Electricity Information

Sub-divided Unit Electrical Safety

Electrical Installations in Residential Units

The electrical installation in a residential unit includes the distribution board, electrical wiring, switches, socket outlets and any electrical appliance that receives power from other than a socket outlet.

The owners of the electrical installation in a residential unit include the landlords, occupiers and tenants of that unit.

Responsibilities of the Owners of Electrical Installations
1. Take appropriate measures (e.g. arranging for proper maintenance and repair) to prevent electrical accidents.
2. Ensure that their electrical installations are free of any illegal addition or alteration.
3. Arrange registered electrical contractors to carry out any electrical work (e.g. addition to, alteration of, inspection, testing and repair of an electrical installation), including those in connection with a renovation work. Registered electrical contractors shall arrange registered electrical workers of appropriate grades to carry out different categories of electrical work.
4. Arrange registered electrical contractors to inspect and test their electrical installations periodically.

Registered Electrical Contractors and Workers
1. Name lists of registered electrical contractors / workers are available for reference at the Registration and Permit Office of the Electrical and Mechanical Services Department (EMSD). The name lists are also available at the website of the Electrical and Mechanical Services Department (EMSD) via the following path: EMSD Website -> Electricity Safety -> Registers.
2. Registered electrical contractors shall display their registration certificates prominently in their places of business.
3. Registered electrical workers hold registration certificates issued by EMSD for identification purpose.

General Tips for Electrical Installations
1. Concealed electrical wiring of new electrical installations must have suitable mechanical protection (e.g. conduits).
2. Electrical wiring must be segregated from telephone / telecommunication wiring. The wiring of these two categories must not be installed inside the same conduit or trucking unless specific safety requirements are complied with.
1. Distribution boards must have identification labels to indicate the purposes of individual circuits.
2. An electrical appliance with high power consumption should receive power supply from a single socket outlet. Therefore, sufficient nos. of socket outlets should be installed.
1. Socket outlets should be installed as far away as practicable from any water tap, gas tap and cooking range.
2. Circuits for socket outlets must be protected by a residual current device (RCD) (also called "earth leakage circuit breaker (ELCB)").

Proper Use and Maintenance of Electrical Installations
1. Arrange for immediate inspection and repair by a registered electrical contractor if the safety of an electrical installation is in doubt (e.g. current leakage or frequent tripping).
2. Avoid touching any socket outlet or switch with wet hands.
3. Each socket outlet should only be inserted with one adaptor or one extension unit to prevent circuit overload.
4. To ensure safety, arrange a registered electrical contractor to inspect and test an electrical installation periodically even though its approved loading does not exceed 100A.
1. When a blackout occurs, major electrical appliances should be switched off to prevent, when power supply is resumed, the occurrence of momentary circuit overload and hence a blackout again.

Household Electrical Products

Safety Tips

Electric Fan

Fitted with a 3-pin plug.
Avoid leaving an operating fan unattended. Switch off power before going out.
Clean the electric fan regularly according to the user manual.
Prevent paper and clothes, etc. from being sucked into the electric fan.
If any abnormalities (e.g. excessive noise or vibration, or abnormal smell) are detected, stop the fan and arrange for repair.

Air-Conditioner

Do not connect other electrical appliances to the same socket outlet.
Turn off the switch when the room is not in use.
Arrange for regular maintenance.
If the power is supplied from a fixed electrical circuit, the connection work must be done by a registered electrical contractor.
If any abnormalities (e.g. excessive noise or vibration, or abnormal smell) are detected, stop the unit and arrange for repair.
Domestic air conditioners using mildly flammable refrigerants (e.g. R32 Refrigerant) 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.

Dehumidifier

Switch off power before leaving home.
Stop using the dehumidifier immediately in case of anomaly, such as overflowing water tank, abnormal sound, smell or any sign of overheating.
Ensure that the air intake and outlet grilles and the humidity sensor are not obstructed, and clean air filter regularly.
Place the dehumidifier on a flat and firm surface to prevent it from collapsing and causing fire.
Do not place the dehumidifier in the bathroom or below the dripping clothes.
Clean the water container regularly to prevent mould or harmful bacteria.
Connect to a fixed independent socket outlet, and avoid plugging other appliances into a single socket outlet or using an extension unit.
Avoid prolonged use to prevent overheating.

Washing Machine

Avoid leaving an operating washing machine unattended.
Do not place a washing machine in a humid environment (e.g. bathroom or outdoor area).
Arrange for regular maintenance.
Do not use inflammable chemical substances (e.g. insecticide) in the vicinity of an operating washing machine.
Remove articles (e.g. coins) from pockets before washing and clean up the drainage filter regularly.

