(Acknowledgement : ATV)
Ken reminds you:
In this issue of Electricity News , we would like to convey to you the message from the Director of Electrical and Mechanical Services, Mr. Stephen H C Chan. We have also invited Mr. Ken Chan to be our artist featured in Electricity News to remind us that the new cable colour code has been fully implemented in July this year and the registered electrical contractors / workers should renew their registration certificates on time.
The new Code of Practice for the Electricity (Wiring) Regulations was published in February 2009. We will explain the requirements of the new Code of Practice in detail. In the "News" section, we will give accounts of the electromagnetic fields safety standards for household electrical products and the amendment of the Electricity Supply Regulations . We will also give you an update on the full implementation of the new cable colour code and introduce to you the new certificate of registration of electrical worker which will be issued soon.
In "Snapshots", we will report on the first Registered Electrical Workers Safety Competition, the Annual Technical Seminar for the trade and also the news that our Electricity Legislation Division won awards under the Civil Service Outstanding Service Award Scheme 2009. All in all, this informative issue of Electricity News is something that you should not miss!
Stephen H C Chan
Director of Electrical and Mechanical Services
I am pleased to talk to you for the first time as the Director of Electrical and Mechanical Services. As the regulator of electricity, gas, mechanical and railway safety as well as energy efficiency issues in Hong Kong, the EMSD is responsible for drafting and enforcing the relevant laws to ensure the safety of the public and to promote energy efficiency. On the electrical safety aspect, we are committed to enhancing the work safety of the trade and raising the electrical safety awareness of the public. In recent years, the number of electrical incidents has been at a relatively low level while public awareness of electrical safety has been increasing. These achievements are made possible not only by the efforts of our staff, but also by the cooperation and support of the trade and the community.
I have been with the EMSD for more than 20 years. During my time in the Electricity Legislation Division, I engaged in work relating to the registration of electrical contractors and workers. Over the years, we have been working closely with the electrical trade in enhancing the professional status of the trade and in enforcing the Electricity Ordinance .
Looking forward to the future, the EMSD will continue to enforce the relevant laws, organise public educational activities and assist the trade and citizens to comply with the law in order to ensure public safety and meet the expectations of the community. We will also make every effort to make Hong Kong a safer and more energy efficient metropolis.
Finally, I would like to take this opportunity to wish you all safety at work and every success in the future.
The last issue of Electricity News briefly introduced the major amendments to the Code of Practice for the Electricity (Wiring) Regulations (CoP) . Starting from this issue, we will focus on the details of some amendments so as to enable the readers to grasp the requirements of the latest edition of the CoP more easily.
Code 2 - Interpretation
Code 4 - General Safety Requirements
(d) Electrical equipment should be so selected and erected that its temperature in normal operation and foreseeable temperature rise during a fault cannot cause a fire.
(e) Suitable precautions should be taken where a reduction in voltage, or loss and subsequent restoration of voltage, could cause danger.
(a) A Registered Electrical Contractor (REC) should appoint a responsible Registered Electrical Worker (REW) of appropriate grade to take charge of electrical work to ensure the quality of the electrical installations and safety of the work.
(b) Suitable and adequate personal protective equipment and proper tools should be used in carrying out electrical work. A list of standards for common personal protective equipment and tools for electrical work is given in Appendix 14.
(d) The conditions and safety precautions for live work are stated in Appendix 15.
(v) Electrical installations, including but not limited to those newly installed, maintained, repaired or tripped under fault conditions, should be properly inspected and tested prior to energisation.
The new Appendix 15 "Safety for Live Work" aims at reducing the danger of live work so that accidents can be avoided. The definition of "live work" is added to Code 2. "Live work" means electrical work on or near any live conductor. This is anywhere a worker is exposed to energised conductors, terminals, busbars or contacts. Under the new requirements, restrictions are placed on live work. It can only be performed under the following special circumstances:
Even though the above conditions are satisfied, a series of safety precautions must be taken when performing live work. Apart from setting up screens and fixing warning notices for repair which are mentioned in the previous CoP , attention should also paid to the following:
To sum up, the EMSD does not encourage live work. Please bear in mind the publicity slogan on the cover of the CoP -
For your safety,
switch off electricity
supply before work!
Code 5 - Segregation of Circuit Categories
Code 8 - Isolation and Switching
(b) Suitable means should be provided to prevent electrically powered equipment from becoming unintentionally reactivated during mechanical maintenance, unless the means of switching off is continuously under the control of any person performing such maintenance.
(c) Where electrically powered equipment is within the scope of BS EN 60204 (Safety of machinery - Electrical equipment of machines) , the requirements for switching off for mechanical maintenance of that standard apply.
