LI-3P-2X Series – Three-Phase V-AMN LISN for CISPR 16-1-2 & ANSI C63.4 (9 kHz–30 MHz)
The Com-Power LI-3P-2X series consists of four models of four-conductor, 50Ω, 50/250 μH +5Ω Line Impedance Stabilization Networks, also known as Artificial Mains V-Networks (V-AMN). Covering current ratings from 16 A to 100 A per line, these LISNs operate across the extended 9 kHz to 30 MHz frequency range required by the latest revisions of CISPR 16-1-2 and ANSI C63.4. The 50/250 μH +5Ω network topology provides proper impedance characterization starting from 9 kHz, making the 2X series the correct choice when test standards require measurements below 150 kHz. All models support Delta and Wye three-phase configurations, include the RLI V2.0 fiber optic remote interface, a bypassable built-in transient limiter with dual 5 dB attenuation pads, and air-core inductors to prevent saturation.
Model Comparison
| Specification |
LI-3P-216 |
LI-3P-232 |
LI-3P-263 |
LI-3P-2100 |
| Current Rating (per line) |
16 A |
32 A |
63 A |
100 A |
| Frequency Range |
9 kHz – 30 MHz |
| Network Type |
50Ω, 50/250 μH +5Ω, Four-Conductor |
| Standards Compliance |
CISPR 16-1-2 (CE) & ANSI C63.4 (FCC) |
| Insertion Loss (9 kHz – 150 kHz) |
< 17 to < 11 dB (decreasing linearly with log of frequency) |
| Insertion Loss (150 kHz – 30 MHz) |
< 11 dB |
| Isolation (9 kHz – 50 kHz) |
> 0 to > 40 dB (increasing linearly with log of frequency) |
| Isolation (50 kHz – 30 MHz) |
> 40 dB |
| Max AC Voltage (line-to-line) |
865 Vrms |
| Max AC Voltage (line-to-ground) |
500 Vrms |
| Max DC Voltage |
600 V DC |
| Power Connector Rating |
25 A |
50 A |
100 A |
100 A |
| RF Measurement Port |
50Ω N-Type (Female) |
| Remote Interface |
RLI V2.0 via Fiber Optic |
| Transient Limiter |
Built-In, Bypassable, with Dual 5 dB Attenuation Pads |
| Operating Temperature |
40°F to 104°F (5°C to 40°C) |
| Cooling |
Louvered Panels + Top Air Outlets (passive) |
Louvered Panels + 3 Internal Fans (15 VDC) |
| Weight |
55.6 lbs (25.2 kg) |
64.6 lbs (29.3 kg) |
118.9 lbs (54.0 kg) |
184.6 lbs (83.8 kg) |
| Warranty |
Three Years |
LI-3P-2X vs. LI-3P-1X – Key Differences
Both the 2X and 1X series target CISPR 16-1-2 and ANSI C63.4 commercial standards, but they use different LISN network topologies and cover different frequency ranges. They are not interchangeable:
| Parameter |
LI-3P-2X (Extended Range) |
LI-3P-1X (Standard Range) |
| Network Type |
50Ω, 50/250 μH +5Ω (V-AMN) |
50Ω, 50 μH |
| Frequency Range |
9 kHz – 30 MHz |
150 kHz – 30 MHz |
| Standards |
CISPR 16-1-2 / ANSI C63.4 |
CISPR 16-1-2 / ANSI C63.4 |
| When to Use |
When the test standard requires measurements starting from 9 kHz (e.g., latest CISPR revisions, certain product standards referencing the 9 kHz–150 kHz band) |
When the test standard only requires measurements from 150 kHz (traditional CISPR/ANSI conducted emissions range) |
| Transient Limiter |
Bypassable, with dual 5 dB attenuation/impedance matching pads |
Non-bypassable |
| Insertion Loss (9–150 kHz) |
< 17 to < 11 dB |
N/A (below operating range) |
Important: The 50/250 μH +5Ω network in the 2X series is specifically designed to provide the correct impedance characteristics below 150 kHz as defined in CISPR 16-1-2. If your applicable product standard requires conducted emissions measurements starting at 9 kHz, the LI-3P-2X is the correct series. If measurements start at 150 kHz, the LI-3P-1X is sufficient and appropriate.
How to Choose the Right Model
All four models share identical electrical performance and differ only in their maximum continuous current rating per line. Select based on the EUT’s maximum per-line current draw:
| Model |
Best Suited For |
Typical EUT Examples |
| LI-3P-216 (16 A) |
Low-power three-phase equipment up to 16 A per line |
Small three-phase motors, laboratory instruments, low-power PLCs, LED lighting drivers, small industrial control panels |
| LI-3P-232 (32 A) |
Medium-power three-phase equipment up to 32 A per line |
Commercial HVAC blowers, mid-range VFDs, industrial pumps, packaging machinery, small CNC machines, commercial kitchen equipment |
| LI-3P-263 (63 A) |
High-power three-phase equipment up to 63 A per line |
Large variable frequency drives, industrial compressors, heavy conveyor systems, large HVAC chillers, welding equipment, EV chargers |
| LI-3P-2100 (100 A) |
Very high-power three-phase equipment up to 100 A per line |
High-capacity motor drives, large industrial machinery, high-power EV charging stations, UPS systems, large solar inverters, data center power distribution |
Selection Rule: Always choose a LISN with a current rating that meets or exceeds the maximum continuous per-line current draw of the EUT. Operating a LISN beyond its rated current can cause overheating and damage the internal inductors.
