This is the 14th issue of Electricity News. Thank you for your continuous support and active encouragement.
The new Code of Practice for the Electricity (Wiring) Regulations (CoP) has been published since February 2009, which is the result of the concerted efforts of the EMSD and the trade. In this issue, we will report in a feature article the amendments to the technical requirements in the CoP.
As several electrical incidents happened last year, we will analyse two cases in this issue so that we could understand the causes of the accidents and prevent the recurrence of these incidents. Another feature article will describe the duties of registered electrical contractors (REC) and registered electrical workers (REW) for your reference.
Last but not least, I hope that we would all continue to equip ourselves to enhance the electrical safety and professional standards in Hong Kong!
Electricity News
Leila Tong: Leila
Hello, Leila! You have been quite successful in your career as a singer, television entertainer and film actress in recent years. I believe you must be very busy. What do you do in your leisure time? | |
Since I have a busy job, I like to have a rest at home in my leisure time. Different electrical products at home enable me to live a modern and cozy life. | |
Regarding electrical products, will you replace or purchase any household electrical appliances as summer approaches?? | |
To protect the environment and save energy, I may purchase an electric fan so that I can reduce the use of air-conditioners. | |
Where will you buy your electrical products and how can you ensure the safe use of them?? | |
I will purchase electrical products from reputable suppliers to avoid getting non-compliance items. In addition, I am very concerned about the safety of electrical products. I will use them according to the instructions of product manuals. | |
You can watch for the new television announcement recently made by the Electrical and Mechanical Services Department on the safe use of summer electrical products. As for your home, does it need any renovation due to moving or residential refurbishment?? | |
I have no plan to move, but my friend needs to renovate the entire flat. What should we pay attention to? | |
While renovating their homes, people would normally pay more attention to the flat appearance and overlook the importance of the safety of electrical installations. Pursuant to the law, owners of electrical installations must employ registered electrical contractors to carry out electrical work and should request the contractor to issue a Certificate after work completion to confirm its safety. | |
As we use electricity everyday, the safety of electrical installations is very important. Thank you for reminding me. I will tell my friend to employ a registered electrical contractor to carry out electrical work. | |
Thank you for granting the interview and paying attention to household electrical safety. I wish you every success in your performing career. |
Acknowledgement: L & M Co. Limited
The 2009 edition of the Code of Practice for the Electricity (Wiring) Regulations (CoP) has been published. The soft copy of the CoP can be downloaded free of charge from the home page of Electrical and Mechanical Services Department (EMSD) (www.emsd.gov.hk). The hard copy of the CoP can be purchased from the Publications Sales Unit of the Information Services Department at Room 402, Murray Building, Garden Road, Central, or ordered by calling 2537 1910, by visiting the online Government Bookstore or by e-mail.
There will be a grace period of 2 years. For the implementation of the new CoP, the new requirements apply to electrical installations that are completed and connected to electricity supplies after 31 March 2011, including newly installed and altered to electrical installations.
Since February 2009, EMSD has been organizing seminars and talks with the trade to introduce the revisions to the CoP.
This article outlines the major revisions to the CoP according to the sequence of the codes in the CoP. Starting from the next issue, the Electricity News will give details of some technical revisions.
Revised Parts | Revisions | |
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Code 2 | Interpretation | Add new definitions, including 'basic protection', 'fault protection', 'live work', 'busbar trunking system', 'powertrack system', etc |
Code 4 | General Safety Requirements | Enhance the safety precautions for electrical work, e.g. avoid live work and use proper and adequate personal protective equipment and suitable tools. |
Code 8 | Isolation and Switching | Enhance the guidelines on switching off for mechanical maintenance and emergency switching. |
Code 11 | Earth Leakage and Earth Fault Currents |
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Code 13 | Conductors, Joints and Connections | Add the requirements on the new cable colour code. |
Code 17 | Display of Labels and Notices | Ditto |
Code 18 | Alterations and Additions | Ditto |
Code 21 | Procedures for Inspection, Testing and Certification |
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Code 26A | Domestic Installation and Appliance | Stipulate that in a bathroom, circuits supplying electrical equipment with exposed conductive parts within 2.25m height should be protected by residual current device (RCD). |
Code 26 I | Lightning Protection Installation | Adopt IEC 62305, BS EN 62305, AS/NZS 1768 and NFPA 780 as the new reference standards. |
Code 26K | Temporary Supply Installation for Construction and Demolition Sites or Repair and Testing | Where the electricity supply is obtained from a temporary generator set, the TN-S earthing system should be used. |
Code 26L | Hot Air Saunas Installation |
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Code 26M | Swimming Pools and Fountains Installation |
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Code 26P | Renewable Energy Power System (A New Code) |
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Code 26Q | Temporary Electrical Installation for Exhibitions, Shows, Stands and Festive Lighting (A New Code) | Require the installation of RCD, means of isolation, weather proof equipment etc. |
Appendix 9 | Performance Monitoring Points System for Registered Electrical Workers /Contractors (New Appendix) | Add an introduction to this system. |
Appendix 12 | Worked Examples for Application of the CoP | For the part "Determination of Extraneous Conductive Parts", raise the resistance from 21,000 Ohm to 45,000 Ohm. |
Appendix 13 | Sample of Schedule of Test Results for Electrical Wiring and Checklists |
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Appendix 14 | References |
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Appendix 15 | Safety for Live Work (New Appendix) | Add the conditions and safety precautions for live work. |
Appendix 18 | New Cable Colour Code for Fixed Electrical Installations - Installation Guidelines | Provide technical and safety guidelines on the new cable colour code. |
In this issue, we will look into two electrical incidents. We hope that you can learn from these accidents and prevent them from recurring.
