Electrical extension cords.

[Fchild]

Where can I find the code concerning the allowable length for extention cords? For example there is a H&V unit on about 10 feet in the air and there is a cord set comming out of a junction box with an electrical connector that is plugged into another cord set that comes from the device.
I did find some stuff in Osha regs but can't find a maximum length.

 

[dpc]

Basically, any use of an plug-connected extension cord for a permanently installed piece of equipment is a code violation.

I don't think there is a specific maximum length.

 

[rbulsara]

Read NEC article 400 (2005) completely.

While no restriction on length where permitted, but its not permitted in lieu of permanent wiring as dpc suggested. Your installation will not meet the Code, I am afraid.

 

[stevenal]

From the handbook:

The flexible cords and cables referred to in Article 400 are not limited to use with portable equipment. They may not be used, however, as a substitute for the fixed wiring of a structure or where concealed behind building walls, floors, or ceilings (including structural, suspended, or dropped-type ceilings).

Really a violation? Lots of power strips out there on computers and entertainment systems.

 

[weh3]

If it gets too long, you have excessive voltage drop and will start burning up your portable equipment.

William

 

[rbulsara]

stevenal:

If you have the handbook read the commentary below 400.7(A).
Computer equipment cords are covered by 645.5. 400.7A lists permitted equipment.

 

[gmatov]

If it gets too long, as every answer and the OP are regged as "Electrical", wouldn't you know to upsize your wire?

My own primary extension is 125 feet of 10/3/wG, some type of SJ. Heavy, but what the hey?

And I'm mechanical, don't know much about you guys turf, just enough to get along, or get in trouble.(Where's the smileys when you need them?)

Cheers,

George

 

[peebee]

Computer equipment cords are NOT covered by NEC 645.5 unless you're in a data center. I don't quite understand how everyone gets away with those power strips either.

For years, here in Chicago, they did not permit power strips. If they thought there was even a chance that computers would be installed, they'd require sufficient duplex outlets to be installed to support all the PC's and monitors. Then, about 5 years ago, they gave up on that and started allowing power strips.

Yeah, eveyone uses them (even me). But where NEC permits them is beyond me.

 

[rbulsara]

For what its worth, see the follwing link, and Q&A no. 18 in it by Mike Holt on the subject.

http://www.mikeholt.com/mojonewsarchive/NECQ-HTML/HTML/NEC-Questions-016~20041007.php

 

[stevenal]

I didn't know tables were building structures. The unmounted one under my desk has slots designed to accept screw heads. Looks like they intended it to mount to something.