COM-power corporation LI-325C User manual

Page 1 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
INSTRUCTION MANUAL
For
LINE IMPEDANCE STABILIZATION NETWORK
Model LI-325C
10 kHz to 400 MHz

Page 2 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
Table of Contents
1.0 Introduction ....................................................................................................................................... 3
2.0 Products Available from Com-Power ............................................................................................ 4
3.0 Product Safety Information.............................................................................................................. 5
3.1 Product Hazard Symbols Definitions ............................................................................................... 5
3.2 Incoming Inspection ........................................................................................................................ 6
3.3 Package Inventory ........................................................................................................................... 6
3.4 General Safety Instructions.............................................................................................................. 6
4.0 Product Specifications ..................................................................................................................... 9
5.0 Product Description......................................................................................................................... 10
5.1 Overview........................................................................................................................................... 10
5.2 Product Setup ................................................................................................................................... 10
5.3 Front & Rear Panel Marking ............................................................................................................ 11
6.0 LISN Theory ....................................................................................................................................... 13
7.0 Typical Performance Data.............................................................................................................. 14
8.0 Warranty ........................................................................................................................................... 15
8.1 Maintenance .................................................................................................................................... 15
List of Figures
Figure 1: Single Phase connection with one set of LISN 10
Figure 2: Three Phase connections with two sets of LISN 11
Figure 3: Rear Panel 11
Figure 4: Front Panel 11
Figure 5: Example of equivalent LISN circuit 13
Figure 6: Typical Impedance curve (AE port: 10µF to ground) compared to RTCA/DO-160G Std requirement 14
Figure 7: Typical Impedance curve (AE port: Open) compared to Mil Std 461 requirements 14

Page 3 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
1.0 INTRODUCTION
This manual includes descriptions of front and rear panel ports, controls and indicators;
product specifications, safety precautions, operational instructions and warranty
information and guidelines and instructions for its proper usage.
Information contained in this manual is the property of Com-Power Corporation. It is issued
with the understanding that the material may not be reproduced or copied without the
express written permission of Com-Power.

Page 4 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
Antennas
Antenna Kits
Absorbing Clamps
Coupling/Decoupling
Networks (CDN)
Comb Generators
Current Probes
Emissions Test
Systems
Conducted Immunity
Test Systems
Impedance Stabilization
Networks (ISN)
Line Impedance Stabilization
Networks (LISN)
Antenna Masts
Near-Field
Probe Sets
Preamplifiers
Power Amplifiers
Spectrum Analyzers
Product Safety Test
Equipment
Transient Limiters
Turntables
Antenna Tripods
Telecom Test
Systems
2.0 PRODUCTS AVAILABLE FROM COM-POWER
www.com-power.com

Page 5 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
3.0 PRODUCT SAFETY INFORMATION
3.1 Product Hazard Symbols Definitions
The hazard symbols appearing on the product exterior are defined below.
The yellow triangle with an exclamation mark indicates the
presence of important operating and/or maintenance (servicing)
instructions in the literature accompanying the product.
The yellow triangle with a lightning bolt indicates an alert to the
user that un-insulated dangerous voltages are present within the
product enclosure and on output connectors. These voltages may
be of sufficient magnitude to constitute a risk of electric shock to
persons.
The Ground symbol inside a circle indicates terminal which is
intended for connection to an external conductor for protection
against electric shock in case of a fault, or the terminal of a
protective earth (ground) electrode.
To indicate on the rating plate that the equipment is suitable for
AC current.
To indicate on the rating plate that the equipment is suitable for
direct current.

