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SYSTEM OF WIRING

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The systems of wiring is also known as the types of wiring in the house/industry installation.

Mainly there are five main systems of wiring which are as following :-

1. Cleat wiring
2. Wooden casing and capping 
3. CTS and TRS wiring or PVC sheathed wiring
4. Lead sheathed / Metal sheathed wiring
5. Conduit wiring

1. CLEAT WIRING:-

• In this system of internal wiring the cables used are either VIR or PVC type.
• The cables are held by porcelain cleats about 6 mm above the walls or ceilings
• The cleats are made in two halves, one base and the other cap. As shown in the fig below

TWO HALVES CLEAT WIRING | LEARN AS TOPPER

• The base is grooved to accommodate the cables and the cap is put over it and whole of it is then screwed on wooden plugs (gutties) previously cemented into the wall and ceiling.

The cleats are of three types:-

1. One groove,
2. Two groove and
3. Three groove

 to accommodate one , two and three

cables respectively.

NOTE:- For long life Cleat should be usually used at intervals of 30 cm and in no case at more than 60 cm.

 ADVANTAGES OF CLEAT WIRING:-

1. It is the cheapest system of internal wiring
2. Its installation and dismantlement is easy and quick
3. Material is recoverable after the dismantlement.
4. Inspection, alternations and additions can be easily made.
5. Skill required is little.

DISADVANTAGES OF CLEAT WIRING:-

1. It is not good looking
2. It is quite temporary and perishes quickly
3. The wires are exposed to mechanical injury.
4. Oil and smoke are injurious to VIR insulation.
5. The insulation catches dampness from the atmosphere and a common salt like substance appears on the insulation which lowers the insulation resistance and causes leakage.
6. Hence this system of wiring cannot be used in damp places unless precautions in an approved manner are adopted to effectively prevent dampness from deteriorating the insulation of conductors.

FIELD OF APPLICATION:-

plastic cleat for wiring 

1. The wiring of this type is very suitable for temporary installations in dry places.
2. This is also used where appearance is not so important and cost is the main consideration
3. The system is not suitable for use in domestic premises

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2.WOODEN CASING AND CAPPING:-

1. In this type of wiring are either VIR or PVC or any other approved insulated cables are used.
2. The casing consist of V-shaped grooves and its covered at the top of means rectangular strips of wood known as capping of same width as that of casing.
3. To protect the casing against white ants first class seasoned teak wood and well varnished is employed.

ADVANTAGES:-

1. Cheap in cost as compared to lead sheathed and conduit wiring system
2. Easy to install and rewire
3. It provides good insulation as conductors are good distance apart.
4. Free from trouble of consideration, so advantageous in tropical countries where there might be trouble from condensation of moisture in steel conduit.
5. Easy to inspect by opening the capping.

DISADVANTAGES:-

1. There is a high risk of fire in casing & capping wiring system.
2. Not suitable in the acidic, alkalies and humidity conditions
3. Costly repairing and need more material.
4. Material can’t be found easily in the contemporary
5. White ants may damage the casing & capping of wood

FIELD OF APPLICATION:-

• This type of wiring is suitable for low voltage domestics  installations in dry places and where there is no risk of fire hazard.

3. CTS or TRS or PVC SHEATHED WIRING:-

1. Single core or double core or three core TRS cables with a circular oval shape cables are used in this kind of wiring.
2. Mostly, single core cables are preferred.
3. TRS cables are chemical proof, water proof, steam proof, but are slightly affected by lubricating oil.
4. The TRS cables are run on well seasoned and straight teak wood batten with at least a thickness of 10mm.
5. The cables are held on the wooden batten by means of tinned brass link clips (buckle clip) already fixed on the batten with brass pins and spaced at an interval of 10cm for horizontal runs and 15cm for vertical runs.

ADVANTAGES:-

1. Wiring installation is simple and easy
2. Cheap as compared to other electrical wiring systems except cleat wiring
3. Paraphrase is good and beautiful
4. Repairing is easy, strong and long-lasting
5. It can withstand the action of most chemicals such as acids and alkalies
6. Within certain limits it is fire proof
7. Less chance of leakage current in batten wiring system.

DISADVANTAGES:-

1. Can’t be install in the humidity, Chemical effects, open and outdoor areas.
2. High risk of fires
3. Not safe from external wear & tear and weather effects (Not recommended for use in open to sun, rain, heat, dust, steam and smoke unless preventive steps are taken).
4. Heavy wires can’t be used in batten wiring system.
5. Only suitable below 250V supply.

FIELD OF APPLICATION:-

1. CONDUCTOR  2. RUBBER INSULATION
3. RUBBER SHEATH   4. BRAIDING

• The TRS wiring is suitable for low voltage installations and is extensively used for lighting purposes everywhere i.e. in domestic, commercial or industrial buildings except workshop where it is liable to mechanical injury. It cannot be used in damp places.
• This type of wiring is suitable in situations where acids and alkalies are likely to be present.

