645.5(e)

[jeremysterling]

...

Jeremy, what are you doing with 1000 ft reels of 1/2 liquid tite? I don't think I have ever installed more than 10 feet at a time.

Well, because of Art 645 ( 645.5(E) ) we pull many lengthy under floor power whips from PDU's to colocation cabinets. The sealtight terminates to a bell box with a twistlock recept under the cabinet. Not necessarily the best way because adding more sealtight stacks up under the data floor and disrupts air flow from the CRAC units. The runs can be well over 150'.

 

[WinZip]

I guess you blow pull lines in them at 150 feet , what about strapping at 3 ft intervals.

 

[jeremysterling]

I guess you blow pull lines in them at 150 feet , what about strapping at 3 ft intervals.

Yes, we blow lines in them but about 160' it gets tougher to blow so we have to fish them.

I'm guessing you did not read the code I cited or you would catch the drift. We do not mount the bell box nor strap the seal tight and it is legal.

 

[stevenje]

Well, because of Art 645 ( 645.5(E) ) we pull many lengthy under floor power whips from PDU's to colocation cabinets. The sealtight terminates to a bell box with a twistlock recept under the cabinet. Not necessarily the best way because adding more sealtight stacks up under the data floor and disrupts air flow from the CRAC units. The runs can be well over 150'.

I remember working on underfloor whip projects at IBM where you would have so many layers of existing whips you couldn't see the concrete floor.

 

[iwire]

Yes, we blow lines in them but about 160' it gets tougher to blow so we have to fish them.

I'm guessing you did not read the code I cited or you would catch the drift. We do not mount the bell box nor strap the seal tight and it is legal.

No what you are doing id a direct violation of the Article you sited.

To remain unsecured they must be UL listed assemblies.

 

[iwire]

645.5(E) Securing in Place. Power cables; communications
cables; connecting cables; interconnecting cables; and associated
boxes, connectors, plugs, and receptacles that are
listed as part of, or for, information technology equipment
shall not be required to be secured in place.

You cannot 'field' construct LFMC whips and boxes and a comply with this code section.

 

[mxslick]

You cannot 'field' construct LFMC whips and boxes and a comply with this code section.

Oh yes you can..look at the highlited part of 645.5(E):

645.5(E) Securing in Place. Power cables; communications
cables; connecting cables; interconnecting cables; and associated
boxes, connectors, plugs, and receptacles that are
listed as part of, or for, information technology equipment
shall not be required to be secured in place.

Those two little words allow it. So says L.A. County Building and Safety.

 

[LarryFine]

Those two little words allow it.

Doesn't that mean "... listed as part of ... information technology equipment" OR "... listed for information technology equipment"?

In other words, required to be listed either way?

 

[iwire]

Oh yes you can..look at the highlited part of 645.5(E):




Those two little words allow it. So says L.A. County Building and Safety.

Let me get this this straight ........... now you are arguring for no securing?:grin:

Well IMO they are wrong, the LMFC would have to be listed for information technology equipment not just list as LFMC.

Lets face it LA is not the capitol of the USA and what CA does is often directly opposite of the rest of the country in other words I think CA is nuts.

 

[jusme123]

Let me get this this straight ........... now you are arguring for no securing?:grin:

Well IMO they are wrong, the LMFC would have to be listed for information technology equipment not just list as LFMC.

Lets face it LA is not the capitol of the USA and what CA does is often directly opposite of the rest of the country in other words I think CA is nuts.

LOL, now on to the 'OR" :grin:, sharpie please

 

[jusme123]

Oh yes you can..look at the highlited part of 645.5(E):




Those two little words allow it. So says L.A. County Building and Safety.

I agree with your OR

 

[iwire]

I agree with your OR

Yeah there is an 'Or' there, lets do away with it for minute.

645.5(E) Securing in Place. Power cables; communications
cables; connecting cables; interconnecting cables; and associated
boxes, connectors, plugs, and receptacles that are
listed as part of, or for, information technology equipment shall not be required to be secured in place.

