Art 645

Status
Not open for further replies.
E

elec_eng

Senior Member
I am reviewing other engineer's work and this is a data center with raised floor that meets the art 645.

He has provided multiple runs of bus ducts under the raised floor with plug-in units. The plug-in unit has (2) 30A rated 10 ft long cords. At the end of the cord, it has a 30A receptacle that goes to the data rack above the floor.

Is this in compliance with 645.5?
 
Gregg Harris said:
I have 2008 and 645.5 (B)(1) states not to exceed 15 feet so I would say that part is ok
Click to expand...

In 2011, 645.5(E)(2) requires that the branch-circuit supply conductors to receptacles to be in raceway or Type MI, MC, or AC cable. He is providing a cord. Am I reading this incorrect?
 
Plug-in busway, actually busway at all is not listed in the list of acceptable branch circuit supply conductors in 645.5(D)(2). Also if 645 is not used to modify the main four chapters of the code, then 300.22(C)(1) doesn't permit plug-in busway at all under the floor.
 
elec_eng said:
In 2011, 645.5(E)(2) requires that the branch-circuit supply conductors to receptacles to be in raceway or Type MI, MC, or AC cable. He is providing a cord. Am I reading this incorrect?
Click to expand...



I had to read that about ten times, it was making me head hurt. Yes you are correct and then the cords can be run through the floor to connect
 
elec_eng said:
In 2011, 645.5(E)(2) requires that the branch-circuit supply conductors to receptacles to be in raceway or Type MI, MC, or AC cable. He is providing a cord. Am I reading this incorrect?
Click to expand...
The female cord caps are not considered receptacles. See 645.5(B)(2) where the male-female combo are referred to as "listed attachment plugs and cord connectors".

As to ron pointing out busduct as not one of the permitted branch circuit wiring methods under a raised floor, assuming the plugin units contain branch-circuit OCPD, the busduct is a feeder, not a branch circuit.

So, with the busduct being a feeder, and power cords being covered under 645.5(B), you have no branch-circuit supply conductors to receptacles.
 
Smart $ said:
The female cord caps are not considered receptacles. See 645.5(B)(2) where the male-female combo are referred to as "listed attachment plugs and cord connectors".

As to ron pointing out busduct as not one of the permitted branch circuit wiring methods under a raised floor, assuming the plugin units contain branch-circuit OCPD, the busduct is a feeder, not a branch circuit.

So, with the busduct being a feeder, and power cords being covered under 645.5(B), you have no branch-circuit supply conductors to receptacles.
Click to expand...

Smart $,

I agree the busduct is a feeder since the plug-in has the OCPDs.

Are you saying this installation is code compliant because there is no branch-circuit supply conductors to receptacles?
 
elec_eng said:
Smart $,

I agree the busduct is a feeder since the plug-in has the OCPDs.

Are you saying this installation is code compliant because there is no branch-circuit supply conductors to receptacles?
Click to expand...
Yep. Cord caps are not receptacles.

Keep in mind, that is contingent on the cord and caps being listed for the purpose, as stated in 645.5(B) via 645.5(E)(3), in addition to compliance with the rest of 645.5(E).
 
Smart $ said:
Yep. Cord caps are not receptacles.

Keep in mind, that is contingent on the cord and caps being listed for the purpose, as stated in 645.5(B) via 645.5(E)(3), in addition to compliance with the rest of 645.5(E).
Click to expand...


Can you clarify my confusion on 368.10(B)(2)?
 
Smart $ said:
The female cord caps are not considered receptacles. See 645.5(B)(2) where the male-female combo are referred to as "listed attachment plugs and cord connectors".

As to ron pointing out busduct as not one of the permitted branch circuit wiring methods under a raised floor, assuming the plugin units contain branch-circuit OCPD, the busduct is a feeder, not a branch circuit.

So, with the busduct being a feeder, and power cords being covered under 645.5(B), you have no branch-circuit supply conductors to receptacles.
Click to expand...

This makes no sense (to me).

Plug is the male configuration, receptacle is female. Looking at art 100 definitions, power outlet includes receptacles and outlet is the point on the wiring system where the supply is taken to utilization equipment.

A female twistlock device clearly meets the definitions of receptacle and is part of the power outlet assembly. There is no difference in the definitions I can see going from a twistlok receptacle device to a twistlok female cord cap. They are both receptacles.

2005 NEC: 645.5 (B) applies above the floor, 645.5 (D) applies below the floor and 645.5 (D) 2 is for wiring methods "to receptacles" where cords are not listed for use.

IMO the cord from the busplug to the female twistlok is "branch circuit supply to receptacles or field wired equipment" and not compliant with 645.5 (D) 2.
 
__dan said:
This makes no sense (to me).

Plug is the male configuration, receptacle is female. Looking at art 100 definitions, power outlet includes receptacles and outlet is the point on the wiring system where the supply is taken to utilization equipment.

A female twistlock device clearly meets the definitions of receptacle and is part of the power outlet assembly. There is no difference in the definitions I can see going from a twistlok receptacle device to a twistlok female cord cap. They are both receptacles.

2005 NEC: 645.5 (B) applies above the floor, 645.5 (D) applies below the floor and 645.5 (D) 2 is for wiring methods "to receptacles" where cords are not listed for use.

IMO the cord from the busplug to the female twistlok is "branch circuit supply to receptacles or field wired equipment" and not compliant with 645.5 (D) 2.
Click to expand...
Receptacle. A receptacle is a contact device installed at the
outlet for the connection of an attachment plug. A single
receptacle is a single contact device with no other contact
device on the same yoke. A multiple receptacle is two or
more contact devices on the same yoke.
Click to expand...

So, is the load end of a supply cord an outlet? Does a cord cap have a yoke?

Well it definitely don't have a yoke. Being an outlet is debatable, considering the definition of an outlet... but typically the outlet is at the source end of a cord, while the cord is considered the utilization side of the outlet. And this is for a hard-wired cord (no receptacle device or cord caps involved). Putting female and male cord caps in the middle of the cord run does not change the preceding. It is no different than installing a "yoked receptacle" at the bus plug and running a cord-and-plug from above to plug into that receptacle.

Why bring up 2005 NEC? What edition is the installation subject to? Let's stick to that...
 
Smart $ said:
So, is the load end of a supply cord an outlet? Does a cord cap have a yoke?

Well it definitely don't have a yoke. Being an outlet is debatable, considering the definition of an outlet... but typically the outlet is at the source end of a cord, while the cord is considered the utilization side of the outlet. And this is for a hard-wired cord (no receptacle device or cord caps involved). Putting female and male cord caps in the middle of the cord run does not change the preceding. It is no different than installing a "yoked receptacle" at the bus plug and running a cord-and-plug from above to plug into that receptacle.

Why bring up 2005 NEC? What edition is the installation subject to? Let's stick to that...
Click to expand...

I quoted 2005 because thats what i'm under here and what I have for reference.

If the yoked receptacle were installed at the busplug, the wiring after that point is interconnecting cable or it would be the cord attached to the utilization equipment, not wiring to receptacles. Different paragraph applies. I do not see how not having a yoke invalidates the female twistlok cord end as a receptacle, it is still a receptacle.

Installing a female and male cord caps in the middle of the cord run clearly makes that an outlet point, especially if the supply end is hardwired, it would be part of the building's permanent branch circuit wiring. The point where the plug attached to the receptacle would begin the utilization equipment or the interconnecting cable.
 
Status
Not open for further replies.
Top