I'm creating a test system for a device that will measure amperage drawn from a 120 Vac source. The device basically passes on the power source from the wall and uses current transformers to read how much current is flowing through mains to some piece of equipment connected to it. I'm looking for ideas on how to draw 20 Amps off the equipment outlet of the device for a small period of time (less than 5 seconds). What was done in the past was to use a couple heaters or a bunch of light bulbs in parallel, but I wanted to see if there was a more compact solution that didn't have as high of risk for break down. I tried looking for some current shunt resistors and combinations of transformers and resistors to do this, but I couldn't find something that worked out at least off the shelf.