Absurdly Simple Question II: Transformers

[George Stolz]

And since you have such a problem with this site, maybe you should just stick to yours.

I was once offended by the actions of a moderator on an internet forum who deleted my posts, which I took to be against the unwritten codes of conduct surrounding internet forums. I felt the most appropriate course of action was not to linger around, complaining about my treatment - I simply deleted my profile and quit participating on the site. There was no sense in complaining on the site, since my posts would be deleted anyway, since the administrator did not share my ethics.

Here, we have a little problem, because the moderators will not delete the complaining out of a sense of fair play, but the complaining is annoying and attempting to turn the forum from it's intent. Hopefully, this whole issue works itself out on it's own.

 

[iwire]

Now back to our previously scheduled programing.

There is nothing that says the "lockable" part must be part of the disconnect like other rules in the code say. There is always a way to lock a disconnect. I stand by my statement that this requires nothing more than a label and that is how I will teach it.

That is an interesting take, one that I had not considered but sure would like to talk about more than the off topic stuff.

Is this the correct wording for the 2011? ( I took this from the draft copy)

450.14 Disconnecting Means. Transformers, other than
Class 2 or Class 3, shall have a disconnecting means located
either in sight of the transformer or in a remote location.
Where located in a remote location, the disconnecting
means shall be lockable, and the location shall be field
marked on the transformer.

 

[George Stolz]

You're no fun.

Pretty close:

450.14 Disconnecting Means. Transformers, other than Class 2 or Class 3 transformers, shall have a disconnecting means located either in sight of the transformer or in a remote location. Where located in a remote location, the disconnecting means shall be lockable, and the location shall be field marked on the transformer.

 

[jwelectric]

I don?t think that in over 40 years of electrical work I have ever seen a panelboard that couldn?t be turned off. Maybe I have missed something through the years.
But to compare a panelboard to a transformer????????????
I thought we were discussing transformers not panelboards.

A feeder is supplying transformers on each of a three floor building. Something goes wrong with the second floor transformer and now all three floors are shut down.
If this can not be seen as a safety issue then so be it but there were enough to see it as one that action was taken. Now supply a disconnect for each transformer and make it either insight of or lockable.

For an appliance such as a water heater or cooking equipment the codes requires a means to lockout the circuit that supplies these appliances when the disconnect is not within sight.
Is by some means other than my poor brain is capable of understanding that makes the circuit supplying a transformer less likely to be inadvertently energized? Well the TCC did not think so as this action was taken due to their study. It was totally outside the purpose as outlined in 90.1

 

[LarryFine]

Oh vey.

That's "Oy vey," but who's counting?

 

[iwire]

A sheynem dank

 

[jumper]

A sheynem dank

Nishto farvos!

 

[don_resqcapt19]

...
A feeder is supplying transformers on each of a three floor building. Something goes wrong with the second floor transformer and now all three floors are shut down.

I think it would be rare where a single OCPD could provide the required primary overcurrent protection for 3 transformers. In most cases there would be some way to lockout the individual transformer OCPD.

Also in the event that there was a single OCPD that could serve all 3 transformers, I see nothing in this rule that would require a means of disconnect for each transformer. We can still have all 3 floors shut down by locking the remote disconnect.

 

[don_resqcapt19]

...
That is an interesting take, one that I had not considered but sure would like to talk about more than the off topic stuff.
...

Bob,
The CMP did not use the standard language that requires the disconnect itself to be lockable. I see this language as substantially different from the language in many of the other rules. This other language from 430.102(B) Exception is shown below. The same language has been used in a number of cases where the code has permitted the use of remote means of disconnect. They just didn't use that language here and I think the lack of that language does make a real difference in the application of the new rule.

The provision for locking or adding a lock to the controller disconnecting means shall be installed on or at the switch or circuit breaker used as the disconnecting means and shall remain in place with or without the lock installed.

The rule in 450.14 does not require anything special for the disconnect. I am sure I can find a way to lock out most any means of disconnect and as long as I can, we don't need to do anything other than to provide a label to comply with this new rule.

 

[iwire]

Don I think Proposal 9-201 may support your view but I cannot find it.



From the proposal for the disconnecting means.

The lockable wording correlates with the task group results reported in Proposal 9-201.

 

[jumper]

Don I think Proposal 9-201 may support your view but I cannot find it.



From the proposal for the disconnecting means.

9-201 Log #1568 NEC-P09 Final Action: Accept
(490.44(C))
_______________________________________________________________
TCC Action: It was the action of the Technical Correlating Committee that
this proposal be reconsidered by Code-Making Panel 9 based upon the
action of Code-Making Panel 1 taken on Proposal 1-63.
This action will be considered by the panel as a public comment.
Submitter: Stanley J. Folz, Henderson, NV
Recommendation: Revise text to read as follows:
(C) Switching Mechanism. The switching mechanism shall be arranged to be
operated from a location outside the enclosure where the operator is not
exposed to energized parts and shall be arranged to open all ungrounded
conductors of the circuit simultaneously with one operation. Switches shall be
a lockable disconnecting means. capable of being locked in the open position.
The provisions for locking shall remain in place with or without the lock
installed.
Substantiation: This lockable disconnect concept is used through the code.
One definition in Article 100 would harmonize its use in all Articles. This
proposal was developed by a Task Group that was appointed by the NEC
Technical Correlating Committee and consisted of Stanley J. Folz, Chair,
Monte Ewing, Ralph Pritchard, Sondra Todd, and Randy Yasenchak.
A companion proposal has been submitted to Article 100 containing a new
definition for “Disconnecting Means, Lockable

Bold was struck out.

