Thanks to your continued support, this issue of Electricity News is now the 29th since its launch. We have much to offer in this issue with the cover girl Ms Cherry Ngan, who pursues a singing career after starring in several films, going over the content of this issue with a feature article on analysis of three recent electrical incidents. As to the news-in-brief column, it covers the Outstanding Registered Electrical Worker Awards Scheme 2017, the supplementary information on the Code of Practice for the Electricity (Wiring) Regulations (2015 Edition), the gentle reminder of the Continuing Professional Development Scheme for Registered Electrical Worker, the requirements for generating facilities under the Electricity Ordinance, the points to note related to the Certificate of Registration of Electrical Worker, the tips on safe use of mildly flammable refrigerant R32, the points to note by competent persons, etc. And what's more, the Electrical Safety Quiz column challenges you to puzzle the answers out, in the hope of adding fun to your reading and enhancing your knowledge about electrical safety.
Members of the electrical trade may be aware that there have been a number of serious electrical incidents in recent years in Hong Kong, resulting in fatalities and injuries (including those involving electrical workers) from suspected electrocution. In view of the increasing trend of incidents involving injuries arising from electric shock, we are going to analyse three of the incidents that took place in 2016 through this feature article with a view to raising trade members' alertness and safety awareness when carrying out electrical work, and preventing electrical accidents from occurring.
Incident 1
The incident occurred at a site where demolition works were being carried out. A demolition worker died after receiving an electric shock during the removal of a wire. An investigation by the Electrical and Mechanical Services Department (EMSD) found that although the earth leakage circuit breaker located at the downstream portion of the circuit concerned had been isolated, the fuse upstream was still connected to power supply, so the circuit was still energised. When the worker was trying to cut the still energised wire manually with a pair of metal scissors and with his hands unprotected, the other exposed parts of his body touched the earthed metal part, resulting in the electric shock incident.
The causes of the incident include:
Incident 2
The incident happened in a switch room where addition and alteration works were being carried out. A registered electrical worker (REW), while checking a newly-installed circuit, touched the exposed live parts accidentally and was electrocuted. He then fainted and was sent to hospital. It was fortunate that a worker at the scene noticed the incident and used a mallet to push the injured worker away from the live parts, otherwise the consequences might have been more serious. An investigation by EMSD found that a circuit control box in the works area, which was still energised, had its cover removed, leading to the exposure of live parts. In carrying out the live work, the worker concerned touched the exposed live parts accidentally, resulting in the electric shock incident.
The causes of the incident include:
Incident 3
The incident occurred in a building where addition and alteration works were being carried out. An REW, while carrying out work at a false ceiling, received an electric shock and passed out. He was sent to hospital and certified dead afterwards. An investigation by EMSD found that there was an exposed live device inside the false ceiling where he was working, and it was therefore suspected that he had come into contact with the exposed live device accidentally while touching the earthed metal part of the false ceiling, resulting in the electric shock incident.
The causes of the incident include:
The causes of the above incidents involve improper work process, live work and improperly installed device. In this regard, here are some suggestions on how to prevent electrical accidents from occurring:
As part of the effort to continuously enhance the professionalism and safety standard of the electrical trade, and to commend the electrical workers with outstanding performance in the trade, EMSD once again collaborated with trade associations to organise the Outstanding Registered Electrical Worker Awards Scheme 2017 to commend the outstanding trade workers. Award recipients will not only receive great prizes, but also have the opportunity to share their daily work experience and insights with other trade members. Registered electrical workers are encouraged to participate actively. For details, please browse the following web page: Outstanding Registered Electrical Worker Awards Scheme 2017
In the last issue of Electricity News, we covered the roles and responsibilities of Responsible Persons and Persons in-charge in the permit-to-work system. In this issue, we will further illustrate with real examples:
Let's say a 300A TPN MCCB inside a switch room requires replacement in an electrical work. According to codes 4G(1)(c) and (e) of the Code of Practice for the Electricity (Wiring) Regulations (Code of Practice), the upstream 800A 4P ACB must first be isolated to ensure that the electrical installation is dead for the work to be carried out safely. In addition, the Responsible Person assigned by the owner of the fixed electrical installation shall issue the permit-to-work and submit the signed copy to the Person-in-charge to ensure that the installation has been rendered dead, isolated, discharged and earthed (if necessary).
