Landscape lighting transformer and wiring

[stickboy1375]

I have 2 600w trans and was going to use 10/2 landscape wiring to run from the trans to the fixtures.

A 600 watt transformer is actually two 300 watt loads, 411.2 will only allow 25 amps max on a secondary circuit.

I checked the code book but I can't find anything that indicates this can't be done. The only thing that worries me is that there is a higher amp on the low volt cable and would it be safer to run this in pipe?

As already mentioned 411.4 is the rule you have to follow, also IMO what your doing is a bad design, voltage drop is going to be a huge factor, I would mount the transformers outside on 4x4's behind a tree or bush...

 

[Dennis Alwon]

The cable I have in my basement is 8-2 underground cable. It is the standand low volt cable only larger. It says low energy underground cable 150 volts. I will have to find some manufacurers info.

 

[iwire]

voltage drop is going to be a huge factor,

This can't be stressed enough.

 

[Dennis Alwon]

10/2 is rated only for 360 watts and 12/2 for 250 watts. If you have a 50 foot run inside I would bet you are going to have issues with drop unless you have very low wattage and a short exterior run. You could easily go 100 feet total if you only have 6 fixtures with 7 or 10 watt bulbs like they sell at home depot, etc.

 

[stickboy1375]

Here is a great chart to show you how bad that extra 50' is going hurt you.

 

[iwire]

10/2 is rated only for 360 watts and 12/2 for 250 watts.

?

 

[Pierre C Belarge]

Pierre that picture is fine but that does not let us know it is not code compliant. I would be interested in some documentation if you have. I will check my cables also and call the manufacturers.

Dennis
You can go to the UL website to start.

Here are a couple of quick links.

http://www.calvertwireandcable.com/show_product_list.php?subcatid=205


This is a specific cable makers product sheet. Scroll down to Applications.
http://www.generalcable.com/NR/rdonlyres/B8A37392-5284-475D-84E2-B61E3F73914A/0/Pg37_LwVltgLndscpLghtgWr.pdf

 

[Dennis Alwon]

?

I read that at a few sites. The cables were rated that way...

http://www.ccl-light.com/docs/cable10-2.html

 

[Dennis Alwon]

Dennis
You can go to the UL website to start.

Here are a couple of quick links.

http://www.calvertwireandcable.com/show_product_list.php?subcatid=205


This is a specific cable makers product sheet. Scroll down to Applications.
http://www.generalcable.com/NR/rdonlyres/B8A37392-5284-475D-84E2-B61E3F73914A/0/Pg37_LwVltgLndscpLghtgWr.pdf

Yes and neither site say it cannot be used indoors. I realize they are design for exterior above and below grade but so is other cables that are allowed indoors. I don't doubt it possible that it is not allowed indoors. I just haven't seen documentation on it.

 

[iwire]

I read that at a few sites. The cables were rated that way...

http://www.ccl-light.com/docs/cable10-2.html

But you know that cable can not be rated in watts.

 

[infinity]

?

At 12 volts?

 

[Pierre C Belarge]

Yes and neither site say it cannot be used indoors. I realize they are design for exterior above and below grade but so is other cables that are allowed indoors. I don't doubt it possible that it is not allowed indoors. I just haven't seen documentation on it.

As I mentioned, you can further research this at UL or other cable manufacturer's websites. Email those companies and you will get your response for clarification.

 

[Dennis Alwon]

But you know that cable can not be rated in watts.

I was surprised but if that is the manufacturers info then.... I was just passing that on. I am not sure why it cannot be rated in watts if the voltage is limited to 12V or 24 volts. 12/2 at 120 volts is basically limited to watts.

 

[Dennis Alwon]

As I mentioned, you can further research this at UL or other cable manufacturer's websites. Email those companies and you will get your response for clarification.

I understand Pierre but I really don't think that an ec should be responsible to check every product with UL. If this stuff is listed then it should be their responsibility to provide this info. If it is not allowed in the house then the product should say it on it "for outdoor use only". There are plenty of toxic things in a house including NM cable.

 

[Pierre C Belarge]

I understand Pierre but I really don't think that an ec should be responsible to check every product with UL. If this stuff is listed then it should be their responsibility to provide this info. If it is not allowed in the house then the product should say it on it "for outdoor use only". There are plenty of toxic things in a house including NM cable.

As a licensed EC, or as an EC/installer, it is definitely their responsibility to know.
When laws/codes are written, it is the person's responsibility to know them. Just like all of the motor vehicle laws are, as another example.


To me, that is the difference of being a "professional" and a non professional. (of course this past sentence is strictly my opinion)

 

[iwire]

As a licensed EC, or as an EC/installer, it is definitely their responsibility to know.

Pierre has a good point, we are already expected to know building codes about fire stoping and local power company issues etc.

It ain't easy being us.............thats why we get the big bucks. :grin:

 

[iwire]

I was surprised but if that is the manufacturers info then.... I was just passing that on. I am not sure why it cannot be rated in watts if the voltage is limited to 12V or 24 volts. 12/2 at 120 volts is basically limited to watts.

They are aiming that at DIYs and it is meaningless.

 

[Pierre C Belarge]

Pierre has a good point, we are already expected to know building codes about fire stoping and local power company issues etc.

It ain't easy being us.............thats why we get the big bucks. :grin:

This is an important issue that has been discussed and, pardon my opinion in the middle of a sentence, whined about a lot lately in the field. Our industry has become very complex (it was already complex years ago). The length of the NEC is enough of a clue to let us be aware of this...yet now we have other documents that I can say personally, I never used or heard of earlier in my career, that are also important to know and understand.
What was an industry where generally we used to work close to home and in smaller territories than today, and also did primarily one or two different types of work; we are now persuing much greater diversity of work and working over much larger territories than say 20 - 30 years ago.


So, do we have a harder time trying to keep up with the changes...absolutely. How do we handle it? Maybe by picking a "niche" portion of the industry and try to be good at that.
I don't know, there are probably a lot of good answers.

 

[Dennis Alwon]

Let's be realistic. It is not practical for an EC to call up and investigate every product that they install. Other outdoor products are installed indoors (outdoor sconces) so are we expected to check every listed thru the process of UL. To some degree I agree but let's face reality-- it's not going to happen on a large scale if at all. If the product does not tell me suitable for outdoor only I don't see that many or any perhaps would call UL or spend the time to look it up. You call the manufacturers and it's is still no guarantee that the answer they give is correct.

How far does one go. I can't ven get an answer as to why NM cable is rated 60C when the jacket and cable are rated 90C. Who knows that answer. Sure we know because it's in the code book but my point is this situation is not in the NEC and the product material, as far as I know, does not have that info on it.

Perhaps tomoroow I will find it but gee whiz, it should not be that difficult. UL or a third party should make the manufacturer encose that info on there product the same was the USFDA makes cereal list it's ingredients. If there is so much danger in it then make the info available to the everyday EC..

 

[iwire]

Let's be realistic. It is not practical for an EC to call up and investigate every product that they install. EC..

Dennis all you really need to do is read the instructions.

IMO if the instructions for an outdoor lighting system say nothing about being used inside the assumption should be it's not OK for inside.

Then if you still want to use it inside it becomes your issue to pursue.

The instructions certainly do not say 'not for hazardous locations' but you would not assume they where because of that. The instructions do not say 'not for use in tub areas' but again the lack of that wording would not mean you could use them in the tub.