(a) Means should be provided for emergency switching of any part of an installation where it may be necessary to control the power supply to remove an unexpected danger.
(c) Where electrically powered equipment is within the scope of BS EN 60204 , the requirements for emergency switching of that standard apply.
(c) The means of operation should be capable of latching or being restrained in the "off" or "stop" position, unless both the means of operation for emergency switching and for re-energising are under the control of the same person. The release of an emergency switching device should not re-energise the relevant part of the installation.
The use of appropriate device for emergency switching can prevent accidents.
The above-mentioned amendments are made in response to the frequent enquiries on the requirements of isolation and switching devices for electrical installations, for example, whether it is necessary for a split type air-conditioner to install a device for emergency switching. The new CoP makes reference to the relevant provisions in the latest IEC 60364 and BS 7671 (2008 edition) (i.e. IEE Wiring Regulations - 17th Edition) and provides more specific guidelines on this issue.
Code 11 - Earth Leakage and Earth Fault Currents
* for circuits supplying only fixed equipment within the equipotential zone, disconnection must occur within 0.4 second (the previous requirement was within 5 seconds);
* for circuits supplying fixed equipment outside the equipotential zone, disconnection must occur within 0.2 second (the previous requirement was within 0.4 second).
(For Figure) Apart from the RCDs, there are also some MCBs which can disconnect the supply within 0.2 second.
After considering the necessity of the circuits, for example whether the stopping of the equipment's operation due to tripping may have serious consequences, 4 types of circuits can be exempted from the new requirements. This means they can continue using the previous time for automatic disconnection of supply. These circuits include circuits exceeding 32A, Category 3 circuits, circuits supplying essential equipment which are not readily accessible to the general public, and circuits supplying life-support systems.
Shortening the time for automatic disconnection of supply can further enhance fault protection. According to a study report on the international standard IEC 60479 (Effects of current on human beings and livestock) (2005 edition) , for the 225V contact voltage, the safe time for disconnection of supply is 0.4 second, which means that if the duration of the electric shock does not exceed 0.4 second, it will not cause a fatal incident.
Many people interpret the shortening of the time for automatic disconnection of supply in the new CoP as requiring them to install residual current devices (RCDs). Actually this is not the case. There are other protective devices which can meet the requirement of disconnecting the supply within 0.2 second, e.g. type B and type C miniature circuit breakers (MCBs) which comply with the requirements of IEC 60898 . Please contact the manufacturers for the specifications of these products.
Code 11 - Earth Leakage and Earth Fault Currents
(f) For application of equipotential bonding and earthing in buildings with information technology equipment, reference can be made to BS EN 50310 .
(f) In particular, lightning protection conductors connecting to the main earthing terminal should be properly identified.
The details of the major amendments to the Code of Practice for the Electricity (Wiring) Regulations (CoP) will be continued in the next issue of Electricity News .
The two-year grace period for the new cable colour code ended on 30 June 2009. For electrical installation works (i.e. cable installation works) commencing on-site on or after 1 July 2009, only the new cable colours should be used, i.e. brown
In view of the change in cable colour, the EMSD has recently carried out more on-site inspections to check whether the electrical installations have complied with the technical and safety requirements stipulated in the relevant installation guidelines of the Code of Practice for the Electricity (Wiring) Regulations .
Apart from Hong Kong, Singapore has also implemented the new cable colour code. Since 1 March 2009, Singapore has adopted the same cable colour code that Hong Kong is using. There is also a two-year grace period. The EMSD will continue monitoring the implementation of the new cable colour code in Hong Kong and pay close attention to the latest development in other countries to make sure that the change in the cable colour code can be implemented smoothly.
The new cable colour code adopted by fixed electrical installations
According to the Electrical Products (Safety) Regulation , the suppliers of electrical products should make sure that the household electrical products they supply conform to the relevant safety specifications and have equipped with the Certificate of Compliances to prove that applicable international safety standards or equivalent standards of other countries have been met. Moreover, the design and manufacturing of the household electrical products have to ensure that radiation which may cause danger should not be generated.
The EMSD and the trade have reached a consensus on the time frame for adopting the electromagnetic fields safety standards for household electrical products. The details are shown in the table below:
Product Type | Applicable International Safety Standards | Implementation Time Frame |
---|---|---|
Household Electrical Products | EN 50366 Household and similar electrical appliances - Electromagnetic fields - Methods for evaluation and measurement | Starting from 1 January 2011, the suppliers must supply electrical products that comply with the relevant electromagnetic fields standards. |
IEC 62233 Measurement methods for electromagnetic fields of household appliances and similar apparatus with regard to human exposure |
The draft sample of the new Certificate of Registration of Electrical Worker
The existing Certificate of Registration of Electrical Worker has been in use for many years. To enhance the recognition of the registered electrical workers (REWs) and to facilitate the checking of the REWs' identity by the public, the EMSD is considering issuing a new Certificate of Registration of Electrical Worker in 2010. The new certificate will incorporate the photo of the electrical worker and enhanced security features.
