Would this be poss, I would like to build, with the help of you guys a self powered load tester for testing long run underground wiring, I have access to both ends of the wire and also have a 12 volt power supply, the power supply is capable of producing 80 ish amps, Ive been testing the wiring with a vehicle headlamp bulb that draws about 4 amps and DMM.

What I would like if poss is a small'ish project box with a volt and amp meter built, something like
https://www.ebay.co.uk/itm/Digital-...hash=item2398b29147:m:m_oggB8PrmZeLzRSclZd-Wg

in and a pot so I can crank up the the amps, I I'd like aprox 0 to 4 amps

if it is poss, where would I start

Thanks

 

I assume you want to test for shorts and opens(?).
What is the normal cable operating voltage and current?
Why do you want a variable current?

 

Normally the testers such as the Megger version measures insulation via a high voltage and total reistance via low voltage.
These can also be had combined in one unit off the shelf if needed.
Max.

 

I want to test for opens and corrosion, I have a Megger MIT that ive used for insulation testing
They say the operating voltage will be from 9 to 20 volts, current no more than about 10 amps
I would like something with variable current as each tube has different size wiring inside, from small, say 250ma - 500m to heaver wiring that could cope with a lot more load

Thanks

 

If you want to test for opens, which would be relatively easy to partial open due to corrosion etc, then for the latter, the gauge and total distance may be needed in order to measure the calculated resistance.
Max.

 

I think I might have worded it wrong, you will have to excuse my terminology, Ive seen variable dummy load for power supply testing and thought maybe I could build a cheap DIY version as that would test the PS and the wiring at the same time

 

Wire testers can range from really simple to fiendishly complicated.

It would help if you could define what the pass/fail criteria are.

For example:

How many conductors?
Max resistance?
Max leakage?
AC voltages nearby?
Safety? Could the wires be accidentally energized?

 

Sorry dont understand,,,,,,,,,,How many conductors?
Max resistance? about 5 ohms'ish
Max leakage? none as low voltage
AC voltages nearby? only lighting cable but overhead and not underground
Safety? Could the wires be accidentally energized? no as both ends are open at moment

Thanks