 

[iwire]

Thanks!

 

[jwelectric]

I think it would be rare where a single OCPD could provide the required primary overcurrent protection for 3 transformers. In most cases there would be some way to lockout the individual transformer OCPD.

The key to your statements are the words ?rare? and ?most cases?. Neither of these means ?never? but instead hint toward the term of ?likely?.

It is very obvious that there is a safety issue or the proposal would have been rejected.

Also in the event that there was a single OCPD that could serve all 3 transformers, I see nothing in this rule that would require a means of disconnect for each transformer. We can still have all 3 floors shut down by locking the remote disconnect.

450.14 Disconnecting Means. Transformers, other than Class 2 or Class 3 transformers, shall have a disconnecting means located either in sight of the transformer or in a remote location. Where located in a remote location, the disconnecting means shall be lockable, and the location shall be field marked on the transformer.

Sounds to me like each and everyone will have their own disconnect. It also sounds to me that every objection I have heard about this change revolves around the old clich?, ?it has worked fine for the past 20 years so why mess with it now?

 

[iwire]

The key to your statements are the words “rare” and “most cases”. Neither of these means “never” but instead hint toward the term of “likely”.

They can hint to whatever you want but there are no facts that are presented in the substantiation and there should be some before a proposal is accepted.

It is very obvious that there is a safety issue or the proposal would have been rejected.

Another falsehood, obviously enough of the CMP felt there was a safety issue that needed to be addressed but it does not at all prove that there was an issue.

450.14 Disconnecting Means. Transformers, other than Class 2 or Class 3 transformers, shall have a disconnecting means located either in sight of the transformer or in a remote location. Where located in a remote location, the disconnecting means shall be lockable, and the location shall be field marked on the transformer.

Sounds to me like each and everyone will have their own disconnect.

I do not see that in there.

It also sounds to me that every objection I have heard about this change revolves around the old clich?, “it has worked fine for the past 20 years so why mess with it now”

Much more than 20 years .... and the best reason presented in this thread to make this change has been 'to bring it in line with motors' etc. Weak. :grin: The reason given to the CMP was the inconvenience of shutting systems down. That is a design issue. And it also sounds to me that some lose all commonsense in the guise of safety.

No one has yet to answer my questions why this rule is so important for a transformer but not for a panel. But I understand I ask difficult questions that point out the holes in peoples logic so my questions go unanswered.

 

[chris kennedy]

No one has yet to answer my questions why this rule is so important for a transformer but not for a panel.

FWIW, I am currently working on a proposal that will require safety switches for safety switches.

 

[don_resqcapt19]

I see nothing in the code section that requires an individual means of disconnect. It is my opinion that the service disconnect for the building would meet the requirements of this code section. There are other sections of the code that require disconnects and specify an individual disconnect. This section for example:

430.102 Location.
(A) Controller. An individual disconnecting means shall be provided for each controller and shall disconnect the controller. The disconnecting means shall be located in sight from the controller location.

The CMP did not chose to use that wording in 450.14 so we cannot infer that they intended that the means of disconnect be an individual one. If they want that they have to say that.

 

[iwire]

FWIW, I am currently working on a proposal that will require safety switches for safety switches.

Thanks for the heads up, I have to get on my line of safety switch safety switches.

 

[don_resqcapt19]

FWIW, I am currently working on a proposal that will require safety switches for safety switches.

That is sort of required, but not done, for manual switches that are used as motor controllers. The code rule that I quoted in my previous post requires a disconnect within sight of all motor controllers. There is no exception for the cases where a switch is the motor controller. The rule requires two switches in series, but I have never seen that in the field.

 

[jwelectric]

Bob and Don

If there is a feeder that is supplying more than one transformer the disconnect for the feeders would not be the disconnect required by the new 450.14.

The new 450.14 is directed to transformers not the overcurrent device for the feeders as outlined in 215.3. There is no mention of feeders in this new section but it clearly states transformers will be having a disconnect.

Bob please explain what you are talking about with panels. I thought this discussion was about transformers. Are we reaching for straws here or some other tactic of distraction?

 

[don_resqcapt19]

Mike,
There is nothing in the rule that says anything about what disconnect that I use to disconnect the transformer. Until the code wording is changed to require an individual disconnect, it will remain my opinion that any disconnect that kills the power to the primary of the transformer meets the rule.

For what it is worth, I think they wanted an individual disconnect, but you can't enforce what they wanted...you can only enforce what they wrote.

How does the feeder disconnect not disconnect the transformer???