INTERNAL

HOUSE
WIRING

REGULATIONS
2016
Contents

CHAPTER I ............................................................................................................................................ 1
PRELIMINARY ..................................................................................................................................... 1
Title and Commencement .................................................................................................................... 1
Application .......................................................................................................................................... 1
Transitional provision .......................................................................................................................... 1
Objective ............................................................................................................................................. 1
Amendment ......................................................................................................................................... 1
CHAPTER II........................................................................................................................................... 2
GENERAL REQUIRMENTS FOR ELECTRICAL WIRING .................................................................. 2
Technical Standards, Materials and Workmanship ............................................................................... 2
CHAPTER III ......................................................................................................................................... 2
REQUIREMENTS FOR SAFETY .......................................................................................................... 2
CHAPTER IV ......................................................................................................................................... 3
APPLICATION FOR ELECTRICITY SUPPLY ..................................................................................... 3
CHAPTER V .......................................................................................................................................... 3
PROTECTION ........................................................................................................................................ 3
General Principles ............................................................................................................................... 3
Protection against over current and short circuit ................................................................................... 3
Protection against over voltage and earth faults .................................................................................... 4
Electric Shock Protection ..................................................................................................................... 4
Earthing............................................................................................................................................... 4
Lightning Protection ............................................................................................................................ 5
CHAPTER VI ......................................................................................................................................... 5
INSTALLATION REQUIREMENTS ..................................................................................................... 5
Lighting............................................................................................................................................... 5
Cables ................................................................................................................................................. 5
Switch Board ....................................................................................................................................... 6
Socket Outlets ..................................................................................................................................... 6

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 Conduits and Trunking ........................................................................................................................ 6
CHAPTER VII ........................................................................................................................................ 7
INSPECTION AND TESTING OF INSTALLATION............................................................................. 7
CHAPTER VIII ....................................................................................................................................... 8
FINES AND PENALTY ......................................................................................................................... 8
CHAPTER VIII ....................................................................................................................................... 8
DEFINITIONS ........................................................................................................................................ 8

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 INTERNAL HOUSE WIRING REGULATIONS

In exercise of the power vested by section 87 of the Electricity Act, 2001; in order to provide
for the safe electrical wiring system and electrical installations, the Bhutan Electricity Authority
hereby adopts the Internal House Wiring Regulations as follows:

CHAPTER I
PRELIMINARY
Title and Commencement

1. This Regulation shall:

(1) Be cited as the Internal House Wiring Regulations 2016; and
(2) Come into force with effect from January 2016.

Application

2. This Regulation shall apply to all users of low voltage electricity supply provided or
connected by an electricity supplier including:

(1) The owner of the buildings and public premises;

(2) Person involved in the installation, maintenance or operation of electrical installations;
and
(3) All electrical installations including alterations and modifications to existing
installations which are constructed after commencement of this regulation.

Transitional provision

3. Any owner and users who installed the electrical system before entry into force of this
Regulation shall comply with the provisions within two years from the date of entry of
this Regulation.

Objective

4. The objective of this Regulation is to facilitate the safe installations, operation and
maintenance of internal house wiring to ensure that these do not endanger life, health and
property, whilst fulfilling the intended functions.

Amendment

5. The Regulations may be amended as and when deemed necessary by the Authority.

1Internal House Wiring Regulations 2016

 CHAPTER II
GENERAL REQUIRMENTS FOR ELECTRICAL WIRING

Technical Standards, Materials and Workmanship

6. The electrical wiring shall be consistent with the principles contained in the Bhutan
Building Rules 2002 and amendment thereof.

7. All materials, equipment and installations shall comply with the relevant standards/codes
prescribed by the relevant agency.

8. The materials, equipment and installations shall be in accordance with the instructions
provided by the manufacturer.

9. Only electricians certified by the competent authority shall execute all works involving
internal house wiring, repair or installation of electrical connections.

10. Earthing shall be carried out as per the standards prescribed by relevant agency.

11. Earthing of exposed metallic parts of an installation and appliances, as well as extraneous
metallic parts in a premise shall be carried out for safety reasons, protection system
requirements, and provide a path for electrical discharge.

12. All electrical installations shall be inspected and tested at the time of completion and at
intervals thereafter to ensure ongoing safety, as detailed under Chapter VII of these
Regulations.

