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AC, DC, Volts, AMPs, Watts I don’t understand it!

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DKRITTER

RVF Supporter
Joined
Nov 19, 2019
Messages
370
Location
Haslet TX
RV Year
2013
RV Make
Newmar
RV Model
Dutch Star 4318
RV Length
43
Chassis
Freightliner
Engine
Cummins 450hp
TOW/TOAD
2022 Ford F250 4X4
Fulltimer
No
I have a house that’s 110V AC with a 200amp breaker and a bunch of smaller breakers for all my stuff. My dryer and my water heater run on 220V yet some of my appliances and all my bulbs talk about watts. What’s a watt? How does it relate to volts and amps?

My car is 12V DC some of it is in amps and some of it is in watts, why? In DC the red is hot and the black is ground. It’s not the same with AC, why?

What’s a Neutral? It’s not a ground but it kinda is.

Is the white wire always the neutral?

Is the black wire always the ground?

Is the red wire always hot?

Is the green wire always the ground?

My motorhome is both AC/DC 110V and 12V. The black wire is hot, the red wire is hot, the white wire is neutral, and green is ground.

Some of the white wires inside are hot not neutral.

I have 2 110V AC lines coming in, each has 50 AMPS capacity so how many watts is that?

I have an inverter it changes 12V into 110V, it also changes 110V into 12V.


I wonder why I don’t understand?

My black tank says it’s 1/3 full but I know it’s empty, wait that’s another thread…
 
Yes, it can be confusing if you don’t understand the fundamentals. Now, as for your house being...
110V AC with a 200amp breaker
...it isn’t; it is 240V AC with a 200A main breaker. :oops: The 240V AC is split into a pair of 120V AC buss bars with a neutral for the 120V AC circuits and re-combined without the neutral for the 240V AC range, water heater, dryer, etc. circuits. That should clear things up! :ROFLMAO:

Here’s a link to a pretty good explanation of Volts, Amps, Ohms, Watts, etc.:


TJ
 
Last edited:
Wow @DKRITTER I don't know if I should chuckle with you or answer.

That said, if you are serious then:

the 110/220 ac world we live in two wires that come into the box are black and one red. Both are hot. One white a neutral or for clarity an insulated ground. and a bare or green wire(a ground).

in low voltage red is V+, black is V-(or ground) However we should say most of the time as the rules change.(use a multi meter to verify.

Amps is used to determine wire size and other component sizes.
Watts is the available power used.
volts is the force, like psi is to tire pressure.
relating these three things are done with ohms law:
volts(v)
amps(a)
watts(w)
w=a x v
a=w / v
v=w / a

because voltage is a standard we use for our systems i.e. 110v, 12v, 24v, we don't mess with this in our calculations unless we are converting from one voltage to another as is 12 to 110 or 110 to 12 as in inverters and converters. these converting circuits include transformers that are rated in "volt amps" a close cousin to watts because this is the power converted from one system to the other.

Because we need a standard when sizing systems like solar systems we like to convert everything to watts because that is how our panels are rated. Most heating systems are rated in watts when we are looking at electrical heaters. Lights are the same even when looking at L.E.D.s. Most TV sets I have seen lately use watts for power consumed, heck the A/C in my rig has the power in watts and amps. Things like refrigerators are in amps but it is a quick conversion with the formulas above. OH yah! 50a service at 220v is 11000w.

But amps volts and watts are not all we need. We also need to relate these items to time. we do this with the standard of one hour. So our figures measure as an example 5 hours of sun on a panel producing 100 watts on average. 5 times 100 is 500 watt hours. at 12 volts that would be amp hrs = 500w / 12 volts = 41.66 amp hours into the system.
 
Electricity does not give second chances.

Other than resetting a tripped breaker, I find it best to leave home electrical issues to the professionals.
 
Electricity does not give second chances.

Other than resetting a tripped breaker, I find it best to leave home electrical issues to the professionals.
I don't find electricity to intimidating, It's kind of like a rain storm in my book. When it fills the arroyo then it has my attention.
 

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