The Zen of A/C Maintenance

We've been experiencing day time highs of between 100 and 110 for the past week. While not extraordinary for later parts of the summer, it is unusual for the end of June and beginning of July. In any event, returning from an enjoyable time at the shooting range, I got a call from my wife that the the central air conditioning unit had stopped working: the internal fan unit ran, but no cool air, and the fan on the outside unit had stopped working. Poking around, we discovered that with a little assistance, the fan would begin to run, but only at a fairly slow speed; while the compressor would kick in for only 2 or 3 seconds before shutting down again.

Consulting with a relative who did HVAC work (but unfortunately lives several hundred miles away), he indicated that it probably was a bad capacitor. Going to You Tube, I found the following video extremely helpful:

After shutting off power at the main breaker box and at the outside fuse box for the air conditioner unit, I first opened the fuse box to check the fuses. Testing the fuses with a multi-meter for continuity, I found that both fuses were still good (which was as I expected). I then removed the access panel to the side of the a/c unit exposing the electrical connections and the capacitor. The photo below shows what I discovered:

As you can see, the top of the capacitor--which is normally flat--is badly bulged. A sure sign of a bad capacitor. There are not a lot of places to purchase these capacitors, and of the handful in our area, all but two were closed because of the Independence Day holiday. Of the two that were open, one of them was a wholesaler that only sold to licensed HVAC businesses. Unfortunately, they didn't tell us that over the telephone, and it was only after driving to their store that we learned that useful information. However, we found another store that carried the item and sold to the public at large.

The capacitor unit is actually two capacitors. When looking at the label, it indicated 5 micro-farads on one line and 35 micro-farads on the line below (the new unit just said 35-5). These are the two numbers needed for finding a replacement. Installation was easy, but I made sure to take photographs of the wiring (which is color coded) and markings for each connection post before taking the old unit out. After vacuuming out the spider webs, I closed everything up and restored power, and adjusted our thermostat so the air conditioning would start. Everything worked fine.

There are three lessons I took away from this experience. First, it is helpful to know people with various skills. Take time to make friends, or at least the acquaintance, of people with useful skills. Second, You Tube is an incredible resource. Third, the conveniences we rely on are just one small failure from not being there.