Page 6 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
3.2 Incoming Inspection
To avoid possibility of electrical shock, do not apply power to the LISN if there is
any evidence of shipping damage. If shipping damage to the product or any of
the accessories is suspected, or if the package contents are not complete,
contact Com-Power or your Com-Power distributor.
Please check the contents of the shipment against the package inventory in
section 3.3 to ensure that you have received all applicable items.
3.3 Package Inventory
Equipment, accessories, and documents supplied with the model LI-325C LISN are
as follows:
Calibration data and Certificate traceable to NIST.
Superior Electric shrouded plugs for EUT and power connection.
Optional items
ISO-17025 calibration data and certificate.
External 10 dB, 2 watt attenuator.
3.4 General Safety Instructions
The following safety instructions have been included in compliance with safety
standard regulations. Please read them carefully.
•READ AND RETAIN INSTRUCTIONS - Read all safety and operating
instructions before operating the instrument. Retain all instructions for
future reference.
•HEED WARNINGS - Adhere to all warnings on the instrument and
operating instructions.
•FOLLOW INSTRUCTIONS - Follow all operating and use instructions.
•WATER AND MOISTURE - Do not use the instrument near water.
•VENTILATION - The instrument should be used/installed only in locations
where the flow of air through the ventilation openings is not impeded.
•MOUNTING –The instrument can be used in Horizontal or vertical
orientation as long as the ventilation holes are not obstructed and the
protective grounding is not defeated.
•HEAT - The instrument should be situated away from heat sources such as
heat registers or other instruments which produce heat.

Page 7 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
•POWER SOURCES - Connect the instrument only to the type of power
source described in the operating instructions or as marked on the
instrument.
•GROUNDING - Take precautions to insure that the grounding of the
instrument is not defeated. Grounding conductor with adequate cross-
section must be connected between a grounding conductor
connection for the measurement area and the grounding conductor
connection (grounding bolt) on the back/front panel of the LISN and the
LISN bottom plate, before applying any power to the LISN. At shutdown
or before dismantling the LISN setup, ensure that the power to LISN is
discontinued before the ground conductor connection is disconnected.
CAUTION:
The LI-325C is based on the 5 µH LISN circuit specified in RTCA DO-160
and Mil-Std 461G.
The specified minimum line to ground capacitance induces leakage
currents in excess of the value permitted under EN 61010-1 standard –
safety requirements for electrical equipment for measurement, control
and laboratory use.
In addition, the basic insulation required for a category I protection
device cannot be assured. Therefore it is imperative to provide
additional measures safeguarding against direct or indirect contact by
user.
The operator is responsible for ensuring that protection is maintained
during work with the line impedance stabilization network (LISN).
Before using the LISN, a secure ground connection must be made to the
LISN’s grounding bolt and/or the bottom metal plate (The bottom surface
of the LISN is left unpainted for effective ground connection). It must not
be removed until after the LISN has been disconnected from the mains
power supply, in order to avoid electric shock.
The safety notes in the accompanying operating instructions and on the
outside of the device must be followed at all times.
•POWER CORD PROTECTION - Place power supply cords so that they are
not likely to be walked on or pinched by items placed on them or
against them.
•CLEANING –Clean the instrument outside surfaces of the device with a
soft, lint-free cloth. If necessary, a mild detergent may be used.
•NON-USE PERIODS - Unplug the power cords of the instrument when it will
be left unused for a long period of time.
•OBJECT AND LIQUID ENTRY - Take care that objects do not fall into the
instruments and that liquids are not spilled into the enclosure through
openings.
•DEFECTS AND ABNORMAL STRESS - Whenever it is likely that the normal
operation has been impaired, make the equipment inoperable and
secure it against further operation.

Page 8 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
•SITTING OR CLIMBING - Do not sit or climb upon the instrument or use it as
a step or ladder.
•ENVIRONMENTAL CONDITIONS -This equipment is designed for indoor use.
Ambient temperature range during operation should be between 5° C to
40° C.
•STORAGE AND PACKAGING - The device should only be stored at a
temperature between –25 and +70 °C. During extended periods of
storage, protect the device from dust accumulation. The original
packaging should be used if the device is transported or shipped again.
If the original packaging is no longer available, the device should be
packed carefully to prevent mechanical damage.