This electrical incident involved renovation work carried out in a shop. The electrical installation at the scene of the incident was equipped with seven distribution boards. Six of them were switched off because of the renovation and the remaining one supplied electricity for the work. At the time of the incident, a worker was demolishing the cables in the false ceiling. The worker tried to cut a cable by a scissor, but the cable was still energized. The worker was killed by electrocution.
1. Renovation work was carried out at the scene of the incident. The site was very untidy and the live cables were not properly labelled;
2. The worker did not check whether the cable was energized before cutting it;
3. The worker was not a registered electrical worker (REW) and was not supervised by any registered electrical worker on site at the time of the accident.
The other electrical incident involved maintenance work carried out in a shopping mall. A REW found that a down light could not be turned on, so he climbed up to the "false ceiling" for inspection. However, when he touched the light fittings, he was suddenly killed by electrocution.
1. The cable of the faulty down light touched the metallic fittings (exposed conductive parts) which was not properly earthed. As a result, the residual current device failed to activate for disconnecting the faulty circuit;
2. The REW did not isolate the power circuit of the down light or check whether the installation was de-energized before conducting the inspection.
In conclusion, if registered electrical contractors (RECs) and REWs have paid attention to the following points, the accidents should have been avoided:
1. Before electrical work is performed, the concerned electrical installations should be isolated from the power source. The metallic parts of the installations should be checked to see if they are energized.
2. Electrical contractors should, prior to the work, liaise with the owners or management companies of buildings to disconnect the power supply of the installations where practicable, so that electrical workers can work on de-energized installations.
3. REWs must ensure that the electrical installations are installed in compliance with the requirements of the Code of Practice for the Electricity (Wiring) Regulations and are inspected, tested and certified before being energized.
4. RECs must employ REWs to perform electrical work.
5. RECs should provide their employees, including REWs, with sufficient training and appropriate personal protective equipment and tools.
According to Code 4 "General Safety Requirements" of the Code of Practice for the Electricity (Wiring) Regulations, electrical equipment should be isolated as far as practicable before any electrical work is performed on the respective electrical installation. REWs should learn from the above accidents and avoid carrying out work on energized installations. They should strictly observe Code 4 I : General Safety Practices of the Code of Practice - check before act, isolate and lockout, de-energize and take other safety measures. If the electrical work involves repairing the consumer's distribution board or switchboard, the registered electrical worker should isolate and lockout the main switch of the switchboard. If live work is unavoidable, REWs should be particularly careful and carry out work in compliance with the requirements and safety precautions in Appendix 15 of the new Code of Practice.
Pursuant to the Electricity Ordinance, electrical work must be carried out by registered electrical contractors (RECs) and registered electrical workers (REWs). Hence, the technical skill standard and conduct of them are very important to the electrical safety of the community. In this connection, we would like to share with you the following guide to good practices for RECs and REWs.
Contractors who undertake or contract to carry out electrical work must be electrical contractors registered with EMSD, regardless of whether they will carry out the work directly or subcontract the work to other persons. In addition, an electrical contractor should check the expiry date of the registration regularly. Renewal applications must be made to EMSD at least 1 month before and no earlier than 4 months before the expiry date.
A REC should pay attention to the following points when contracting to carry out electrical work:
1. Work included and excluded in the contract must be stated clearly in the quotation or contract document.
2. If the customer requests the registration information on the REC, the REC must provide the enquirer with the relevant information such as registration number and expiry date of registration etc.
3. REC must employ REWs to carry out electrical work. If the electrical work is subcontracted, make sure that the subcontractor is also a REC.
