Question: If using a 240V, 4800W heater, the current draw should be about 20A, according to P=IV. How does that current flow with respect to L1 and L2? Would it be split peak to peak or does it alternate between L1 and L2? Would you expect to measure 20A on L1, and 20A on L2, or something else? Because they are both "hot" ref to gnd, I am confused. Thanks!
240v current draw quiz
- Thread starter whiteg77
- Start date
offroadsteve
Well-known member
You would measure 20A on both L1 and L2. The current is flowing from L1 to L2 during one half of the cycle, and reverse during the other half.
justsam
Well-known member
Not to get too far off in the weeds here, but be careful with saying something like "peak to peak" when referencing AC voltage.
What most electricians measure today is really RMS (Root Mean Square) and there is also a "peak" voltage when discussing sine wave AC. It is 1.414 times RMS, and "peak to peak" is twice that.
Like I say, not to get off in the weeds, but best not to use terms like "peak to peak" if you are discussing sinusoidal AC, unless of course you meant exactly that.
What most electricians measure today is really RMS (Root Mean Square) and there is also a "peak" voltage when discussing sine wave AC. It is 1.414 times RMS, and "peak to peak" is twice that.
Like I say, not to get off in the weeds, but best not to use terms like "peak to peak" if you are discussing sinusoidal AC, unless of course you meant exactly that.
ishiboo
Well-known member
Yes.
The math adds up since each leg measures 120V.
20A * 120v = 2400W. Multiply by 2 and you have your 4800W rating
