Repairing home air conditioners (Failing compressor)

This is a followup to the earlier post about repairing air conditions. This post however is more targeted to an experienced DIY person because we will discuss electronics.

1. Compressor fan starts but dies a couple of seconds later.
2. Compressor fan starts only if you manually help it turn.
3. Compressor outlet pipes not cold.

Please note that there are some air condition units which switch off when the compressor fails as a safety mechanism. So if your air condition unit switches off after a couple of minutes, then check the compressor.

These are the symptoms of a bad 'run capacitor' - a run capacitor helps a single phase motor to start and keep it running but holding electric charge. The run capacitor in an air condition unit is called a Dual Run Capacitor because it supports two electric motors - the fan and the compressor. If the capacitor busts or weakens by time (loses more than 10% of the holding capacity) then you need to change it.

The capacitor looks like this:

The only tricky part when replacing the capacitor is to pay attention to the terminals:

C: common
FAN: fan
HERM: compressor

Also make sure you use the same voltage rating -  440 volt capacitor can be used in place of a 370 volt, but not a 370 in place of a 440 volt. The microfarads must stay the same within 5% of its original value.

Good luck!

Repairing home air conditioners (Leaking Water)

When summer comes in Malta, the temperature can soar to 50 degrees celsius. My main bedroom is just below the roof and to make it worse (not that I complain as I have fantastic green views) the windows overlook the east rising sun. Now consider the case when the air condition fails as it happened this week...The result would be a frustrating hell.

Anyhow, this week with the help of an electrician, my engineering background and some further research, I learned a couple of things on air conditioning units faults and repairs, which can be done by yourselves. In this post I would like to talk about a very common problem - leaking water from the indoor unit due to a blocked drain.

I am not going into much theoretical detail because this post is more directed to the housewife or beginner DIY person. I will just mention that the cool gas from the compressor will produce condensation in the inside unit and the water is drained out from the pipes (by gravity). Now what happens is that by time dirt will block the drain pipes and water will accumulate inside the unit instead of piped out. I mentioned that water is drained by gravity - there is not a pump - therefore congestion is very easy especially if you leave the windows open and let dust inside the air condition.

How to fix - this is very model specific but the idea is to get to the inside of the unit by removing the front cover, normally secured by 3 screws at the bottom of the frame and then locate the water tray (normally on top of the air guide) and disconnect the drain pipe, normally on the left hand side.

Now fill a plastic bottle with hot (not boiling) water and pour it in the drain pipe - of course if it is blocked you should not expect it to drain from the other end but bounce back - so what you need to do is blow inside the pipe (if you have a good breathe, no pun intended) and consequently push the warm water inside the pipes to help the unblocking, or else use a vacuum cleaner to suck out the air and cleaning the pipes in the process.

Good luck!

Happy Birthday Alan Turing

Like Google Doodle, I am dedicating this post to Alan Turing, the father of Computer Science and inventor of the Turing Machine, which most people attribute to the later invention of the computer.

Cold Start XR400

I did a remake of the video explaining better the procedure for those XR400 owners who have trouble cold starting it:

The procedure is as follows:
  1. Set choke to full
  2. Find TDC (Top Dead Center)
  3. Give a good kick
  4. Drop choke to half
  5. Ride and after a couple of minutes turn off choke

Back on the rock

I am back on the rock, all refreshed and smiley and most importantly looking forward to next half of the year!

I got many projects and experiences I want to share in the next couple of months. Until then, I stumbled across a forgotten quote by one of my favorite actors:

Time for a holiday

At the moment I am at the la vallette VIP lounge waiting for the beautiful receptionist to inform me when it's ready to board my plane to Frankfurt.

With a glass of whiskey on one hand and the iPhone on the other, see you in a couple of weeks!