4. Before the work commences, he should discuss in detail the arrangement of the work with the customer (e.g. the duration of power suspension, arrangements for temporary electricity supply etc).
5. He should provide the registered electrical workers and other workers with sufficient training, practical guidelines and suitable tools (including personal protective equipment).
A REW should pay attention to the following points when carrying out electrical work:
1. Before the work commences, REW should check the validity of his registration and make sure that he will only carry out the grade and type of work for which he is registered;
2. REW should carry his registration certificate while doing electrical work and should produce the certificate upon the customer's request.
3. REW should carry out the electrical work in accordance with the relevant workmanship and safety requirements stipulated in the Code of Practice for the Electricity (Wiring) Regulations.
4. REW should avoid live work. If live work is unavoidable, he should be particularly careful and carry out the work in compliance with the requirements and safety precautions stated in Appendix 15 of the new Code of Practice.
5. When working with non registered electrical workers, he should supervise the electrical work performed by them on site to ensure the safety of the workers;
6. REW should maintain communication with the customer when the work is underway to let the customer know about the progress of the work.
7. If REW would like to make any alterations to the work, he should explain to the customer in detail and make the alterations after obtaining the customer's consent to avoid possible dispute.
8. After completing the work, REW should inspect, test and issue the Work Completion Certificate (WR1) for the electrical installation before the installation is energized. For periodic inspection and testing of electrical installations, the duly signed Periodic Test Certificate (WR2) should be submitted to EMSD for endorsement within 2 weeks after the completion of the test.
Finally, the REC should return all relevant documents such as certificates, test reports, drawings etc to the installation owner and keep the copies of the relevant records for at least 5 years in accordance with regulation 22 of the Electricity (Wiring) Regulations.
As providers of electrical services, RECs and REWs should meet the expectations of customers (consumers) and ensure the safety of the customers and workers while providing services (i.e. carrying out electrical work). We hope that through the implementation of the above recommendations, the standard of work of RECs and REWs would be enhanced and high quality electrical services could be provided to the public.
The new CCC has been implemented since 1 July 2007. So far, the implementation has been smooth and the new CCC is becoming more widely adopted. The 2-year grace period will end soon. EMSD would like to remind trade members that for electrical work commencing on-site on or after 1 July 2009, only the new CCC, i.e. brown, black, grey (phase), blue (neutral) and green-and-yellow (protective conductor) can be used. The change is applicable to all newly installed fixed electrical installations as well as additions and alterations to fixed electrical installations.
In the old cable colour system, blue and black are used for phase and neutral conductors respectively. However, it is just the opposite in the new colour system - blue and black are used for neutral and phase conductors respectively. In order to ensure electrical safety, electrical workers should avoid carrying out live work. Before commencement of electrical work, electrical workers must use instrument to check whether a cable is live and must not just treat the black cable as dead cable. They should also correctly identify all conductors, i.e. identify whether the conductors are phase or neutral in a single phase installation, or which phase they are in a three-phase installation.
Attention:
EMSD, the Hong Kong and Kowloon Electrical Engineering & Appliances Trade Workers Union and the Hong Kong Electrical Contractors' Association jointly organised a large-scale seminar on electricity regulations at the Jockey Club Auditorium of the Hong Kong Polytechnic University in December 2008. The seminar was well attended by members of the electrical trade and the response was overwhelming.
The theme of this year's seminar was "Construction and Safety". Three engineers of EMSD gave presentations on the revisions to the Code of Practice for the Electricity (Wiring) Regulations, how to carry out electrical work safely, the Building Energy Codes and the energy efficiency labels for electrical products. The participants showed great interest in the seminar and were very attentive to the presentations. To make the seminar more interactive and interesting, quizzes were arranged at the end of each presentation. Participants who gave the correct answers were awarded souvenirs.
EMSD will continue to organise such technical seminars for the trade and have information exchanges with them to ensure electrical safety and enhance the technical standards of the trade.
To help the Mainland manufacturers better understand the Mandatory Energy Efficient Labelling Scheme (EELS) in Hong Kong, EMSD and the AQSIQ organised the "Seminar on Mandatory Energy Efficient Labelling Scheme and Electrical Products (Safety) Regulations" for the trade. The seminar was held on 6 January 2009 in the office of Nanhai Administration for Entry-exit Inspection and Quarantine Bureau of Foshan and was attended by representatives of more than 20 electrical product manufacturers throughout the Pearl River Delta. In the seminar, EMSD explained in detail the requirements of the Energy Efficiency (Labelling of Products) Ordinance and the practical guidelines and technical details of the Code of Practice on Energy Labelling of Products. EMSD also introduced the Voluntary EELS in Hong Kong and encouraged the manufacturers to participate in the scheme. Representatives of the manufacturers raised questions and participated in the discussion with enthusiasm. In response to the representatives' request, EMSD explained the requirements of the Electrical Products (Safety) Regulations that apply to the electrical products supplied in Hong Kong and answered the electrical product manufacturers' queries on the Regulations. In conclusion, the seminar enhanced mutual understanding and communication between Hong Kong and the Mainland in respect of energy efficiency and electrical product safety.
