Installed a 300 amp switch between my 12 volt 2000/4000 watt inverter, as soon as it drew 1500 watts for 5 minutes it cut out due to under voltage. The machine will not pass 100 amps. Measure the voltage on both sides and it dropped to 9 volts after the switch and stayed at 12.9 before that. So I removed it and plugged it straight in and the inverter works great.