120V, 20A equipment arrived with 250V, 20A inlet - does this meet code?

Jamesco

Senior Member
Location
Iowa
I think 406.8 is clear, and it would be a violation. This is a field fabricated cord and must comply to NEC.
Even using 406.8 for your argument.
If the OP buys a UL listed adapter cord and uses the UL listed adapter to the feed the piece of equipment, the NEC is satisfied.
https://www.lockingpowercords.com/products/978-5-20p-to-l6-20r.aspx

Question is, does the manufactured adapter cord even fall under the NEC? Does the piece of equipment fall under the NEC?

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Jamesco

Senior Member
Location
Iowa
You think it's 120v 1ph, or, 208 3ph? Likely not the case. More likely it's 1ph equip.
3ph?

The piece of equipment has a factory installed 3 wire L6-20P male inlet connector.
The unit can be purchased wired for single phase 208V or 120V.


On the back, it has a 250V, 20A flanged L6-20P inlet, HBL2325. The manufacturer wires machines for either 120V or 208V, as requested by the end user, but uses the same plug on the back of all units.
We don't know if the equipment can be field wired for 208V.

It would be nice to know where, what, country it was designed and manufactured in.
It also would be nice to know if it is safety tested and listed by any third party recognized testing laboratory for use in the US.

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FionaZuppa

Senior Member
Location
AZ
3ph?

The piece of equipment has a factory installed 3 wire L6-20P male inlet connector.
The unit can be purchased wired for single phase 208V or 120V.
The same gear 120v, or, 208v, internally wired that way??
Would indicate to me that whatever is inside is logically something like two 120v items wired in parallel, but if you wanted to use 208v they would be wired in series. Will 208v work on two 120v coils in series, probably so, but probably US 240v would be a-ok.

Some things are rated 208/230v (±10%) 1ph 60Hz, that's the brochure words, name plate would say something like "197-253 volts / 1ph / 60Hz"

It just seems odd to me that it's "120v20A or 208v", it's more likely to be "120v20A, or, 240v10A". But maybe it's not the amps that is the issue here, maybe it's just crap insulation on the wires??

Would like to see the nameplate of this thing.
 

Jamesco

Senior Member
Location
Iowa
The same gear 120v, or, 208v, internally wired that way??
Would indicate to me that whatever is inside is logically something like two 120v items wired in parallel, but if you wanted to use 208v they would be wired in series. Will 208v work on two 120v coils in series, probably so, but probably US 240v would be a-ok.
We don't know what the piece of equipment is or what the internal configuration of power wiring is.
As for configuring two 120V loads in series for a 208V feed I don't think I have ever seen that before. Now 3 wire 120/208V yes. But the the power inlet connector would need to be a 4 wire.

One thing to consider is it can be fed from 120V Hot and neutral (neutral being the grounded conductor) or 208V 2 hot ungrounded phases of a 3ph 4 wire power system. Is there any internal safety fusing? For 208V the manufacturer should fuse both hot ungrounded conductors. When the unit is fed with 120V The fusing best be only on the hot ungrounded conductor and not on the neutral, grounded conductor. That could prove dangerous.

Surely the OP could provide more info and possibly a photo of the wiring diagram or an internet PDF.

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FionaZuppa

Senior Member
Location
AZ
My guess, wherever it's made or sold most often, the service is common with 208Y/120v. That's common in US for many commercial supply.

But that does not mean the internal wiring is ideally suited for 208v or 120v, it could just operate there.
For all we know, the equip is using more power using 120v vs using 208v. If it were two coils inside wired in series, maybe each coil is really rated 104v(ideal) but they will work in parallel using 120v.

For all we know, the internal CCC's (two of them) are already fused, making it ez to switch between 120 and 208v. The 3rd wire must be EGC for both.

Why is a 4 wire needed for 208? Line-Line + EGC

Need the nameplate or something.
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Engineer
The same gear 120v, or, 208v, internally wired that way?
The OP said the manufacturer wires the equipment as either 208V or 120V. The OP did not say the manufacturer reconnects the same components, maybe different ones are used. The OP did not mention a nameplate with dual voltages on it.

The OP simply asked if a 208V inlet could be used with a 120V source.
 

FionaZuppa

Senior Member
Location
AZ
The OP said the manufacturer wires the equipment as either 208V or 120V. The OP did not say the manufacturer reconnects the same components, maybe different ones are used. The OP did not mention a nameplate with dual voltages on it.

The OP simply asked if a 208V inlet could be used with a 120V source.
True.
 

jusme123

Senior Member
Location
NY
Equipment should not leave the manufactures warehouse ,IMHO!

We have to supply all the properly rated plugs and receptacles, what makes them any different ( besides money)?
 

myspark

Senior Member
Location
SCV Ca, USA
Occupation
Retired EE
So, my questions are these:
1) Does putting an L6-20P inlet on a 120V piece of equipment meet NEC?
2) 2020 NEC Article 406.8, noninterchangeability, says that “receptacles, cord connectors, and attachment plugs shall be constructed such that receptacle or cord connectors do not accept an attachment plug with a different voltage or current rating from that for which the device is intended.” Does this apply to the equipment? Or just to the construction of the receptacles and plugs? If not, what article would apply?
3) This setup would allow someone to connect this to 208V, 20A power in the future, which is a safety hazard. What part of NEC should prohibit this?
4) If we make a cord that has L6-20R on one end and 5-20p on the other, someone could use this cord in the future to try to plug a 208V item in to a 120V receptacle. Does this cord violate NEC?
5) Is it allowable, even if a bad idea, to use L6-20 components on a 120V circuit because they have a higher voltage rating? It says 250V, but doesn't provide a minimum.

