ni.com/info and enter rdsoftwareversion to determine
which software youneed for the modules youare using. For
information about installing, configuring, and programming the
system, refer to the system documentation. Visit ni.com/info and
enter cseriesdoc for information about C Series documentation.
Note The safety guidelines and specifications in this
document are specific to the NI 9481. The other
components in the system might not meet the same safety
ratings and specifications. Refer to the documentation for
each component in the system to determine the safety
ratings and specifications for the entire system. Visit
ni.com/info and enter cseriesdoc for information
about C Series documentation.

© National Instruments Corp. 3 NI 9481 Operating Instructions and Specifications
Safety Guidelines
Operate the NI 9481 only as described in these operating
instructions.
Hot Surface This icon denotes that the component may be
hot. Touching this component may result in bodily injury.
Safety Guidelines for Hazardous Voltages
If hazardous voltages are connected to the module, take the
following precautions. A hazardous voltage is a voltage greater
than 42.4 Vpk 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 Make sure that devices and circuits connected to
the module are properly insulated from human contact.

NI 9481 Operating Instructions and Specifications 4 ni.com
Caution When module terminals are hazardous voltage
LIVE (>42.4 Vpk/60 VDC), youmust ensure that devices
and circuits connected to the module are properly
insulated from human contact. Youmust use the NI 9932
connector backshell kit to ensure that the terminals are
not accessible.
Figure 1 shows the NI 9932 connector backshell.
Figure 1. NI 9932 Connector Backshell

© National Instruments Corp. 5 NI 9481 Operating Instructions and Specifications
Safety Guidelines for Hazardous Locations
The NI 9481 is suitable for use in Class I, Division 2, Groups A, B,
C, D, T4 hazardous locations; Class I, Zone 2, AEx nC IIC T4
hazardous locations; and nonhazardous locations only. Follow
these guidelines if youare installing the NI 9481 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 Zone 2 applications, install the system
in an enclosure rated to at least IP 54 as defined by
IEC 60529 and EN 60529.

NI 9481 Operating Instructions and Specifications 6 ni.com
Special Conditions for Marine Applications
Some modules are Lloyd’s Register (LR) Type Approved for
marine applications. To verify Lloyd’s Register certification, visit
ni.com/certification and search for the LR certificate, or
look for the Lloyd’s Register mark on the module.
Caution To meet radio frequency emission requirements
for marine applications, use shielded cables and install
the system in a metal enclosure. Suppression ferrites
must be installed on power supply inputs near power
entries to modules and controllers. Power supply and
module cables must be separated on opposite sides of the
enclosure and must enter and exit through opposing
enclosure walls.

© National Instruments Corp. 7 NI 9481 Operating Instructions and Specifications
Connecting the NI 9481
The NI 9481 has a 10-terminal detachable screw-terminal connector
that provides connections for 4 electromechanical relay channels.
Figure 2. NI 9481 Terminal Assignments
03
0
1
2
3
4
5
6
7
8
9
CH0a
CH0b
CH1a
CH1b
CH2a
CH2b
CH3a
CH3b
NC
NC

NI 9481 Operating Instructions and Specifications 8 ni.com
Each electromechanical relay channel has two interchangeable
terminals, CHa and CHb.
Each channel has an LED that indicates the state of the channel.
When a channel LED is lit, the channel is on. When the LED is
dark, the channel is off. The LEDs are disabled when the chassis
is in sleep mode. Refer to the Sleep Mode section for more
information about sleep mode.
When connecting a load to the NI 9481, connect the positive lead
of the load to either the CHa or the CHb terminal, and the ground
of the load to one of the leads of the power supply. Connect the
remaining CHa or CHb terminal to the other lead of the power
supply. Figure 3 shows a possible configuration.
Figure 3. Connecting a Load to the NI 9481
NI 9481
+
–
CHa
CHbAC
or
Load

© National Instruments Corp. 9 NI 9481 Operating Instructions and Specifications
Note Youmust use 2-wire ferrules to create a secure
connection when connecting more than one wire to a
single terminal on the NI 9481.
When the channel is turned on, the terminal connected to the load
drives current or applies voltage to the load. When the channel is
off, the terminal does not drive current or apply voltage to the load.
Wiring for High-Vibration Applications
If an application is subject to high vibration, National Instruments
recommends that youeither use ferrules to terminate wires to the
detachable screw-terminal connector or use the NI 9932 backshell
kit to protect the connections. Refer to Figure 4 for an illustration
of using ferrules. Refer to Figure 1 for an illustration of the
NI 9932 connector backshell.