Precautions to be observed

1. The batten used must be of well seasoned and perfectly straight teak wood and thickness 10mm at least.
2. The batten should be well varnished (on all four sides)
3. The wooden gutties or plugs to which batten is to be fixed should be spaced at an interval not exceeding 75 cm.
4. While passing throuh structural steelwork the wooden bushes should be provided in holes and also at the ends of conduit or pipe used while wiring is being passed through walls or ceilings.
5. Fibre clips should not be used in damp situations as these are hygroscopic.

4. LEAD SHEATHED AND METAL SHEATHED WIRING:-

1. The type of wiring employs conductors that are insulated with VIR and covered with an outer sheath of lead aluminum alloy containing about 95% of lead.
2. The metal sheath given protection to cables from mechanical damage, moisture and atmospheric corrosion.
3. The whole lead covering is made electrically continuous and is connected to earth at the point of entry to protect against electrolytic action due to leaking current and to provide safety in case the sheath becomes alive.
4. This system is similar to C.T.S wiring except that the cable used is different in this wiring system.
5. Same as C.T.S wiring system cables are run on wooden batten and are fixed with the help of tinned link clips

lead sheath wiring structure| learnastopper

Advantages

1. Conductors are protected against mechanical injury
2. It is suitable employed under damp situations
3. It gives better appearance
4. It has longer life
5. Conductors are protected against chemicals
6. It can be installed in open space

Disadvantages

1. Cables are costlier than C.T.S OR T.R.S wires
2. In case of leakage ,there is risk of shock skilled labour and proper supervision is
3. required
4. It is not suitable for places where chemical corrosion may occur

Field of application

1. This wiring system is suitable for low voltage (up to 250V) installations. It may be used in places exposed to sun and rain provided no joint is exposed.
2. It may be used in damp placed with a suitable protective covering.
3. This type of wiring is very common in use these days except for some small installations and distribution boards etc.

 5. CONDUIT WIRING:-

There are two additional types of conduit wiring according to pipe installation

1. Surface Conduit Wiring
2. Concealed Conduit Wiring

Surface Conduit Wiring

If conduits installed on roof or wall, It is known as surface conduit wiring. in this wiring method, they make holes on the surface of wall on equal distances and conduit is installed then with the help of rawal plugs.

Concealed Conduit wiring

If the conduits is hidden inside the wall slots with the help of plastering, it is called concealed conduit wiring. In other words, the electrical wiring system inside wall, roof or floor with the help of plastic or metallic piping is called concealed conduit wiring. obliviously, It is the most popular, beautiful, stronger and common electrical wiring system nowadays.

Types of Conduit:-

Following conduits are used in the conduit wiring systems (both concealed and surface conduit wiring) which are shown in the above image.

• Metallic Conduit
• 
  
• Non-metallic conduit

METALLIC CONDUITS TUBES

• Metallic Conduit:

Metallic conduits are made of steel which are very strong but costly as well.

There are two types of metallic conduits.:-

• Class A Conduit: Low gauge conduit (Thin layer steel sheet conduit)
• Class B Conduit: High gauge conduit (Thick sheet of steel conduit)

• Non-metallic Conduit:

1. A solid PVC conduit is used as non-metallic conduit now a days, which is flexible and easy to bend.
2. Conduit wiring system is best for domestic and commercial installations.
3. It provide proper protection to the installation against fire hazards, shock, mechanical damage and dampness.
4. The cable used in this system is either V.I.R or P.V.C insulated and is run in mild steel or P.V.C pipes called conduits.
5. Conduits carrying the insulated wires can be installed on the surface of the walls or concealed in the walls and the ceiling.
6. Modern practice is to conceal the conduit in the plaster of the wall , so that the appearance of the house remains unuffected.

Advantages

1. Conduit provides protection against mechanical injury and fire & is shock proof
2. Conduit provides protection against chemicals
3. The whole system is water proof
4. Conductors are safety secured from moisture
5. This wiring has far better look
6. It has a longer life

Disadvantages

1. It is expensive wiring system (due to PVC and metallic pipes, additional earthing for metallic pipes tee(s) and elbows etc.
2. Very hard to find the defects in the wiring.
3. Installation is not easy and simple.
4. Risk of electric shock (in case of metallic pipes without proper earthing system)
5. Very complicated to manage additional connection in the future.

Field of application

1. Places where considerable dust of puff is present such as textile mills, saw mills, flour mills etc.
2. Damp situations
3. In workshops for lighting and motor wiring
4. Places where there is possibility of fire hazards such as in oil mills, varnish factories, etc.
5. Placed where important documents are kept such as record room
6. Residential and public buildings where the appearance is of prime importance

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