voltage drop 4-20mA loop powered device
Its been way too long since electronics class. Can anyone tell me if I am on track or not??
Does anyone know whats the maximum distance I can get a can power up a transducer with 24vDC and receive a mA signal back for a DDC input? I was curious if anyone would know a voltage drop formula that I could use to see what my maximum wire length could be...
The max current draw of the Veris transducer is 29mA and I dont know what the resistance would be for 500' of 18 or 16 gauge cable calculate total resistance.
Something I found online, voltage drop equals 2 x i x L x R x t / 1000
Where I=current, L=length in Meters, R is the Resistance of the conductor, t is a temperature correction factor
So 24vDC/.029 Amps = 828 ohms using ohms law
(2 x .029 x 152.4 (feet to meters) x 828) / 1000
=7.31 volt drop
Your off in the weeds.
>So 24vDC/.029 Amps = 828 ohms using ohms law
That would be the resistance of the total circuit, including the sensor. Your formula needs ohms/m of the wire I'm assuming.
I wouldn't even bother doing the math unless your going to exceed thousands of feet. I can't ever remember having an issue with voltage drop on 4-20ma.