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bench top high current variable resistor testing

harpo

Good at many things, master of none
Joined
Oct 1, 2019
Messages
98
Location
PA, FL
I want to find a variable resistor box that will handle high current (up to 100 amps). Here is what I want it for at the present but I will have other applications. I had a 50 amp circuit breaker installed between my Cotek 30 amp battery charger and the battery. I use the charger to supplement solar when there is not enough sun to replenish the batteries. Even though my charger was only putting out 30 amps (measured) the circuit breaker continually kicked out. I figured it was a bad circuit breaker so I replaced it with another one from a different company. This is a remote cabin and will not be back for a while so I can't monitor how the new breaker will respond until I have to use the charger again.
I brought the old breaker home and want to test it. I plan on hooking up a 12v battery, installing the breaker between it and something that I can adjust the amp draw on so I can see where this breaker will trip. I have seen such devices used by various youtubers but can't readily find a source or product name. Most of the ones I see when I put in "variable resistor box" will only handle smaller amp loads.
I know Will usually hooks up an inverter and then powers various AC components to get his high current draws (100amps or more sometimes). I guess I could do this but I'd like something where I could linearly increase the amp draw until the breaker trips thereby knowing exactly where this thing breaks the circuit.

If you have any recommendations I'd love to hear them.
 
Something like this maybe?
I don't believe this has a high duty cycle, something like 15-30 seconds on a the highest amp setting (& 6000 Watts) on time then let it cool off. It is not designed to shed the heat for sustained high amperage. Maybe at a much lower amperage setting -of just guessing 20 amps -you might not melt this sucker. It does not have a fan. Plus your thumb will get tired holding on the spring back to off switch.
 
Some nichrome heater wire in a bucket of water might be the trick. Not nice and easy like a resistor wheel though. The only other stuff I can think of is generator load banks but that's getting a little excessive.
 
I don't believe this has a high duty cycle, something like 15-30 seconds on a the highest amp setting (& 6000 Watts) on time then let it cool off. It is not designed to shed the heat for sustained high amperage. Maybe at a much lower amperage setting -of just guessing 20 amps -you might not melt this sucker. It does not have a fan. Plus your thumb will get tired holding on the spring back to off switch.
Anything designed to dissipate 6000 watts on a continuous basis is going to be massive (and $$$). He's just testing the trip point of breakers, so it will only be 10-20 seconds to slowly ramp up the current until it trips, it should be more than capable of that type of use.
 
I just used an old cpu heatsink + 4x25 watt 6ohm resistors + plus a little inline watt hour meter.
 
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