Industrial Resources, Inc Cable and Wire Termination
I&E MaintenanceIRI-IE-05-EMD
CABLE WIRE & TERMINATIONS
IRI-IE-05MD
EQUIPMENT MAINTENANCE DESCRIPTION
INDUSTRIAL RESOURCES, INC.
A TRAINING SERVICES COMPANY
©This document is the property of Industrial Resources, Inc. Copies and distribution of this document is prohibited unless written authorization is granted by Industrial Resources, Inc.
PREFACE
This Training Equipment Maintenance Description (EMD) has been designed to assist you in meeting the requirements of the I&E Maintenance Training Program. It contains information about the Cable Wire and Terminations. This includes function, quantity of parts, location of parts, description of the physical construction of the part, and description of the operation of the part, equipment preventive and corrective maintenance, and references.
You should review each chapter objective. In doing so you will be better prepared to learn the required information. You should also inspect the equipment, identifying its components and controls. Should you have additional question about the equipment, ask your supervisor.
A separate document, Cable Wire and Terminations Equipment Maintenance Procedure IRI-IE-05-EMP, covers detailed maintenance of the Cable Wire and Terminations Equipment.
CABLE WIRE AND TERMINATIONS
IRI-IE-05-EMD
TRAINING EQUIPMENT MAINTENANCE DESCRIPTION
TABLE OF CONTENTS
1.0Introduction
1.1Equipment Function
1.2Equipment Description
1.2.1Cable and Conductor Classification
1.2.2Cable and Conductor Ratings
1.2.4Cable and Conductor Splices
1.2.3Cable and Conductor Terminations
1.3Equipment Connections and Interface
2.0Equipment Major Parts
2.1Cable Termination Equipment
2.2Preparing the Cable for Termination
2.3Attaching the Cable Lug
2.4Cleaning the Cable
2.5Applying Stress Relief Material to the Cable
2.6Positioning and Shrinking the Stress Relief Tube on the Cable
2.7Grounding the Cable Shield
2.8Applying Sealant to the Cable
2.9Placing and Shrinking the HV Tube on the Cable
2.10Completing Outdoor Termination of the Cable
3.0Equipment Preventive and Corrective Maintenance
3.1Cable Termination Preventive Maintenance
3.2Cable Termination Corrective Maintenance
List of Figures:
Figure 1 – Conductors
Figure 2 – Solid Conductor
Figure 3 – Stranded Conductor
Figure 4 – Insulated Conductor
Figure 5 – Insulated Conductor with Jacket and Sheath
Figure 6 – Thermal Lug
Figure 7 – Cable and Wire Connectors
Figure 8 – Ring and Spade Terminals
Figure 9 – Typical Wire and Cable Terminators
Figure 10 – Cable and Wire Stripper
Figure 11 – Determining the Required Amount of Insulation Cutback
Figure 12 – Wire Crimper
Figure 13 – Determining the Required Amount of Jacket Cutback
Figure 14 – Insulation Cutback for Cable Shielded with Copper Tape
Figure 15 – Installing Ground Braid on Cable Shielded with Copper Tape
Figure 16 – Insulation Cutback for Cable Shielded with Wire
Figure 17 – Installing the Lug on Wire Shielded Cable
Figure 18 – Insulation Cutback for Cable with UniShield
Figure 19 – Installing Lug for Cable with UniShield
Figure 20 – Insulation Cutback for Cable with Lead Sheath
Figure 21 – Soldering the Ground Braid for Cable With Lead Sheath
Figure 22 – Positioning the Ground Braid for Cable with Lead Sheath
Figure 23 – Applying Red Sealant to Lug Barrel
Figure 24 – Installing the Shim Tube
Figure 25 – Abrading and Cleaning the Cable
Figure 26 – Applying Stress Relief Material to Cable
Figure 27 – Positioning and Shrinking Stress Relief Tube
Figure 28 – Preparing to Ground Cable with Copper Tape or Lead Sheath
Figure 29 – Applying Red Sealant to Cable
Figure 30 – Applying More Red Sealant to Cable
Figure 31 – Preparing to Ground Wire Shield or UniShield
Figure 32 – Cleaning the Jacket for Wire Shield or UniShield
Figure 33 – Continue Wrapping Red Sealant for Wire Shield or UniShield
Figure 34 – Applying Sealant to Cable at Lug
Figure 35 – Applying Sealant to Cable with No Lug
Figure 36 – Placing and Shrinking HV Tube on Cable
Figure 37 – Trimming the HV Tube on Cable
Figure 38 – Positioning Skirt on Cable
Figure 39 – Positioning Skirt for Top Feed Termination
Figure 40 – Adding Extra Skirts on Cable
Figure 41 – Adding Extra Skirts for Top Feed Termination
Tables:
Table 1 – AWG Copper Wire
Table 2 –Ring Terminal Sizes
Table 3 - Cable Termination Kits
References:
Raychem HVT Series Terminations 5-35kV Class
PowerStream Wire Gage and Power Limits
AWG Cable Description – American Wire Gage
Facilities Instruction, Standards, and Techniques Volume 3-3 – “Electrical Connections for Power Circuits” – Facilities Engineering Branch Denver Office Denver, Colorado
1.0Introduction
Chapter Objectives:
1.State, from memory, the functions of the Cable and Wire Termination equipment.
