| Title: | DEChub/HUBwatch/PROBEwatch CONFERENCE | 
| Notice: | Firmware -2, Doc -3, Power -4, HW kits -5, firm load -6&7 | 
| Moderator: | NETCAD::COLELLA DT | 
| Created: | Wed Nov 13 1991 | 
| Last Modified: | Fri Jun 06 1997 | 
| Last Successful Update: | Fri Jun 06 1997 | 
| Number of topics: | 4455 | 
| Total number of notes: | 16761 | 
    I have a customer that wants some detailed information on the DEChub 90
    power supply.  He wants to know how we tested for ground fault
    isolation and what the impedance is.  Does the power supply use a
    transformer for isolation?  
| T.R | Title | User | Personal Name | Date | Lines | 
|---|---|---|---|---|---|
| 2400.1 | Ethernet port/power supply isolation? | CGOOA::CRICK | Wed Jun 21 1995 11:34 | 5 | |
|     Further to my original note, I have contacted the customer again and got
    clarification on what he was really looking for.  He is concerned that
    a power supply failure could cause a DC or AC voltage to appear on a
    Ethernet segment.  I assume that we have some form of isolation between
    the power supply and the Ethernet ports.  Can someone verify that?
 | |||||
| 2400.2 | Most or all LAN standards *require* isolation of some type... | NETCAD::BATTERSBY | Wed Jun 21 1995 11:42 | 10 | |
|     <-----RE: 2400.1
    Most Ethernet port designs that I know of definitely do have
    isolation within the physical layer logic per the appropriate
    IEEE standard.
    For example both the AUI and TP ports of the HUB DECswitchs and PEswitch
    products have isolation transformers in the physical layer logic.
    This is done for the express reason such as stated in the previous
    note.
    
    Bob
 | |||||