110.21(B)

[sketchy]

One of my AHJ has made a point to me about my existing labeling will not be compliant in 2014; i.e. stickers. I've thought about hard plastic label machines but they are expensive, although I might not have any choice. Would you violate the UL listing if you riveted these to the equipment? What are you guys doing to comply?

 

[SolarPro]

We just published an article about NEC 2014 revisions. Here is the content related to field-applied markings:

Section 110.21(B) ?Field-Applied Hazard Markings?

Electrical systems in general, and PV systems in particular, require numerous plaques, labels, directories and signs. In practice, the materials that contractors use for field-applied signs or labels range from the clearly inadequate (laminated paper used in outdoor locations) to exemplary (engraved metal). Further, different contractors and facility operators tend to use different styles for labels, in terms of both the label color and the text color, size and font.

While field-applied labels and signs are inherently project and application specific, Section 110.21(B) seeks to standardize marking requirements for improved safety. The intent of the new language is to more effectively identify and communicate potential hazards in the field by improving the consistency with which Code-mandated hazard labels are deployed. In effect, these labels must provide adequate warning, be permanently affixed and be sufficiently durable.

Per Section 110.21(B)(1), field-applied hazard markings ?shall adequately warn of the hazards using effective words and/or colors and/or symbols.? Per 110.21(B)(2), the label ?shall be permanently affixed to the equipment or wiring method.? While this section also states that hazard markings in general ?shall not be handwritten,? an exception is provided for specific portions of the label or marking that are variable or subject to change. Lastly, per 110.21(B)(3), the label ?shall be of sufficient durability to withstand the environment involved.?

Note that labeling and marking requirements found throughout the Code?including many of those in Article 690?now refer back to Section 110.21(B). While the adequacy and durability of field-applied hazard markings is potentially subjective, two informational notes in this section refer to the American National Standard for Product Safety Signs and Labels (see Resources), otherwise known as ANSI Z535.4-2011, for application guidelines. This standard includes guidelines for appropriate colors based on signal words such as ?Danger,? ?Warning? or ?Caution.? It describes the letter style and size required for a label?s signal word panel and message panel, as well as location requirements related to visibility. It also addresses durability, in terms of label life expectancy and replacement requirements. Except where more stringent local requirements apply, AHJs are likely to accept labels and signs designed to meet this ANSI standard.

Todd Fries is a member of CMP No. 4 and the marketing manager for identification systems at HellermannTyton. Regarding material durability, Fries explains: ?The NEC and other codes, like the International Fire Code, do not specify a unit of time that a label must withstand the environment. Typically, these codes simply state that the label must be suitable for the environment where it is installed. This does not mean that the label must last the life of the installation. Everything wears out over time, including PV modules, inverters and other system components. However, Article 10.2.2 of ANSI Z535.4-2011 does state that a label shall be replaced when it becomes unreadable.?

To protect against premature failures and recurring replacement costs, Fries recommends that system integrators request label-material durability information and accelerated aging test data from the product vendor or manufacturer.

While engraved labels are certainly durable, they likely do not conform to the ANSI standard referred to in the new informational notes. My take is that "stickers" can still be used to meet NEC 2014, but the formatting of these stickers is more defined now, and more limited as a result. Also, this is an area where many AHJs have minimum technical requirements that exceed or are more narrowly defined than the Code minimum requirements.

 

[ggunn]

Would you violate the UL listing if you riveted these to the equipment?

You would void the NEMA rating, at any rate.

 

[Zee]

1. I use Hellerman Tyton, pre-printed labels for the 90% of my labels that are worded the same on every install.
I trust their quality a bit more than mine, below.

2. For the custom made labels (AC and DC Discos, A and V numbers), I have been using a Brother P-touch labeller (PRO XL) for a desktop. I print on "strong adhesive TZ tape". They claim some UV resistance.

(This is what i do. Not necessarily a recommendation, matter of fact, I am curious what others think!)

3. I am a big fan of the Phenolic (PVC?) coils made specifically for pv conduit (same mfctr: HT). Like a placard that is curved into a cylinder and coils around it....i figure the coil will disintegrate as they all will - but it is gonna last a good while.
It is thicker than a label,
and wraps around about twice , double deep...so one layer can burn off and leave the other layer to follow in a delayed fashion. It also avoids the issue of the oils vs the adhesive on EMT/steel conduit.

4. Finally, where you stick can be as crucial as what you stick. Wherever possible, i locate labels
in shade,
on north edges/sides,
and do double duty on outer and inner panels.

I often stick a copy inside DC discos, CB's. (or just lay them in - backing intact - if nothing else)
The Sun is a beast. Metal is impermeable.

 

[shortcircuit2]

For the custom made labels (AC and DC Discos, A and V numbers), I have been using a Brother P-touch labeller (PRO XL) for a desktop. I print on "strong adhesive TZ tape". They claim some UV resistance.

