Wires, Wire Splicing and Termination

Transcription

1 Electrical Services Design (EEE 350) Muhammad Asad Rahman Lecturer, Dept. of EEE CUET Muhammad Asad Rahman 1 Wires, Wire Splicing and Termination Muhammad Asad Rahman 2 1

2 Learning Objectives To familiar with the different types of wires To know the method of splicing termination and jointing Muhammad Asad Rahman 3 Wires and Cables A wire is a single slender rod or filament of drawn metal. Wires are used to bear mechanical loads and to carry electricity and telecommunications signals. Muhammad Asad Rahman 4 2

3 Wires and Cables A conductor is a wire suitable for carrying an electric current. A stranded conductor is a conductor composed of a group of wires or of any combination of groups of wires. Muhammad Asad Rahman 5 Wires and Cables A cable is either a stranded conductor (singleconductor cable) or a combination of conductors insulated from one another (multiple-conductor cable). Muhammad Asad Rahman 6 3

4 Wires and Cables The term "cable" is a general one and usually applies only to the larger sizes of conductors. A small cable is more often called a stranded wire or cord (such as that used for an iron or a lamp cord). Cables may be bare or insulated. Insulated cables may be sheathed (covered) with lead, or protective armor. Muhammad Asad Rahman 7 Sizes of Wires Two standard - British Standard Wire Gauge (S.W.G.) - American Wire Gauge (Brown and Sharp s Gauge) Muhammad Asad Rahman 8 4

5 Sizes of Wires British Standard Wire Gauge (S.W.G.) Largest Smallest Muhammad Asad Rahman 9 Sizes of Wires British Standard Wire Gauge (S.W.G.) Muhammad Asad Rahman 10 5

6 Sizes of Wires American Wire Gauge (AWG) Muhammad Asad Rahman 11 Sizes of Wires American Wire Gauge (AWG) Muhammad Asad Rahman 12 6

7 Construction of Cables Insulation impregnated paper, varnished cambric or rubber mineral compound Sheath a metallic sheath of lead or aluminum Bedding a fibrous material like jute or hessian tape Armouring one or two layers of galvanised steel wire or steel tape Serving a fibrous material like jute Muhammad Asad Rahman 13 For Bangladesh Different nomenclatures & Designation N According to VDE standard B According to British standard (B.S. 6004) I According to B.S. 2004:1961 Y Insulation or sheath of thermoplastic based on PVC A Insulated single core cable E Earth continuity conductor Muhammad Asad Rahman 14 7

8 For Bangladesh Different nomenclatures & Designation re Conductor of single solid wire circular cross-section rm Conductor of multiple stranded wires having circular cross-section sm Conductor of multiple stranded wires having sector shaped cross-section having Muhammad Asad Rahman 15 For Bangladesh BYA 7 / 0.85 rm B According to British standard (B.S. 6004) Y PVC Insulation A Nonsheathed single core 7 / 0.85 = No. and nominal diameter of wires rm = Conductor of multiple stranded wires having circular cross-section Muhammad Asad Rahman 16 8

9 Types of Wires Rubber covered, taped, braided and compounded or V.I.R. wires (Vulcanized Indian Rubber insulated cable) A layer of rubber insulation a cotton protective braid (saturated with flame retarding and moisture-resistant compound) finished with wax Muhammad Asad Rahman 17 Types of Wires Lead Alloy Sheathed Wires Recommended for moisture condition. The lead covering is usually thin about 1.25 mm thick. Muhammad Asad Rahman 18 9

10 Types of Wires Tough Rubber Sheathed (T.R.S.) or Cab Tyre Sheathed (C.T.S.) Wires Much cheaper than lead alloy sheathed wires. Muhammad Asad Rahman 19 Types of Wires Weather Proof Wire For outdoor purpose. consists of 3 braids of fibrous yarn. braid are saturated with a water proof compound. Muhammad Asad Rahman 20 10

11 Types of Wires Flexible Wire used for household appliances. Muhammad Asad Rahman 21 Wiring Splicing & Termination Western Union Splice remove insulation only for a required length i.e., 2.5 cm. gently clean with sand paper. for making the joint, cross the two bare wires at ends at a distance of about 2 cm. from insulation of either of the wires. solder the joint using a soldering iron or blow lamp. taping the splice. Muhammad Asad Rahman 22 11

12 Wiring Splicing & Termination Married Joint for wires having a number of strands, married joint is used. Muhammad Asad Rahman 23 Wiring Splicing & Termination Staggering Splices It has double advantages avoids the accidental short circuit between the two cores. does not make the splice bulky. Muhammad Asad Rahman 24 12

13 Wiring Splicing & Termination Rattail Joint required for termination of the wire in switches, holders etc. Muhammad Asad Rahman 25 Wiring Splicing & Termination Fixture / Pigtail Joint Muhammad Asad Rahman 26 13

14 Wiring Splicing & Termination Knotted Tap Joint Muhammad Asad Rahman 27 Muhammad Asad Rahman 28 14

15 Terminal Lugs Muhammad Asad Rahman 29 Terminal Lugs Muhammad Asad Rahman 30 15

16 Terminal Lugs Muhammad Asad Rahman 31 Summary Different types of standard used for wire Various types of wires used in electrical work Wire splicing and termination Muhammad Asad Rahman 32 16

17 The end Muhammad Asad Rahman 33 17