General Duty Safety Switch not permited?
- Thread starter iwire
- Start date
- Status
- Location
- Massachusetts
BINGO! We have a winner, the check is in the mail. :grin:
They said a typical mechanical time clock is OK because it has that plastic shield over the terminals.
IMO the enclosure of a general duty safety switch is an 'approved enclosure' so it meets code.
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sfav8r
Senior Member
- Location
- San Francisco Bay Area
So they wouldn't object to a general duty safety switch with a padlock on it?
You da man Gus
only because Bob guided us there on Post 18
- Location
- Massachusetts
I do not know, they moved on quickly.
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Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
110.27(A) is generally for enclosures.
The 4 conditions that follow the general paragraph provide conditions.
These conditions are not about the enclosure itself, such as the "switch" enclosure, but the "space" enclosure, which is the space about the safety switch, in essence the room or fenced in area the safety switch is located in.
Notice the wording in the general paragraph.
"...live parts of electrical equipment operating at 50 volts or more shall be guarded against accidental contact by approved enclosures or by any of the following."
Definition of Enclosure
The case or housing of apparatus, or the fence or walls surrounding an installation to prevent personnel from accidentally contacting energized parts or to protect the equipment from physical damage.
With all of that being posted by me, I believe they have read into 110.27(A) incorrectly, assuming that it is in regards to the safety switch itself and not the area/room/enclosure.
The 4 conditions that follow the general paragraph provide conditions.
These conditions are not about the enclosure itself, such as the "switch" enclosure, but the "space" enclosure, which is the space about the safety switch, in essence the room or fenced in area the safety switch is located in.
Notice the wording in the general paragraph.
"...live parts of electrical equipment operating at 50 volts or more shall be guarded against accidental contact by approved enclosures or by any of the following."
Definition of Enclosure
The case or housing of apparatus, or the fence or walls surrounding an installation to prevent personnel from accidentally contacting energized parts or to protect the equipment from physical damage.
With all of that being posted by me, I believe they have read into 110.27(A) incorrectly, assuming that it is in regards to the safety switch itself and not the area/room/enclosure.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
I suspect they wanted a horsepower rated switch (440.12) which, by definition, a general-use switch does not have; it has an ampere rating.
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
I'll have to have a look tomorrow, unless someone can post the text of that article, and save me the wait.
- Location
- Massachusetts
No, they specifically cited 110.27(A) and the fact a GD switch can be opened in the on position.
- Location
- Massachusetts
I'll have to have a look tomorrow, unless someone can post the text of that article, and save me the wait.
This is from the California electrical code but should match the 2005 NEC and I imagine the 2008 as well.
peter d
Senior Member
- Location
- New England
Hahaha...I sure wish I had been at the class!
But I remember the question. The same instructors posed the same question to a different CEU course that I took.Anyway, their argument was that since the terminals aren't guarded then the homeowner can get shocked trying to replace a fuse...blah blah blah. I can see their point as the NEC is about safety. However, from a professional point of view, the unqualified should not be messing around in disconnect switches anyway.
- Location
- Massachusetts
I can see the concern, what I do not see is any code to back it up.
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
When the general duty switch door is closed, it provides protection from shock and is considered enclosed by the NEC.
How many enclosures are there that are not protected according to the instructors description? too many to think about.
The space about it may not be enclosed.
In regards to a homeowner opening the door and being exposed to the shock potential is now past the code requirement. If the homeowner is not properly qualified to work on such items, it is their perogative to do so, and at their own risk. Sort of like an iron...which provides no protection from someone being burned, once it is turned on.
How many enclosures are there that are not protected according to the instructors description? too many to think about.
The space about it may not be enclosed.
In regards to a homeowner opening the door and being exposed to the shock potential is now past the code requirement. If the homeowner is not properly qualified to work on such items, it is their perogative to do so, and at their own risk. Sort of like an iron...which provides no protection from someone being burned, once it is turned on.
TOOL_5150
Senior Member
- Location
- bay area, ca
Yeah, that really is a far stretch. Nothing even comes close to even hinting GD switches cannot be used because the door will open in the ON position.
~Matt
M. D.
Senior Member
You know what I noticed ,. what with the two threads concerning A.C. disconnects, and all ?? every one of the disconnects that was advertized one for an A.C. has either a dead front or is like the Milbank u3800 , listed without the need of a dead front ...Don't know what it means ,.if anything ,..but there it is.
article 404.13(C) says anthing less than 404.13(A&B) is considerd general use.
404.13 Knife Switches.
(A) Isolating Switches. Knife switches rated at over 1200 amperes at 250 volts or less, and at over 600 amperes at 251 to 600 volts, shall be used only as isolating switches and shall not be opened under load.
