Electronics > Power/Renewable Energy/EV's

lightning and exclamation mark power shock warning symbols

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waveman:
Hello,
I am looking for information of the lightning an exclamation mark hazard warning symbols that we see on 110V input to devices- what they mean, which ones are required. What standard document do I need to get?

ejeffrey:
The left is "general hazard" and the right is "electrical hazard"

I'm not sure when or if they are actually required.  You don't generally see them on consumer equipment so I'd guess that it is an OSHA / workplace safety issue than a product safety issue.

Someone:
IEC60417 and ISO7000 have the symbols themselves, but other standards say where/how they have to be used.

TimNJ:
Under IEC62368-1, these types of symbols are called instructional safeguards. You can't (or wouldn't want to) rely upon an instructional safeguard to provide essential safety, in most cases. After all, an ordinary person may completely not see or understand the symbol(s) at all. In fact, I do not believe any standard lets you "protect" ordinary people from electric shock, by means of an instructional safeguard. For ordinary people, electric shock risk must be mitigated by "real" countermeasures, i.e. isolation, voltage limitation, and leakage current limitation.

However, some products (or situations) are inherently more dangerous than others and you cannot remove the risk completely. For example, equipment which needs to remain powered while being serviced may present some risk to the skilled person involved. In this case, an instructional safeguard may be used to warn the skilled person of potential danger.

So, practically speaking, these types of symbols probably make the most sense when directed at a skilled/trained person. For instance, they can be placed on an access panel door, or added to a PCB which carries mains or high voltage. You can put it on the enclosure of your product, but that somewhat implies that the product (as a whole) is not intended for ordinary people.

If you have access to it, I think IEC62368-1 actually does a pretty good job at covering risk mitigation. They address different types of "energy sources" and different energy levels of each type. Off the top of my head, it discusses:

ES: Electrical source (shock hazard)
TS: Thermal source
PS: Power source (actually not really sure the difference between TS and PS)
RS: Radiation source (X-rays, etc.)
MS: Mechanical source (moving parts, etc.)

waveman:
Hello,
Thanks all for your replies.

TimNJ
I have access to IEC61010 (safety requirements) and 61508 (functional safety). I found in 61010 the two symbols in a table. I didn't find when we have to put the electrical shock one.

>If you have access to it, I think IEC62368-1 actually does a pretty good job at covering risk mitigation.
Thanks for that. With google search on IEC62368-1, it says the the IEC62368-1 replaces  IEC60950-1. I have IEC60950-1.

I have the AC power main input and one high voltage output plus other small voltage input ouputs.  I have to decide on how high I should limit the high voltage output and what kind of warning symbols I should put.

ejeffrey
>You don't generally see them on consumer equipment so I
The product is to be sold to physicists.

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