NI 9481 Operating Instructions and Specifications 10 ni.com
Figure 4. 10-Terminal Detachable Screw-Terminal Connector with Ferrule
Sleep Mode
This module supports a low-power sleep mode. Support for sleep
mode at the system level depends on the chassis that the module is
plugged into. Refer to the chassis manual for information about
support for sleep mode. If the chassis supports sleep mode, refer to
the software help for information about enabling sleep mode. Visit
ni.com/info and enter cseriesdoc for information about
C Series documentation.

© National Instruments Corp. 11 NI 9481 Operating Instructions and Specifications
Typically, when a system is in sleep mode, youcannot
communicate with the modules. In sleep mode, the system
consumes minimal power and may dissipate less heat than it does
in normal mode. Refer to the Specifications section for more
information about power consumption and thermal dissipation.
Specifications
The following specifications are typical for the range –40 to 70 °C
unless otherwise noted.
Output Characteristics
Number of channels.......................... 4 electromechanical relay
channels
Relay type ......................................... Single pole single throw
(SPST)
Power-on output state ....................... Channels off

NI 9481 Operating Instructions and Specifications 12 ni.com
Switching capacity (resistive load)
Switching voltage ....................... 60 VDC max, 250 Vrms max
Switching current, per channel
One channel on .................... 4 A max at 30 VDC,
1 A max at 60 VDC,
4 A max at 250 Vrms
All channels on .................... 2 A max at 30 VDC,
1 A max at 60 VDC,
2 A max at 250 Vrms
Resistance per channel,
channel on......................................... 50 mΩ
Switching rate ................................... 1 operation per second
Relay release time............................. 5 ms max
Relay operate time ............................ 10 ms max
Relay bounce time ............................ 3 ms
Off state leakage ............................... 10 μAmax
Life expectancy
Mechanical (no load).................. 20,000,000 operations
Electrical (connecting to load) ... 100,000 operations

© National Instruments Corp. 13 NI 9481 Operating Instructions and Specifications
MTBF ............................................... 460,321 hours at 25 °C;
Bellcore Issue 2, Method 1,
Case 3, Limited Part Stress
Method
Note Contact NI for Bellcore MTBF specifications
at other temperatures or for MIL-HDBK-217F
specifications.
Power Requirements
Power consumption from chassis
Active mode ............................... 580 mW max
Sleep mode ................................. 5 mW max
Thermal dissipation (at 70 °C)
Active mode ............................... 1.5 W max
Sleep mode ................................. 5 mW max

NI 9481 Operating Instructions and Specifications 14 ni.com
Physical Characteristics
If youneed to clean the module, wipe it with a dry towel.
Screw-terminal wiring ...................... 12 to 24 AWG copper
conductor wire with 10 mm
(0.39 in.) of insulation
stripped from the end
Torque for screw terminals ............... 0.5 to 0.6 N · m
(4.4 to 5.3 lb · in.)
Ferrules ............................................. 0.25 mm2to 2.5 mm2
Weight............................................... 150 g (5.3 oz)
Safety
Safety Voltages
Connect only voltages that are within the following limits.
CHa-to-CHb...................................... 250 Vrms max,
Measurement Category II
Measurement Category II is for measurements performed on
circuits directly connected to the electrical distribution system.
This category refers to local-level electrical distribution, such as

© National Instruments Corp. 15 NI 9481 Operating Instructions and Specifications
that provided by a standard wall outlet, for example, 115 V for U.S.
or 230 V for Europe.
Caution Do not connect the NI 9481 to signals or use
for measurements within Measurement Categories III
or IV.
Isolation
Channel-to-channel
Continuous ........................... 250 Vrms
Withstand ............................. 1,400 Vrms, verified by a 5 s
dielectric withstand test
Channel-to-earth ground
Continuous ........................... 250 Vrms
Withstand ............................. 2,300 Vrms, verified by a 5 s
dielectric withstand test
Hazardous Locations
U.S. (UL) .......................................... Class I, Division 2,
Groups A, B, C, D, T4;
Class I, Zone 2,
AEx nC IIC T4

