Oscar Hernandez
Kingsburg
Summary
Hello, my name is Oscar Hernandez. I've been in the manufacturing and service side of the ammonia trade for six years. I've had a fair share of experience within my time in this trade, but I am always up to the challenge of learning and becoming more effective as a tech and resource.
Overview
6
6
years of professional experience
Work History
Ammonia Refrigeration Technician
Ross & Sons Refrigeration & Construction
Fresno
01.2025 - Current
- Replace mechanical seals on screw compressors and viking oil pumps.
- Replace oil filters on screw compressors and spin on filters on reciprocating compressors.
- Replace coalescing filters on screw compressors
- Replace gaskets/o-rings to compressor package or related parts to fix leaks
- Replace or clean oil pump strainers and suction strainers on compressor packages
- Rebuild/replace/clean valve gaskets or seals and their parts
- Replace modulating motors for suction regulators and set their pressure according to needed temperature.
- Replace evaporator fan motors
- Replace evaporator fans
- Replace defrost actuator water valves
- Replace faulty pressure transducers or temperature sensors to related ammonia equipment.
- Replace condenser fan motors, fans, belts, shafts, hubs, and shrouds.
- Mounting guage boards and running their tubing lines.
- Diagnosing ammonia systems to solve high level failures related to floods.
- Diagnosing ammonia systems to solve starved or flooded coils affecting desired temperatures.
- Troubleshooting compressor micro panels for inputs and outputs causing false failures or alarms.
- Cleaning out condenser sumps, eliminators, and sprayers.
- Purging non-condensables through a condenser's service valve on the inlet pipe to lower discharge pressures.
- Testing ammonia detectors and temperature sensors
- Draining oil from mud legs, oil pots, and evaporators.
- Breaking system vaccums on brand new systems to introduce small charge of ammonia for leak testing before commissioning.
- Moving ammonia with hoses to hasten pump out procedure on vessels needing service.
- Changing out float switches and mechanical floats assembelys that cause starving or flooding probelms.
- Talking over the phone to customers to help solve ammonia issues.
- Blowing down equipment pressure to do service work.
- Replacing relief valves
- Cleaning out oil coolers (heat exchangers) providing poor cooling to compressors.
Ammonia Refrigeration Operator
Wawona Frozen Foods
Fresno
04.2019 - 01.2025
- Operating IQF tunnels.
- Operating Cold Storage defrost systems. (DIP Switches or manually)
- Operating chillers and adjusting their pressures to provide less or more cooling.
- Turning on and off ammonia equipent in response to plant demands.
- Electrical troublshooting of the plant process to maintain process flow
- Repairing or maintenancing IQF tunnel integrity.
- Electrical troubleshooting of IQF tunnels to restore included equipment such as fan motors, belt motors, beater motors, belt wash systems, air knife system, etc.
- Diagnosing ammonia control equipemnt such as hansen level probes and their controllers to fix over feeding or under feeding issues.
- Draining oil from ammonia process equipement during shutdown periods to maintain good performance of equipment.
- Monitoring system pressures and temperatures and logging to make trends to help control process quality
- Rebuilding valves to cold storage rooms to restore Refrigeration process.
- Diagnosing the ammonia system using pressures and temperatures and numbers on system computer monitor to solve problems. (Poor evaporator performance, hot gas defrost failing to melt snow of evaporators, recirculators experiencing low levels or high levels, high discharge pressures, etc.)
- Doing compressor servicing (oil filters, coalescers, new oil charge, cleaing oil and suction strainers.
- Communicating with production to slow down or speed up process in relation to refrigeration capacity and or struggling system.
- Maintenance of condenser integrity
- Maintenance of waste water pumps and their electrical controls
- Maintenance of plant drains and their pumps and pump controls.
- Camera installation
- Electrical installation
- Control Panel building for 480V control using 120V or 24V
Education
Operator 1 - Operator 1 Course
Garden City Ammonia Program
Kansas , CA 01.2023 - 01.2023
Operator 2 - Operator 2 Course
Garden City Ammonia Program
Kansas, CA 01.2023 - 01.2023
Skills
- Strong Electrical Installs
- Ammonia system diagnosis
- Basic Electric Troubleshooting
- Building control panels and using VFDs to build advanced process controls
Languages
Spanish
Native/ Bilingual
References
References available upon request.
Timeline
Ammonia Refrigeration Technician
Ross & Sons Refrigeration & Construction
01.2025 - Current
Operator 1 - Operator 1 Course
Garden City Ammonia Program
01.2023 - 01.2023
Operator 2 - Operator 2 Course
Garden City Ammonia Program
01.2023 - 01.2023
Ammonia Refrigeration Operator
Wawona Frozen Foods
04.2019 - 01.2025