13. All parts of an electrical installation shall be sufficiently sized and rated to safely carry
out the function for which they are required.

14. All parts of an electrical installation shall be insulated appropriate to the function they
serve, in consideration of the expected operating environment, so as to prevent danger.

15. Main bus bar connection and wiring shall follow the color coding as per the standard
practice prescribed by the relevant agency.

CHAPTER III
REQUIREMENTS FOR SAFETY

16. The owner and person engaged in electrical installations and maintenance shall ensure the
safety of all general public and property against dangers and damage.

2Internal House Wiring Regulations 2016

17. The owner and person shall ensure that any dangers arising from contacts with live wire
or exposed-conductive-parts of the installation are prevented.

18. The owner and person shall prevent the risk of damage or ignition of flammable materials
due to high temperature, electric arc or mechanical stress during the installations and
operation.

19. The owner and person shall ensure that all parts of electrical installation shall be suitably
located and protected against accidental or deliberate interference, as well as risk of
damage from other services including water supply.

20. The cautionary signs shall be placed on main distribution box and wherever necessary by
the owner and person.

CHAPTER IV
APPLICATION FOR ELECTRICITY SUPPLY

21. The owner and person shall seek approval of the relevant agency on the proposed design
of the installation before commencement of the construction.

22. The owner and person shall provide an estimate of the expected maximum electricity
demand and/or connected load at the premises.

23. The owner and person shall submit application to the electricity supplier for new supply
connections or alteration to an existing supply.

24. The owner and person shall not undertake any extension or alteration to an electrical
installation without prior approval of the relevant agency.

CHAPTER V
PROTECTION

General Principles

25. The owner and person shall design, install and maintain all electrical installation to
provide protection against overload, short circuits and associated electrical hazards.

Protection against over current and short circuit

26. The owner and person shall ensure that:

(1) All electrical installations shall be provided with devices that protect against overload
and short circuits, located at suitable sections and circuits as to give effective isolation

3Internal House Wiring Regulations 2016

 of such conditions; and
(2) The main circuit breaker shall include Miniature Circuit Breaker for protection of the
circuits and Moulded Case Circuit Breaker shall be used for protection of the sub
main and main cables. Miniature Circuit Breaker and Moulded Case Circuit Breaker
shall be enclosed in an enclosure or mounted on such material that is heat resistive
and free from ignition.

Protection against over voltage and earth faults

27. The owner and person shall ensure that:

(1) The installation withstands the overvoltage as and when it occurs;
(2) All exposed metallic parts of an installation is earthed via appropriate earth conductors;
(3) All electrical installations are fitted with an earth leakage circuit breaker, residual
current device, or similar protective device at appropriate points; and
(4) All electrical installations shall be provided with a means of isolating the electricity
supply at suitable sections, subsections and circuits, and at points where appliances
are used.

Electric Shock Protection

Direct Contact

28. The risk of person coming into direct contact with electricity by touching phase or neutral
conductors shall be prevented by one or more of the following ways:
(1) appropriate insulation of conductors;
(2) secure enclosures, barriers or covers on all un-insulated parts including connection
terminals, busbar sections; and
(3) limitation of contact time and current by use of a Residual Current Device.

Indirect Contact

29. The risk of electric shock through indirect contact shall be prevented by ensuring that the
maximum voltage rise on the earthing system is limited to a safe value and that different
parts of the earthing system are maintained at similar voltage levels.

Earthing

30. The neutral and metal parts of all the mains, sub-mains, distribution mains and trunk or
conduit lining including the socket outlets shall be effectively connected to earth
electrode with suitable size wire in accordance with the relevant standard.

31. The earth electrode resistance shall be reduced by appropriate treatment of the soil where
necessary.

4Internal House Wiring Regulations 2016

 32. Proper care shall be taken while choosing the location of the earth electrode so that
excavations for earth electrode may not affect the foundation of the building. Entrances,
pavements and roadways shall be avoided for locating the earth electrode.

Lightning Protection

33. Lightning protection systems and associated earth electrodes shall be kept separate from
main earthing system.

34. Lightning protection systems shall be designed and installed in accordance with the
relevant standards or codes.

CHAPTER VI
INSTALLATION REQUIREMENTS
Lighting

35. All switches provided for local isolation of appliances and equipment shall comply with
relevant Standards and Codes prescribed by relevant agency.