Page 9 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
4.0 PRODUCT SPECIFICATIONS
Model:
LI-325C
Electrical
Frequency range:
10 kHz to 400 MHz
Compliant standards:
RTCA DO-160G & Mil-Std 461G
Number of lines:
Two lines
Max current rating:
25 Amp AC, 17 Amp DC
Max Voltage rating:
270 VAC, DC- 400 Hz (Line to Ground)/
380 VDC
Inductor type:
5 µH
EUT & Power connector:
Shrouded Superior Electric Banana
Connector
RF measurement connector:
50Ω, N type (female)
Insertion Loss
<0.3 dB (150 kHz to 30 MHz)
Mechanical
Dimensions of Each LISN (L x W x H):
11.8 x 5.7 x 5.3 inches / 30 x 14.5 x 13.5
cm
Weight of each LISN :
5 lb. /2.2 kg
Environmental
Operating Temperature
5° C to 40° C / 40° F to 104° F

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INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
5.0 PRODUCT DESCRIPTION
5.1 Overview
The LI-325C Line Impedance Stabilization Network is specifically designed to
provide necessary measurement platform for performing power line conducted
emissions (disturbance measurements) compliance testing in accordance with
RTCA DO-160 (external 10 uF capacitor required) and Mil Std 461.
The LI-325C performs each of the following functions during the measurement:
•provides a defined, stable impedance throughout the measurement
frequency range;
• isolates the EUT and measurement circuit from the power source, thereby
minimizing its influence on the measurements; and,
• couples the disturbance voltages to the coaxial measurement port for
connection to the measuring instrument like EMI Receiver or Spectrum
Analyzer.
5.2 Product Setup
Before initiating use of LISN, ensure that,
•PE conductor is connected to ground.
•The ventilation openings are unobstructed.
• No signal or operating voltages above the permissible limits given in
specification.
• The LISN’s power input port is connected to an appropriate power source
employing properly rated mains protection, as over current protection is
not provided in the LISN.
Failure to comply with any of these points may damage the equipment and/or
pose an electrical hazard.
5.2.1 Typical connection diagrams
The LISNs can be used with single phase power sources with one set of
LISNs and also three phase power sources (requires two sets of LISNs). Given
below are the typical connection setup’s for each configuration.
Figure 1: Single Phase connection with one set of LISN

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INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
5.3 Front & Rear Panel Marking
5.3.1 Power input port
The Model LI-325C has a Superior Electric Shrouded pin receptacle for
connection to an external DC or AC input power source. The LISN is
shipped with two matching shrouded socket plug, for connection to the
input power source cables.
CAUTION
Due to the high level of earth leakage current, the device cannot be
connected to any power source protected by either a ground fault circuit
interrupter (GFCI) circuit breaker or residual current devices (RCDs).
The power source must be protected by a circuit breaker with a current
rating which is greater than or equal to the rating of the LISN.
5.3.2 Grounding bolt (GND)
The threaded bolt with hex nut marked 'GND' are found on both front and
back panel of the LISN. This bolt is used for Protective grounding
connections. In addition to this, the un-painted bottom surface of the LISN
5.3.3
5.3.2
5.3.4
5.3.1
5.3.2
Figure 3: Rear Panel
Figure 4: Front Panel
Figure 2: Three Phase connections with two sets of LISN

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INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
should be bonded directly to an earth referenced ground plane for
effective RF reference ground. In cases where no ground plane is
available, a mains isolating transformer shall be used.
Please refer Safety instructions for more information on importance of
grounding. The grounding instructions are to be followed at all times.
5.3.3 EUT power port
The LI-325C has a Superior Electric Shrouded socket receptacle to power
the equipment under test. The LISN is shipped with the matching shrouded
pin plug for making the connections to EUT power cable.
5.3.4 EMI measurement Port
The LI-325C provides a 50 Ω N-Type (female) connector to connecting the
Spectrum analyzer or EMI receiver for making conducted noise
measurements. The shielding connection of the N connector shield is
connected to the housing of the LISN and thus to ground.
Note: Mil-Std recommends the use of 10 dB attenuator at the output of the
LISN measurement port. Also, as the input circuitry of EMI receivers and
spectrum analyzers are extremely sensitive; it is highly recommended to use
transient limiter in line with the cable connecting the measurement port to
the measuring equipment in order to protect the input circuits from
damage by high voltage transients. Com-Power transient limiters also
incorporate both a low pass and high pass filter to attenuate out of band
signals, as well as a 10 dB attenuation pad. Both, the 10 dB attenuator and
the transient limiter are available with Com-Power.