- Draw a simplified arrangement of the Cable and Wire Termination equipment.
- Describe how the Cable and Wire Termination equipment is operated and maintained.
- List the normal Cable and Wire Termination operating parameters.
1.1Equipment Function
The function of Cable and Wire Termination is to provide a means of connecting conductors to electrical equipment and completing electrical circuits.
1.2Equipment Description
A conductor is a metal wire constructed of a material that provides an easy path for the flow of electric current. Almost all materials will conduct electricity, but certain materials, such as copper, aluminum, and silver, are very good conducting materials. Copper is the material that is most commonly used in standard electrical applications.
A cable is a multiple conductor. It is two (2) or more insulated conductors insulated from each other, but bound together by a common covering. The term conductor is used as a general term to identify a single insulated wire. Single conductors may be called cables, and cables may be referred to as conductors.
Conductors can be divided into two (2) categories: bare conductors and insulated conductors. A bare conductor, shown in Figure 1, is a length of bare metal wire. The amount of current a bare conductor can carry is determined by the type of metal it is made of and its size.
Figure 1 – Conductors
Conductors can be either solid or stranded. A solid conductor, shown in Figure 2, is made of a single strand of wire. A stranded conductor, shown in Figure 3, made up of several strands of wire wound together to form a single conductor. Stranded conductors are easier to manipulate than solid conductors because stranded conductors are more flexible.
An insulated conductor is either a solid or stranded bare conductor that is surrounded with insulating material, as shown in Figure 4. Insulating materials are materials that offer high resistance to current flow, such as glass, rubber, and plastic. Each of these materials is a poor conductor.
The insulation around a conductor provides both electrical protection and mechanical protection. Insulation helps to keep the current flow within its boundaries, thereby affording electrical protection. It also helps to prevent the metal portion of the conductor from mechanical damage such as nicks or scrapes.
Figure 2 - Solid Conductor
Figure 3 - Stranded Conductor
Figure 4 - Insulated Conductor
Figure 5 shows an insulated conductor with two (2) additional layers, a jacket and a sheath. The first layer of insulation around this conductor is made of rubber, a common insulating material. A conductor might need additional mechanical protection due to special circumstances. Some conductors need extra protection when being pulled through conduit. In that case, it might be necessary to use a conductor that is covered with a jacket. A jacket covers the primary, or initial, layer of insulation. Jackets are commonly made of hard plastic material that provides additional mechanical protection. A sheath is sometimes placed over a jacket to provide additional mechanical protection. A sheath might be used on a conductor that is designed for direct burial in the earth.
Figure 5 - Insulated Conductor with Jacket and Sheath
1.2.1Cable and Conductor Classification
The classification of cables and conductors is based on two (2) factors: the size of the metal wire and the type of insulation surrounding the wire. Systems have been developed within the industry to classify cables and conductors by trade size and by insulation type.
Wire Size
The "trade" size of a cable or conductor is the standard size of the wire as recognized in the electrical industry. There are two (2) systems used to express the size of a metal wire: the American Wire Gauge (AWG) system and the circular mil system.
Most of the wires used in routine electrical work are sized according to the AWG system. The sizes range from number 40, which is the smallest size in the system, to number 4/0 (four (4) ought), which is the largest size. As the AWG number decreases from 50, the actual size of the conductor increases. Therefore, a number one (1) AWG conductor is a great deal larger than a number 50 AWG conductor. The four (4) largest sizes in the AWG system are the ought sizes from one ought (1/0 or 0), which is the smallest, to four (4) ought (4/0 or 0000), which is the largest.
Table 1 shows the various AWG wire gages as well as the Diameter [in mils], the resistance per 1000 foot, the current carrying capability [Ampacity], and Pounds per Foot [number of feet required to weigh 1 pound].
