How Will Your Air Conditioning Perform This Summer?

Poor maintenance is a primary reason for many air conditioning breakdowns. This is especially true prior to starting up air conditioning units for the first time in the cooling season and during heavy use in the hotter months. Here are nine maintenance tips for smaller hermetically sealed units that you can use to help avoid costly breakdowns.

1. Crankcase Heater

A critical control for most rooftop and pad-mounted units is the crankcase heater, usually a strap-on heater strip attached to the hermetic motor-compressor unit. At the beginning of the cooling season, before starting a unit, the crankcase heater must be energized. Verify this with a clamp-on ammeter. The crankcase heater should be energized for at least eight hours before running the compressor and should be left energized for the rest of the season.

2. Condenser Coils

These are the outside fins or coils, and they should be cleaned at least twice per year; once before start-up, and once before peak cooling demand (typically in July).

3. Electrical

The motor-compressor starter should be inspected prior to start-up. The contacts are a common cause of problems and should be inspected and replaced on a scheduled basis. At the same time, terminal connections should be checked and tightened.

4. Moisture

Most systems have moisture filters and indicators. Once the compressor is up and running, check the color indicator. If moisture is present have your service technician take appropriate steps to clean, dry and repair the system.

5. Low Charge

If your system has ever needed a refrigerant charge because it was low on refrigerant, it is very likely you'll need a recharge sometime again, unless all leaks were identified and repaired.

6. Check for Leaks

Check for leaks if conditions warrant, not only for operational reasons, but to protect the environment.

7. Evaporators

These are the inside coils/fins. These heat transfer surfaces need to be clean and air flow unobstructed. Change air filters regularly and keep a log to document the work.

8. Electrical Protection

"Line disturbances" are often cited as the cause of air conditioning equipment losses. Improve your level of protection by installing surge protection, a programmable thermostat and phase protection. See the full-text of this article and previous Locomotive articles for more information about electrical protection.

9. Operating Characteristics

Make regular visual checks of equipment. Pay attention to patterns of noise, vibration, speed, temperature and pressure. Any change in normal operating characteristics is a warning. Call a service technician and correct the problem at once.