Compressor Operation and Maintenance Flashcards

What is the main value of recording compressor readings on a log sheet at regular intervals?

Answer: It reveals trends that signal developing problems before failure

Comparing readings over time lets operators spot gradual changes such as rising discharge temperature or falling oil pressure.

Routine compressor oil sample analysis is mainly used to detect:

Answer: Wear metals, moisture, and oil breakdown

Lab analysis finds wear particles, water contamination and degraded oil properties that point to internal problems.

A rising pressure drop across a compressor oil filter most likely indicates:

Answer: The filter element is becoming clogged and needs replacement

As the filter traps contaminants its resistance increases, which shows up as a larger pressure difference.

Which tool is commonly used to check compressor-to-motor coupling alignment?

Answer: A dial indicator or laser alignment system

Dial indicators and laser systems measure angular and offset misalignment between the shafts.

Vibration analysis on a compressor is most useful for detecting:

Answer: Bearing wear, misalignment, and imbalance

Changes in vibration amplitude and frequency point to mechanical faults in bearings, couplings and rotating parts.

In a two-stage ammonia system, the low-stage (booster) compressor discharges into:

Answer: The intermediate-pressure intercooler or vessel

The booster raises gas to intermediate pressure, where the intercooler desuperheats it before the high-stage compressor takes it.

Frequent compressor short cycling on and off is harmful mainly because it:

Answer: Causes excessive motor starts, overheating windings and increasing wear

Every start draws high inrush current and puts stress on parts, so frequent cycling shortens motor and compressor life.