how do I work this out

[lofty84]

A 1.5mm2 conductor has a design current of 4 a and a length of 10 meters. its volt drop is 29 mv/A/m what is the volt drop across the terminals.

Can anyone show me how to work this nasty little bugger out

Answers are

11.6v
17.4 v
1.16v
1.74 v

 

[Guest123]

Sure.

Volt Drop = design current x length of circuit x mV/A/m value / 1000.

So, 4 x 10 x 29....divided by 1000 = 1.16V.

 

[lofty84]

Cheers Lenny mate.

Easy when you no how, just need to remember 1000 really , how comes its a 1000 though do you no, or is it it is as it fits.

 

[ugetwhatupayfor]

Sure you prob have the answer to this by now, but the division by '1000' is the conversion of mV per amp per metre to volts per amp per metre.

You could do calc this way:- 4 x 10 x (29/1000) which becomes 4 x 10 x 0.029 equals 1.16v.

 

[Guest123]

Cheers Lenny mate.

Easy when you no how, just need to remember 1000 really , how comes its a 1000 though do you no, or is it it is as it fits.

because it's millivolts per amp per metre used in the calc, so we need to divide by 1000 to give us the answer in volts.

 

[m4tty]

It's because the answer is in mv and you need it in volts so decide by 1000 gets you from mv to v. Hth

 

[m4tty]

3 replies at same time lol all say the same but others better explained doh

 

[Guest123]

3 replies at same time lol all say the same but others better explained doh

At least we all learned something at college......

 

[ezzzekiel]

not sure i did, whats a volt again?