Table 1 - AWG Copper WireAWG / Diam. (mils) / Circular mils / Ohms/1000ft / Current Carrying / Fusing Current / Feet per Pound
0000 / 460 / 212000 / 0.050 / - / - / 1.56
000 / 410 / 168000 / 0.063 / - / - / 1.96
00 / 365 / 133000 / 0.077 / - / - / 2.4826
0 / 324.85 / 105531 / 0.096 / - / - / 3.1305
1 / 289.3 / 83694 / 0.1264 / 119.6 / - / 3.947
2 / 257.6 / 66358 / 0.1593 / 94.8 / - / 4.977
3 / 229.4 / 52624 / 0.2009 / 75.2 / - / 6.276
4 / 204.3 / 41738 / 0.2533 / 59.6 / - / 7.914
5 / 181.9 / 33088 / 0.3915 / 47.3 / - / 9.980
6 / 162 / 26244 / 0.4028 / 37.5 / 668 / 12.58
7 / 144.3 / 20822 / 0.5080 / 29.7 / 561 / 15.87
8 / 128.5 / 16512 / 0.6405 / 23.6 / 472 / 20.01
9 / 114.4 / 13087 / 0.8077 / 18.7 / 396 / 25.23
10 / 101.9 / 10384 / 1.018 / 14.8 / 333 / 31.82
11 / 90.7 / 8226 / 1.284 / 11.8 / 280 / 40.12
12 / 80.8 / 6529 / 1.619 / 9.33 / 235 / 50.59
13 / 72.0 / 5184 / 2.042 / 7.40 / 197 / 63.80
14 / 64.1 / 4109 / 2.575 / 5.87 / 166 / 80.44
15 / 57.1 / 3260 / 3.247 / 4.65 / 140 / 101.4
16 / 50.8 / 2581 / 4.094 / 3.69 / 117 / 127.9
17 / 45.3 / 2052 / 5.163 / 2.93 / 98.4 / 161.3
18 / 40.3 / 1624 / 6.510 / 2.32 / 82.9 / 203.4
19 / 35.9 / 1289 / 8.210 / 1.84 / 69.7 / 256.5
20 / 32.0 / 1024 / 10.35 / 1.46 / 58.4 / 323.4
21 / 28.5 / 812 / 13.05 / 1.16 / - / 407.8
22 / 25.3 / 640 / 16.46 / .918 / 41.2 / 514.12
23 / 22.6 / 511 / 20.76 / .728 / - / 648.4
24 / 20.1 / 404 / 26.17 / .577 / 29.2 / 817.7
25 / 17.9 / 320 / 33.0 / .458 / - / 1031
26 / 15.9 / 253 / 41.62 / .363 / 20.5 / 1300
27 / 14.2 / 202 / 52.48 / .288 / - / 1639
28 / 12.6 / 159 / 66.17 / .228 / 14.4 / 2067
29 / 11.3 / 128 / 83.44 / .181 / - / 2607
30 / 10.0 / 100 / 105.2 / .144 / 10.2 / 3287
31 / 8.9 / 79 / 132.7 / .114 / - / 4145
32 / 8.0 / 64 / 167.3 / .090 / - / 5227
33 / 7.1 / 50.125 / 211.0 / .072 / - / 6591
34 / 6.3 / 39.75 / 266.0 / .057 / 5.12 / 8310
35 / 5.6 / 31.5 / 335 / .045 / 4.28 / 10480
36 / 5.0 / 25.0 / 423 / .036 / 3.62 / 13210
37 / 4.45 / 19.83 / 533 / .028 / - / 16660
38 / 3.97 / 15.7 / 673 / .022 / 2.5 / 21010
39 / 3.5 / 12.47 / 848 / .018 / - / 26500
40 / 3.14 / 9.89 / 1070 / .014 / 1.77 / 33410
41 / 2.8 / 7.842 / - / - / 1.52 / -
42 / 2.494 / 6.219 / - / - / 1.28 / -
43 / 2.221 / 4.932 / - / - / 1.060 / -
44 / 1.978 / 3.911 / - / - / 0.916 / -
45 / 1.761 / 3.102 / - / - / - / -
46 / 1.568 / 2.460 / - / - / - / -
47 / 1.397 / 1.951 / - / - / - / -
48 / 1.244 / 1.547 / - / - / - / -
49 / 1.107 / 1.227 / - / - / - / -
50 / 0.986 / 0.973 / - / - / - / -
The circular mil system is used to designate the trade size of conductors larger than a number 4/0 AWG conductor. In this system the size designation is based on the cross-sectional area of the metal wire measured in circular mils (cm). A circular mil is a circle that has a diameter of one (1) mil, or one one-thousandth of an inch. The sizes in the circular mil system range from 250,000 thousand circular mils (250 MCM), which is the smallest size, to 2,000,000 circular mils (2,000 MCM), which is currently the largest size in the system. In this system, as the size designation increases, the size of the conductor also increases. A size 600 MCM conductor is larger than a size 500 MCM conductor.
