Low, Medium & High Voltage Definition

[iwire]

It is that easy, if you read the OP's question.

Right.


But the issue is that you have decided the only "qualified definition" is the one that you work with.

In other words "My standard is better then your standard"

 

[ItsHot]

general idea?

general idea?

I use to think I had a general idea to the op, but not anymore! "under 24v ..low voltage, over 24v..high voltage!:grin:

 

[zog]

Right.


But the issue is that you have decided the only "qualified definition" is the one that you work with.

Not at all, it simply is the answer to the OP's question.

 

[iwire]

Not at all, it simply is the answer to the OP's question.

It is one possible answer to the OPs question.

I'm looking for a qualified definition for Voltage levels ie. Low Voltage < ? Medium Voltage > to < & High Voltage > ? There are various definitions for these in the NEC & NFPA - Is there a definitive answer for construction, maintenance & utility electricians? Is there a standard and if not why not?

I consider myself a construction and maintenance electrician and the NEC, not the IEEE rules what I do. That being the case using the NEC definition makes the most sense. Building construction, maintenance electricians know little of the IEEE, we don't have to. The IEEE is not the standard we are required to work to.

If I worked on utility type equipment then I imagine the IEEE would become my 'go to' standard.

Really the answer to the OPs question

Is there a definitive answer ...

is no, there is not a definitive answer.

 

[zog]

is no, there is not a definitive answer.

True, but there should be

 

[iwire]

True, but there should be

Yes, that would be the ideal solution. :smile:

They might have to add an 'Ultra Low Voltage' category for 0 to 120.

 

[George Stolz]

My question is, what's in a name?

 

[iwire]

My question is, what's in a name?

Well theres an N and a A and a M and a.....

 

[zog]

My question is, what's in a name?

I think Groundskeeper Willie explains it all.

 

[zog]

Yes, that would be the ideal solution. :smile:

They might have to add an 'Ultra Low Voltage' category for 0 to 120.

Thats a good ise but I propose 2 lower voltage classses, to more easily comply with OSHA and NFPA 70E EEWP's.

120-600 - Low voltage (As it is now per IEEE and parts of the NEC)
50-120 - Some new class, maybe "extra low voltage"?
<50V - Something new, "irevelant voltage"?

 

[dnem]

Is there a definitive answer for construction, maintenance & utility electricians? Is there a standard .....

a standard, as in one standard for all situations ?
That answer would be NO !

..... and if not why not?

Because no one governing body covers everything. . And each governing organization wants to do its own thing its own way.

charlie is obviously more familiar with the IEEE than I am

I am having a problem with the reason this is such a great consternation since you would use the scale of the code you are working with. The IEEE scale would fit with the NESC since the IEEE publishes the NESC. Use the scale that the NEC uses when using the NEC.

The following is the best answer given here yet.

I consider myself a construction and maintenance electrician and the NEC, not the IEEE rules what I do. That being the case using the NEC definition makes the most sense. Building construction, maintenance electricians know little of the IEEE, we don't have to. The IEEE is not the standard we are required to work to.

If I worked on utility type equipment then I imagine the IEEE would become my 'go to' standard.

With zog, you get alot of bravado and arrogance

Yep, the difference is I answered it

spark2, you're free to listen to whomever you wish

 

[zog]

"I know there are many answers and none can claim to be the only right one. . Here on this website, the best answer is the NEC answer.

So what do you call this?

 

[iwire]

I know there are many answers and none can claim to be the only right one. . Here on this website, the best answer is the NEC answer.

So what do you call this?

I would call it one sided.

IMO there is no 'best' answer. Only the OP knows which standard is applicable to the work they do. :smile:

 

[ELA]

Thats a good ise but I propose 2 lower voltage classses, to more easily comply with OSHA and NFPA 70E EEWP's.

120-600 - Low voltage (As it is now per IEEE and parts of the NEC)
50-120 - Some new class, maybe "extra low voltage"?
<50V - Something new, "irevelant voltage"?

I feel the problem is that no one user of "voltage" can claim their modifiers such as "low" and high" are the only correct ones. These are generic terms that anyone can mold to their particular use.

