Skip to main content

Installation of electrical conduits, accessories and boxes

Installation of electrical conduits, accessories and boxes :


Normally using three types of conduits.

1. EMT conduits - Electrical metallic tubing

2. PVC conduits - poly vina chloride 

3. Flexible conduits.

What are the equipment and machinery required for installation?

Electric grinder - cutting of support elements

Bending spring - bending pvc pipes

Heat gun - softening pvc pipes before bending

Hack saw - cutting of pvc / EMT pipes

EMT pipe bending machine - bending of EMT pipes

Round file - removing the burr from cuts

Drilling machine - Drilling for anchors

Line dori, marker pen, plump line - marking for conduit route.

Hand tools - hammer, screw driver, spanner set etc.

Concrete hole saw cutter - coring hollowcore slabs

General and procedure for installation :

Size of conduits to be used shall be as per the drawing 

Conduit shall be inspected before installation, and if not smooth inside and outside, free of flows and imperfect of any kind, it shall not be installed. 

Ensure that joiint connections are smooth and such that no damage is caused to cables or conduit system during installation. 

Size of conduits 20mm and 25mm and 32mm.

Conduits must be secured outlet boxes, junction boxes, or cabinets by placing locknuts on outside of box and locknuts and busing in the inside of box. 

Conduit runs must be mechanically and electrically continous, and water tight. 

There will be no welding of conduits or any other conductor raceway to steel structures. 

Run conduits in square, symmetrical lines, parallel to or at right angles to the wall and in accordance with the accepted practices. 

Do not support conduits with wire or perforated pipe straps. 

Cut conduits using hacksaw, de-burr cut ends by hand round file. 

On straight runs, inspection boxes /draw in points must be installed every 10m.

Provide suitable fittings to accommodate expansion and deflection where conduit crosses expansion joints. 

All runs shall be supported at no more than 1200mm. Where directional changes occur support shall be provided at no more than 150mm either side of the bend. 

Only continuous length of buried conduits shall be installed between boxes, no joints boxes being allowed in the floor screed. 

Keep conduits at least 100mm or 150mm from pipes and other non electrical services. 

Whenever metallic tubing are connected to trunking or cable tray, male bushing and necessary access shall be used.

PVC conduits buried in plaster shall have 6mm depth minimum of cover over its entire length. 

PVC conduits buried in screed shall have 20mm depth minimum of cover over its entire length. 

Flexible conduits to equipment shall be terminated in the conduit fitting. The final connection being made with appropriate adoptable flexible connector. 




Labels:

Comments

Post a Comment

Popular posts from this blog

Star Delta starter working principles, control circuit, components, advantages and disadvantages

  Star delta starter working principle theory There are many different starting methods are used to start a three-phase induction motor like Star delta starter. One of them, popular and cheapest is a Direct online starter. But its use limited for smaller HP motor, to start higher rating 3 phase motors star-delta starter is used. Star-delta starter is useful where all six terminals of the motor are accessible.  we will discuss star delta starter working principle with help of power and control diagram, Theory, connection wiring diagram, parts like contactor, mcb, fuses, a timer circuit, overload relay. Star-Delta starter is the simplest starting method for reducing the inrush starting current of Induction motor. The starter can be used with all squirrel-cage induction motors that are delta-connected for normal operation.  The reduction of the high motor current causes a reduction of the starting torque of the motor. Star-delta starting is therefore especially suitable for drives that a
Post a Comment
Read more

How to do Installation and termination of Electrical cables(HV, MV, LV)?

How to do Installation and Termination of Electrical cables(HV, MV, LV) : 1.Material : All wires and cables to be examined prior to installation. No wire or cable with bruised, cut or abraded insulation, or wire that does not pass a continuity test shall be used. 2.Tools and equipment : Truck, crane, cable drum jacks, cable drum shaft, cable socks, cable rollers, cable cutter, hydraulic crimping tools, hand crimping tools, scaffolding with wheels, ladders, torque wrench, box spanner set, ring spanner set, open end spanner set, screw driver, hack saw frame, measuring tape, drilling machines, holesaw cutter, cutting pliers.  3.Preparation : Cables shall be identified with regard to type, size, length etc. And shall be inspected for any physical damage. The cable shall be free from any damages and the ends sealed with caps to prevent the ingress of water during transportation or storage.  4.Installation : All cable shall be megger tested prior to pulling cable.  Prior to commencing the ca
4 comments
Read more

Vaccum circuit breaker construction, working principle, advantages and disadvantages.

  Vacuum Circuit Breaker A breaker which used vacuum as an arc extinction medium is called a vacuum circuit breaker . In this circuit breaker, the fixed and moving contact is enclosed in a permanently sealed vacuum interrupter. The arc is extinct as the contacts are separated in high vacuum. It is mainly used for medium voltage ranging from 11 KV to 33 KV. Vacuum circuit  breaker  has a high insulating medium for arc extinction as compared to the other circuit breaker  .  The pressure inside the vacuum interrupter is approximately 10 -4   torrent and at this pressure, very few molecules are present in the interrupter. The vacuum circuit breaker has mainly two phenomenal properties. High insulating strength: In comparison to various other insulating media used in circuit breaker vacuum is a superior dielectric medium. It is better than all other media except air and SF 6 , which are employed at high pressure. When an arc is opened by moving apart the contacts in a vacuum, an interruptio
Post a Comment
Read more