First Post

[Wheezl]

Hey guys I'm in school and have been reading here for awhile now. This is a great site and im really glad i stumbled across it and look forward to learning all I can from you guys. I'm interested in obtaining 'professional' status, so I'm trying to get 15 posts, and since I don't know anything yet I figure I will ask a few questions on subjects that are eluding me in class. Hope this is the appropriate forum for this.

Can someone please explain to me how TIME relates to WATTs...We learned that Watts=Volts*Amps. So if a compressor is pulling 10 amps @ 230 volts it is consuming 2300 watts of power. Does this mean 2300 watts per second? per minute? per hour? I'm guessing hour since electric companies charge KWH...

I know this is proabably a dumb question, but I need to understand this before I can ask my next question.

Thanks

[VTP99]

[QUOTE=Wheezl;13812291] I'm guessing hour since electric companies charge KWH...

Bingo we have a winner
No such thing as a stupid question bring it on.

[tbirdtbird]

http://en.wikipedia.org/wiki/Kilowatt_hour

which also mentions
"Confusion of kilowatt hours and kilowatts:
The terms power and energy are frequently confused. Power is the rate at which energy is generated or consumed. Power therefore has the unit watts, which is joules per second. A unit of energy is kilowatt hour."

[Wheezl]

Ok, so we are learning about ECM motors and how they are supposed to be more energy efficient because they avoid LRA. As I understand it, LRA is generally 5 times RLA and is for a very brief period of time (1 second or less?), so in my example the compressor would consume 11,500 watts/3600 seconds or 3.19 watts of power in that one second correct? But in an hour long cycle the remaining 3599 seconds would be consuming at a rate of (2300/3600) .638888888888 Watts/second. This brings the average watts/second to .640708333333.

This translates to 2300 Watts/hour without LRA VS. 2306.55 Watts/hour with LRA

I'm sure i'm missing something conceptual or messed up the math but if not....

How is this not negligible?

Edit: Fans not compressors were what we were really talking about with ECMs but the concept of my question still remains...

[Wheezl]

Anyone? I'd like to know if im way off base here or not