NI 9481 Operating Instructions and Specifications 16 ni.com
Safety Standards
This product meets the requirements of the following standards of
safety for electrical equipment for measurement, control, and
laboratory use:
• IEC 61010-1, EN 61010-1
• UL 61010-1, CSA 61010-1
Note For UL and other safety certifications, refer to the
product label or the Online Product Certification section.
Electromagnetic Compatibility
This product meets the requirements of the following EMC
standards for electrical equipment for measurement, control, and
laboratory use:
• EN 61326 (IEC 61326): Class A emissions; Basic immunity
• EN 55011 (CISPR 11): Group 1, Class A emissions
• AS/NZS CISPR 11: Group 1, Class A emissions
• FCC 47 CFR Part 15B: Class A emissions
• ICES-001: Class A emissions

© National Instruments Corp. 17 NI 9481 Operating Instructions and Specifications
Note For the standards applied to assess the EMC of this
product, refer to the Online Product Certification section.
Note For EMC compliance, operate this device with
shielded cabling.
CE Compliance
This product meets the essential requirements of applicable
European Directives as follows:
• 2006/95/EC; Low-Voltage Directive (safety)
• 2004/108/EC; Electromagnetic Compatibility Directive
(EMC)
Online Product Certification
Refer to the product Declaration of Conformity (DoC) for
additional regulatory compliance information. To obtain product
certifications and the DoC for this product, visit ni.com/
certification, search by module number or product line, and
click the appropriate link in the Certification column.

NI 9481 Operating Instructions and Specifications 18 ni.com
Shock and Vibration
To meet these specifications, youmust panel mount the system and
either affix ferrules to the ends of the terminal wires or use the
NI 9932 backshell kit to protect the connections.
Operating vibration,
sinusoidal (IEC 60068-2-6) .............. 5 g, 40 to 500 Hz; 0.062 in.
double amplitude,
10 to 40 Hz
Environmental
National Instruments C Series modules are intended for indoor use
only but may be used outdoors if installed in a suitable enclosure.
Refer to the manual for the chassis youare using for more
information about meeting these specifications.
Operating temperature
(IEC 60068-2-1, IEC 60068-2-2) ..... –40 to 70 °C
Storage temperature
(IEC 60068-2-1, IEC 60068-2-2) ..... –40 to 85 °C
Ingress protection.............................. IP 40

© National Instruments Corp. 19 NI 9481 Operating Instructions and Specifications
Operating humidity
(IEC 60068-2-56).............................. 10 to 90% RH,
noncondensing
Storage humidity
(IEC 60068-2-56).............................. 5 to 95% RH,
noncondensing
Maximum altitude............................. 2,000 m
Pollution Degree (IEC 60664) .......... 2
Environmental Management
NI is committed to designing and manufacturing products
in an environmentally responsible manner. NI recognizes that
eliminating certain hazardous substances from our products is
beneficial to the environment and to NI customers.
For additional environmental information, refer to the NI and the
Environment Web page at ni.com/environment. This page
contains the environmental regulations and directives with which
NI complies, as well as other environmental information not
included in this document.

NI 9481 Operating Instructions and Specifications 20 ni.com
Waste Electrical and Electronic Equipment (WEEE)
EU Customers At the end of the life cycle, all products
must be sent to a WEEE recycling center. For more
information about WEEE recycling centers and National
Instruments WEEE initiatives, visit ni.com/
environment/weee.
⬉ᄤֵᙃѻક∵ᶧ᥻ࠊㅵ⧚ࡲ⊩ ˄Ё೑
RoHS
˅
Ё೑ᅶ᠋
National Instruments ヺড়Ё೑⬉ᄤֵᙃ
ѻકЁ䰤ࠊՓ⫼ᶤѯ᳝ᆇ⠽䋼ᣛҸ (RoHS)DŽ݇Ѣ
National Instruments Ё೑ RoHS ড়㾘ᗻֵᙃˈ䇋ⱏᔩ
ni.com/environment/rohs_chinaDŽ(For information
about China RoHS compliance, go to ni.com/
environment/rohs_china.)