Anyone see a problem with this definition of Normally Open?

justplumducky

Normally Open-
State where current flows until the plunger pin is actuated to close the electrical circuit.

Found this definition in an online EPA certification practice test site. Anyone see a problem with it, or is it just me?

JJboy

NC - Normally Close
NO - Normally Open

Original state when doesn't have power voltage applied.

__________________

**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.

justplumducky

Thx for your reply JJBoy

What I was getting at: Seems to me this is saying that current flows in an open circuit. Since when does current flow in an OPEN circuit?

JJboy

It isn't clear, but may be the voltage of the coil

__________________

**Always kill the power ** Hot air rises, but heat will always move from higher to lower temperatures. ** Real man shoot in manual. ** If it ain't grounded, it ain't dead.

gregzoll

When does traffic flow along a city street? When does water flow out along water pipes and out of your faucet or garden house? When does pedestrian flow downtown a busy metropolis along sidewalks?

justplumducky

Thx for your reply Greg~, but I have no clue what you're talking about - can't tell if you agree or disagree with my statement "Since when does current flow in an open circuit?"

beenthere

The practical definition of an open circuit. is no flow.

So it should read: State where no current flows until the plunger pin is actuated to close the electrical circuit.

justplumducky

Thank you beenthere.

gregzoll

The point that I was trying to prove, is to think about your question that you posted, to figure out the answer about what is Normally Closed, and What is Normally Open.

justplumducky

I already knew the answer from a purely electrical point of view, but when I brought it to the attention of the aforementioned EPA Practice Testing site, he told me his definition was correct. That got me wondering if there wasn't some sort of application in HVAC/R where maybe the usual electrical definition didn't apply. Then I got to realizing that electrical symbols (and their definitions) would probably have to be universal, thus my statement, "Since when does current flow in a normally OPEN circuit?"

Sorry for being a bit obtuse and missing your meaning Greg~.

beenthere

As with going to seminars. The people that write test, often interject their own personal interpretations. And thats what it sounds like the guy did that wrote the test you saw/took.

gregzoll

Don't worry. When I went to Basic Electricity & Electronics for the Navy, they had their way of stating things, that was different than how my father taught me about stuff. Then of course, it all changed when you actually got to do the work at your duty station. The process changed along with the way of doing things, but the way things worked in a circuit didn't.