Question about 480 Volt Extension cord
- Thread starter Otterbox
- Start date
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- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
I don't think there is a maximum length. But the rules for portable cords are in article 400. Take particular note of 400.8.
Welcome to the forum.
But let me ask, "asked by whom?" I mean is this a work-related question, or a home-related question?
Welcome to the forum.
But let me ask, "asked by whom?" I mean is this a work-related question, or a home-related question?
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Not a whole lot of people have 480V at their homes.
I don't think the NEC covers extension cords for the most part. OSHA has a fair amount to say about it though in the work place. And you generally can't use cord as a substitute for permanent wiring according to the code.
as far as length goes, you can pretty much make it as long as you need, but there are some practical limits like weight and voltage drop that might come into play.
This is a work related question. We usually use gas power washer, but our operation manager asked aboutan portable electric power washer. So I was doing some research on 480 volt extension cord requiremnts.
I have looked at ART. 400, and haven't seen anything about length. From what I have read, Table 400.4 is a good start. Also, ART. 400.8
Thanks for your help.
I have looked at ART. 400, and haven't seen anything about length. From what I have read, Table 400.4 is a good start. Also, ART. 400.8
Thanks for your help.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I am not convinced anything in article 400 applies if it is a temporary thing, such as using the cord to be able to move the washer around to different locations and different positions at those locations.
- Location
- Massachusetts
In my opinion a field made extension cord is a clear example of something article 400 applies to.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
IMO an extension cord is not part of an installation so pretty much by definition it can't be covered by the NEC.
i do not see how something for temporary use like an extension cord can be considered "installed". it would be like claiming a vacuum cleaner is subject to NEC rules just because it is plugged in.
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kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I can agree but at same time a long cord shouldn't be used as a substitute for fixed wiring - as in lets only put in one receptacle and use a 100 foot cord so we can move this thing to nearly any point within the facility.
One thing that maybe needs considered is a fixed location for the pump and distributing high pressure piping around the facility instead of cord and plug and extension cords all around for this.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Would not be a very big facility if the whole thing could be reached with a 100 foot long cord. This kind of situation might well be a safety problem and should be attacked from that end rather than claiming it is an electrical code violation which is a serious stretch.
or just install outlets where they are actually needed.
I kind of envisioned a warehouse where they had trucks parked in several parking spots outside and they go out with their pressure washer to wash the trucks down. an extension cord is really the only practical answer.
keep in mind that the length of the extension cord will likely be not much more than the length of the hose feeding the thing with water. the sheer weight and size of the extension cord and hose will enforce a fairly limited length for both.
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
I kind of envision running piping and quick connect hose couplings for the pressure wands and a common pump location, and have seen that done many times
- Location
- Massachusetts
Well here is the thing, regardless of what 90.2 says the NEC is full of articles that contradict it. Just like the NEC says it is not a design manual but it contains many sections regarding design.
In my experience AHJs will say 400 applies.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
I can just imagine pulling a permit to use my electric chainsaw in the backyard.
The issue of the NEC not being a design manual, is misdirection.
What ever gets designed must meet the NEC requirements, but the NEC requirements, by themselves, are not sufficient for performing a design. Where in the NEC are the requirements for locations and mounting heights of light switch for habitable rooms?
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
What about a motor that uses a plug for a disconnect?
- Location
- Massachusetts
Who said you should?
The discussion was about a field made extension cord.
So you argument is that design issues addressed in the NEC do not contradict 90.1(C) because it does not cover all points of design?:huh:
We disagree on that.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
that is a permanent install, not an extension cord.
- Location
- Massachusetts
OSHA has much of the same wording as the NEC, it was taken from the NEC
Is anyone going to tell me OSHA does not apply to extension cords?
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9882&p_table=STANDARDS
Is anyone going to tell me OSHA does not apply to extension cords?
https://www.osha.gov/pls/oshaweb/owadisp.show_document?p_id=9882&p_table=STANDARDS
- Location
- Illinois
- Occupation
- retired electrician
So where in Article 400 is the answer to the OPs question?
If Article 400 applies and if "flexible cord" means the same thing as a "cord set" (assembly of cord and ends) then does 400.20 prohibit the field construction of cord sets?
(do not read this as me agreeing that 400 applies to this application, because as you know it is my opinion that it doesn't)
kwired
Electron manager
- Location
- NE Nebraska
- Occupation
- EC
Somewhere the line has to be drawn as to whether or not it is temporary, subject to frequent interchange, or otherwise permitted to be cord and plug connected, and when such a cord is truly a substitute for permanent wiring. Then we can maybe determine what if any of art 400 applies. Temporary usually has time limits that go with it.
OSHA would only apply to places of employment, so if we are talking elsewhere - forget OSHA.
OSHA would only apply to places of employment, so if we are talking elsewhere - forget OSHA.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
So you argument is that design issues addressed in the NEC do not contradict 90.1(C) because it does not cover all points of design?:huh:
We disagree on that.
The NEC barely covers any useable design parameters. Yes, there are some requirements on features that must be included, such as GF protection on vending machines plugs, but that is not enough qualify it as a design manual. Where in the NEC are the requirements for position of the ground pin on that required plug? Where are the requirement for if the plug should be angled or not?
Where in the OP, is field fabrication of the extension cord mentioned?
gadfly56
Senior Member
- Location
- New Jersey
- Occupation
- Professional Engineer, Fire & Life Safety
520.5 (B) kinda goes where you're headed. I've seen "temporary" cord installations that are older than my 7-year old.
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