SC Alarm Test Question

[AprilGaye]

I am currently studying/taking the SC Burgular Alarm exams. There is one question that I cannot find the answer to. I has to do with low voltage/general electricity.
The question goes something like this....What type of class 2 wire do you use in a HVAC?
The answer or a suggested place of where I can find it would be of great help. I have looked through all of the suggested material but cannot seem to find the answer. Thanks.

 

[tom baker]

Re: SC Alarm Test Question

A class 2 circuit is defined in Article 725.
the type of cable must be a CL2.
Take a look at 725.61 and 725.71
UL also has a wiring marking guide that you will find very valuable, it will explaing all the markings and use of cables:
http://www.ul.com/regulators/mgwire.pdf

 

[AprilGaye]

Re: SC Alarm Test Question

Thanks for the help.
I have a few more questions that hopefully you can help me with.
Is is necessary to change your resistors? If so, how often and what would be the benefit of changing them? Also, if you have slack in your wiring, what kind of problems would it cause?
The last question is like the test question, but the first one is for my own knowledge.