(This is what i do. Not necessarily a recommendation, matter of fact, I am curious what others think!)

Zee...Brother doesn't list anything on their website referring to the labels being UV resistant. Are you still using this product?

 

[Zee]

Zee...Brother doesn't list anything on their website referring to the labels being UV resistant. Are you still using this product?

Yup. Says outdoor.

How do you label V and Amps?

 

[jaggedben]

Yup. Says outdoor.

How do you label V and Amps?

If it's outdoor I think the best system is metal placards that I mark the numbers on with a punch set.

It's worth noting that none of the required signs that need customizing (namely 690.52, 690.53, and 705.10) are required to meet 110.21(B). So by the NEC, none of those are prohibited from being handwritten. If indoors and out of the sun I use a Sharpie.

 

[Carultch]

If it's outdoor I think the best system is metal placards that I mark the numbers on with a punch set.

It's worth noting that none of the required signs that need customizing (namely 690.52, 690.53, and 705.10) are required to meet 110.21(B). So by the NEC, none of those are prohibited from being handwritten. If indoors and out of the sun I use a Sharpie.

So if I were a manufacturer, how would I make this good for my installers? Would I supply an aluminum panel with engraved general text, riveted to the enclosure in a listed manner? And 10 punch dies, one for each digit, to fill in the system specific data?

There are also the directory requirements. In a practical sense, I often specify a summary in text for the location of the devices to be located by the directory. Such as "Inverter is fed by DC combiner #1 located on the west roof. AC disconnect located in panel PV1." This is field specific, and very difficult to manufacture a template to fit.

On more major pieces of equipment, this would mean a map. I often laminate a computer drawing, and put it on the door interior of the AC combiner. Not easy to put it on the outside, due to environmental factors.

 

[ggunn]

So if I were a manufacturer, how would I make this good for my installers? Would I supply an aluminum panel with engraved general text, riveted to the enclosure in a listed manner? And 10 punch dies, one for each digit, to fill in the system specific data?

There are also the directory requirements. In a practical sense, I often specify a summary in text for the location of the devices to be located by the directory. Such as "Inverter is fed by DC combiner #1 located on the west roof. AC disconnect located in panel PV1." This is field specific, and very difficult to manufacture a template to fit.

On more major pieces of equipment, this would mean a map. I often laminate a computer drawing, and put it on the door interior of the AC combiner. Not easy to put it on the outside, due to environmental factors.

Most of the signs and placards I see around here are red engraved plastic (white lettering) attached with double sided tape. There is a trophy shop in town that makes them.

As someone else has pointed out, riveting involves drilling holes, and that would invalidate a NEMA listing.

 

[Zee]

I stick a label on the outside to appease AHJ...
.....and one on the inside to appease my conscience and avoid all destructive UV.

Sharpie will fade and burn out. So will my labels (when don't know??)

Quality ranking: Sharpie < self-printed labels < phenolic placards (red and white etched plastic) < metal placards
Fair to say?

I think the metal is a superior solution...however , to be frank, that is one more thing i do not want to deal with either....:ashamed1:

 

[jaggedben]

I think the metal is a superior solution...however , to be frank, that is one more thing i do not want to deal with either....:ashamed1:

I get that, especially on residential systems without combiner boxes. If you're not a qualified person then you hardly need to know the system voltage, and having the info probably won't help you. If you are a qualified person then you can count the panels and/or measure the voltage with your meter. Nice to have it labeled, code requires it, but if it fades or falls off in 5 years or 15 years then I still expect myself or anyone I ask to service a system to be able to figure it out. You know the Isc is about 8-9A if it's silicon. I'm not feeling guilty about putting up stickers when it's three or four jobs a week.

On large systems with combiner boxes, including anything over 600V, I'm gonna do the most diligent job I can with the signs. It's too small a percentage of the cost and time of the project to make excuses about it.

 

[Zee]

I get that, especially on residential systems without combiner boxes. If you're not a qualified person then you hardly need to know the system voltage, and having the info probably won't help you. If you are a qualified person then you can count the panels and/or measure the voltage with your meter. Nice to have it labeled, code requires it, but if it fades or falls off in 5 years or 15 years then I still expect myself or anyone I ask to service a system to be able to figure it out. You know the Isc is about 8-9A if it's silicon. I'm not feeling guilty about putting up stickers when it's three or four jobs a week.

On large systems with combiner boxes, including anything over 600V, I'm gonna do the most diligent job I can with the signs. It's too small a percentage of the cost and time of the project to make excuses about it.

Yes, my unstated point too: plenty of labels warn of high voltages already, ungr. circuits, line and load energized etc, . And on larger systems labelling well becomes worthwhile.