Take the term "quality" and now apply "low and high" as modifiers to this term. Don't you believe there will be lots of differing opinions on that?
I would say this would be a totally relative or subjective depiction.


I think a lot of computer engineers would take issue with your proposed catagory of
"<50V as irrelavent".
You seem to be totally focused on what is relavent for your world only. There are a lot of different users of the term "voltage" and it will always be relative to the industry you work in.
Perhaps a term like "logic levels" might be more appropriate for some?

There is a very real need to catagorize voltage levels relative to your type of work.
I often perform bench testing and want to alert people to a possible hazard. I often put out a sign that states " Caution - High Voltage Hazard" even when there may only be 120 -240Vac present. It is intended to make a point that the area is to be avoided.

Using the phrase "Caution - Extra Low voltage hazard" just does not have the same impact. :grin:

 

[dnem]

I'm glad this thread came up because it not only gives an answer to spark2s question, but also gets the rest of us thinking. . A more accurate answer is always better.

I used to give my students an info sheet that included this:
EQUIPMENT
0-600 . . Standard
601-2000 . . Low Industrial
2001-35,000 . . Medium Industrial
35,001 & up . . High Industrial

SYSTEMS
0-49 . . Low Distribution
50-1000 . . Medium Distribution
1000-4160 . . High Distribution
4160 & up . . Transmission

Now I'm rewriting that section to say this:
EQUIPMENT [NEC90.2(A)]
0-600 . . Standard . . [110.26 also see T310.13(A)]
601-2000 . . Low ?High?/Low Industrial . . [110.30 + 490.2]
2001-35,000 . . Medium ?High?/Medium Industrial . . [328.2 def, 328.10]
35,001 & up . . High ?High?/High Industrial . . [example: 450.21(C)]

SYSTEMS / DISTRIBUTION [NEC90.2(A)]
0-49 . . Low . . . . . . [250.20(A), 720]
50-1000 . . Medium . . . . . . [250.20(B)]
1000 & up . . High . . . . . . [250.20(C), examples: 250.180 + 410.140]

UTILITY / TRANSMISSION [NEC90.2(B)]
as defined in the IEEE standard
0-600 . . Low
601-69,000 . . Medium
69,001-230,000 . . High
230,001-800,000 . . Extra High
800,000 & up . . Ultra High

 

[iwire]

I'm glad this thread came up because it not only gives an answer to spark2s question, but also gets the rest of us thinking. . A more accurate answer is always better.

David, it is only one of at least a few possible answers to the OPs question.

The IEEE standard is just as valid as any NFPA standard, the person doing the work will need to figure out which standard applies.

 

[iwire]

I often perform bench testing and want to alert people to a possible hazard. I often put out a sign that states " Caution - High Voltage Hazard" even when there may only be 120 -240Vac present. It is intended to make a point that the area is to be avoided.

Using the phrase "Caution - Extra Low voltage hazard" just does not have the same impact. :grin:

Nope, "Extra Low voltage hazard" does not convey a sense of danger. :grin:

 

[zog]

I think a lot of computer engineers would take issue with your proposed catagory of
"<50V as irrelavent".
You seem to be totally focused on what is relavent for your world only. There are a lot of different users of the term "voltage" and it will always be relative to the industry you work in.
:

I meant irrevelant in regards to Electrical Safe Work Practices as defined by OSHA and the NFPA 70E (As I stated). <50V does not require PPE or the system to be denergized, therefore from a safety <50V is irrelevant.

If OSHA and NFPA 70E do not apply to your world, then I apolgize.

 

[iwire]

I meant irrevelant in regards to Electrical Safe Work Practices as defined by OSHA and the NFPA 70E (As I stated). <50V does not require PPE or the system to be denergized, therefore from a safety <50V is irrelevant.

Interesting, so large stack of batteries operating in parallel providing thousands of amps of fault current are not considered a safety concern?

 

[zog]

I think a lot of computer engineers would take issue with your proposed catagory of
"<50V as irrelavent".
You seem to be totally focused on what is relavent for your world only. There are a lot of different users of the term "voltage" and it will always be relative to the industry you work in.

I meant irrevelant in the aspect of electrical safe work practices (As defined by OSHA and NFPA 70E