Searched this forum and the NEC, can't find an answer. The question is can I mount a service disconnect horizontal? I need to mount five disconnects, one for each solar PV array (DC side)and I can save a lot of room if I mount them sideways. They are type 3R enclosures, but will be indoors so weather is not an issue.
Horizontal Disconnect?
- Thread starter jerry12
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joe tedesco
Senior Member
- Location
- Boston, Massachusetts
Re: Horizontal Disconnect?
Look in Section 230.70 and possibly here:
240.33 Vertical Position
Look in Section 230.70 and possibly here:
240.33 Vertical Position
pierre
Senior Member
- Location
- Westchester County, New York
Re: Horizontal Disconnect?
240.33 permits the installer to mount the enclosure to be mounted horizontally if the breaker complies with 240.81. I believe you will not have a problem complying with this requirement.
Pierre
240.33 permits the installer to mount the enclosure to be mounted horizontally if the breaker complies with 240.81. I believe you will not have a problem complying with this requirement.
Pierre
charlie
Senior Member
- Location
- Indianapolis
Re: Horizontal Disconnect?
230.70 Enclosures for overcurrent devices shall be mounted in a vertical position unless that is shown to be impracticable. Circuit breaker enclosures shall be permitted to be installed horizontally where the circuit breaker is installed in accordance with 240.81.
Is it impractical? Does the AHJ agree with you?
230.70 Enclosures for overcurrent devices shall be mounted in a vertical position unless that is shown to be impracticable. Circuit breaker enclosures shall be permitted to be installed horizontally where the circuit breaker is installed in accordance with 240.81.
Is it impractical? Does the AHJ agree with you?
pierre
Senior Member
- Location
- Westchester County, New York
Re: Horizontal Disconnect?
Charlie
The second sentence in 240.33 permits the horizontal mounting provided it complies with 240.81. If the handle of the breaker is horizontal that is permited.
Pierre
Charlie
The second sentence in 240.33 permits the horizontal mounting provided it complies with 240.81. If the handle of the breaker is horizontal that is permited.
Pierre
charlie
Senior Member
- Location
- Indianapolis
Re: Horizontal Disconnect?
OK Pierre, but how do you reconcile the last part of the sentence, "unless that is shown to be impracticable"?
This then begs the two questions that I asked, "Is it impractical? Does the AHJ agree with you?"
OK Pierre, but how do you reconcile the last part of the sentence, "unless that is shown to be impracticable"?
This then begs the two questions that I asked, "Is it impractical? Does the AHJ agree with you?"
pierre
Senior Member
- Location
- Westchester County, New York
Re: Horizontal Disconnect?
Helllo Charlie
There are two distinct sentences in this section. The first requires vertical installation unless it is 'impracticable'. I am not sure how one can or cannot prove this, I believe it is a subjective statement, which makes it up to the AHJ.
The second sentence PERMITS horizontal installation provided 240.81 is followed. By turning the 'disconnect' on its side (horizontal), the breaker will be in a permitted position, therefore the installation is acceptable.
The first sentence is more for panelboards and such, where horizontal mounting will create a situation of breaker handles being in violation of 240.81.
Pierre
Helllo Charlie
There are two distinct sentences in this section. The first requires vertical installation unless it is 'impracticable'. I am not sure how one can or cannot prove this, I believe it is a subjective statement, which makes it up to the AHJ.
The second sentence PERMITS horizontal installation provided 240.81 is followed. By turning the 'disconnect' on its side (horizontal), the breaker will be in a permitted position, therefore the installation is acceptable.
The first sentence is more for panelboards and such, where horizontal mounting will create a situation of breaker handles being in violation of 240.81.
Pierre
charlie
Senior Member
- Location
- Indianapolis
Re: Horizontal Disconnect?
If the AHJ agrees (since it is a subjective statement), you are home free.
Pierre, your first paragraph is exactly what I am talking about. The problem is that I don't think you can take a section and just pull out one sentence and apply it to a situation, the whole section works together. Look at both sections together, if you find it to not be practical to mount a panelboard of switch in its verticle position, then you may mount it in the horizontal position but you must follow 240.81.
If the AHJ agrees (since it is a subjective statement), you are home free.
Re: Horizontal Disconnect?
Sorry I haven't been back since posting, but thanks to all for the interesting conversation. I think in my application (fused disconnect) horizontal installation does conform but as Charlie said,
"If the AHJ agrees (since it is a subjective statement), you are home free."
So now that I am armed with better information, That is where I'll turn next.
Jerry
Sorry I haven't been back since posting, but thanks to all for the interesting conversation. I think in my application (fused disconnect) horizontal installation does conform but as Charlie said,
"If the AHJ agrees (since it is a subjective statement), you are home free."
So now that I am armed with better information, That is where I'll turn next.
Jerry
pierre
Senior Member
- Location
- Westchester County, New York
Re: Horizontal Disconnect?
Hello Charlie
Not to make excuses for any of us, but the english language can be very difficult at times and when it is not well written, even more difficult.
