Interpretation the term "in sight from"

[dnatoy]

We have installation in a single room with high voltage (480/277V) and low voltage (208/120V) panels located next to each other on same wall. Transformer is located above 2'x4' grid ceiling with removable acoustic tiles in the same room. Transformer is fed from circuit breaker located in the high voltage panel. Low voltage panel has main circuit breaker. Feeder from transformer to panel is less than 10 feet long. OCPD's are sized per NEC requirements. We were enforced by local building electrical inspector to install disconnect switch on the primary side of the transformer, because "when somebody works with transformer above the ceiling grid, this person cannot see high voltage panel and transformer's circuit breaker." We provided this modification, but it seems overkill on building department's side. What is you thought about it?

 

[infinity]

Within sight means within sight for up to 50'. Under the 2011 NEC, there is no requirement to have a disconnect within sight of a transformer if the feeder can be locked in the open position and a sign is affixed to the transformer stating where the disconnect is located.

Welcome to the Forum.

 

[dnatoy]

We are talking about panel and transformer in same room within six feet from each other.

 

[Hv&Lv]

We have installation in a single room with high voltage (480/277V) and low voltage (208/120V) panels located next to each other on same wall. Transformer is located above 2'x4' grid ceiling with removable acoustic tiles in the same room. Transformer is fed from circuit breaker located in the high voltage panel. Low voltage panel has main circuit breaker. Feeder from transformer to panel is less than 10 feet long. OCPD's are sized per NEC requirements. We were enforced by local building electrical inspector to install disconnect switch on the primary side of the transformer, because "when somebody works with transformer above the ceiling grid, this person cannot see high voltage panel and transformer's circuit breaker." We provided this modification, but it seems overkill on building department's side. What is you thought about it?

Yea, it can be aggravating, but, from definitions...(bold and underlines are mine)

In Sight From (Within Sight From, Within Sight).
Where this Code specifies that one equipment shall be “in
sight from,” “within sight from,” or “within sight of,” and
so forth, another equipment, the specified equipment is to be
visible and not more than 15 m (50 ft) distant from the other.

 

[charlie b]

They may be close by, and they may be in the same room, but they are not "within sight." That is because there is a removable ceiling between them. That said, they are not required to be within sight. The electrical inspector was wrong, in forcing you to install the disconnect.

 

[charlie b]

Under the 2011 NEC, there is no requirement to have a disconnect within sight of a transformer if the feeder can be locked in the open position and a sign is affixed to the transformer stating where the disconnect is located.

Prior to the 2011 NEC, there was no requirement to have a primary disconnect at all. You had to have overcurrent protection, and that device could serve as a disconnecting means, but the specific requirement to have a disconnecting means was introduced in 2011.

 

[augie47]

They may be close by, and they may be in the same room, but they are not "within sight." That is because there is a removable ceiling between them. That said, they are not required to be within sight. The electrical inspector was wrong, in forcing you to install the disconnect.

charlie,
the OP's profile states he is under the '11 Code so the transformer would have to have a disconnect "in sight" or lockable with a location plaque at the transformer.
If the inspector sees it as you do, "not within sight" then his call would be good, IMHO.

Sight unseen (no pun intended) it;s seem a bit of a "stretch" considering the proximity, but I would admit that if one was on a ladder at the transformer he would probably not be within sight.


(oppps I answered before I saw your post #6)

 

[dnatoy]

We agreed that this requirement was overkill, but inspector was backed up by his Chief. Change order was just about 1,000, so we went with it. Also, did not want to spoil relations with this guy. Hope that for next code issue this definition will be better made or Mike Holt could issue article about it. Because this practice is enforced citywide.

 

[infinity]

charlie,
the OP's profile states he is under the '11 Code so the transformer would have to have a disconnect "in sight" or lockable with a location plaque at the transformer.
If the inspector sees it as you do, "not within sight" then his call would be good, IMHO.

Sight unseen (no pun intended) it;s seem a bit of a "stretch" considering the proximity, but I would admit that if one was on a ladder at the transformer he would probably not be within sight.

I checked that before answering. :happyyes:

 

[Hv&Lv]

Prior to the 2011 NEC, there was no requirement to have a primary disconnect at all. You had to have overcurrent protection, and that device could serve as a disconnecting means, but the specific requirement to have a disconnecting means was introduced in 2011.

What about 110.58?

 

[charlie b]

the OP's profile states he is under the '11 Code so the transformer would have to have a disconnect "in sight" or lockable with a location plaque at the transformer.

I did not notice that detail in his profile. So now we have the question (for future installations, since this one has been resolved already), is the breaker on the high voltage panel lockable? If so, then all you needed to do (or need to do for the next install) was (is) to write upon the side of the transformer, in hand, using a magic marker, the location of the primary feeder breaker.

 

[augie47]

What about 110.58?

over 600 volt section, I believe

 

[charlie b]

What about 110.58?

That is within Part IV, and applies only to "Tunnel Installations over 600 volts, Nominal." Therefore, it is not relevant to the present question.

 

[Hv&Lv]

over 600 volt section, I believe

You are correct, my apologies...:dunce: