Chilled-water O&M routines

Before a chiller can load:

• water flows proven (CHW and CW if water-cooled),
• valves in correct positions,
• oil heaters/sumps ready where required,
• safeties reset honestly (not permanently bypassed),
• tower basin level and fans available.

Starting against no flow risks freeze or high-pressure events depending on side.

Log leaving and entering water temps, refrigerant pressures/temps as applicable, motor amps, unusual noises, and alarm history. Walk the tower: screens, fans, bleed. Check for oil traces, water leaks, and unusual vibration.

Fouled condenser tubes raise head and kW/ton. Scheduled eddy-current tests and cleaning belong on large plants. Evaporator fouling hurts leaving-water capability.

Keep electrical connections tight, sensors calibrated, water treatment in spec, and filters/strainers on a calendar — not only when the building is already hot.

Spring start-up includes tower fill, leak checks, and control proof tests. Winter layup may include glycol strategies on air-cooled evaporators or tower drain-down. Write the sequence once and reuse it.

For compression machines, track oil levels, color, and any feed/return events. Sudden oil loss means find where it went before the next bearing conversation.

A fifteen-minute walkthrough of normal sounds, normal pressures, and “call the tech if X” beats heroic midnight guesses. O&M is culture, not only filters.

Gaskets, belts, sensors, and fuses on site shorten outages. Exotic boards on backorder should be identified before the heat wave.

HVAC techs and water-treatment vendors share the plant. Read their reports. Rising conductivity or biological counts predict tower and condenser pain before the first high-pressure trip of summer.

### Field memory hooks

Write the key temperatures, flows, or mode checks for this topic on your job notes. Teach the helper beside you to repeat the layered order aloud before tools come out. Most callbacks shrink when the first visit follows a written order instead of a parts guess.

When OEM data exists — capacity tables, wiring diagrams, water-flow charts — photograph the rating plate and the page you used. Future you (or the next tech) should not have to rediscover the same facts under pressure.

Situation. Summer peak, capacity short. Logs show condenser approach climbing for three months while treatment reports were ignored. After tube clean, approach returns near design and high-pressure trips stop.

What to think. O&M data predicted the failure. Cleaning is maintenance, not a miracle repair.

Conclusion. Read the logs; schedule condenser care.

### Teach-back for the helper

Before leaving the topic, have the helper explain in their own words: what is normal, what is measured first, and what must never be skipped for safety. If they cannot teach it back, review the main “How it works” blocks again with a sketch on paper.

Connect this lesson to the previous one and the next one as a chain. Field skill is sequence memory — not isolated trivia. Keep OEM charts and job photos with the work order so the next visit starts smarter.

### Common measurement habits

Use the same meter locations every time so readings compare day to day. Steady the system before judging pressures or temperatures — mid-shift and mid-defrost lie. Write ambient conditions on every note page.

If a reading disagrees with the control display, believe the calibrated handheld until sensors are proven. Controls cannot fix what they cannot see accurately.

### Safety and professionalism

Apply LOTO where energy can hurt you. Wear eye protection around refrigerants, chemicals, and coil fins. On roofs and at window units, respect fall hazards. Explain findings to the owner without jargon soup — clear next steps beat impressive vocabulary.

Dispose of oil, filters, and refrigerant legally. Cutting corners on recovery or tower chemicals is not “saving the customer money”; it is transferring risk.