Forum: Low Voltage and Limited Energy
Today, 08:44 PM
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Replies: 34
Views: 263
If the cables are in a metallic Chapter 3...
If the cables are in a metallic Chapter 3 raceway, within the other space used for environmental air, they can be any type of cable. If they are in a listed plenum raceway, they must be CMP.
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Forum: Electrical Calculations/Engineering
Today, 08:32 PM
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Replies: 38
Views: 781
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Forum: NEC
Today, 04:53 PM
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Replies: 38
Views: 625
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Forum: Electrical Calculations/Engineering
Today, 04:47 PM
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Replies: 1
Views: 47
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Forum: Electrical Calculations/Engineering
Today, 04:42 PM
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Replies: 22
Views: 305
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Forum: NEC
Today, 07:37 AM
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Replies: 8
Views: 185
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Forum: Electrical Calculations/Engineering
Today, 07:28 AM
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Replies: 22
Views: 305
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Forum: Electrical Calculations/Engineering
Today, 07:25 AM
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Replies: 22
Views: 305
Just put a length of flexible metal conduit in...
Just put a length of flexible metal conduit in the MCC wireway and install the Ethernet in the flex.
I don't really think fiber is a real option here. The communications is being run to multiple...
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Forum: Low Voltage and Limited Energy
Today, 07:18 AM
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Replies: 34
Views: 263
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Forum: Electrical Calculations/Engineering
Yesterday, 08:27 PM
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Replies: 38
Views: 781
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Forum: Safety
Yesterday, 08:24 PM
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Replies: 7
Views: 161
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Forum: NEC
Yesterday, 08:19 PM
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Replies: 38
Views: 625
Yes, it is my opinion that the code is a...
Yes, it is my opinion that the code is a permissive code and that which is not specifically prohibited is permitted.
It is not a single branch circuit....it is multiple branch circuits.
It is not...
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Forum: NEC
Yesterday, 05:24 PM
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Replies: 7
Views: 74
It doesn't really seem silly when you take a...
It doesn't really seem silly when you take a close look at it. The purpose of derating is to limit the heat. The heat is from the I^2R losses in the conductors. If you look at the currents in each...
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Forum: NEC
Yesterday, 05:14 PM
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Replies: 10
Views: 201
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Forum: NEC
Yesterday, 05:06 PM
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Replies: 38
Views: 625
Charlie,
I don't see it there. I don't see...
Charlie,
I don't see it there. I don't see anything in the definition of a branch circuit that says all of the wires must be exclusive to that circuit. I don't see a provision that says a branch...
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Forum: NEC
Yesterday, 02:08 PM
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Replies: 38
Views: 625
Charlie,
The installation would be something...
Charlie,
The installation would be something like this: Three #12s on 20 amp breakers and all of the breakers on the same phase. The #12s would be used with a #6 grounded conductor. There is...
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Forum: Electrical Contracting and Estimating/Management
Yesterday, 01:50 PM
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Replies: 20
Views: 565
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Forum: Electrical Calculations/Engineering
Yesterday, 11:50 AM
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Replies: 38
Views: 781
What edition of the code applies to this...
What edition of the code applies to this installation? If this is under the 2005 code or earlier, you could rebond the grounded conductor at each structure (pole) and not use an EGC. If this is...
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Forum: Electrical Contracting and Estimating/Management
Yesterday, 11:47 AM
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Replies: 20
Views: 565
That can happen with any breaker and the fact...
That can happen with any breaker and the fact that it can happen is one of the reasons that the code now requires AFCIs in dwelling units.
When there is an accidental fault like this you have no...
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Forum: NEC
11-18-2009, 02:25 PM
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Replies: 35
Views: 946
Sometimes even the CMPs get caught up in this...
Sometimes even the CMPs get caught up in this problem. If you go back to the 84 code the rule that is now found in 344.26 read as follows:
The CMP was using the field meaning of fitting...that is...
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Forum: NEC
11-17-2009, 10:57 PM
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Replies: 6
Views: 175
You have to remember that the OCPD rules in...
You have to remember that the OCPD rules in Article 450 apply only to the protection of the transformer itself. 240.21(C) applies to the protection of the transformer secondary conductors. 408.36...
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Forum: NEC
11-17-2009, 10:11 PM
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Replies: 8
Views: 138
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Forum: NEC
11-17-2009, 09:42 PM
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Replies: 8
Views: 138
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Forum: NEC
11-17-2009, 07:27 PM
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Replies: 40
Views: 695
Larry,
First you can't use a dictionary...
Larry,
First you can't use a dictionary definition for any term that is defined in the code. Device is a code defined word and for the application of the NEC that is the definition that must be...
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Forum: NEC
11-17-2009, 07:21 PM
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Replies: 8
Views: 138
Actually such a cable is available...
Actually such a cable is available (http://www.tycothermal.com/assets/americas/english/document/installation%20operation%20and%20maintenance%20manuals/1428/01fire_rated.pdf). Look on page 7 of the...
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