450.14 Disconnecting means for outdoor transformer

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rojay

Senior Member
Location
Chicago,IL USA
I have an outdoor transformer supplied by a panelboard located indoors. Is the remote circuit breaker suitable as the sole disconnecting means(it is considered lockable- correct? ) or do I need to do more to satisfy 450.14?
 

don_resqcapt19

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Staff member
Location
Illinois
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retired electrician
You need signage at the transformer to indicate the location of the supply side disconnect and the disconnect must be capable of being locked in the open position.
What are you doing with the secondary conductors? They will require overcurrent protection per one of the rules in 240.21(C).
 

rojay

Senior Member
Location
Chicago,IL USA
You need signage at the transformer to indicate the location of the supply side disconnect and the disconnect must be capable of being locked in the open position.
What are you doing with the secondary conductors? They will require overcurrent protection per one of the rules in 240.21(C).
The secondary conductors are feeding an outdoor sub-panel w/ main breaker. But as far as the primary side goes, it sounds like we are talking about a permanent means of locking and the removable- style breaker lock that I'm thinking of would not be acceptable?
 

don_resqcapt19

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Staff member
Location
Illinois
Occupation
retired electrician
I believe that a "permanent" means of lockout is the intent of the code rule, but this rule stops short of saying that. Many of the other lockout rules have wording the requires the means of lockout to be a part of the breaker or disconnect.

There will be a new section in the 2014 code that will make this clear. The following is from the draft copy of the 2014 NEC.
110.25 Lockable Disconnecting Means. Where a disconnecting means is required to be lockable open, elsewhere in this Code, it shall be capable of being locked in the open position. The provisions for locking shall remain in place with or without the lock installed. [ROP 1?130]
 

rojay

Senior Member
Location
Chicago,IL USA
I believe that a "permanent" means of lockout is the intent of the code rule, but this rule stops short of saying that. Many of the other lockout rules have wording the requires the means of lockout to be a part of the breaker or disconnect.

There will be a new section in the 2014 code that will make this clear. The following is from the draft copy of the 2014 NEC.
Yeah, I just read 450.14 again and I see what you are saying. There is definitely a difference between what is actually written and what may be intended. The way it is written seems to me to require nothing more than a sign that tells where the disconnecting means (circuit breaker) is located. Circuit breakers are lockable- right? Seems like either a breaker lock-on type device or a hasp type setup would be going even above and beyond the actual wording here.
 
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