"Warning: Most buildings before 1985 have supply wire rated 60°C[...]"

[mesame]

"[...]Consult a qualified electrical before installing. Risk of fire."

...so it says on the top flap of a Hampton Bay Track light kit. The installation instructions then also mention "Required Supply Circuit: 120V, 60Hz".
What does this mean? Does the fixture itself become more than 60°C hot so that I have to be concerned about the sheathing of the wires in its vicinity melting? Or does this mean that the fixture can put such a strain on the supply line causing it to heat to more than 60°C? How can I determine if the supply wire is rated 60°C and that I have a supply circuit of (120V,) 60Hz?

The house was build in 1963 and most of the wires I found feature a type of black woven/rope-like sheathing and contain only a black and a white wire.

I was planning to install the kit in a freshly remodeled room, replacing an old 3x60W bulb fixture (=180W) with this track light. The track light comes with 5x50W halogen (GU10-16 50W) lights (=250W). The old fixture was supplied by a black and a white wire only -- no grounding. As such I was planning on installing the track light without grounding either. Would this be reasonably safe?

Is the "60°C supply wire" warning save and the lack of a grounding wire acceptable to ignore?

Thank you for your help!

[giddonah]

I'm seriously not trying to be rude, but by the way you ask these questions it sounds like you really need to call an electrician to put that in. At the very least get yourself a book on electrical work and start studying. You really are risking a fire.

Edit: As this site is for diy, and I"m pro-diy, I'll offer this: You can do what you plan provided you're not overloading your circuit. Chances are low that you will, but it's a possibility. Try to figure out everything that's on that circuit and add up the power consumption. The other problem with your project is the old wiring. At the time the house was built there was no code for a ground wire, so you'd be "ok" to just replace wire for wire.

BTW, the 60°C stuff is like saying you need non-leaded gasoline, it's just a given these days. Nearly any wire you buy will be 60°C rated. You're not replacing the wire though, so yes, you can ignore this.

PROCEED WITH CAUTION AND READ A BOOK ANYWAY! You'll learn all kinds of neat stuff that can help you keep your house from burning down.

[mesame]

Thanks for your response, giddonah!

No offense taken, albeit I wonder what exactly you're referring to... From what I gather, something in my post must have suggested that I am an absolute greenhorn when it comes to electrical tasks. Well, I can't say I have a whole lot of experience, apart from exchanging a few light fixtures, outlets and light switches. Was there something in my terminology?

Either way, I appreciate your tips as well as the warning to use caution as well as your suggestion to refer to a book for electrical questions (I do indeed have a book on electrical work, but it didn't offer any answers for the particular questions I had) and to do a load calculation.

Regarding the two quotes that I asked about, that is, a supply wire of 60°C and a supply circuit of 120V & 60Hz, both of these quotations correspond to items stressed in the install instructions for the track light in question. I don't remember that the instructions that came with other fixtures I previously installed stressed (or even mentioned) these particular points, so I thought that I better try to find out more about them before proceeding to install the new track light, which is why I posted my question here. Believe me, the last thing I want is my house to burn down! With this in mind I always try to be extra thorough.

Before posting my questions here, I did a general web search on the items in question but couldn't find any answers. The same goes for my book, so I'm guessing that neither the 60°C or 60Hz specs come up all the often but also, that I'm likely not alone in not knowing what these specs really mean.

Based on your response, I gather that the 60°C spec shouldn't be a concern. However, I'm still not quite sure what it refers to... You mention something about non-leaded gasoline -- how does gasoline relate to residential electricity?

For the fellow reader who might stumble upon this post and wonder what the 120V, 60Hz requirement refers to: It seems to refer to the utility frequency, i.e., "the frequency at which alternating current is transmitted from a power plant to the end user" based on en.wikipedia.org (http://en.wikipedia.org/wiki/Utility_frequency). This page also mentions that many different frequencies were in use and in some cases, _are_ still in use or even necessary. I'm guessing that a sure way to know the specs of your supply circuit is by calling your utility company.

Thanks!

[Mike44]

Lol, I think I know what giddonah means about the gas. 60°C rated wire is pretty much all that is sold and installed in houses for the past few decades. Wire rated for 75°C is typically not installed in houses (at least not the last time I've seen a house built) because it is unecessary. Just like gas; unleaded gas is the norm everywhere and you won't find leaded gas anywhere, yet they still mention that it is unleaded - sort of redundant I guess. So, they still mention that it is 60°C rated wire, even though they don't really have to.

So, if that makes any sence to you???.....

As for the 60Hz current: since you are being supplied with AC (alternating current) into your house from the power company, 60Hz refers to the number of times the current switches, or alternates, between each wire, or pole. It switches 60 times per second, so that's where the 60Hz comes in since 1Hz is once per second. And to my knowledge, that is pretty much standard supply as well into houses.

So, I've rambled about nothing really, and didn't even answer your question. In my experience though, working with ungrounded boxes is a hazard when it comes to me doing it - sparks and all. So I don't think I'll even go there with you because I seriously don't want you to go ahead with something and have it be wrong. Sorry, but I'm really not sure about what you should do about ground the box.

Mike

[mesame]

Thanks for your comments, Mike...

