Without a doubt, there is something wrong with your 200NCP. At 0, there should be no stim. Do you know anyone with a 1900 or better? They come with a tester, which works like a light bulb. You connect it to the prongs and when you apply stim, the tester lights up, and gets progressively brighter as you raise stim levels. At 0, the tester should not light up at all.
As far as dogs and humans feeling levels is concerned, it's not rocket science, as some would lead you to believe. As someone already mentioned, every one and every dog has different tolerances, it's as simple as that. Some people simply feel it at lower levels than their dogs, and some feel it at higher levels than their dogs.
I use Dogtra collars exclusively, because their rheostat adjuster allows precise stim levels, and I don't like shocking dogs. With collars like PetSafe, Innotek, Tri-tronics, etc., there is no finite adjustment, and more often than not, one level is too low and the next level is too high. With collars like these, you most often can train with negative corrections only, because there is no in between. Even if you're lucky and your dog barely feels, say level 2, level 3 can easily be too high. Rather than risk shocking a dog, I use good Dogtra models only. And, every owner I've ever trained with one agrees.
Most dogs I've worked with have a sweet spot between 18 and 24 in low to medium distraction areas. I've found that most humans first start feeling it between 11 and 19 (interestingly, women tend not to feel it at the lower end, presumably since they are capable of having babies, and I keel over at the though of passing a kidney stone), although a good male friend feels 3! What a wuss!
Indoors and outdoors, is not a matter of environment (wet eather notwithstanding); it's more a matter of what the dog is doing. Typically, the level required indoors is lower due to lower distraction and the dog is more relaxed. With that said, when initially setting levels, I have experienced dogs falling asleep at levels up to 50, which is darned high. Presumably, this is because during this process you start low and work up slowly, and I suspect that because you can move up so gradually with the Dogtra line, their tolerance builds along with it, and it starts to feel good after awhile so they fall alseep. Similar to applying a TENS unit at physcial therapy. They gradually turn it up and finally set it at, let's say 20, on a human and you feel it, but after awhile you get densitized to it and they graudally turn it up and reset it it at, say, 30, and now I feel it again. I find myself falling asleep every time I've been on one. But, if they just set it at 20 without gradually turning it up to that level, it would definitely make my hair stand up!
But, the same dogs that fall asleep at 50 you can bet jump out of their skin if you use it at that level when you practice Heeling, for example. So, you have to be careful, and repeatedly test to find their base level before use, and be prepared to turn it down when you begin to use it.