(B) To Interrupt Currents. To interrupt currents over 1200 amperes at 250 volts, nominal, or less, or over 600 amperes at 251 to 600 volts, nominal, a circuit breaker or a switch of special design listed for such purpose shall be used.
(C) General-Use Switches. Knife switches of ratings less than specified in 404.13(A) and (B) shall be considered general-use switches.
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Thanks for the citation, Bob. Now here is my answer to your instructors:
The fact that the enclosure is capable of being opened means nothing. Let me say that again: It means NOTHING! The fact that there is an enclosure is all that the code requires.
What the code is talking about here is eliminating the possibility that a chunk of metal that is electrically live might be sticking out into a hallway, such that a person walking past it might accidentally come into contact with it, thus receiving a shock. However, if the electrically live chunk of metal is inside an enclosure, and if a person bumps into it while walking through the hallway, then the worst that will happen is a bruise and the utterance a few of those words that we don't allow to be used on this forum. Youse gots an enclosure (an approved one, that is)? Then the code is satisfied. Chapter closed.
So the instructors then say, "Well, what about when the homeowner opens the enclosure to get at the fuses, and what about when he accidentally touches the live part? Huh? Huh? Gotcha, eh?" My response is cruel, heartless, uncaring, and very much contrary to the things I hear from the guy in the robes in that fancy building I visit on Sunday mornings: "It is not 'accidental contact,' in the context of the NEC wording."
I know the newspapers would speak of the tragic accident, and the coroner would report the cause of death as accidental electrocution. But let us, I say once again, not confuse the language of our profession with common conversational English. Yes, it was an accident. No, it was not "accidental contact." And don't try to tell me that this is a "one or the other" situtation, that is has to either be an accident or not. Don't tell me that there is "accidental" and there is "intentional," and there is nothing in between. I disagree most emphatically. Speaking as a private citizen, I would call it an accident. Speaking as the author of "Charlie's Rule," and speaking in the language of the NEC, I would not apply the phrase "accidental contact."
Is this just "double speak"? Not at all. Once the homeowner opened the enclosure, he took the situation out of the context of the NEC article. This was no longer just a person minding his own business, walking down what should have been a safe hallway, and bumping into a live wire. This was a person voluntarily undertaking a task that is inherently dangerous. I would equate this situation with that of a person driving 40 mph faster than the posted speed limit, and ending up smashing into a wall. The newspapers would speak of the tragic accident, and so it would be in the language of their profession. I would call it tragic that the person took a voluntary and unnecessary risk with his own life.
That is all you need. Might I presume that I would be correct in believing that in a "General Duty Safety Switch," the live parts are inside an enclosure? I will go on as if I had received the answer "yes."
The fact that the enclosure is capable of being opened means nothing. Let me say that again: It means NOTHING! The fact that there is an enclosure is all that the code requires.
What the code is talking about here is eliminating the possibility that a chunk of metal that is electrically live might be sticking out into a hallway, such that a person walking past it might accidentally come into contact with it, thus receiving a shock. However, if the electrically live chunk of metal is inside an enclosure, and if a person bumps into it while walking through the hallway, then the worst that will happen is a bruise and the utterance a few of those words that we don't allow to be used on this forum. Youse gots an enclosure (an approved one, that is)? Then the code is satisfied. Chapter closed.
So the instructors then say, "Well, what about when the homeowner opens the enclosure to get at the fuses, and what about when he accidentally touches the live part? Huh? Huh? Gotcha, eh?" My response is cruel, heartless, uncaring, and very much contrary to the things I hear from the guy in the robes in that fancy building I visit on Sunday mornings: "It is not 'accidental contact,' in the context of the NEC wording."
I know the newspapers would speak of the tragic accident, and the coroner would report the cause of death as accidental electrocution. But let us, I say once again, not confuse the language of our profession with common conversational English. Yes, it was an accident. No, it was not "accidental contact." And don't try to tell me that this is a "one or the other" situtation, that is has to either be an accident or not. Don't tell me that there is "accidental" and there is "intentional," and there is nothing in between. I disagree most emphatically. Speaking as a private citizen, I would call it an accident. Speaking as the author of "Charlie's Rule," and speaking in the language of the NEC, I would not apply the phrase "accidental contact."
Is this just "double speak"? Not at all. Once the homeowner opened the enclosure, he took the situation out of the context of the NEC article. This was no longer just a person minding his own business, walking down what should have been a safe hallway, and bumping into a live wire. This was a person voluntarily undertaking a task that is inherently dangerous. I would equate this situation with that of a person driving 40 mph faster than the posted speed limit, and ending up smashing into a wall. The newspapers would speak of the tragic accident, and so it would be in the language of their profession. I would call it tragic that the person took a voluntary and unnecessary risk with his own life.
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