Since amendments have been made to Part 1 of the permit-to-work, here we will demonstrate how to fill in the amended version of Part 1.
Please click here for the demonstration
It has been quite some time since the publication of the Code of Practice for the Electricity (Wiring) Regulations (2015 Edition), and you should already be fairly familiar with the content of the new Code of Practice.
According to code 1 of the Code of Practice, electrical installations (including those that are newly installed and altered) completed and connected to electricity supply on or after 30 November 2017 must comply with the new requirements. In view of this, if you are in the process of designing any electrical work with its completion date and the date of connection of the electrical installations to electricity supply estimated to be on or after 30 November 2017, you should now consider designing the work in accordance with the Code of Practice (2015 Edition).
Within the grace period, EMSD will attend the relevant technical seminars at the invitation of the trade unions, associations and organisations to introduce the major amendments of the new Code of Practice. For those who are interested in learning more about the new amendments, please keep an eye on the relevant arrangements and attend the seminars.
The Continuing Professional Development (CPD) Scheme for Registered Electrical Worker (REW) has been included as a requirement for renewal of registration since 1 January 2012. According to the CPD Scheme, REWs applying for each registration renewal are required to have completed two modules of training, including Module (1): Legislative and Safety Requirements and Module (2): Technical Knowledge, before submitting their renewal application.
The CPD Scheme has been widely supported by the trade with spectacular achievements since its launch. Apart from advising you to complete the above two modules of training before applying for each registration renewal, we would also like to take this opportunity to encourage you to refresh your knowledge, from time to time, through the enrolment for seminars or training courses related to electrical works which are organised by EMSD or conducted by recognised trainers in order to enhance the technical know-how of individuals and the electrical engineering industry as a whole.
We will continue to discuss with the related trade organisations to organise more different types of seminars or training courses on up-to-date technical knowledge about electrical works for REWs. For details of the CPD Scheme and the latest information on the relevant seminars and training courses, please visit our web page.
Under section 22 of the Electricity Ordinance, an owner of a generating facility shall (a) maintain the generating facility in continuous safe working order; and (b) display at the facility a notice showing the name and registration number of the registered electrical contractor employed for the purpose of item (a) if the facility:
As such, the owner of the generating facility is reminded to display at the facility a notice showing the name and registration number of the registered electrical contractor who carries out maintenance on the facility.
A registered electrical worker shall take note of the following when carrying out electrical work:
In response to climate change, the world is committed to reducing greenhouse gas emissions and phasing out the use of high Global Warming Potential (GWP) gases. At present, refrigerants that are widely adopted in domestic air conditioners usually have high GWP. Leakage of these refrigerants to the atmosphere will accelerate global warming. So individual manufacturers of domestic air conditioners have opted for lower GWP refrigerants, but some of which may have mild flammability. A notable example of mildly flammable refrigerants is R32.
Domestic air conditioners using mildly flammable refrigerants should be labelled with a "Flammable" symbol for identification. Before purchasing such products, consumers should pay particular attention to the restrictions on use as specified by the manufacturers, such as requirements on minimum room area and minimum installation height, etc. They may check with the agents or suppliers for relevant restrictions. Installation, inspection or maintenance of the products should be carried out in compliance with the specified restrictions by the agents, suppliers or technicians who have experience in mildly flammable refrigerants.
Since electrical trade practitioners may have the opportunity to engage in the installation, inspection or maintenance work of domestic air conditioners, the employer concerned should provide relevant training and equipment to his staff and effectively supervise them to carry out such work with good workmanship and under safe procedures with a view to protecting the work safety of the staff and the safety of others.
Please apply for renewal in time and notify EMSD of any change in the name/address within the specified time limit.
As a competent person engaged in the detection of electricity supply lines, have you ever taken note of the validity period of your certificate of approval? If your certificate is due to expire soon, you should apply for renewal of approval as early as possible.
The Electricity Supply Lines (Protection) Regulation made under the Electricity Ordinance (Cap 406) provides that a competent person applying for renewal of approval shall have had not less than three months' practical experience in locating underground electricity cables within the period of three years immediately preceding the application for renewal, and such application shall be made at least one month before, but not earlier than four months before, the expiry of the current approval. Please note that the renewal application submitted after the expiry date of the certificate of approval will not be accepted and a fresh application is required to be submitted.
The Registration and Permit Office of EMSD
A competent person applying for renewal of approval shall submit an application form CPA1, a certificate of service or employment and three underground electricity cable detection reports.
How to apply:
Moreover, under the Electricity Supply Lines (Protection) Regulation, if there is any change in the name or address of a competent person, a written notice shall be given to EMSD of the changed particulars within 21 days after the change takes place. Those who fail to comply with this requirement commit an offence and are liable to a fine.
Enquiries
For any enquiries, the applicant may contact the Registration and Permit Office of EMSD at G/F, 3 Kai Shing Street, Kowloon, Hong Kong from 9:00 am to 5:15 pm, Mondays to Fridays (closed on Saturdays, Sundays and Public Holidays), or call the 1823 Citizen's Easy Link.
Photo(1): A circuit breaker equipped with lockable function
Photo(2): An MCB added with an auxiliary locking device
A new safety provision has been incorporated into the 2015 Edition of the Code of Practice for the Electricity (Wiring) Regulations (Code of Practice), requiring the use of lockable switches on miniature circuit breakers (MCBs) or moulded case circuit breakers (MCCBs) to ensure that the switches of such devices can be securely kept in "off" mode (see code 9A(3)(d) of the Code of Practice for details). Therefore, if you are procuring MCBs or MCCBs and the completion date of the electrical work concerned and the date of connection of the electrical installations concerned to electricity supply are estimated to be on or after 30 November 2017, you should now consider procuring circuit breakers equipped with lockable function (see Photo(1)) in accordance with the 2015 Edition of the Code of Practice.
As the old models of MCBs or MCCBs may not be equipped with lockable function when they were manufactured, to prevent the occurrence of electrical incidents caused by inadvertent activation of circuit breakers in the course of electrical work, you should, as far as practicable, add an auxiliary locking device (see Photo(2)) to the circuit breakers for your own safety.
Q1 |
Which of the following proposals can prevent the occurrence of electrical incidents? |
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Q2 |
According to the Code of Practice for the Electricity (Wiring) Regulations (2015 Edition), electrical installations (including those that are newly installed and altered) completed and connected to electricity supply on or after which of the following dates must comply with the new requirements? |
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Q3 |
Under section 22 of the Electricity Ordinance, an owner of a generating facility shall: |
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Q4 |
Under which of the following circumstances will a registered electrical worker be prosecuted when carrying out electrical work? |
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Q5 |
Under the Electricity Supply Lines (Protection) Regulation, if there is any change in the name or address of a competent person, what is the time allowed for him to notify EMSD in writing of the changed particulars after the change takes place? |
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(Ans: 1d, 2b, 3d, 4d, 5b)
We look forward to receiving your valuable feedback about this newsletter for continuous improvement. Please complete this feedback and update form and return it to the Electricity Legislation Division of EMSD by post, fax or e-mail (contact details at the bottom of this page) on or before 30 September 2017.
Address : Electricity Legislation Division, EMSD, 3 Kai Shing Street, Kowloon, Hong Kong
Tel : 1823
Fax : 2895 4929
Email : info@emsd.gov.hk