Page 13 of 15
INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
6.0 LISN THEORY
Line Impedance Stabilization Networks provide standardized line impedance to the EUT
during conducted emissions testing which is independent of the external power line
impedance. The standardized impedance enables consistent readings for RF noise
measurements on the power line. The model LI-325C consists of two separate LISN
networks housed in separate enclosures for testing EUTs with single phase power
requirements.
In addition to providing standardized impedance, the LISN also acts as a low pass filter for
the power to equipment under test. The LISN blocks RF noise from the power line from
reaching the equipment under test, however, the power to the equipment passes
through the LISN with minimal attenuation. This filter is comprised of a single stage low
pass LC filter. The inductors (L) used in the LI-325C are air core type to eliminate the
possibility of saturation and to provide stability.
The LISN also provides a low impedance path for the RF noise from the EUT to the
measuring equipment, thereby facilitating the measurement of the EUT RF noise. The
insertion loss factors provided with every LISN network. It may be significant at low
frequencies; especially below 400 kHz. Therefore, the insertion loss correction factors
should always be considered for the highest measurement accuracy.
Below is a typical schematic of the 5 µH LISN as specified in Mil Std. The RTCA/DO-160G
and Mil Std 461 specifies the impedance requirements. The RTCA/DO-160G requires the
impedance measurement be done with a 10 µF capacitor at AE port (as shown) whereas
the Mil-Std requires the AE port be left open. The LI-325C is calibrated according to both
standards respectively.
Figure 5: Example of equivalent LISN circuit

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INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
7.0 TYPICAL PERFORMANCE DATA
Figure 6: Typical Impedance curve (AE port: 10µF to ground) compared to RTCA/DO-160G Std requirement
Figure 7: Typical Impedance curve (AE port: Open) compared to Mil Std 461 requirements
0.1
1
10
100
0.01 0.1 1 10 100 1000
Impedance (Ω)
Frequency (MHz)
0
10
20
30
40
50
60
70
0.1 1 10 100
Impedance (Ω)
Frequency (MHz)

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INSTRUCTION MANUAL
LI-325C LINE IMPEDANCE STABILIZATION NETWORK
19121 El Toro Rd ●S i l v er a d o, C a li f o rn i a 92 6 7 6 ● ( 9 4 9 ) 4 5 9 - 9 6 00 ● com-power.com
REV022017
8.0 WARRANTY
Com-Power warrants to its Customers that the products it manufactures will be free from
defects in materials and workmanship for a period of three (3) years. This warranty shall
not apply to:
Transport damages during shipment from your plant.
Damages due to poor packaging.
Products operated outside their specifications.
Products Improperly maintained or modified.
Consumable items such as fuses, power cords, cables, etc.
Normal wear
Calibration
Products shipped outside the United States without the prior knowlege of Com-
Power.
In addition, Com-Power shall not be obliged to provide service under this warranty to
repair damage resulting from attempts to install, repair, service or modify the instrument
by personnel other than Com-Power service representatives.
Under no circumstances does Com-Power recognize or assume liability for any loss,
damage or expense arising, either directly or indirectly, from the use or handling of this
product, or any inability to use this product separately or in combination with any other
equipment.
When requesting warranty services, it is recommended that the original packaging
material be used for shipping. Damage due to improper packaging will void warranty.
If you feel that the product is not working as intended, or is malfunctioning, please
contact Com-Power for assistance. In the case of repair or complaint, Please visit our
website www.com-power.com and fill out RMA form (http://com-
power.com/repairservicereq.asp). Our customer service personnel The RMA
number should be displayed in a prominent location on the packaging and on the
product, along with a description of the problem, and your contact information.
8.1 Maintenance
This product contain no user serviceable parts inside. If the unit does not operate
or needs calibration, please contact Com-Power Corporation. Any modifications
or repairs performed on the unit by someone other than an authorized factory
trained technician will void warranty.
The exterior surface may be cleaned with mild detergent and then be wiped with
a dry, clean, lint-free cloth. Use care to avoid liquids or other foreign objects
entering the chassis.