Galvanic Isolator - How to test?

[WotEver]

10 minutes ago, jonathanA said:

As with any post on a forum people need to weigh up the opinions expressed and make up their minds what’s appropriate for their situation. I think it’s important to debunk some of the self appointed experts when they are wrong/misleading or at least present a differing view - don’t you agree ? 

Absolutely. And in time they will be able to determine who is the arrogant fool and who is not.  
 

 

Edited February 26, 2020 by WotEver

[nicknorman]

10 hours ago, jonathanA said:

The point made by many people is that yes a GI can POTENTIALLY fail following some sort of fault current and therefore should be tested after an overload trip.  This thread demonstrates how simple that is.  
 

if in your opinion then this makes me a fool well  I can live with that because I care not.

 

Educated to honours degree level and working in telecoms for 40 year I’m not merely a craftsman or technician masquerading as an ‘engineer’ but I expect that distinction would be totally beyond yours and wotevers comprehension so I shall waste no more time with you.
 

As with any post on a forum people need to weigh up the opinions expressed and make up their minds what’s appropriate for their situation. I think it’s important to debunk some of the self appointed experts when they are wrong/misleading or at least present a differing view - don’t you agree ? 

 

I too have an honours degree, from a red brick university. Mine is in electrical and electronic engineering, not media studies.

 

If as you say you have some knowledge of electricity then surely you would understand that a dead short on a mains supply is going to create a very high current transient, into the 1000s of amps. If you have any knowledge of semiconductors you would understand that the thermal mass of the junction of a diode rated at a few 10s of amps is very small, and thus a few 1000 A will melt it in a very short time. If that time is less than 20mS there is a chance that the diode will open circuit before the mechanical trip, trips. Even if it does trip, chances are the diode is toast and then you are relying on your average Joe to have the nouse to check it. The probability of this being carried out is fairly low.

[cuthound]

16 hours ago, jonathanA said:

The point made by many people is that yes a GI can POTENTIALLY fail following some sort of fault current and therefore should be tested after an overload trip.  This thread demonstrates how simple that is.  
 

if in your opinion then this makes me a fool well  I can live with that because I care not.

 

Educated to honours degree level and working in telecoms for 40 year I’m not merely a craftsman or technician masquerading as an ‘engineer’ but I expect that distinction would be totally beyond yours and wotevers comprehension so I shall waste no more time with you.
 

As with any post on a forum people need to weigh up the opinions expressed and make up their minds what’s appropriate for their situation. I think it’s important to debunk some of the self appointed experts when they are wrong/misleading or at least present a differing view - don’t you agree ? 

 

I too have a degree and a lifetime of experience of working in a power environment, from DC power syatems & batteries, diesel generators and their electronic control systems, UPS systems, building distribution & protection systems to high voltage AC up to 66kV.

 

However as Nick says large currents can flow under fault conditions (ohms law) and semi-conductor junctions have very limited current carrying capacity.

 

Edited February 27, 2020 by cuthound
Phat phingers