The parts put together in the field would have to be listed for information technology equipment

 

[barclayd]

The NEC doesn't define "Cable" in Art 100, but I don't think field-assembled sealtite whips would be considered cable, thus, 645.5 would not apply, and they would have to be secured in place per 350.30.
That said -
I don't think I've EVER seen a raised floor where the whips are secured in place.
db

 

[iwire]

The NEC doesn't define "Cable" in Art 100,

Cables are described in Article 400, IMO there is no instance where the NEC considers LFMC as cable.

 

[roger]

but I don't think field-assembled sealtite whips would be considered cable,

You are correct, but I have a strange feeling there will be at least two people that will argue that Liquidtight Flexible Metal Conduit is indeed a cable assembly, and all conduit and tubing articles should now be moved to chapter 4. :grin:

Roger

 

[jeremysterling]

No what you are doing id a direct violation of the Article you sited.

To remain unsecured they must be UL listed assemblies.

Thanks for correcting me (as usual).

I'm gonna need a huge bag of tie-wraps!:grin:

 

[mxslick]

Yeah there is an 'Or' there, lets do away with it for minute.

The parts put together in the field would have to be listed for information technology equipment

Great.:roll: Once again you change the language of the Code as written to suit your point of view. You're still wrong. It is clearly permissive as written.

The "OR" makes it ok to leave the LFMC unsecured. It is under a raised floor and NOT subject to the same hazards of physical damage or movement as it would be if exposed. That's why it can be simply laid (lain?) in place.

And the unique requirements of data centers and other facilities using raised floors is WHY this Section exists..and why exceptions are allowed to normal practices. (Another example of exceptions is the sizing of OCPD's for air conditioning condensers over what would be allowed for branch circuits.)

Thanks for correcting me (as usual).

I'm gonna need a huge bag of tie-wraps!:grin:

Jeremy, save yourself the time and money and give a quick call to your AHJ, he will read the section and see that there is no need. And let us know the outcome so if I am wrong I can admit it and make Bob happy. (And if I'm right I can gloat. )

 

[roger]

From EC&M

Q. Is liquidtight flexible metal conduit (LFMC) permitted under the raised floor of a computer room? If yes, must it be secured?

A. It depends on what you mean by a computer room. If you are talking about an information technology equipment (ITE) room as per 645.4, the answer is yes. However, it must be secured in accordance with 300.11 [645.5(D)(2)]. Note: Power cables and associated boxes that are listed as part of, or for, information technology equipment are not required to be secured in place [645.5(E)].

If the computer room does not qualify as an ITE room, and the raised floor is not used for environmental air, the answer is still “yes” if secured in accordance with 300.11. But, if the computer room does not qualify as an ITE room, and the raised floor is used as an environmental air space (for air-conditioning) then LFMC can’t be used at all in this space [300.22(B)(1)].

Roger

 

[iwire]

Great.:roll: Once again you change the language of the Code as written to suit your point of view. You're still wrong. It is clearly permissive as written.

How is it you misread so much of the NEC? :grin:

And the unique requirements of data centers and other facilities using raised floors is WHY this Section exists..and why exceptions are allowed to normal practices.

How many of these types of rooms have you built?

I have been part of the build team for quite a few and no one in this area reads the code as you do.

Jeremy, save yourself the time and money and give a quick call to your AHJ, he will read the section and see that there is no need.

Only if the AHJ does not follow the NEC.

And let us know the outcome so if I am wrong I can admit it

That would be a first.:roll:

 

[iwire]

From 2003 EC&M

Q.

A majority of information technology circuits (wiring under raised floors of data process equipment rooms) that I've come across aren't secured in place; they're laid under the raised floor in liquidtight conduit. Is this practice allowed per the requirements of the NEC?
A.

No. Branch circuit conductors within a raised floor shall be securely fastened in place in accordance with 300.11 [645.5(D)(2)]. However, power cables and associated boxes, connectors, plugs, and receptacles listed as part of information technology equipment don't need to be secured in place [645.5(E)].

http://ecmweb.com/nec/electric_stumped_code_3/