MALAYSIAN STANDARD -MS 1979:2007

ELECTRICAL INSTALLATION OF BUILDINGS - CODE OF PRACTICE [ COP]

Requirement are as prescribed in the Electricity Supply Act 1990 - ACT 447 and the Electricity Regulations 1994, and parts of Malaysia Practice as in MS IEC 60364.

1. General characteristics of electricity supply
     - COP 01: The public electricity supply has the following characteristics.

                       Voltage: 230 V a.c  for single phase system

                                     400 V a.c for three phase 4-wire system

                                     Variation is +5%  and  -10%

                                      Frequency  50Hz    ±1%

                       Wiring System: TT  - system ( the user has to establish his own earth)

    -COP 04: Protection against direct contact.

                     To protect against direct contact, all live conductors in the wiring system shall be insulated with a dielectric medium such as poly vinyl chloride [PVC] or cross linked poly ethylene [XLPE]. Supplementary measures to protect  against direct contact by the use of barriers  or enclosures and placing live conductors out of reach are encourage.

   - COP 05: Earthing of equipment.

                    All metal enclosures of electrical equipment shall be earthed [connected to a protective conductor]. Also, water and gas pipes, structural metal parts of the building and the ducting of the air conditioning system shall also be connected to the main equipotential bonding. (take note on COP 71)

   - COP 06:Isolation on fault
                    In case of a fault between a live conductor and the metal enclosure of electrical equipment. the fault shall be isolated by a circuit breaker, fuse or residual current device (RCD).
Protection against electric shock requires the fulfillment of the condition,
 

                                 R_A  x I_a ≤ 50 V        where,
                                                                             I_a is the operating current of the protective device

                                                                      (l∆n in the case of RCD) 

                                                                       R_{A  is the resistance of the earth electrode and protective} 

                                                                              _conductor.