Introduction section1: general requirements

Stand-by Generators

The change-over circuit breaker or isolator shall have 4 - Poles for 3 - Phase supply and 2 - Poles for 1 - Phase supply to ensure that the phases and neutral of the two systems remain separate and distinct.

The installation shall ensure that there will be no possibility of paralleling generator supply with DEWA supply under any circumstances or conditions.

The full details of the equipment, circuit and wiring diagrams, details of essential loads, etc. shall be submitted to DEWA for approval before commencement of the works.

Provision for connecting mobile generator for maintaining power supply under mains failure conditions, shall be provided in the MDB/LV panel with incomer rating 2500A/1600A. The circuit breaker must be 4- poles type with adequate mechanical and electrical interlock between the incomer circuit breakers of both mobile generator and DEWA supply.

The location of main Electrical room shall be near to the front entrance/approach road and sleeves are to be provided for intake generator cables. This provision is not mandatory for the main LV panel connected with standby generator in Auto/manual change over Mode.

7. ASSESSMENT OF CONNECTED LOAD AND MAXIMUM DEMAND

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   Lighting and small power circuits
   

All lighting and fan circuits shall generally be installed with maximum load per circuit within 2000 watts. The minimum size of the circuit wires/Earth continuity conductor (ECC) shall be 2.5sq.mm PVC CU with maximum circuit breaker protection 16Amps. A minimum of 100watts shall be considered for each normal lighting & fan point, if light fixtures are not selected at the design stage. Fluorescent lamps may be assessed as 1.8 times the lamp watts.

Wherever fittings with discharge light, compact fluorescent lamps or low volt lamps are installed, the circuit breaker rating, circuit conductor sizes and number of fittings may be suitably selected based on the actual load, including losses, for specific application. Prior approval from DEWA shall be obtained for every installation.

A radial final sub-circuit may be installed to serve a maximum of five 13 Amps, switched socket-outlets in rooms other than Kitchen and controlled by a 20 Amp., circuit breaker in the distribution board. A maximum of ten socket-outlets in rooms other than kitchen may be connected to a ring circuit, controlled by a 30 Amp. circuit breaker.

A current demand of 13 Amps shall be assumed for each 13 Amp. switched socket outlet circuit. A minimum of 200 Watts per point may be considered for each 13 Amps. Switched socket-outlet, installed for general utility purpose, other than kitchen. All twin socket-outlets shall be considered as two separate socket-outlet points, kitchen area may need separate circuits.

A current demand of 15 A shall be assumed for each 15 A switched socket-outlet circuit. However, for general purpose utility socket-outlets, an assumed load of 1000 Watts per socket- outlet installed in commercial and industrial premises and 500 Watts per socket-outlet in residential premises may be permitted.

For stationary appliance and equipment including air-conditioners, the actual load of each appliance and equipment shall be considered as connected load.

For multi consumer installation which include commercial type of premises such as Shops, Showrooms, Garages, Workshops, etc. where provision for connection of additional load may be required, the assumed connected load of each spare/space/circuit shall also be indicated in the load distribution schedules submitted for DEWA's approval.

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