GCAP Industrial Ammonia Refrigeration Training ALL VERSIONS 2025 | LATEST AND ACCURATE REAL EXAM QUESTIONS WITH DETAILED ANSWERS | VERIFIED FOR GUARANTEED PASS | LATEST UPDATE

What is one of the most important aspects that an operator must look for before starting up a compressor? A. Check refrigerant level B. Check discharge pressure C. Check oil levels D. Check ambient temperature Rationale: Proper oil level is critical to lubricate internal components and prevent compressor failure. ________________________________________ Capacity control mechanism of the compressor is actuated by: A. Discharge pressure B. Suction pressure C. Oil pressure D. Ambient temperature Rationale: Suction pressure influences compressor loading/unloading to maintain desired performance. ________________________________________ Typically, reciprocating compressors require a minimum difference in oil pressure of __________ above suction pressure: A. 10–20 PSI B. 30–40 PSI C. 50–60 PSI D. 5 PSI Rationale: This pressure differential ensures sufficient oil flow for lubrication. ________________________________________ High discharge temperatures are good for a compressor, creating a black sooty deposit. True or False? A. True B. False Rationale: High discharge temperatures can damage the compressor and cause carbon buildup. ________________________________________ How are blades forced outwards in a rotary vane compressor? A. Oil pressure B. Gravity C. Centrifugal force D. Suction pressure Rationale: As the rotor spins, centrifugal force pushes blades outward to maintain contact with the casing. ________________________________________ If a small percentage of ammonia enters the oil, what will happen when the pressure on the oil is lowered? A. Boil B. Foam C. Harden D. Crystallize Rationale: Ammonia release from solution causes the oil to foam under reduced pressure. ________________________________________ Are oil and liquid ammonia miscible (able to form a homogeneous solution)? A. Yes B. No, ammonia is heavier than oil C. Only under pressure D. Only when heated Rationale: Ammonia and oil are immiscible; ammonia settles below due to higher density. ________________________________________ If the compressor takes a slug of liquid ammonia and is pounding hydraulically, what should the operator do? A. Increase suction pressure B. Shut it off, and notify management immediately C. Reduce discharge pressure D. Let it run for a few minutes Rationale: Liquid slugging can destroy the compressor and must be stopped immediately. ________________________________________ What is a style of oil cooling or pulling for compressors? A. Heat pump B. Liquid injection, thermosiphon, water/glycol C. Compressor venting D. Suction bypass Rationale: These are standard oil cooling methods to manage compressor oil temperature. ________________________________________ With impingement-style oil separators, what are the steps of separation? A. Gravity only B. Impingement, change of direction, gravity, coalescing filters C. Centrifuge D. Thermal separation Rationale: These steps progressively remove oil from refrigerant discharge. ________________________________________ Two-stage compression is considered to be: A. Two compressors in parallel B. At least two compressors compressing gas in series C. One compressor running longer D. Dual evaporators Rationale: Multi-stage compressors compress vapor in stages for efficiency and capacity control. ________________________________________ Which compressor may have internal safety springs for handling liquid? A. Screw B. Reciprocating C. Scroll D. Centrifugal Rationale: Reciprocating compressors may use internal springs to mitigate minor liquid entry. ________________________________________ Which compressor is commonly started first in a two-stage system? A. Booster B. High-stage compressor C. Evaporator fan D. Oil separator Rationale: Starting the high-stage compressor prevents system over-pressurization. ________________________________________ Rotary vane compressors are typically used in what application in ammonia refrigeration? A. Condenser circuits B. High-stage compression C. Low-stage booster applications D. Oil return systems Rationale: Rotary vane compressors are best suited for low-stage or booster duties. ________________________________________ What is a style of condenser? A. Tube only B. Air-cooled, water-cooled, evaporative-cooled C. Fanless D. Gravity condenser Rationale: These are standard condenser types based on cooling medium. ________________________________________ Before a condenser can convert gas to liquid, the gas must be: A. Subcooled B. Compressed C. De-superheated D. Expanded Rationale: Desuperheating removes excess heat above saturation, enabling condensation. ________________________________________ Evaporative condensers derive heat rejection from: A. Cold ambient air B. Cold water C. Evaporation of water D. Compressor heat Rationale: The latent heat of evaporating water removes heat from refrigerant vapor. ________________________________________ Where do you manually purge a condenser when it is off? A. Bottom of condenser B. Highest point (inlet gas) of the condenser C. Suction line D. Oil separator Rationale: Non-condensables rise, so manual purging is done at the top. ________________________________________ Where should an auto purger be piped from on the condenser? A. Top of condenser B. Discharge line C. Lowest point (drain outlet) of a running condenser D. Suction line Rationale: Auto purgers work best at the outlet where gases accumulate under flow. ________________________________________ Liquid draining from a condenser is 82°F and head pressure is 182 psiG. What does this indicate? A. System undercharged B. Normal conditions C. Presence of non-condensable gases D. Oil in condenser Rationale: Higher-than-expected pressure at a given temperature signals non-condensables. ________________________________________ What is the refrigerant flow direction in a condenser? A. Bottom to top B. Enters at top, exits at bottom C. Horizontal only D. Random Rationale: Top-down flow supports gravity-assisted condensation and drainage.