First, the
clamp meter must be used only around a single wire conductor, not around cable. Second, the clamp meter will only tell you amperage, not voltage, without physical contact using the included probes.
Disclaimer: Always use every available precaution when working around live electrical circuits! Here's the one I use,
Fluke 30--it's not the best, but adequate for my purposes. It has been replaced by the
Fluke 333A, MSRP $149.95 US.
Sounds like yours is not a very good manual. Out of curiosity, what make and model is your meter? Here is a link to the
manual for the Fluke 333. It will probably help clear up your confusion.