Use of a Light Blue conductor for neutral

[ELA]

I would like to ask for either electricians opinions or any standard I can site to help justify my use of a (Light blue & Brown conductor) for power input to a control unit we are trying to get UL Listed.

I chose light blue rather than white because it is a widely accepted international standard for power input. The light blue can then be either a grounded or ungrounded conductor.

This control unit accepts "universal" power input in the range for 85 -264V.
In some cases it will be powered by 120V with a grounded neutral and in other cases it may be run from 220, 230, 240 volt supplies (without a grounded conductor).

I feel the Light Blue is the best choice for this application.

The installation diagram clearly shows the input connections when connected to a grounded neutral system to be white->light blue.

Anyone able to cite a justification for or against this decision? I am used to designing to international standards that mandate the use of Light Blue & Brown.

Would you as an electrician feel comfortable with connecting a light blue to a white wire at the field connection point?

I do not like being forced to use a white conductor when in some cases the white would need to be connected to a black or red "hot" conductor.
If use of the Light Blue would be an issue for electricians installing the equipment then I need to reconsider.
I would apppreciate your input.

 

[bphgravity]

What does the UL standard mandate for conductor idenitification for the equipment in question?

 

[ELA]

Like many standards I believe it is up for interpretation.

It states:
"A lead intended for the connection of a grounded power-supply conductor shall be finished white or grey color and shall be distinguishable from the other leads."


So some will read this and say it is obvious it should be white. If this equipment were only "intended to be" connected to a 120V grounded neutral supply then I would agree.

This is a universal power supply input and I feel that puts it up for intrerpretation. The equipment itself has no need to be connected to a grounded power supply conductor in order to operate.

I also remember reading some place that UL will be moving towards the international wire standard of Light Blue and Brown in the future but I cannot locate where I read that at present.

 

[petersonra]

virtually no premade cord sets use white insulated conductors.

besides, what difference does it make?

the cord is not part of the premises wiring so does not fall under the NEC.

if your device needs UL approval, you should ask UL.

 

[winnie]

Is this 'universal' supply being designed such that _either_ supply lead could safely be ungrounded or grounded? For example, my laptop power brick has an unpolarized power cord; the supply is (presumably! ) designed so that it is safe with either supply conductor ungrounded.

If this is the case with your system, then IMHO the internal conductor is not _intended_ to be connected to a grounded supply lead, but instead _may_ be connected to a grounded supply lead.

-Jon

 

[ELA]

yes this equipment does not care at all about being connected to a grounded neutral.

Thanks for your opinion winnie

And thanks for nothing petersonra

 

[winnie]

Ummmm, Bob's answer was correct and professional, though I think that it missed the point of your question.

As I understand it, you are looking at the UL standard, and want outside opinions as to its interpretation, and you also want 'man on the street' responses from electricians or technicians that might encounter your device.

But of course, Bob's is the only 'real' answer. Where the buck will stop is with the UL, when they decide that your equipment appropriately meets the standard or if it does not. At that point none of our opinions will be worth the photons emitted from your screen

-Jon

 

[Dennis Alwon]

I have seen many third party approved equipment that was designed with a blue wire intended for the grounded conductor. I believe the Fan Tech remote fan has a blue wire as the grounded conductor. I suspect it can get approval with a blue wire.

 

[ELA]

Thanks you Dennis. That is useful information for me.

Perhaps I missed the intent of Bobs response but I did not find it helpful.

I guess maybe I did not understand the comment;
"virtually no premade cord sets use white insulated conductors."

I know of many premade cordsets with while insulated conductors. If Bob meant to support the choice for Blue conductor with that comment then I misunderstood and I appologize.

When he said;
"the cord is not part of the premises wiring so does not fall under the NEC."

Ok but what? This left me hanging. I posted under the UL section of the forum because I knew it would not be appropriate under the NEC section.

Last he commented;
"if your device needs UL approval, you should ask UL."

That may seem obvious but easier said than done. I am looking to collect supporting documents or as Dennis was kind enough to offer, other product examples.

I probably misconstrued what Bob had written. Sorry.

Dealing with UL approvals is no fun at all and I was anxious to gather useful information.

 

[ELA]

Dennis,
I could not locate a reference to input wiring on the Fan Tech remote fan.
At that site I found a number of installation guides but no blue wire. Do you have a link by chance?

It appears that section 400.22C of NEC does support the use of the Blue wire as a grounded conductor in a Jacketed cord. That addresses my external connection point. Hopefully they will then allow use of the blue wire inside of the equip. as well.

 

[petersonra]

Thanks you Dennis. That is useful information for me.