36. For outdoor locations or damp or wet areas, weather protected switches shall be used.

37. The normal mounting height for switches shall be as specified in relevant standards and
codes prescribed by relevant agency.

38. Heat resistant cables between luminaries and connection points shall be used where
necessary.

39. Luminaries and other fittings shall be installed with due consideration to the weight taken
by fixings and supports with adequate ventilation and heat dissipation.

40. Outdoor lighting shall be weatherproof installation with appropriate connection points
and fittings.

Cables

41. All cables shall conform to relevant Standards and Codes prescribed by relevant agency.

42. Poly Vinyl Chloride (PVC) and rubber insulated stranded copper or equivalent conductor
shall be used for internal wiring.

43. The size of cables shall be selected according to the expected load and voltage drop using
relevant standards and codes prescribed by relevant agency.

5Internal House Wiring Regulations 2016

 44. All cables which are not armoured, shall be installed in plastic or metal conduit or trunking.

45. Cables running through inaccessible areas such as walls, floors and ceilings shall be
installed in conduit or trunking so as to be withdrawable in the future. In such a case,
suitable inspection plates and pulling out points shall be provided.

Switch Board

46. Switch boards shall be of robust construction, capable of withstanding expected

electrical, thermal and environmental stresses during normal operation and faults.

47. All switch boards shall be installed in locations easily accessible for inspection, operation
and maintenance. Such locations shall be secured from unauthorized interference,
particularly from children.

48. Switch board shall be placed in dry and ventilated rooms. It shall not be placed in the
vicinity of storage batteries, gas and exposed to chemical fumes. If the switch board is
exposed to harsh or humid weather conditions, the outer casing shall be weather proof
with cable glands and bushing for incoming and outgoing cable.

49. All main switches, sub-main switches and distribution main switches shall be provided
with appropriate enclosure having proper insulation.

Socket Outlets

50. Socket outlets accessible for normal use may be positioned at a height as specified in
standards and codes prescribed by relevant agency.

51. Socket outlets in kitchen/toilet or other areas where water is used shall be positioned as
specified in standards and codes prescribed by relevant agency.

Conduits and Trunking

52. In a conduit system, pipe shall be continuous when passing through walls and floors.

53. If the materials are of the galvanized iron (GI) or steel, the outer surface of the conduit
including all bends, unions, tees, junction boxes forming part of the conduit system shall
be adequately protected against rust when such system is exposed to weather as specified
in standards and codes prescribed by relevant agency.

54. Metal conduits shall not be used as the sole means of providing an Earth. A separate earth
conductors may run inside the conduit.

6Internal House Wiring Regulations 2016

55. Conduits and trunking shall be installed so as to provide ease of access to cable circuits
throughout the route. Sufficient inspection plates and pulling points shall be provided to
enable inspection, repair and drawing out of cables throughout the life of the installation.

56. Separate conduits shall be provided for different network installations.

CHAPTER VII
INSPECTION AND TESTING OF INSTALLATION

57. Every new installation, alteration, extension or modification shall, on completion and
before being energized, be inspected, tested and certified by the electricity supplier.

58. Routine inspection and testing shall be recorded and shall include:

(1) Insulation Resistance Test;

(2) Polarity Test of Switch;
(3) Earth Continuity Test; and
(4) Earth Electrode Resistance Test.

59. The insulation resistance test shall be carried out as per the standards prescribed by the
relevant agency.

60. The polarity test of switch shall be carried out as per the standards prescribed by the
relevant agency.

61. The earth continuity test shall be carried out as per the standards prescribed by the
relevant agency.

62. No earth electrode shall have a resistance greater than the one specified by the electricity
supplier. However, in rocky soils, higher resistance may be allowed. The earth resistance
measurement shall be carried by an approved earth testing apparatus as per the standards
prescribed by the relevant agency.

63. Insulation resistance test and polarity test of switch shall be inspected, tested &certified
at least once in every ten years and for earth continuity test & earth electrode resistance
test, inspection, testing and certification shall be carried out atleast once in every four
years or earlier when requested by the owner or users.