Electric Heater

Do not purchase or use an electric heater fitted with a 2-pin plug.
Do not use electric heater inside a bathroom.
Do not put any combustible materials such as magazines, clothes, etc. near an operating electric heater.
Keep children away from an electric heater.
Stop using an electric heater if there is any abnormal condition such as overheating, oil leakage, etc. and arrange for inspection by an experienced technician.
Switch off and unplug before cleaning.
Adhere to the user manual for use and maintenance.
Check for damage before use.

Electric Water Heater

For new installation of electric water heater, the fixed electrical installations and water pipes shall be installed by a Registered Electrical Contractor (REC) and a designated person^# as required by Water Supplies Department (WSD) respectively.
Switch off the power source of the electric water heater after use.
Arrange for an experienced technician to inspect and maintain the electric water heater regularly.
If there is an abnormality (such as tripping) with the electric water heater while in use, stop using it immediately and contact the supplier for inspection and repair.
Do not install shower head with an on/off control valve on a "shower storage type" electric water heater. Also, do not install an on/off control valve at the water outlet of such water heater or connect the water outlet to a basin or bath tub to prevent explosion of the electric water heater’s water tank due to excessive pressure.

^# For the details of designated person, please visit WSD website.

Induction Cooker

Switch off an induction cooker if its surface is cracked or there is any abnormal condition.
Switch off an induction cooker after use.
Ensure good ventilation for an induction cooker.
Use only a cookware with a flat bottom or curved bottom matched with the induction cooker surface.
Adhere to the user manual for use and maintenance of an induction cooker and arrange regular checks by an experienced technician.
Do not use a steam cleaner to clean an induction cooker.
Do not place metallic objects such as knives, forks, spoons and lids on an induction cooker.
Do not touch the induction cooker surface immediately after cooking.
Do not place a sealed can on an induction cooker.
Do not connect other electrical appliances to the same socket outlet supplying an induction cooker.

Electric Blanket

Check for damage before use.
Do not fold when in use.
Do not use a wetted electric blanket.
Do not use electric blankets for infants and persons incapable of self-care or insensitive to heat.
Do not put weight on an electric blanket.
Switch off and unplug after use.
Store an electric blanket in a dry place.
Adhere to the user manual for use and maintenance.

Publication	Collection
Household Electrical Safety Handbook	Registration and Permit Office, EMSD

Electrical Safety Checklist

In order to prevent electrical accidents or incidents, please check the fixed electrical installations and equipment in your unit / sub-divided unit against this checklist. If you selected ”True” for any of the items, please notify the owner/agent as soon as possible and engage a registered electrical contractor for further inspection and repair.

Item	Description	Result	Reference Photo
1	There is no distribution board in your unit / sub-divided unit.	True/False
2	The distribution board is not installed with a residual current device (RCD). Note: RCD should come with an in-built test button.	True/False
3	The distribution board does not have separate miniature circuit breakers (MCBs) for electric water heater, air-conditioner, socket outlets and lighting system.	True/False
4	There are no identification labels for the main switch and protective devices in the distribution board to indicate the purpose of circuits. Note: Protective devices in the distribution board consist of RCD and MCBs.	True/False
5	There is loosened power switch / socket outlet.	True/False
6	There is exposed conductor in the electrical installation.	True/False
7	The water outlet or shower head of the “shower storage type” electric water heater is installed with an on/off control valve, or its water outlet is connected to a basin, a bath tub or other facilities.	True/False
8	When using the electric water heater or other electrical appliances, you feel slight electric shock and numbness.	True/False	---
9	The protective device of the electrical installation trips frequently.	True/False	---

Attention:

According to the Electricity Ordinance and its subsidiary legislation, electrical work (e.g. installation, modification, inspection, testing and maintenance of fixed electrical installations) shall be carried out by a registered electrical contractor. Registered electrical contractors and registered electrical workers shall carry out electrical work in compliance with the technical and safety requirements of the Code of Practice for the Electricity (Wiring) Regulations. After completion of electrical work and before the installation is energised for use, a Work Completion Certificate (Form WR1) shall be issued.
If you suspect that an electrical installation is dangerous, such as having frequent tripping or current leakage, please notify the owner/agent as soon as possible and arrange a registered electrical contractor to conduct inspection and repair. For information about registered electrical contractors, please visit the website of the Electrical and Mechanical Services Department (EMSD) via the following path: EMSD Website -> Electricity Safety -> Registers -> Registered Electrical Contractors.
When water is being heated in a “shower storage type” electric water heater, water may drip from the shower head due to discharge of water vapour from the electric water heater. If there is any abnormality while using an electric water heater, please stop using it immediately and contact the supplier for inspection and repair.
For safety concerns about electrical installations, please make an enquiry or report to the EMSD via the following methods:
- Tel: 1823 (Hotline)
- Fax: 2895 4929
- Email: info@emsd.gov.hk

Publication	Collection
Electrical Safety Checklist [PDF format (8.18MB)]	Download

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