Why do my lights surge and dim when I turn on my microwave?

Have you ever turned on the microwave and noticed all the lights in the house dim? Or sometimes lights throughout the home flicker? What causes this and what is the solution? The answer is a possibility of a few things. The first situation that I see a lot is the microwave is on a shared circuit with the lights and maybe a few other outlets. Simple answer you are overloading the circuit. Your home was probably built before the invention of the microwave, so the electrician that wired your home did not take into account the load on the receptacle. The second situation is that the circuit has a loose neutral. This can occur in the receptacle, the panel, or anywhere else along the circuit. I get a lot of calls where I have to go through and check all the devices until I can identify where the loose connection is at. Sometimes the bad connection is in the power companies lines. A qualified electrician should be able to find this using his voltage testers. The last circumstance we will discuss today is a faulty breaker. You could be experiencing a direct short and the breaker is failing. If your panel is pre-1985 it is at the end of its life cycle and would be worth getting checked out by a licensed electrician. Several brands of panels are notorious for this including Zinsco, Federal Pacific and Bryant.