64. The electricity supplier may inspect and enforce provisions of this Regulation or
otherwise, assign a relevant agency for the purpose.

7Internal House Wiring Regulations 2016

 CHAPTER VIII
FINES AND PENALTY

65. Failure to comply with these regulations, or any part thereof, shall result in action in line
with Guidelines for Fines (Punitive and Correctional) of Bhutan Electricity Authority.

CHAPTER VIII

DEFINITIONS

66. In this Regulation, unless the context otherwise requires,

(1) Appliancemeans an item of current using equipment;

(2) Cables means one or more than one insulated conductors, which are laid and
surrounded by armour or protecting cover;

(3) Competent Authority means the capacity of an official body to certify the
electricians;

(4) Circuit breaker means a mechanical switching device capable of breaking or closing
flow of currents under normal circuit conditions;

(5) Earthing or Earthed means a general term used to describe the connection of
metallic parts of an Electrical installation or an Appliance to Earth;

(6) Earth Conductor means the protective conductors used to connect the Exposed
Metallic Parts of an Electrical installation and associated Appliances to Earth, via a Main
Earth Terminal to local Earth Electrodes;

(7) Earth Electrode means a conductor or group of conductors in intimate contact with
Earth, providing an electrical connection to Earth, and normally having a known and
measurable value of Earth Resistance;

(8) Earth Leakage Circuit Breaker (ELCB) means a circuit breaker which is designed
to open the phase and neutral conductors of a circuit upon detection of a leakage of
current (above a specified value) through the Earth Conductor or through Extraneous
Metallic Parts of an installation;

8Internal House Wiring Regulations 2016

(9) Earth Resistance means the resistance (in Ohms) of any point on an installation to
Earth, being measured using an approved testing device and approved procedure;

(10) Electrical installation means an installation that generally comprises any fixed or
temporary cable, switchgear, transformer or other electrical equipment or apparatus within a
Premises or other place where there is an electricity supply (including outdoor locations);

(11) Electricity Supplier means the holder of a Licence for the distribution of electricity
issued by the Authority under the Electricity Act of Bhutan, 2001;

(12) Exposed Metallic Part means a metallic part of an installation or appliance which can
be touched by person and which is not normally live but may become live due to a fault
condition;

(13) Extraneous Metallic Part means a metallic part, structure or any metalwork within
Premises which is not part of the electrical installation and which is not designed to carry
current, but which may become live due to a fault condition. Extraneous Metallic Parts
are required to be connected to Earth using Equipotential Bonding Conductors where
there is significant risk that they may become live due to a fault condition;

(14) Indirect Contact with electricity can occur when a voltage rise appears on the
earthing of an installation due to the passage of earth fault current and whilst a person is
in contact with either:

(1) an Exposed (earthed) Metallic Part of an Appliance;

(2) an Exposed (earthed) Metallic Part of an Installation;
(3) an Extraneous (earthed) Metallic Part in a Premise.

(15) Low Voltage means voltage not exceeding 400 volts between phase to phase for three
phase supply or 230 volts between phase to neutral in case of single phase supply;

(16) Electrician means a person who has been certified by a competent authority to work
on electrical installations in the country;

(17) Network Installations means installations including telephone network, television

network, LAN, security system, etc.

(18) Other fittings means fittings including fans that serve purposes other than lighting.

(19) Outdoor means electrical equipment intended for outdoor application without any
protection but shall withstand damage from external environmental factors.

9Internal House Wiring Regulations 2016

(20) Owner includes the legal owner of a building or property in which an electrical
installation is installed and connected to a supply of electricity;

(21) Person means a certified electrician involved in the installation, maintenance or

operation of electrical installations;

(22) Property means anything that is owned by a person or entity;

(23) Public Premises includes any occupied or un-occupied building or enclosure or other
place where there is an electricity supply. Such locations would include institutions like
school, hospital, army cantonment;

(24) Safe means no significant risk of injury or death to any person, or of damage to any
property, as a result of the use of electrical equipment;

(25) Switchboard means a large single panel, frame or assembly of panels having
switches, over current and other protective devices; and

(26) User means a person(s) or institution making use of the electricity supply for
permanent and temporary structures.

10Internal House Wiring Regulations 2016