Oct 3, 2009 07:33 am
Re: Showing voltage over disconnect breaker when off?
Wow! Reading some of these posts I began to realize that "talking" and "writing" electrical can become a language all on its own. The English language may not be totally adaptable to electrical language. Kinda like if someone were to read musical notation over a telephone to someone else. For example, A minor, C, A minor, B, but, one can't here the music over the phone. You would need a musician with a musical instrument. But you know this. You know you need an electrician or at least would like to have an electrician check your work.
Even among electrical workers there can be miscommunication. There have been several occurrences here at this forum. For example, I mentioned in one that #12 awg copper is good up to 20 amps. Which is primarily true but depending on the circumstances under which it is used it may only be good for 5 amps or less. But it doesn't stop there. There are so many different fittings and conduits and conduletts and all in many different sizes, it can get very frustrating. Even an electrical schematic, a lot of the time, is a typical rendering and may leave one with questions concerning a specific problem to overcome on a particular adaptation. I had a master electrician tell me that it was code that utilities power must go on the top lugs of a transfer switch and the back up power on the lower lugs with of course the load on the middle lugs. Horse pucky! There is no such code in the NEC. It maybe the most popular concensus among licensed electrical contractors and electrical inspectors, but its not a code.
Now we start to get into the nitty gritty of it all and thats if, you could put it all into a pot and boil it down to its trace minerals what you would be left with is, money! Or in some cases, a lack of money! Someone spends their time and money to gain an education in some genre or other because they want to use it to earn a substantial income. Ok, most people but not all.
The internet is changing that in its own way but that in its self still takes a certain amount of self education and hands on experience and even a little trail and error. The error typically meaning money spent to learn a lesson and as Jame's pointed out it could cost one the ultimate price where electrical is concerned. I mean, how do we know that the first person to invent gunpowder was really the first? The first one may have blown themselves up in the process with nobody the wiser for it. This is starting to get lengthy I know, so I'll move on.
I am sure you have read many books and magazines on the subject of electrical wiring but what you lack is confidence that what you know and what you have installed is correct. Am I right? Doubts pop up and you would like a second opinion. Your not alone Ann Byers. This happens to everybody in every occupation, even the learned ones. One thing that make electrical frustrating sometimes is the language. Phrases like LINE and LOAD are agreed upon. LINE is the power source and LOAD is the device using power. Although LINE typically goes in at the top of a breaker and LOAD out off the bottom, its not always the case. So its typically referred to as just LINE and LOAD.
You have full voltage on the LINE side of your breaker at all times, but only on the LOAD side when the breaker is in the CLOSED position. LOAD is lost when the breaker is in the OPEN position. LINE should be considered eternal even though we now its not. Makes no difference if its a battery, PV module or, 120/240 vac from a pole mounted utilities transformer. OK!
If I assume you meant to say that you were getting;
(A) some voltage - or
(B) full voltage (which one?)
on the LOAD side of the breaker with the breaker in the OPEN position, would this be correct?
If (A) some voltage - then how much and what is the nominal voltage? You might be reading resistance from a device (load side) through the negative. Your meter could be acting like a partial conductor, almost but, not quite, completing the circuit just enough to give a reading on your meter.
If (B) full voltage - you might have a bad breaker or polarity is reversed somewhere.