The General Administration of Quality Supervision, Inspection and Quarantine (AQSIQ) and EMSD held the sixth Annual General Meeting on the Cooperation Arrangement on Electrical and Mechanical Products Safety in Hong Kong from 25 to 26 February 2009. Representatives from the bureaux of different locations such as Beijing, Shenzhen, Tianjin, Jiangsu and Zhuhai attended the meeting. The AQSIQ delegation was led by Deputy Director-General, Mr. LIU Shiyuan. Director of Electrical and Mechanical Services, Mr. HO Kwong-wai, led members of the 4 working groups on electrical products, gas appliances, lifts & escalators and energy efficiency to meet with the delegation. They conducted reviews and strengthened mutual cooperation. Through enhancing information exchange, technical exchange and training and product certification, greater and more effective protection on electrical product safety and energy efficiency could be provided to consumers in both Mainland and Hong Kong.
E & M Safety Carnival 2008
The E&M Safety Carnival held on 15 and 16 November 2008 at the Victoria Park in Causeway Bay was one of the highlights of the E&M Safety Campaign 2008. The Carnival included game booths, pop singers' performance, drama and a children's corner with a bouncing castle and games. The Carnival offered a good opportunity for parents and children to have fun while learning about electrical & mechanical safety and saving energy. More than 12,000 people participated in the two-day carnival.
Our former Chief Electrical and Mechanical Engineer of the Electricity Legislation Division, Dr. LEUNG Kin-man, was invited by the Hongkong Electric Company Limited to officiate at the opening ceremony of the Condition Monitoring Centre for Transmission and Distribution on 10 October 2008. The Centre is located on 15/F of the Electric Tower in Ap Lei Chau and is equipped with various condition monitoring devices for transmission and distribution facilities. After the ceremony, the Chief Construction and Maintenance Engineer of the Transmission and Distribution Division introduced the various condition monitoring facilities in the Centre, including optical fibre cable for measuring soil temperature around the underground electricity cables, water tree analysis for XLPE cables, concentration monitoring for abnormal combustible gas of transmission transformer, status of 132kV overhead line surge arresters, signal synchronization of high voltage breakers, partial discharge alarms, endoscope, etc. Some of the condition monitoring devices are controlled by computer system and, in case of abnormalities, the operating division will be immediately notified for emergency inspection and maintenance. The operation and future expansion of the Centre will help to minimize the failures of transmission and distribution facilities and enhance the reliability of power supply.
In order to raise the safety awareness level of electrical workers and to encourage the electrical trade to promote the culture of electrical work safety, EMSD and the trade will jointly organise the "Safe Electrical Worker Competition".
The competition will be opened for applications in the middle of this year. EMSD will send letters to all registered electrical contractors inviting them to nominate their registered electrical workers to join the competition. Details of the competition will also be announced in the EMSD website ( www.emsd.gov.hk). All trade members are welcome to join.
1. |
Which of the following materials can be accepted as earth electrode for electrical installations? |
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2. |
In rising mains installation, which of the following equipment is not suitable for isolating purpose? |
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3. |
For low voltage switchgear having a rating not exceeding 100A, what is the minimum clearance that should be provided behind or by the side of such equipment where access from behind or the side is required for connection and maintenance purposes? |
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4. |
For 5A, 15A or 30A industrial type socket final circuits, the rating of over current protective device should not exceed ________ A. |
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5. |
According to Electricity (Wiring) Regulations, the fixed electrical installations of which of the following type of buildings needs yearly inspection, testing and certification?(i) places for public entertainment(ii) premises for manufacture or storage of dangerous goods (iii) premises with high voltage installation (iv) schools |
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6. |
The date for full implementation of new cable colour code in Hong Kong is: |
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( Answers : 1B, 2C, 3A, 4B, 5A and 6A )
We look forward to receiving your valuable feedback about this newsletter for continuous improvement. Please complete the feedback form below and return it to our Electricity Legislation Division by post, fax or
e-mail on or before 30 May 2009 (please refer to the contact information at the bottom of this page). To show our appreciation, the first 500 respondents will receive a small gift by post.
Electricity Legislation Division, EMSD, 3 Kai Shing Street, Kowloon, Hong Kong
1823
2895 4929