Com-Power LI-350 User manual

Page 1 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
INSTRUCTION MANUAL
For
LINE IMPEDANCE STABILIZATION NETWORK
Model LI-350
10 kHz to 400 MHz

Page 2 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
Table of Contents
1.0 Introduction.............................................................................................................. 3
2.0 Product Description .................................................................................................. 4
3.0 Product Specifications .............................................................................................. 5
4.0 Important Safety Precautions .................................................................................. 6
5.0 Warranty ................................................................................................................... 7
6.0 Front and rear panel marking................................................................................... 8
7.0 LISN Theory ............................................................................................................... 9
8.0 Typical Performance Data .......................................................................................10

Page 3 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
1.0 Introduction
This manual includes product specifications, safety precautions, product maintenance and
warranty information. It also includes some basic guidance on LISN operation.
Information contained in this manual is the property of Com-Power Corporation. It is issued
with the understanding that none of the material may be reproduced or copied without
permission from Com-Power.

Page 4 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
2.0 Product Description
Overview
The LI-350 Line Impedance Stabilization Network was specifically designed for providing
standardized line impedance during Electromagnetic Compatibility (EMC) testing in accordance
with RTCA DO-160 & MIL-STD 461 requirements. In addition, it minimizes the noise generated
by equipment other than the EUT to be included in the measurement.
The LI-350 is shipped with two LISN housed in separate enclosures for single phase power
applications. For wiring convenience, each LISN has either a black or red shrouded banana for
both power and EUT connection. The following items are included with each LI-350 LISNs.
Standard items included:
Equipment, accessories, and documents supplied with the LI-350 LISN are as follows:
oCalibration data and Certificate traceable to NIST.
oSuperior Electric shrouded 50A plugs for EUT and power connection.
Optional items
oISO-17025 calibration data and certificate.

Page 5 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
3.0 Product Specifications
Model:
LI-350
Electrical
Frequency Range:
10 kHz to 400 MHz
Compliant Standards:
RTCA DO-160 / MIL-STD 461
Number of lines:
Two lines
Max current rating:
50 Amp AC, 35 Amp DC
Max Voltage Rating:
480VAC, 50/60 Hz (Line to Ground) / 676 VDC
Insertion Loss:
<0.2 dB (150 kHz –30 MHz)
Inductor type:
5 µH
EUT & Power Connector:
50 Amps Shrouded Superior Electric sockets
RF measurement connector:
50Ω, N type (female)
Operating Temperature:
5° C to 40° C / 40° F to 104° F
Mechanical
Dimensions of each enclosure (L x W x H):
15.4 x 7 x 6.6 inches / 39.1 x 17.7 x 16.7 cm
Weight (each network):
6 lb. / 2.7 kg
This equipment is designed for indoor use only.
3.1 Other items available from Com-Power
SPA-series Spectrum Analyzers
LIN-120A, LISN 150 kHz –30 MHz, 20 A
LI-220A, LISN 10 kHz –30 MHz, 20 A
LI-125A, LISN 150 kHz –30 MHz, 25 A
LI-550A, LISN 150 kHz –30 MHz, 50 A
Special order LISNs with higher voltage and / or current
LIT-153 Transient Limiter
Cables and connectors

Page 6 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
4.0 Important Safety Precautions
The LISN must be securely fastened to the earth ground before making any connections to
external power. Proper grounding of the LISN not only ensures correct conducted emissions
measurements, it also prevents potential high leakage current from presenting a hazard to test
personnel. To help establish proper grounding the bottom surface of the LISN is unpainted. In
addition, the bottom plate has holes for securely bolting the LISN to the ground plane.
Only connect power plugs with a protective earth contact into LISN power input port / AE. The
protective action must not be negated by the use of a cheater plug or an extension cord without
a protective conductor.
Environmental conditions
This equipment is designed for indoor use to be safe under the following environmental
Conditions:
Temperature: 5° C to 40° C
Maximum relative humidity: 80%

Page 7 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
5.0 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 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 seperately 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.
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 techincal assistance personnel
will contact you with RMA number. Please ensure to have the RMA number stated on
shipping documents.
5.1 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.

Page 8 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
6.0 Front and rear panel marking
6.1 Power input port
The Model LI-350 has a 50 Amps Superior Electric pin receptacle on the back panel for
connection to external DC or AC power source. The matching shrouded banana socket plug is
included with the LISN. See specification table on page 5 of this manual for the voltage and
current ratings.
6.2 EUT power port
The LI-350 uses a 50 Amps Superior Electric Shrouded banana socket receptacle as the EUT
power port. The matching color coded plug is included for making the connection to the EUT.
6.3 EMI measurement Port
The 50 Ω Type 'N' connector located to the right of the EUT Power Port for connecting the
Spectrum analyzer or EMI receiver for making conducted noise measurements.
6.4 Grounding bolt (GND)
The bolt marked 'GND' are found on both front and back panel of the LISN. This bolt is used for
PE grounding with a braid or short wire. This is in addition to mounting the LISN on the RF
ground plane using conductive bottom surface.

Page 9 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
7.0 LISN Theory
7.1 Overview
Line Impedance Stabilization Networks used supply 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-350 consists of two separate LISN networks housed in separate
enclosure 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 effect. This filter comprises of single stage low pass LC filter. Therefore, it has capacitor
and an inductor for the filter. The inductor used in the LI-350 is 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 RF noise. The insertion loss of the
measured noise may be significant especially at low frequencies. Therefore, at frequencies
below 400 kHz, the insertion loss correction factor must be compensated for highest accuracy
noise measurement.
The figure below is a typical schematic of a 5 µH LISN as specified in the MIL-Std 461 standard.
The LISN does not incorporate any internal 10 µF capacitor, so the requirement specified in DO-
160 for the 10 µF capacitor at the AE port is to be fulfilled externally.
Figure 1 –Example of an equivalent LISN circuit

Page 10 of 10
INSTRUCTION MANUAL FOR LI-350
LINE IMPEDANCE STABILIZATION NETWORK (LISN)
19121 El Toro Road, Silverado, California 92676 ●[phone] ●com-power.com
REV081916
8.0 Typical Performance Data
Figure 2 –Impedance (AE Port: 10 µF capacitor to ground ) compared to DO-160
requirements.
Figure 3 –Impedance (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)