Hi-Pot Test Current, Leakage Current and Insulation Resistance
Can the hi-pot test and the insulation resistance test be combined into a single measurement? Let’s discuss each of these parameters as circuit parameters and as safety parameters.
More on the 25-Amp Grounding Impedance Test
For production-line testing, the 25- or 30-amp grounding continuity test is not likely to identify construction anomalies that would not also be identified by a simple low-current test.
The 25-Amp Grounding Impedance Test
High-current grounding impedance tests have been specified in safety standards for many years. There are two, independent sources for these tests.
The Dielectric Withstand (Hi-pot) Test
There always seem to be questions about hi-pot testing. Maybe I can present some of those questions and their answers.
Models for Protection Against Injury
How does safety work? That is, given a hazardous situation, how do we prevent injury from that situation?
Derivation of Ground Impedance
Did you ever wonder why we use 0.1 ohm (and sometimes 0.5 ohm) for the ground impedance value for plug-and-socket connected equipment?
Absolute Safety
Recently, a colleague remarked to me, “Philosophically, of course, there is no such thing as absolute safety.” Could this be true? Is there a situation where a man could not possibly injure himself?
Operational Insulation in IEC 950
This issue’s topic is rather unique because this column addresses safety requirements for a non-safety critical device, “operational” or “functional” insulation.
Two Measures, Two Levels
What is a “level of protection”? What are “measures of safety”? Why do they apply only to electric shock and not to other injuries?
Markings and Other Aggravations
Why? Why is it that one of the biggest aggravations in product safety is that of markings? For some reason, it seems that we can never get the markings right the first time. Furthermore, it seems that markings that have been acceptable for years will suddenly go bad.