Wiring System

1. Cleat Wiring

2. Batten Wiring

(a) PVC Batten wiring.

(b) TRS Wiring.

(c) Lead Sheath Wiring.

3. Casing Capping wiring

(a) Wood Casing capping Wiring

(b) PVC Casing Capping Wiring.

Types of Wiring

4. Conduit Wiring

(a) Surface conduit wiring

Metal Conduit Wiring

PVC conduit wiring

(b) Concealed Conduit Wiring

Metal Conduit Wiring.

PVC Conduit wiring

Contd..

Introduction

The types of wiring to be adopted is dependent on various factors, viz, durability, safety, appearance, cost, consumer’s budget etc.

Cleat wiring

This System uses insulated Cables sub protected in porcelain cleats.

CLEAT WIRING

Cleat wiring is recommended only for temporary installations.

The cleats are made in pairs having bottom and top halves. The bottom half is grooved to receive the wire and the top half is for cable grip.

Initially the bottom and top cleats are fixed on the wall loosely according to the layout. Then the cable is drawn, tensioned and the cleats are tightened by the screw.

Cleats are of three types, having one, two or three grooves, so as to receive one, two or three wires.

Two types of cleats.

Cleat Wiring…

Cleat wiring is one of the cheapest wiring considering the initial cost and labor, and is most suitable for temporary wiring.

This wiring can be quickly installed, easily inspected and altered. When not required, this wiring could be dismantled without damage to the cables, cleats and accessories

Cleat Wiring...

Batten Wiring

Tough rubber-Sheathed (T.R.S.) or PVC- Sheathed cables are suitable to run on teak wood battens.

Varnishing of teak wood battenMethod of securing the battensSuitability of tough rubber-sheathed cableSuitability of PVC sheathed cablePaintingBending in wiringPassing through the wallsBuried cable

Batten Wiring

Link Clips

Link clips are used for family clipping the cables in position.

Link clips are of two types.Link clip which has separate linking eye.Joint link clip which has combined linking eye.

Link clip are available in the following size.

25mm, 32mm, 40mm, 50mm, 63mm, 80mm, out of which up to 40mm clips have one hole, while above that they have two holes for fixing.

Fig below shows the joint link clips. These are available in the sizes 16mm, 25mm, 32mm, 40mm, 50mm, 63mm, 80mm with a thickness of 0.32mm and have one hole up to 40mm while above that they have two hole for fixing.

Link clips are made of tin or brass- coated tin or aluminum

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Introduction

This system of wiring is suitable for low voltage installation. In this wiring, cables like vulcanized rubber, insulated cables or plastic insulated cables are use and carried within the wood casing enclosures. The wood casing wiring system shall not be use in damp places and in ill-ventilated places, unless suitable precautions are taken.

Casing –Capping Wiring

Material and pattern of casing

All casing shall be of first class, seasoned teak wood or any other approved hardwood free from knots, shakes, saps or other defects, with all the sides planed to a smooth finish, and all sides well varnished, both inside and out side with pure shellac varnish. The casing shall have a grooved body with a beaded or plain- moulded cover as desired

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Dimensions of casing.

The size of casing and capping to be used for various sizes of 250 volts grade insulated cables in a groove shall be in accordance with those specified in table 1.

Bunching of circuits.Attachment of casing to wall and ceiling.Attachment of capping.Passing over the floors.Joints in casing and capping.

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• Types of Joint• Straight joint.• Tee joint.• Right- angled joint.• Corner joint.• Tee-bridge joint.• Cross- bridge joint.

Specifications

1. Straight Joint

2. Tee Joint

3. Corner Joint

4. Cross Joint

IntroductionA conduit is defined as a tube or channel. Tubular conduit is the most commonly used material in electrical installations. When cables are drawn through the conduit and terminated at the outlet or switch points, the system of wiring is called conduit wiring.

Conduit Wiring

Types of conduits.

There are four types of conduits used for wiring.