Do you sea, see what I seem, seam to be trying to say.
I believe the meaning they are trying to get across in this section is that they prefer the disconnect to be vertical, but it is perfectly acceptable if the horizontal position has the handle in the proper position.
Pierre
Hello Charlie
Not to make excuses for any of us, but the english language can be very difficult at times and when it is not well written, even more difficult.
Do you sea, see what I seem, seam to be trying to say.
I believe the meaning they are trying to get across in this section is that they prefer the disconnect to be vertical, but it is perfectly acceptable if the horizontal position has the handle in the proper position.
Pierre
charlie
Senior Member
- Location
- Indianapolis
Re: Horizontal Disconnect?
Pierre, you need to know that I argue my points with vigor until I realize I am wrong if that is the case. On issues like this, there is indeed gray area and that is where the AHJ comes into the picture. It is their responsibility to interpret the Code. As 90.4 says, "The authority having jurisdiction for enforcement of the Code has the responsibility for making interpretations of the rules, . . . "; that leaves the interpretation to the AHJ.
With all that said, it is OK to disagree. We all have a right to our opinions and we should all respect the opinions of others even when we don't agree. Additionally, just because I am on a Code making panel does not make me right. I accept the mantel of being a Code expert under my own terms. My definition of an expert is someone who knows how much he doesn't know about a particular subject. There is a lot I don't know about the Code but I know what areas are outside my expertise.
I respect everyone who will stand up for their own interpretations of the Code and will defend their positions. This exchange will allow others to see both sides of an interpretation and they may make up their own minds as to the correctness of one side or the other.
The bottom line is that I really respect your opinion and knowledge and I am not always right. The AHJ is always right because they are the authority, but I am not.
Pierre, you need to know that I argue my points with vigor until I realize I am wrong if that is the case. On issues like this, there is indeed gray area and that is where the AHJ comes into the picture. It is their responsibility to interpret the Code. As 90.4 says, "The authority having jurisdiction for enforcement of the Code has the responsibility for making interpretations of the rules, . . . "; that leaves the interpretation to the AHJ.
With all that said, it is OK to disagree. We all have a right to our opinions and we should all respect the opinions of others even when we don't agree. Additionally, just because I am on a Code making panel does not make me right. I accept the mantel of being a Code expert under my own terms. My definition of an expert is someone who knows how much he doesn't know about a particular subject. There is a lot I don't know about the Code but I know what areas are outside my expertise.
I respect everyone who will stand up for their own interpretations of the Code and will defend their positions. This exchange will allow others to see both sides of an interpretation and they may make up their own minds as to the correctness of one side or the other.
The bottom line is that I really respect your opinion and knowledge and I am not always right. The AHJ is always right because they are the authority, but I am not.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Horizontal Disconnect?
I heard a comment last year on this subject, relating to a code change, by Alan Manche, of Sq D. He stated he had researched the horizontal vs vertical issue, and it turns out the intent of "horizontal" was in the 1920's, disconnects used to be mounted horizontially on the ceiling of a room. We now are interpertating this rule based on horizontal on a wall.
I heard a comment last year on this subject, relating to a code change, by Alan Manche, of Sq D. He stated he had researched the horizontal vs vertical issue, and it turns out the intent of "horizontal" was in the 1920's, disconnects used to be mounted horizontially on the ceiling of a room. We now are interpertating this rule based on horizontal on a wall.
- Location
- Massachusetts
Re: Horizontal Disconnect?
Here is the original question
It seems he is talking about disconnect switches.
I do not believe mounting a disconnect on it's side is acceptable.
Here is the original question
I do not believe he is talking about a breaker at all, we do not even know if he is talking about the OCPD.
It seems he is talking about disconnect switches.
I do not believe mounting a disconnect on it's side is acceptable.
Re: Horizontal Disconnect?
Pierre:
You are right, there are two distinct sentances. The first one refers to enclosures for overcurrent devices and says vertical unless impracticable. The second sentance seems to allow circuit breaker enclosures to be mounted horizontally. The problem I see is that circuit breakers are also overcurrent devices. The two sentances seem to conflict with each other, so I would have to agree it would be the AHJ's call.
However, since they are service disconnects, wouldn't the power company also have to agree to the horizontal mounting?
Pierre:
You are right, there are two distinct sentances. The first one refers to enclosures for overcurrent devices and says vertical unless impracticable. The second sentance seems to allow circuit breaker enclosures to be mounted horizontally. The problem I see is that circuit breakers are also overcurrent devices. The two sentances seem to conflict with each other, so I would have to agree it would be the AHJ's call.
However, since they are service disconnects, wouldn't the power company also have to agree to the horizontal mounting?
charlie
Senior Member
- Location
- Indianapolis
Re: Horizontal Disconnect?
No, the electric utility stops at the service point which is normally at the cash register (meter) if the service is UG or at the connections at the service head if it is OH. In other words, it is normally out of our purview.
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