JONATHAN F. SALAZAR JR.

3. Troubleshooting

* Error U4/U5: communication error - check wiring F1-F2, loose connection/reverse

* Error E3/E4: high pressure / low pressure - check dirty filter, low freon, blocked EEV

* J3 / J5/ J6 : thermistor error - check sensor,replace if defective

*L4 / L5 : inverter PCB, compressor overload - check PCB, current, heatsink overheat

* Conducted leak checks using 15 psi nitrogen, followed by bubble test and vacuuming to 500 microns

* Charging - weigh R410A based on pipe length

1. Preventive Maintenance (PMS)

* Follow checklist: Monthly / Quarterly / Yearly

* Clean air filter, evaporator coil, condenser coil, blower, drain line

* Check and clean body cover, obstruction around outdoor unit

* unclog drain, check drain pump for abnormal sound

2. Inspection and Monitoring

* Monitored refrigerant pressure within specified ranges: cool 110-140 psi, heat 250-400 psi

*check running amp vs rated amp with clamp meter

*check indoor temp,outdoor temp, airflow

*check rubber pads , bracket, insulation, screw like your note "screw loose, bracket rusty."

4. Completed end-of-day procedures

* Testing of all indoor units repaired

* Prepared and submitted turnover report to supervisor/client detailing completed repairs and issues addressed

3. Troubleshooting and Repair

* Diagnose: compressor won't start,low suction pressure, high discharge pressure,ice build up, not reaching temp

* Replace: compressor, expansion valves, solenoid valves, Danfoss controls, thermostat, defrost timer

* Responded to emergency calls to restore cold storage functionality, preventing product spoilage

1. Installation and Commissioning

* Read engineering drawings, piping layout, electrical diagram

* Install compressor rack, evaporator, condenser, piping, controls

* Pressure test with nitrogen, vacuum to 500 ,microns, charge correct refrigerant by weight

* Start-up and test run - check superheat, subcooling, oil pressure

2. Preventive Maintenance (PMS)

* Check compressor oil level, oil pressure, vibration and noise

* Check condenser coil, evaporator coil, fans, defrost heaters

*Monitored refrigerant pressure, temperature, and superheat to ensure optimal system performance

* Clean condenser, check belt,bearing, electrical terminals

* Monitored temperature in cold rooms to ensure optimal storage conditions.

4. Documentation and Safety

* Fill up service report,pressure readings, parts used

* Follow safety: ammonia leak procedure, lockout/tagout, work at height

* Follow montreal protocol - no venting of CFC/HCFC

3. Troubleshooting ( if there is a problem)

* Ex. costumer complaint "not cooling"

* Check: dirty filter, low freon, leak on flare.

* Do: leak test with bubbles, vacuum, charge freon, brazing if there is a hole

2. Preventive Maintenance (PMS)

* Turn off breaker, open indoor unit

* Clean outdoor condenser. Check for obstruction

* Flush drain line - pour water. check if clogged

* Tighten screws, check bracket for rust

1. Engaged in toolbox meetings to review and reinforce safety protocols and outline daily tasks.

* Inspected tools including manifold gauge, vacuum pump, clamp meter, and brazing set for functionality.

* Inspected assigned units including master bedroom and dining area for maintenance needs.

4. Documentation

* Fill up form: date, unit model, pressure, temperature,amp, work done.

* Write remarks: "drain line clogged-flushed"/"screw loose - tightened"

* Take photos before and after cleaning

2. Conducted inspections to monitor equipment performance and safety, identifying and addressing potential issues to maintain operational integrity.

* Check the refrigerant pressure

* Check running amp vs rated amp with clamp meter

* Check rubber pads, bracket, insulations, screws like your note "screw loose, bracket rusty"

* Check electrical connections, retighten if loose.

1. Executed preventive maintenance on heating and cooling systems, ensuring optimal performance and reliability.

* Follow checklist: Monthly / Quarterly / Yearly

* Check and clean body cover, obstruction around outdoor unit.

* Unclog drain, check drain pump for abnormal sound.

* Clean air filter, evaporator coil, condenser coil, blower, drain line.