Widely used, domestic air-conditioners come in two types: window type and the split type. The split type is divided into two units: the compressor, which is the heart of the air-conditioner and also the noisier part which works outside the room, and the evaporator which works inside the room. The split type is more convenient because the noise of the AC is kept well outside the room. Choosing an AC's tonnage depends on where you instal it & the size of the room. For an average sized living room or office cabin, you would need a 1-ton or 1.5-ton AC. A 1-ton AC can cool approximately 180 sq. ft. If installed in a restaurant of the same proportions, added tonnage is required since the head count and the body heat are greater, increasing the load on the AC. For an office set up, the best choice is an Air Cooled Split Ductable which conveys cool air through ducts into space. This is recycled with some fresh air. If soft water and space for a cooling tower are available, go for water-cooled self-contained units. For rooms with computers and in electronic telephone exchanges, where control of temperature, humidity and air cleanliness are important, close control units of 7.5 tons to 10 tons are recommended. If your AC is exposed to sunlight, insulate. Reduce glass area in a room with an AC, since glass allows a lot of heat inside. Always allow for free circulation of air behind the condenser.

An Electrical Contractor Should Possess A License From The Govt.

Choosing an electrical contractor :

Once you have your job requirements ready, ask for quotations from well-established contractors. Remember, the lowest price is not always the best.
Hire only a contractor who possesses a valid license from the state government.
Check if he has sound technical background. Ask him to show you a list of clients and check back with them to find out his quality of work and his reliability.
Along with him, make a list of all the materials required, and check the quality of materials he will use later on. How to get the best from your contractor ? Keep machinery details and your layout plan ready before estimation to ensure that your estimate and the final billing do not vary by a wide margin. Ensure timely payments as agreed upon for timely completion of your work.

Test For The Insulation Value...

Cables are a mode of transmission of power from the source to the point of distribution or load. There are different types of cables like PVC sheathed, XLPE, rubber insulated, etc. Note the following points while selecting cables:

• Voltage class you require.
• Current required by the load.
• Material of the conductor, i.e aluminium or copper.
• Application Eg: for a chemical industry flame proof cables (FRL's) need to be used.
• Since there are many spurious cables available in the market, always buy cables with the ISI mark.
• Test for the insulation value (Megger test) and core continuity before buying the cable.
• Check the number of cores required.

Buy Gensets Only From An Authorised Dealer

When you buy any type of portable genset, the most important qualities you should look for are fuel efficiency and durability.

Buy a genset according to the total output you require - length of time and amount of power. For instance: to run two 60 watt bulbs, two tubelights (45 watts each), two fans (60 watts each), one TV (60 watts) and one VCR (40 watts), you would need a 650 watts generator. On the other hand if you need to run three fans (180 watts), two bulbs (120 watts), one refrigerator (270 watts), two PCs and a printer (270 watts), and a cooler (360 watts), you would need a 2000 watt generator. Buy only from an authorised dealer and always demand a bill. See that the dealer gives you prompt after sales service.