It seems that I got giddonah's explanation about 60°C completely wrong -- in fact, it's no explanation, rather an analogy...

Well, it's good to know that 60°C is standard today but the original question was, just as the warning on the track light box implied: do I have to worry about this given that my house was built before 1985 (i.e. 1963)? If at least I understood exactly why a 60°C rating is required (i.e. in what situations/under what circumstances anything less would be bad and what would happen) I would be able to make a judgment as to how likely it is that my house is OK, knowing all the other types of fixtures and appliances that I have installed.

Thanks.

[giddonah]

the rating is just the minimum required, which is pretty universal. This means manufacturers need to adhere to this in order to sell their products, which means pretty much anything you buy in the 'depot will follow suit. I don't even look for it, and when I see it on a package I don't even think about it.

Here's the thing about old wiring - It's fine for a hundred years unless it gets knocked around. It's when you start messing with it that it gets brittle and breaks. There are lots of houses that still safely utilize knob and tube wiring that's 100 yrs old. The only thing I'd look for is aluminum house wiring. Your main feeders into your panel don't count. Aluminum is cheaper but is more easily installed in an unsafe manner. If you have Al, you don't need to rip out all of it and pull in copper, you just need to be more careful with it. Other than that, if the wires are handled carefully and are never overloaded, they'll serve you well for the life of the house. The only thing that I'd re-pull for is a grounding wire, which can just be added to existing wiring, but if you're going to add a ground, might as well redo it all.

Also, if wiring passed code the day it was installed, then it's still ok as far as code goes. You only have to bring things up to code when you're adding and making major repairs.

You'll probably be ok with your light project. Just check to see that you don't have a ton of things on that circuit already, and be careful when you do it. Careful not to kill yourself, but also careful with the wires so they last a long time.


Edit: Oh yeah, the only time you have to worry about the Hz is if you're in a foreign country that doesn't use 60Hz, like England which uses 50Hz. Take a look:
http://en.wikipedia.org/wiki/Mains_power_systems
The 120V though, you do have to deal with because most feeds into houses come in at 240V. That's voltage between two legs. At the main panel that's divided and you get 120v off each leg to ground. Leg to leg=240V, either leg to ground=120V. You just make sure you don't use one when you want the other. It's rare that you'll have 240 unless you're dealing with something major, like a circuit panel, range, dryer, the rare compressor. I'd be surprised to find 240V lights in a residential home.

[mesame]

Thanks, giddonah - that's all good info! Especially the paragraph on old wiring is good to know. A previous technician who had a look at our wiring had told us that it was still OK but didn't add much reasoning as to why. Now I know why he said that. Our wiring already uses copper just no ground and, as mentioned, is wrapped in some black rope/farbic-like sheathing; however, underneath the outer fabric sheathing, the copper wires are wrapped in plastic (one white & one black) just as they're today.

Now that I'm clear on these issues I can actually go ahead and install that thing!

Thanks guys!

[Mike44]

Sounds good! You should be all set to install it. Just one to add, the black rope/fabric sheathing you're talking about sounds like it may be the fire-retardent wrapping that they put on wires back then. If is it, then it probably contains some asbestos in it. I don't know how much is in there, but probably just wash your hands after. After all the testing they've done on it, it's been banned from use, so maybe wear gloves or something too.

Sorry, I probably sound like a health freak, but better safe than sorry.

Mike

[pauls]

The referenced warning (wire before 1985) states that the fixture requires 90 degree wire (current nm-b spec).

The real question is can such a fixture be safely connected to pre-1985 60 degree wire. Is the caution overly conservative? CYA based on current code?

[WireMan]

Most fixtures, well anything really, are made in China or Tiawan or somplace like that and they sell that stuff every where, the 120v/60Hz sticker is just a CYA ( cover your butt) thing for the mfg. cause like stated earlier in Europe they use 240v, 50Hz ( which by the way is WAY more effecient ) while in the US its 120/240 60Hz ( speaking residental anyway) But to be safe call an electrician to have it done, we come with a warrenty and insurance!! ( plus we could use the work its gotten kinda slow latley :) )

[Don_P]

If you are raising the wire temp 200 degrees F sumthin bad is wrong. The rating I believe is the temp rise above ambient for the insulation before it breaks down. If its a run of the mill fixture and if you install the correct bulbs (I'm assuming its a light fixture) then I wouldn't worry. If you are playing with high wattage, more heat than normal, then it might be worth thinking about.

[Mike44]

Mesame, check the label on your wires. If you have pre-1985 wiring, chances are it is only NM wire, which is rated only for 60°C. If it says NMD90, then it has 90°C rating and you'll be fine. I believe 1984 was the year where they switched over from NM to NMD?

Here's something else too you might want to know: I think I remember reading that if you have NM wire (rated for 60°C) that you can splice in NMD wire (rated for 90°C) at a minimum of 18" from the box so that you could still use the fixture and still have it up to code. It would be best if someone else could confirm this though before taking this as advice! You would just have to be sure that your splice is in yet another junction box and accessible (don't hide it!). In my opinion, that's quite the hassle to have to do all that just for a light! But it might be worth it too!

Mike