1.Rigid steel conduit

2.Rigid non-metallic conduit

3.Flexible steel conduit

4.Flexible non metallic conduit

PVC Fittings and accessories couplers

1.Couplers

2.Elbow

3.Bends

4.Tee

5.Circular boxes

6.Rectangular boxes.

Couplers

L- Bow

Bends

Tees

Circular Boxes

Rectangular Boxes

Junction Boxes

Saddles

B.I.S. RECOMMENDATIONS FOR CLEAT WIRINGGeneral

This system shall not be employed for wiring on damp walls or ceilings unless precautions are adopted for effectively preventing dampness and thus the deterioration of the insulation of the conductors.

Accessibility

Cleat wiring shall be run, as far as practicable, so as to be visible. In positions where they would be liable to mechanical injury and where they are less than 1.5 m above the floor, they shall be adequately protected.

BIS Recommendations

Class of cablesVulcanized rubber insulted cables, PVC and polythene insulted cables, braided or unbraided insulted cables could be used without any further protection.

CleatsAll cleats shall consist of two parts, a base piece and a cap. Cleats shall be fixed at distances not more than 60 cm apart and at regular intervals.Where cleat wiring is laid along an iron joist, porcelain cleats shall be inserted either with varnished wood fillets or varnished wood clamps securely fixed so as to prevent the conductors from coming in contact with the metal along witch they are passing.

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Fixing of cleatsIn ordinary cases, cleats shall be attached to wooden plugs fixed to the walls

Crossing of conductorsWhere cleated conductors cross each other they shall be separated

by an insulating bridging piece, which will rigidly maintain a distance of atleast1.3 cm between the conductors. Where joints are required for connecting bifurcating wires, junction boxes with porcelain connectors inside shall be used.

Protection near the floor No cleat wiring shall be left unprotected up to 1.5 m above the

floor level. When brought through the floor it shall be enclosed in a conduit. (IS 732-1963).

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Code of Practice for Interior WiringNo lighting circuit should contain more than 20

points or 800WattsSwitches must be placed only on live wires.Each circuit should be provided with a separate cut-

out in the distribution board for their live wires.When the total load exceeds 8KVA for lighting only,

3-phase supply is to be taken and load must be distributed over all 3 phases.

The main switch of the service must be within 150mm from meter.

Plug socket should be of 3 pin type with 3rd pin connected to ground.

Power or heating circuit must be drawn separately in AEH installation from main board.

Contd..The switch board must be at 1.5m from ground

level.All lamps or fixtures should have a minimum

clearance of 2.5m from floor level.When load exceeds 5KVA installation must have

earth leakage circuit breaker.Current rating of the fuse must be according to

load.All metallic parts such as iron clad, bodies of

appliances must be earthed.All installation must have a miniature circuit

breaker corresponding to load (if load is less than 5KVA)

Specification of Wiring MaterialCasing & Capping:

Varnished TW case with twin grooves having a cross section of 40mmX12.5mm along with varnished teak wood capping of 4mm thick and 40mm width. Or PVC case and cap of 30mm width and 11mm depth.

Batten for CTS system:TW battens, 15mm thick of appropriate width.

Clips for CTS systemBrass clips of appropriate length and thick.

PVC conduit pipe:Diameter and thickness of pipe.

Contd..Saddle:

Depends on the diameter of pipe.Cable:Lamp Holders

Type – Batten or angle or pendentCurrent range – 5AMaterial – Brass or bakelite

SP SwitchCurrent range – 5A or 15ANo of Ways - single way or two wayMaterial Used – Bakelite or porcelain with

Bakelite coverType – Tumbler type or Flush typeVoltage Grade – 250V

Contd..DP Switch

Current range – 15A, 30A, or 60AType – Flush or Iron cladVoltage grade – 250V

Ceiling RoseCurrent rating – 5AType – Two plate or three plateMaterial – BakeliteVoltage grade – 250V

Wall Plug SocketCurrent range – 5A / 15AType – Flush or TumblerNo.of Pins – 2pin or 3pin 3/2pinMaterial – Porcelain base Bakelite covered or fully

Bakelite Voltage – 250V