The EMSD will announce the details of the design of the new certificate, the confirmed issue date and the replacement arrangement in due course.
To ensure a safe and reliable electricity supply system in Hong Kong, the Government intends to amend the Electricity Supply Regulations to bring the existing regulations up to the latest international electricity supply standards. A code of practice will also be drawn up to provide the trade with guidelines on how the new statutory requirements can be met. The public consultation on the proposed amendments ended on 31 December 2008. Opinions received indicated general support of the amendment of the existing Electricity Supply Regulations and the drafting of the new regulations is in progress. In addition, a working group has been set up by the EMSD and representatives of relevant academic institutions, professional bodies, power companies, trade organisations and government departments for the drafting of the code of practice.
The 18-month grace period of the mandatory energy efficiency labelling scheme (EELS) will end on 8 November 2009 . After expiry of the grace period, all prescribed products, namely room air conditioners, refrigerating appliances and compact fluorescent lamps, for supply in Hong Kong shall be listed models assigned with reference numbers and bear energy labels. Any person who contravenes the requirements of the Energy Efficiency (Labelling of Products) Ordinance (Cap. 598), by supplying prescribed products which have no energy labels or are not listed models, violates the law and is liable on conviction to a fine of maximum HK$100,000. After the grace period, the EMSD will carry out site inspections to enforce the Ordinance.
The public and the trade can obtain information about the record of listed models assigned with reference numbers and further details about the mandatory EELS at the EMSD webpage. For enquiries, please contact the Energy Efficiency Office of EMSD at 2808 3465.
Damage to electricity supply lines may cause electrical accidents and electricity supply interruptions. The Electricity Supply Lines (Protection) Regulation stipulates that any person carrying out works in the vicinity of underground electricity cables or overhead electricity lines owned by electricity suppliers must take all reasonable steps to ascertain the existence of electricity supply lines before the commencement of works. All reasonable measures must also be taken in the course of works to protect the electricity supply lines from damage.
To increase the trade's safety awareness and knowledge of the requirements of the Regulation and the relevant Code of Practice , we have organised a series of site safety talks and seminars. Our targets include works departments, works contractors, engineering consultants and site workers (including foremen, competent persons, excavator operators and frontline workers etc). We will continue to enhance communication with the trade through safety talks and seminars and join with the trade to reduce incidents of damage to electricity supply lines.
According to the Electricity (Registration) Regulations , registered electrical workers and contractors should submit applications for renewal of certificate of registration to the EMSD at least 1 month before and no earlier than 4 months before the expiry date of the registration. Registered electrical workers and contractors are reminded to submit their renewal applications before the above-mentioned date. Applications submitted after the expiry date of registration will be treated as new registration applications and will be assessed according to the statutory registration requirements prevailing on the date of receipt of the applications. If the applicant fails to meet the prevailing registration requirements, the EMSD may refuse the application regardless of whether the applicant has been registered or not.
In addition, the renewal of registration will be effective from the date of approval. Any electrical worker or contractor who carries out electrical works or does business as an electrical contractor during the period between the expiry date of the last certificate of registration and the effective date of the renewal of registration violates the law and shall be liable on conviction to a fine and to imprisonment for 6 months.
In order to enhance work safety of electrical workers and encourage the trade to actively implement measures which promote work safety, the EMSD and the trade jointly organised the "Registered Electrical Workers Safety Competition 2009".
This competition was well received by the trade. Over 100 registered electrical workers from several dozen registered electrical contractors and property management companies joined the competition. After the First Stage Written Test which was held in late August, 10 participants were selected for the Second Stage Interview. The Adjudication Panel for selecting the winners in the second stage comprises 5 representatives from the trade unions, the trade associations, the institution of engineers, the academia and the EMSD. Following an assessment of the participants' knowledge of electrical work safety, the adjudication panel will select the winners of the Gold, Silver, Bronze and Merit Prizes. The winners will be invited to attend the Annual Technical Seminar to be held in the evening of 27 November to receive the awards.
According to the Electricity (Registration) Regulations, anyone who applies for registration as an electrical worker shall submit to the EMSD the supporting documents which substantiate his electrical engineering qualifications and experience in electrical work. When considering recent applications, we found that there were cases where false supporting documents were used:
After confirming the cases, the EMSD referred them to the police for investigation, and the persons concerned were prosecuted.
