THE IMPORTANCE OF HIPOT ISOLATION ON INDUSTRIAL ETHERNET SWITCHES

Transcription

1 THE IMPORTANCE OF HIPOT ISOLATION ON INDUSTRIAL ETHERNET SWITCHES

2 THE IMPORTANCE OF HIPOT ISOLATION ON INDUSTRIAL ETHERNET SWITCHES What is Hipot? HIPOT is the short term for high potential (high voltage). A HIPOT test checks for "good isolation." In every phase of a product design, Ethernet Direct carries out HIPOT test by taking two conductors (one from Ethernet port and the other from power input) to be isolated and applies a very high voltage between the conductors. In a typical HIPOT test, high voltage is applied between a product's current-carrying conductors and its metallic chassis. The resulting current that flows through the insulation is monitored by the HIPOT tester. The current that flows is watched carefully. Ideally, not much current will flow. If too much current flows, it means that the points are not well isolated and should result to a test failure. Why do high voltages test? Ethernet Direct engineers do HIPOT tests to make sure that the switch will have good isolation between the Ethernet ports with power input. Having good isolation helps to guarantee the safety and quality of electrical circuits. The purpose of HIPOT is to make sure that no current will flow from one point to another, and turning up the voltage high make sure again no current will flow. HIPOT tests are helpful in finding nicked or crushed insulation, stray wire strands or braided shielding, conductive or corrosive contaminants around the conductors, terminal spacing problems, and tolerance errors in communication cable. All of these conditions might cause the switch to fail. A HIPOT test is also know as Dielectric Withstand test to verify the insulation of a product or to see if a component is sufficient to protect the operator from electrical shock. A switch with HIPOT isolation means longer product life and MTBF. Fig 1. Without HIPOT protection, the un-normal current which caused by surge will damage end devices via the RJ-45 port.

3 Where is high voltage applied? To understand how a HIPOT testing works, first we need to understand where to connect the high voltage supply. A HIPOT tester is an equipment to test HIPOT. HIPOT testers are usually connected to one side of the supply to safety ground (or earth ground) and the other side of the supply is connected to the conductor being HIPOTed. With the supply connected like this, there are two places a given conductor can be connected to high voltage or ground. When you have more than two contacts to be HIPOT tested, you connect one contact to high voltage and connect all other contacts to ground. Testing a contact in this fashion makes sure it is isolated from all other contacts. The following figure explains how Ethernet Direct connects the Ethernet port to safety ground and connects the power input with high voltage resource (1500V). Fig 2. HIPOT test using HMG-828

4 Benefits of HIPOT Isolation on Industrial Ethernet Switches? Nobody wants to build an unsafe product. In order to meet the safety requirements such as those published by UL for the US, by CSA for Canada and by IEC for Europe and other areas, it is a must to perform electrical safety tests on your products during engineering development and often in production. The most important electrical safety test is the HIPOT test since it measures the leakage current passing through, verifying that the product s insulation can withstand high voltages without letting unsafe current pass through to the user. Ethernet Direct always put safety concern as the top priority when designing new products and making sure that industrial Ethernet switches can cope with any given harsh environmental and electrical conditions. Customer satisfaction is a key focus of Ethernet Direct.

5 About Ethernet Direct Corporation Ethernet Direct brings a control system engineering perspective to networking technology. The principals of Ethernet Direct come from process-control and PLC system backgrounds. The Global Ethernet Direct team covers operations from Product know-how, design implementation, quality assurance, manufacturing, logistics, sales, marketing & technical support. We are well-positioned to fulfill customers' needs and markets' demands by providing a great variety of tailor-made products and services. When you work with us, you will experience confidence and dependability. By choosing Ethernet Direct, you have chosen excellence & long-term commitment. Our corporate headquarter is located in Taiwan with Ethernet Direct Partners across United States, Canada, Asia Pacific, Latin America, Europe, and Middle East.