15  |  Consumer Installation 

What is consumer installation? 

Consumer installation is an electrical system installed on to their premise and distribute electricity to all electrical and apparatus needs. The incoming supply system can either be single phase (240 volts) or three phase (415 volts).  Consumer unit is also known as distribution board some countries name this supply center.

The consumer installation covers the following components:

• Consumer metering (meter unit installed by SESCO)

• Consumer supply (consist of cut out fuse and neutral link. (supplied and installed by SESCO)

• Consumer unit (the electrical distribution to serve all the area needed.)

• Consumer earthing (this the premise owner earthing) 

         Before the consumer supply is been installed on a completed premise building, it shall be check first by local approved electrical contractors. The premise shall be inspected by relevant parties and then tested with various test method to ensure the building is safe to occupy. Lastly the town council shall liaises with developer or owner to ensure all M&E are install according to specifications.

Components inside a consumer unit.

Consumer unit shall be install at height from ground at least 1.8 ~ 2 meter. The best place to install the consumer unit is near meter unit or near entrance of the premise.

The component of consumer unit are:

• Main Isolator   (2 pole or 3 pole )  ratings : 40A, 60A, 100A 

• Residual current device (RCD, single phase with sensitivity rating 100 mili-ampere or 0.1A )

• Residual current circuit breaker (RCCB, three phase with sensitivity rating 300 mili-ampere or 0.3A )

• Miniature circuit breaker (MCB)  ratings : 40A, 60A, 100A 

• Earth terminal (Main Earth Terminal)

• Neutral bar

• Fitting  (metal or plastic enclosure)

Figure consumer supply

Type of circuits  applications

A typical consumer unit consists of the followings types of circuits.

1. Lighting circuit   -  This were all types of lighting fittings, ceiling or wall mounted fans and exhaust fans  is been installed on the premise. Commonly this circuit is protected by a 6A MCB with cable sized 1.5mm.sq at least.

2. Power circuit   - This commonly known as ring circuit which applicable to be installed over a floor sized of 100m.sq according to standard requirement and total number of switch socket outlet about 8 to 10 point. This circuit is protected by a 32A MCB with cable sized 2.5mm.sq at least.

3. Cooker point   -  This circuit  requires only 2 nos. of switch socket outlet installed in kitchen area inside the premise. Commonly this circuit is protected by a 20A or 32A MCB depending on the equipment rating. This is known as radial circuit and the cables must be at least 2.5mm.sq to 6mm.sq sized.

4. Air-conditioner point  -  This circuit is used for air-conditioner unit which is installed in the premise. This circuit is protected by a 16A, 20A or 32A MCB depending on the rating of the equipment.

5. Isolator point - This were special equipment is been installed in the premise with rating of 3kW or greater. A two pole isolator is need to installed near the equipment and circuit is been protected by 20A or 32A MCB depending on the rating of equipment. The cable used for this circuit must be at least 2.5 ~ 6.0 mm.sq or greater size depending on the rating of the equipment.

6. Water Heater (for shower) - This circuit is commonly hot water for shower in bathroom consider a fix apparatus. This circuit is protected by a 20A MCB depending on the rating of the equipment. Cable sized must be at least 2.5mm.sq or higher depending on the rating of the equipment.

Consumer earthing

The consumer earthing also known as 'local earthing' , is a protection against earth fault conditions with in the consumer premise. 

This is important part of protection as final in-case other fault detectors fails to operate to cut out electricity supply.  

For more details refer to earthing system topics.    Click here.