I really appreciate everyone's help. I have enjoyed finding answers to many questions on the forum over the years.
The Hubbell 125 VAC 20 Amp Twistlock (male) will not fit in a 230 VAC 20 Amp (female).
Don't get fooled by the appearance of the two.
The locking blades are different and cutouts are different.
Get both models and try plugging one to the other to find out.

Have you tried it?

120 VAC 20 Amp Twistlock Catalog ID HBL 2315

230 VAC 20 Amp Twist lock Catalog ID HBL 2325

I have them in my RV Generator panel.
 

Junkman

Member
Location
North FL
Occupation
Facility Manager
Sure, I can find or make an adapter that will work. I contacted the site that makes the "UL-Listed" adapter. Their answer was that they use UL-listed parts and have a UL-certified process, therefore the cords they make are UL-Listed. They will make any cord that you want. However, they said how we use it is up to us (throw the burden on the end user).

Is there a section in the code that talks about violating UL-listing or other type of listing? What about violating a manufacturer's installation instructions? It just seems that there should be something that prohibits the use of 250V plugs that were intended for two hot wires to be used in a 120V single-phase system. When making the adapter, how does the the person (or the online company) know which pole to use as hot since an L-20P has two hots? It just seems that this is easy to wire backwards, even with an adapter.
 

Junkman

Member
Location
North FL
Occupation
Facility Manager
The Hubbell 125 VAC 20 Amp Twistlock (male) will not fit in a 230 VAC 20 Amp (female).
Don't get fooled by the appearance of the two.
The locking blades are different and cutouts are different.
Get both models and try plugging one to the other to find out.

Have you tried it?

120 VAC 20 Amp Twistlock Catalog ID HBL 2315

230 VAC 20 Amp Twist lock Catalog ID HBL 2325

I have them in my RV Generator panel.
@myspark: The issue is that they used a HBL 2325 (L6-20P) on a 120V piece of equipment. It clearly does not fit the 125V male twistlock (L5-20P). The equipment is wired for 120V, 20A. Since they also make a 208/240V version, they use the same HBL 2325 plug on all of them and ask the end user to fabricate a cord that adapts it to their available receptacle. So, the cord ends up being L6-20R to L5-20P/5-20P depending on the receptacle on the wall.

But nothing stops someone two years from now from plugging this same machine into a 208V outlet (because it fits and people only often only pay attention to what plug fits, not the actual voltage, especially when dealing with students).
 

FionaZuppa

Senior Member
Location
AZ
Is there a section in the code that talks about violating UL-listing or other type of listing? What about violating a manufacturer's installation instructions?
No, and Yes.
Not everything used is UL listed, AND, NEC says right up front that an item installed shall be done in accordance with supplied install instructions.

If the issue is an inspection issue and you are worried about the cord being accidently used the wrong way, then add a "perm warning tag" near end cord describing it's special use. The supply end (plug) will be bound to the smaller 120v20A, so the worst that could happen is someone takes the cord and then somehow comes along the same receptacle setup, a 120v20A supply going to a 250v equip male twist-lok. Very unlikley, and the NEC is written around "very unlikely".

Get the made cord, done.
 
Last edited:

Junkman

Member
Location
North FL
Occupation
Facility Manager
3ph?

The piece of equipment has a factory installed 3 wire L6-20P male inlet connector.
The unit can be purchased wired for single phase 208V or 120V.




We don't know if the equipment can be field wired for 208V.

It would be nice to know where, what, country it was designed and manufactured in.
It also would be nice to know if it is safety tested and listed by any third party recognized testing laboratory for use in the US.

.
So, it was designed and built in the US. Each machine is custom built, but many have been field certified by a NRTL lab (according to the company). No one ever questioned this before, they say.
 

Junkman

Member
Location
North FL
Occupation
Facility Manager
No, the OP asked whether a 250V inlet used for 208 volts could also be used with a 120V source. :)
We might just as easily ask whether a 250V inlet could be used for 208V.
Unfortunately, this is not what I was asking. The 250V inlet (plug) can of course be used for 240V or 208V, but these use two hot wires and a ground. In my system, they used the same 250V plug for a 120V system (1 hot, 1 neutral, 1 ground), never was this wired for 208V. Whether a 250V inlet could be used for 208V is obvious, where the answer to my question is not.
 

FionaZuppa

Senior Member
Location
AZ
This is exactly what I was asking. Can a 205V

Unfortunately, this is not what I was asking. The 250V inlet (plug) can of course be used for 240V or 208V, but these use two hot wires and a ground. In my system, they used the same 250V plug for a 120V system (1 hot, 1 neutral, 1 ground). Whether a 250V inlet could be used for 208V was never the question.
It's just supply semantics. 120v always uses a "grounded" neutral, the other are line-line.

Ask the question from the plug context, does NEMA prescribe how the pins may or may not be used used? Maybe some can argue that a UL listing that uses only line-line test does not cover a line-neutral setup, but in reality line-line test should cover a line-neutral setup as long as you don't exceed rated voltage.

This is likely a snafu in the realm of NEC/UL. What exactly is the danger?
 

Junkman

Member
Location
North FL
Occupation
Facility Manager
Oh, and there is no name plate/data plate on the machine. I plan to make a label. I have also read somewhere in the NEC about requiring a name plate. Anyone have a reference?
 
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