A network isolator enables galvanic network separation for medical devices and systems according to DIN EN 60601-1. A network isolator is a passive electronic component and do not require a separate power supply. The galvanic separation of medical devices and the avoidance of leakage currents are an essential aspect of everyday medical practice. Technical devices and patients are protected against potentially dangerous over voltages and static discharges.

The EN 60601-1 defines different classes of insulation, air and creepage distances, leakage current and grounding depending on the desired MOOP or MOPP level.

MOOP = Means of Operator Protection, Protective measures for operator and user protection.
MOPP* = Means of Patient Protection, Protective measures for patient protection, to reduce the risk of electric shock.

*Patients are at increased risk when coming into contact with electrical equipment and systems. Therefore, higher requirements apply to patient protection (MOPP) than to user protection (MOOP).

Network Isolators – Answers to frequently asked questions:
https://baaske-medical.com/network-isolators/

Installation errors, ageing processes, environmental influences or moisture can make cable sheaths brittle or fragile. The unwanted electrical connection to other live parts can lead to high overvoltages and voltage peaks for a short time and lead to a fault within the electrical system.

Common Mode Choke Filtering
Improves CMRR in Ethernet
Transformer Applications
http://52ebad10ee97eea25d5e-d7d40819259e7d3022d9ad53e3694148.r84.cf3.rackcdn.com/Acal-BFi-Laird-App-Note-1.pdf

http://www.xmultiple.com/xwebsite-surge.htm

The Xmultiple surge protection RJ45 Series of connectors are designed to protect components which are connected to high speed data and telecommunication lines from voltage surges caused by lightning, electrostatic discharge (ESD), and electrical fast transients (EFT). The Xmultiple RJ45 surgre protection connectors utilizes technology for superior electrical characteristics at 3.3 volts. The capacitance of the connector is minimized to ensure correct signal transmission on high speed lines.

Features and Advantages

Integrated RJ45 structure saves board space and
Increases reliability
Protects RJ45 as well as printed circuit board and components
Surge Protection and filtering in the connector package.
Modular Design so the filter is integrated with the magnetic.
Available in various Amp ratings
Surge suppression rating of 60kA
Power and Protection at the entry point of the printed circuit board.
1800 watts peak pulse power (tp = 8/20μs)
Transient protection for high-speed data lines
Low capacitance for high-speed interfaces
Low operating voltage
Low clamping voltage

The IEC 61000-4-5 standard requires five applications of each polarity on the equipment.
This standard defines several acceptance criteria depending on the state of the equipment
after the test (performance still ok, degradation of the performance, damage of the
equipment).
Ethernet applications usually recommend the A criterion of IEC 61000-4-5. That is, normal
performance of the equipment after test.
The most commonly used standard to qualify Ethernet equipment against ESD is the
IEC 61000-4-2 standard.

Generally, Level 4 is required, i.e. the equipment has to withstand 8 kV
contact and 15 kV air discharge.

SLVU2.8-4A1 and SLVU2.8-8A1 present a typical capacitance of 3 pF that allow them to be
compatible with 100 Mbps and Gigabit Ethernet lines since, in this way, they preserve the
signal integrity.
Both devices are compliant with the IEC 61000-4-5 Level 2 requirements. That is, they are
able to withstand a 24 A(8 / 20 µs) surge current. They comply also with IEC 61000-4-2
Level 4 requirements. That is they can support 8 kV contact and 15 kV air discharges for
ESD.

Note that both SLVU2.8-4A1 and SLVU2.8-8A1 can protect 100 Mbps and Gigabit Ethernet
circuits.