Article 645 - Secured Receptacles

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DataCenterGuy

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New York
Article 645.5(E) "Securing in Place" (any version since 1993) states "Power cables, . . . connectors, plugs, and receptacles . . . for information technology equipment shall NOT be required to be secured in place." (Emphasis added.)

I have had AHJ's pass under-floor (air plenum) installations that ARE secured in place and are NOT Article 645 compliant (No EPO). But we can't identify Code that authorizes this.

Does anyone know if anywhere in the Code specifically allows Wireways and Receptacles to be secured in place under an air plenum raised floor in a room with no EPO Switch and still allow under-floor plug-in. (I realize that this can be jurisdiction-specific, but am interested for now in the NEC - any version.)
 
iwire

iwire

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Do you see a difference in meaning between version 1 and version 2?


1) information technology equipment shall not be required to be secured in place


2) information technology equipment shall not be secured in place
 
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DataCenterGuy

Member
Location
New York
Sorry. I don't catch your drift. Yes, I certainly see the difference, but don't see how it answers my question. I'm expecting to find something Outside of Article 645 that allows SECURED raceway and plug-in receptacles under an air-plenum floor. (If they're un-secured then Article 645 compliance is clearly required.) Or are you implying that if it's not excluded, then it's allowed?
 
ron

ron

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645 is an optional article that gives you permission to use leniencies found in 645 (such as 645.5(E)) as long as you adhere to the prerequisites in 645.4.

I would prefer to secure my raceway whips and receptacles a million times, before I would volunteer to comply with the prerequisite items in 645.4 and a few hiding in 645.5.
 
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DataCenterGuy

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Location
New York
Thanks to all. I'm now secure in how to proceed and explain. (And while I agree with the last comment, Article 645 recognizes the realities of Data Centers (by whatever name) and the flexibility that IT people tend to demand. There are things we sometimes just need to do to be practical.
 
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DataCenterGuy

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Location
New York
The whole purpose of this question was in hopes of avoiding the hated EPO. However, we came to realize that 400.8 makes the under-floor receptacles useless, even if secured, unless Article 645 is invoked, which means the EPO. (Can't run connecting cordage through the floor to receptacles.) Thanks to all for thoughts, but it seems we either mount receptacles on top of the raised floor, creating a flexibility nightmare in this particular project, or resort to specifying the EPO (with cover and alarm, of course).
 
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steve66

steve66

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Illinois
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Engineer
DataCenterGuy said:
The whole purpose of this question was in hopes of avoiding the hated EPO. However, we came to realize that 400.8 makes the under-floor receptacles useless, even if secured, unless Article 645 is invoked, which means the EPO. (Can't run connecting cordage through the floor to receptacles.) Thanks to all for thoughts, but it seems we either mount receptacles on top of the raised floor, creating a flexibility nightmare in this particular project, or resort to specifying the EPO (with cover and alarm, of course).
Click to expand...

Notice that 400.8 (2) says you can't run cords through dropped ceilings, suspended ceilings, or structural ceilings.

But when it gets to floors, it only says "floors". It doesn't say "raised floors".

Most of the AHJ's I've had allowed cords to go through a raised floor. I have also seen a "Mike Holt" graphic that says cords through raised floors are allowed, and I don't think it was specific to 645 applications.

Steve
 
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DataCenterGuy

Member
Location
New York
We recognized that same possible differentiation, but thought it would be dangerous to try to claim since the "raised floor" is the "floor" you walk on, and what's below it is usually referred to as the "slab". I'm also used to AHJ's allowing cord pass-thru, but that was before most of them seemed to even be aware of 645. Also, until 2008, 645 technically prohibited it anyway, so was useless unless the AHJ ignored the technicality and allowed the obvious purpose. Things are getting more rigid now, especially in places like NYC where this will be. But I would love to see Mike's illustration and know if your interpretation of 400.8 could be expected to stand up.
 
ron

ron

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Location
New York, 40.7514,-73.9925
We've had a lot of luck with the receptacle mounted to the IT rack frame above the raised floor. The trick is that the last few feet of the raceway, be FMC with slack, so that if the receptacle needs to be relocated, it can simply be unbolted from the rack and moved to a nearby rack.

The flexibility that this limits is paid back 10 fold by not having the reliability nightmare of an EPO and the mass airflow shutdown required in 645.5.
 
S

steve066

Senior Member
ron said:
BTW, the Holt graphic with cords below the floor relies on the use of 645, so I don't like it!
Click to expand...

Does it? It doesn't say so on the graphic.

I did just read in the 2008 handbook, that 645 allows cords to pass through a raised floor via 90.3, which is an exception to the general probition of this in 400.8.

So to make a long story short, I'm still confused.

ron said:
BTW, the Holt graphic with cords below the floor relies on the use of 645, so I don't like it!
Click to expand...


Well, after Ron's post, and after reading the handbook comentary, I'm not 100% sure that settles it. If you have an inspector, I would ask him/her their opinion. Its no use installing a bunch of receptacles only to be told you have to change them.

Steve
 
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ron

ron

Senior Member
Location
New York, 40.7514,-73.9925
Steve,
I think the intent of 400.8 is to regulate cords in hidden places like above suspended ceilings. Since you would only be using 400.8 if you were not using the leniencies provided by 645, then I find the intent of regulating cords in hidden places to also apply to cords below a raised floor considering the language of ..... not passing through holes in the floor.
 
Pierre C Belarge

Pierre C Belarge

Senior Member
Location
Westchester County, New York
The commentary in the '08 Handbook is a little confusing.
The allowance (90.3 Code arrangement) permitting Cord to be passed through the raised floor opening and in the space below still has to meet 645.4(D)(6). Typically that means just making cords up is not the answer. DP rated cords will be required.
 
steve66

steve66

Senior Member
Location
Illinois
Occupation
Engineer
This seems to indicate that cords are OK below a raised floor.

http://www.mikeholt.com/videodisplaynew.php?pageid=1630

It says:

Intent: The change clarifies that flexible cords cannot be located above a suspended ceiling. However, wiring within a raised floor is permitted, because this space is not considered a concealed space.
Click to expand...

In my humble opinion, the jury is still out. I wish I knew exactly what the CMP's intent was.

Steve
 
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