To prevent applicants from using false documents to apply for registration, when considering the applications, the EMSD will contact the issuing organisations for verification of these supporting documents. We will also request these organisations to provide more information on the applicant's electrical work experience. If the EMSD finds that an applicant used suspected false documents, it will refer the case to the police for follow-up action and investigation. According to the Crime Ordinance, any person who willfully makes a false declaration (verbal or written) or provides false proof commits an offence and is liable on conviction to a fine and to imprisonment for 12 months.
The Annual Technical Seminar jointly organised by the EMSD, the Hong Kong and Kowloon Electrical Engineering and Appliances Trade Workers Union (the Union) and the Hong Kong Electrical Contractors' Association (the Association) will be held at 7:30 p.m. on 27 November 2009 at the Jockey Club Auditorium of the Hong Kong Polytechnic University. This year's seminar will cover the following topics:
Just like last year, there will be a quiz at the end of each presentation session to encourage greater participation from the attendees of the seminar. Selected attendees who give correct answers to the questions asked by the presenter will receive a useful souvenir given by the Union and the Association. In addition, every attendee who completes and returns the questionnaire after the seminar will receive a solar calculator ruler from the EMSD (see picture).
Admission tickets for this electricity regulations seminar are available at the offices of the Union (Tel: 2626 1927 or 2393 9955) or the Association (Tel: 2572 0843). Interested parties may also fill in the enrolment form attached to this newsletter and return it to the EMSD by fax (Fax no. 2895 4929) or by post (Address: 7/F, the EMSD Headquarters, 3 Kai Shing Street, Kowloon) on or before 20 November 2009. Those who are offered the admission tickets will be notified.
Our Electricity Legislation Division participated in the Civil Service Outstanding Service Award Scheme 2009 and its "Smart Electricity Safety Regulator" Team won the championship and the Special Citations (Cost Effectiveness) Award in the Team Award (Regulatory / Enforcement Service) category.
The Electricity Legislation Division provides public oriented services and works closely with the trade. It aims to enhance the overall electrical safety of our community through promotional and educational activities and assisting the citizens to comply with the law. We partner with the trade and the public and adopt quality management principles to facilitate continuous improvements in our monitoring and enforcement work. In response to the developments and changes in the society, we will proactively identify the potential risks and take precautionary measures in order to reduce effectively electrical incidents and raise our community's quality of life.
Mr. LAI Hon-chung (right), the Chief Engineer of the Electricity Legislation Division, EMSD received the award from Dr. SUN Tai-lun, Vice Chairman of The Hong Kong Management Association.
The winning of the awards by the Electricity Legislation Division reflects public recognition of the work we have done. Greatly encouraged by this, we will continue our efforts to make improvements and to meet the rising expectations of the public.
The EMSD has been publicising the adoption of the new cable colour code to the trade and members of the public.
The Electricity Legislation Division of the EMSD has publicised the new cable colour code to the trade and members of the public through various means since 2005. On 17 June 2009, the EMSD attended a lunch meeting hosted by the Hong Kong Association of Property Management Companies, during which we introduced the implementation of the new cable colour code in Hong Kong. On 24 June and 26 June, we attended meetings of the Committee on Construction Site Safety under the Construction Industry Council and reported on the promotional and educational activities on the new cable colour code. In addition, on 23 June 2009, the EMSD also gave an occupational safety and health talk on "Changing with New Cable Colour Code" for the Occupational Safety and Health Council. During the talk, we explained the impact of the change in the cable colour code on the trade and the safety requirements to be followed during implementation. There were more than 200 participants and the response was very enthusiastic.
1. |
The effective operating current of an overload protective device should not exceed the lowest of the current carrying capacities of any conductors in the circuit it protects by _____ times. |
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2. |
When an earth fault occurs in a circuit which supplies bathroom installations, within how many seconds should the circuit be disconnected? |
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3. |
Which of the following are the functions of a switch-fuse? |
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4. |
What is creepage distance?(i) The shortest distance between two live conductors in the air.(ii) The shortest distance between the surfaces of the insulators of two live conductors. (iii) The longest distance between the surfaces of the insulators of two live conductors. |
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5. |
A competent person responsible for locating electricity underground cables should submit the application for renewal of the Certificate of Approval as a Competent Person _____ month(s) before the existing certificate expires. |
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(Answers: 1B, 2D, 3B, 4B, & 5C)
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 November 2009 (please refer to the contact information at the bottom of this page).
Electricity Legislation Division, EMSD, 3 Kai Shing Street, Kowloon, Hong Kong
1823
2895 4929