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Q-01 RSOE · Exam Part II
The FDNY Z-52 RSOE practical exam, explained
The Z-52 is the hands-on half of the NYC refrigeration license. Here is how the simulator exam is laid out, what it asks, and how to get ready for it.
What the Z-52 is
To get the Q-01 Certificate of Qualification for Refrigerating System Operating Engineer (RSOE) in New York City you pass two FDNY exams: the Z-51 written exam and the Z-52 practical exam. The FDNY now also calls them RSOE Exam Part I (Fundamentals) and RSOE Exam Part II (Practical).
The practical is not done on real equipment. According to the FDNY instruction manual it is taken on a computer showing a 3D representation of an actual refrigeration system: one centrifugal system and one reciprocating system. You move through the plant with a navigation bar, use a toolbox and look things up in reference documents, then answer what the exam asks you to do on each machine.
Practice it before exam day. The free trainer runs both systems, a centrifugal and a reciprocating chiller, in your browser, with the same kinds of tasks: operations, repairs, refrigerant handling, troubleshooting, multi-step tasks and scenarios.
Launch the free trainerFormat and time
| Session | Time | What happens |
|---|---|---|
| Walk-through and practice | 45 minutes | A practice run on the simulator. Submitted answers get feedback so you learn the controls. |
| Actual exam | 240 minutes | Both systems, centrifugal and reciprocating. You must finish one system before starting the other, and you cannot go back to a system you have completed. |
Source: FDNY Instruction Manual for the Refrigeration System Operating Engineers Q-01/Q-99 Practical Examination.
The six question categories
Each system's questions fall into six categories. Practice every one of them on both machines.
| Category | What it looks like | Practice it in the trainer |
|---|---|---|
| Operations | Read the machine: pressures, temperatures, levels, flows and what they tell you. | Click any gauge, sight glass or thermometer for its live reading and normal range. |
| Validation of repairs / maintenance | Confirm a repair or maintenance task was done and the system is right. | Fault drills end with returning the machine to service and checking the readings. |
| Refrigerant handling | Recovering, charging and isolating refrigerant safely. | The full RSR recovery procedure on CH-1 and pump-down on CH-3. |
| Troubleshooting / diagnosis | Find the cause from the symptoms. | Hidden faults on both machines: high head pressure, low charge, flow problems and more. |
| Multi-step | One question with up to 6 follow-ups. | Chained practice-exam tasks where each answer leads to the next. |
| Scenarios | One longer situation with up to 16 follow-ups. | Scenario tasks in the practice exam, read aloud if you turn the voice on. |
Categories and follow-up limits from the FDNY instruction manual and notice of examination.
Reference documents you can use
The FDNY instruction manual lists reference material available during the exam, including a Safety Data Sheet (SDS), a Pressure-Temperature (PT) chart, the chiller specification sheet, equipment schedules and the RSR operating procedure diagram. Get used to looking things up fast: converting a pressure to its saturation temperature on the PT chart, finding a normal value on the spec sheet, and following the RSR diagram valve by valve. The trainer has its own versions of these documents open beside the plant.
Scoring, fee and attempts
- Passing score: at least 70%.
- Fee: $225 per attempt, non-refundable (FDNY notice of examination, 2026 revision).
- Attempts: up to 3. After a third failure, or if your Z-52 letter expires, you go back and retake the Z-51.
- Scheduling: by appointment, Monday to Friday, after you pay and submit the Z-52 application.
- Rescheduling: allowed once by email at least 14 calendar days ahead; emergencies need documentation at least 3 days ahead.
- After you pass: you get a temporary Q-99 letter, then pick up your Q-01 card. See the full license steps.
Source: FDNY Notice of Examination, Q-01 Refrigerating System Operating Engineer. Fees and rules change; confirm before you book.
How to prepare
- Learn the layout of both machines. Know where every valve, gauge and sight glass is and what it normally reads. Take the trainer's lesson tour once.
- Know the procedures cold. Startup, shutdown, pump-down and refrigerant recovery in the right order, and why each step matters. Run them in Watch mode, then by hand. All the procedure steps are listed here.
- Practice reading the PT chart. Superheat, subcooling and approach come up again and again.
- Drill troubleshooting. Work from symptoms to cause, then make the repair and prove the machine is back to normal.
- Sit timed practice exams. Do one system, then the other, without going back, the way the real exam runs.
- Read the official FDNY materials. The practical exam instruction manual and the notice of examination take priority over anything here.
Practice it before exam day. The free trainer runs both systems, a centrifugal and a reciprocating chiller, in your browser, with the same kinds of tasks: operations, repairs, refrigerant handling, troubleshooting, multi-step tasks and scenarios.
Launch the free trainerZ-52 questions
What is the FDNY Z-52 exam?
Z-52 is the practical exam for the NYC Q-01 Certificate of Qualification for Refrigerating System Operating Engineer (RSOE). It is taken on a computer that shows a 3D model of a centrifugal and a reciprocating refrigeration system. The FDNY now also calls it RSOE Exam Part II (RSOE Practical).
How long is the Z-52 practical exam?
According to the FDNY instruction manual, it has two sessions: a 45-minute walk-through and practice session with feedback, then the 240-minute actual exam covering both systems.
What score do you need to pass the Z-52?
The FDNY notice of examination lists a passing score of at least 70%.
How many times can you take the Z-52?
The FDNY notice of examination allows up to three attempts, each with its own fee. After a third failure, or if your Z-52 letter expires, you must retake the Z-51 written exam.
What do you get after passing the Z-52?
A temporary Q-99 letter. You then bring the Q-99 letter and the other required documents to FDNY to receive your Q-01 Certificate of Qualification card.
Can I practice the Z-52 online?
The FDNY publishes an instruction manual and points to an online version and a tutorial video. Refrigeration Practical is a separate, free 3D trainer that lets you practice the same kinds of tasks on a centrifugal and a reciprocating chiller plant.