HK Grade B Electrical Worker Exam study guide
HK Grade B Electrical Worker Exam · Work through your exam, one topic at a time.
The Grade B Electrical Worker qualification is issued under Hong Kong's electricity legislation and is administered by the Electrical and Mechanical Services Department (EMSD). It is the middle tier of the local electrical worker grades: it permits a registered worker to carry out electrical work of a defined scope on fixed installations, and it is the grade most contractors, property managers and maintenance employers ask for when hiring for installation, alteration, repair and maintenance duties. The HK Grade B Electrical Worker Exam study guide has 9 sections and about 6,350 words.
01Electrical Safety
Electrical Safety is the domain where the paper checks whether you can work on and near live equipment without injuring yourself or anyone else. Questions are practical: the isolation sequence, hazard recognition, your legal duties, and the correct response to an accident.
497 words, about 2 min02Statutory Requirements and Codes of Practice
This domain tests your knowledge of the legal framework that sits behind every Hong Kong fixed electrical installation: who may do the work, what must be certified, and how often. It rewards precise knowledge of the Electricity Ordinance and its subsidiary regulations rather than general awareness of "the regulations".
470 words, about 2 min03Electrical Science and Principles
Electrical Science and Principles underpins every design and fault-finding question in the paper. The exam expects fluent, error-free manipulation of Ohm's law, power relationships, AC impedance and three-phase quantities, plus a working grasp of magnetism, transformers and motors.
428 words, about 2 min04Supply Systems
Supply Systems tests what you know about the electricity you are given before your installation begins: the voltages, the earthing arrangement, the prospective fault current and the limits the supply company imposes. Design answers that ignore the supply characteristics lose marks immediately.
475 words, about 2 min05Earthing and Protective Conductors
Earthing and Protective Conductors is the safety spine of the installation. The exam tests whether you can size circuit protective conductors, main earthing and bonding conductors, and prove that the fault path will operate the protective device within the disconnection time.
457 words, about 2 min06Wiring Systems
Wiring Systems is about choosing and installing the containment and cable route. The exam tests whether you can match the system to the environment, apply the installation rules on support, separation, filling and fire stopping, and recognise where a system must be protected or earthed.
464 words, about 2 min07Cables, Conductors and Installation Methods
Cables, Conductors and Installation Methods tests whether you can select a cable and prove it is safe: correct cross-section for current, acceptable voltage drop, correct identification, and correct termination. Most marks are lost on derating and on the difference between single-phase and three-phase voltage drop.
417 words, about 2 min08Protective Devices
Protective Devices is where the paper tests device selection rather than device names. You must be able to show that the chosen device protects the cable against overload and short circuit, operates within the disconnection time, discriminates from the device upstream, and has an adequate breaking capacity.
456 words, about 2 min09Switchgear and Controlgear
Switchgear and Controlgear tests whether you can specify equipment that switches, isolates and protects safely, and whether you understand the difference between isolation, functional switching and emergency switching. These distinctions account for most of the marks in this domain.
2,686 words, about 13 min