Perhaps I missed the intent of Bobs response but I did not find it helpful.

I guess maybe I did not understand the comment;
"virtually no premade cord sets use white insulated conductors."

I know of many premade cordsets with while insulated conductors. If Bob meant to support the choice for Blue conductor with that comment then I misunderstood and I appologize.

I did not say there are none. they are just not common anymore as UL does not require it and the cord set manufacturers want international approval. Very few newly manufacturered cord sets have white conductors for the neutral. I would not be surprised if it was 1 in 100.

When he said;
"the cord is not part of the premises wiring so does not fall under the NEC."

Ok but what? This left me hanging. I posted under the UL section of the forum because I knew it would not be appropriate under the NEC section.

My point was the code does not care. The only thing that matters is what the UL standard allows. Some people are under the mistaken impression that the code applies to anything with electrical wires. It doesn't.

Last he commented;
"if your device needs UL approval, you should ask UL."

That may seem obvious but easier said than done. I am looking to collect supporting documents or as Dennis was kind enough to offer, other product examples.

It is actually quite easy to get information from UL about such things. It is however, NOT free. You have to get an account and they bill you for every second one of their people talks to you about it, and whatever time it takes them to research the answer and document it.

 

[hurricaneflyer]

quote by ELA:
Would you as an electrician feel comfortable with connecting a light blue to a white wire at the field connection point?
end quote

I recently was called upon to wire an exhaust fan (110 volt residential)that had no white wire available in the wiring compartment. The fan had no schematic or wiring diagram any where on it. There was no paper work (installation instructions) attatched or near by.

From looking at the connections it looked to me that the blue wire was to serve as the neutral, but because I had not come across it before I came to a screeching halt.

I contacted the HVAC contractor (through the GC) and he said the neutral was probably the blue wire but he would have to check. It took them two days to find the shipping invoice and then have the wiring instructions faxed to them from the manufacturer.

Moral of the story: If you make sure there is a Permanent wiring diagram at or near the wiring compartment, even romex monkey electricians like myself will have no problem hooking it up. Just don't rely solely on papers that can be lost to convey the information.

Hope this is included as the type of info you are looking for. If it isn't please don't bite my head off, I am only trying to help

 

[Dennis Alwon]

Dennis,
I could not locate a reference to input wiring on the Fan Tech remote fan.
At that site I found a number of installation guides but no blue wire. Do you have a link by chance?

It appears that section 400.22C of NEC does support the use of the Blue wire as a grounded conductor in a Jacketed cord. That addresses my external connection point. Hopefully they will then allow use of the blue wire inside of the equip. as well.

Try this
http://www.fantech.net/fr_inst.pdf

The diagram is a bit fuzzy (page 4) but I can see the info on the blue wire. If you want I would be happy to send you the installation manual that I have from one of the units.

 

[nakulak]

I'm not sure whether or not you got the responses you were looking for, but here's my 2$.

After many years of careful observation of our guys working in the field, I have noticed that Murphy's laws and Hoyle's laws are beyond reproach. I have guys that could miswire anything, no matter how fool proof it is. They have even been known to plug connectors together backwards which the poor manufacturer though to be impossible. And despite instructions to the contrary, they will almost always throw out both sets of instructions and wire devices up, only then retrieving the instructions from the dumpster if the device is smoking or on fire. In conclusion, if you want to manufacture a device which will (mostly) be wired correctly, a wire-set of black/white or orange/white might be the best choice if that is convenient (from the standpoint of field-wiring).

(jmho)

 

[ELA]

Thank you all ... and sorry if I came off harsh.

We got approval yesterday. We had argued that the light blue wire was not "Intended" to be connected to the grounded conductor. - There is no problem connecting it there if desired but it is not a requirement in order to operate.

I really appreciate the feedback from those of you who might encounter having to field connect these devices. I know that back when I was an electrician 30 years ago a light blue wire would have had be befuddled.

Now a day, with universal power supplies and international commerce I feel the light blue wire makes sense. We were sure to specify a light blue as opposed to a darker blue which many might have enountered as a switched leg on fans etc.

Like you have said a wiring diagram is a must! A very clear wiring diagram is supplied with each controller ( this is also a requirement for listing).

Although I sit behind a desk a lot of the time I have been fortunate to have done a lot of field work. I appreciate having input from others who work there daily.

 

[jrannis]

Blue Wire

Blue Wire

I have connected several pieces of equipment with Blue and Brown wiring. I always double check the instructions and make sure what goes where.
Have you thought of using numbers instead of colors like they do for split voltage motors?