Real-World Applications
| Application |
Description |
| Products Requiring 9 kHz Testing |
Updated product standards such as CISPR 32 (multimedia equipment) and CISPR 14 (household appliances) increasingly reference conducted emissions starting from 9 kHz. The LI-3P-2X series covers this extended band with the correct 50/250 μH +5Ω impedance network. |
| Industrial Motor Drives & VFDs |
Three-phase VFDs generate conducted noise across a wide frequency spectrum. The 9 kHz lower limit of the 2X series captures low-frequency emissions from switching power stages that a 150 kHz LISN would miss entirely. |
| Renewable Energy Inverters |
Grid-tied three-phase solar inverters and wind turbine converters must meet conducted emissions limits. Newer grid-code standards are beginning to require measurements from 9 kHz to capture low-frequency switching artifacts. |
| EV Charging Infrastructure |
Three-phase AC and DC EV charging stations are tested against product standards that may require the extended 9 kHz starting frequency. The LI-3P-2100 provides 100 A capacity for high-power chargers. |
| HVAC & Commercial Refrigeration |
Large commercial HVAC compressors, fans, and pump systems running on three-phase power must pass conducted emissions limits. The LI-3P-232 and LI-3P-263 serve these mid- to high-current applications. |
| Data Center Power Equipment |
Three-phase UPS systems, power distribution units (PDUs), and server rack power supplies undergo EMC testing. High-power data center equipment often requires the 63 A or 100 A models. |
Test Setup Overview
Setting up a three-phase conducted emissions measurement with the LI-3P-2X series follows the same general procedure as other three-phase LISNs. The LISN is inserted between the mains power source and the EUT on a ground reference plane:
- Place the LISN on the ground reference plane. The unpainted mounting plate must make direct metal-to-metal contact with the conductive ground plane for a low-impedance earth connection.
- Connect the mains power source to the LISN Power Input port. Wire L1, L2, L3, Neutral, and Protective Earth to the color-coded input terminals using the supplied plug socket connectors.
- Connect the EUT to the LISN Power Output port. Wire the EUT power cable to the output side using the supplied plug pin connectors.
- Connect the RF measurement port to the EMI receiver or spectrum analyzer. Use a coaxial cable with an N-type connector to the LISN’s 50Ω measurement port.
- Configure the transient limiter. The built-in transient limiter with dual 5 dB attenuation pads is active by default. It can be bypassed via the front panel or remotely using the RLI when the additional attenuation is not desired.
- Power the cooling fans (LI-3P-263 and LI-3P-2100 only). Connect the 15 VDC adapter to the rear-panel fan power jack. The three internal fans are controlled by a rear-panel switch.
- Set up the Remote LISN Interface (RLI V2.0). Connect the fiber optic cable between the LISN and RLI V2.0 unit, and connect the RLI V2.0 to your PC via USB for automated line switching. Alternatively, use front-panel controls for manual line selection.
- Select the line under test and perform the measurement. Non-selected lines are automatically terminated into 50Ω. Measure conducted emissions on each line (L1, L2, L3, N) across the 9 kHz to 30 MHz frequency range per the applicable standard.
Tip: When measuring in the 9 kHz to 150 kHz band, ensure your EMI receiver or spectrum analyzer has sufficient sensitivity and appropriate detector settings (quasi-peak and average) as specified by the test standard for this lower frequency range.
Key Features Across All LI-3P-2X Models
| Feature |
Description |
| 50/250 μH +5Ω Network |
The V-AMN topology provides the correct impedance profile from 9 kHz, meeting the latest CISPR 16-1-2 requirements for extended-range conducted emissions testing. |
| Air-Core Inductors |
Prevent magnetic saturation and permeability variation, ensuring accurate and repeatable impedance across the full frequency range. |
| Bypassable Transient Limiter |
Built-in protection with dual 5 dB attenuation/impedance matching pads, low-pass and high-pass filters. Can be bypassed via front panel or remotely using the RLI when direct measurement path is needed. |
| Remote Line Switching (RLI V2.0) |
Fiber optic–controlled switching between L1, L2, L3, and N enables automated test sequences. |
| Local Line Selection |
Front-panel controls allow direct, manual selection of the line under test. |
| Internal 50Ω Termination |
Non-selected lines are automatically terminated into 50Ω, maintaining proper impedance on all lines during measurement. |
| Individual Calibration |
Each unit is individually calibrated with impedance, phase, isolation, and insertion loss data. ISO 17025 accredited calibration is available upon request. |
Included Accessories
Every LI-3P-2X LISN ships with the following items:
| Accessory |
Quantity |
| Plug Socket Connectors (for Power Input Cable) |
5 |
| Plug Pin Connectors (for EUT Cable) |
5 |
| RLI V2.0 Remote LISN Interface Unit |
1 |
| Fiber Optic Cable (10 m) |
1 |
| AC Power Adapters (6 VDC, 500 mA) – for remote interface |
2 |
| AC Power Adapter (15 VDC, 500 mA) – for cooling fans (LI-3P-263 and LI-3P-2100 only) |
1 |
Optional Accessories: LI-3P-XXXX-ADA Coaxial Adapter with Plug Pins • LI-3P-XXXX-ADA Coaxial Adapter with Plug Sockets
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