SOPEEC 2B3 Exam Guide: Electrotechnology, Air and Gas Compression, and Refrigeration

2B3 is the electrical and refrigeration paper in Second Class Part B. It mixes theory, machine behaviour, compression equipment, and refrigeration plant, so you need both calculation discipline and system recall.

What this paper covers

Electrotechnology covers AC theory, DC machines, AC machines, transformers, protection of electrical systems, and circuit-protective equipment. The paper expects you to understand waveforms, reactance, power factor, machine operation, tests, cooling, synchronising, protection, and basic fault handling.

Air and gas compression covers the applications of compression, the effects of altitude, temperature, and humidity, reciprocating, axial, centrifugal, and rotary compressors, and the ancillary equipment that supports them, such as valves, coolers, receivers, separators, filters, unloaders, safety valves, instruments, piping layouts, and dryers.

Industrial and commercial refrigeration covers compression and absorption systems, thermoelectric and cascade systems, heat pumps, plant layouts, equipment, operation, charging, purging, leak testing, lubrication, controls, safety, code requirements, and performance calculations.

• Electrical theory, machines, and protection
• Compressors and support equipment
• Refrigeration systems, controls, and performance

Exam format facts

2B3 is 100 multiple-choice questions in 3 hours with a 65% pass mark.

It uses the standard Second Class multiple-choice format, so you should train both recall and time management.

The same permitted references apply, including the jurisdictional Act and Regulations, code extracts, formula and constant handbooks, steam and refrigeration tables, and a non-programmable calculator.

What trips people up

The electrical section asks for more than broad theory. Candidates often know the machine names but miss the details of ratings, tests, protection devices, or the relationship between speed, poles, frequency, and load.

Compression questions are easy to blur together because the equipment families share similar parts. You need to know when a machine is being used, how it is controlled, and what ancillary equipment does for it.

Refrigeration problems often hide the real issue in a cycle diagram, a capacity calculation, or a safety requirement. The wrong answer is often the one that ignores operating conditions or code logic.

• Machine details matter more than labels
• Compression equipment families are easy to mix up
• Refrigeration questions hide in cycles and safety

How to study it

Break the paper into three separate passes, one for electrotechnology, one for compression, and one for refrigeration. That keeps the topic switches cleaner in your head.

Use calculation practice on the electrical side, especially for AC relationships, power factor, and transformer behaviour. Then shift to component recognition for compressors and refrigeration plant.

Finish with mixed timed sets and a few full mocks so you can move between theory, plant equipment, and cycle questions without losing your place.

• Study the three subject blocks separately first
• Do calculation drills on the electrical material
• Use mixed mocks to build paper stamina

How SteamTicket covers it

The 2B bank has 733 questions across 2B1, 2B2, and 2B3, sold as a one-time $99 lifetime-access product.

SMART Quiz keeps weak areas moving back into rotation, and every question includes a step-by-step explanation. That is useful on 2B3 because the paper mixes several technical systems in one sitting.

Try the free 2B sample first. SteamTicket also works offline as a PWA and on iOS, so it is usable on a shift schedule.

• 733 questions across the 2B bank
• Worked explanations and SMART Quiz
• Free sample, offline PWA, and iOS

Common questions