I did a practice inspection today on a 2005 townhouse with a Cutler Hammer electrical panel. In one of the bedrooms the AFCI circuit would trip when I plugged my circuit tester(green one) into it. The yellow tester did not trip the circuit though. Could that be a bad breaker or was my cheap tester causing it to trip? Also two of the other AFCIs did not trip when using the test button on the breaker. Thanks.