Insulation Types
Insulation materials can be divided into two (2) general categories: organic and inorganic. Organic insulation usually consists of materials made from plant or animal fibers such as cotton, silk, paper, or rubber. Inorganic insulation usually consists of materials such as glass, porcelain, or plastic. Beyond these two (2) general categories, insulation is further classified by letter designations that identify the composition of the insulation and its application.
1.2.2Cable and Conductor Ratings
Cables and conductors are rated on the basis of two (2) factors: (1) the current carrying capability of the conductor, which is commonly referred to as its ampacity, and (2) the value of the voltage that the insulation can withstand.
Ampacity
Ampacity is based on two (2) factors: the type of metal used to make the wire, and the size of the wire. Ampacity is based on metal and size when dealing with bare conductors. When a conductor is insulated, the insulation around the conductor dictates, to a great extent, the ampacity. This fact leads to the use of two (2) additional terms: maximum ampacity and allowable ampacity.
Maximum ampacity is the maximum amount of current a bare conductor can carry without overheating. Whenever current flows through a conductor, it meets some resistance. The energy that is required to overcome this resistance is given off as heat. Exceeding the maximum ampacity of a conductor may cause the conductor to overheat, or melt.
Allowable ampacity is the amount of current an insulated conductor can carry without overheating. Because, in most cases, insulation will overheat and be damaged before a conductor will, engineers have established a maximum operating temperature for conductors covered by specific types of insulation. Two (2) factors are considered in determining how much current a specific size conductor covered by a specific type of insulation could carry at a specific operating temperature. These factors are the ambient temperature and the internal temperature rise.
Ambient temperature is the temperature of the area in which a conductor is installed. Since the ambient temperature in a given location is not always constant, a standard ambient temperature of 86deg Fahrenheit (30 degC) is used when determining maximum operating temperature.
Internal temperature rise is the amount that the temperature of the conductor raises above the ambient temperature when current is flowing through the conductor. The amount of current flow that causes the conductor to reach its maximum operating temperature, based on the standard ambient temperature, is the allowable ampacity.
Voltage
The voltage rating of a cable or conductor is based on the amount of voltage that can be applied to its insulation without causing the insulation to break down. When more voltage is applied to the conductor than its insulation can withstand, current passes through the insulation to ground, destroying the insulation.
Voltage ratings are determined by two (2) factors: the type of insulation material and the thickness of the insulation
1.2.4Cable and Conductor Splices
A splice is a point at which two (2) or more conductors are connected together to extend the overall length of the conductor, or a point at which two (2) or more conductors branch out from a conductor. All splices should be both mechanically and electrically strong. A spliced conductor should function as well as an uninterrupted length of conductor.
Splices can be divided into two (2) categories: thermal splices and mechanical splices. The National Electrical Code restricts the use of thermal splices in many situations, so they are not used as often as mechanical splices. In most cases, mechanical splices are also easier to use than thermal splices.
Thermal splices are splices in which heat is required to join the ends of the conductors together. Thermal connectors are often used to make thermal splices and to connect conductors to electrical equipment. Figure 6 shows a thermal connector called a thermal lug. One (1) of the most common methods of making a thermal splice uses solder, a metal alloy, which is heated to the melting point and used to connect the ends of the conductors to thermal lugs. The lugs are then bolted together to complete the splice. Solder may also be used to join the ends of the conductors together directly, without using thermal lugs, but this is usually done only with small wire.
Mechanical splices are splices that use mechanical connectors and mechanical pressure to join the ends of conductors together. A wide variety of mechanical connectors are available, including wire nuts, sleeves, split bolt connectors, and mechanical lugs. Several mechanical splice connectors are shown in Figure 7.
Figure 6 - Thermal Lug
Figure 7 – Cable and Wire Connectors
1.2.3Cable and Conductor Terminations
A cable must be properly terminated to safely carry current, with no arcing, grounding, or other problems that could cause an electrical fault in an electrical distribution system. The insulation of the cable must also be replaced in the spliced/terminated area to protect both equipment and personnel. The type of cable determines the exact procedure required to properly splice/terminate that cable.
A termination is a stopping point for a conductor. Terminations provide a means of connecting conductors to electrical equipment and completing electrical circuits. Terminations involve joining two (2) conductors together. Terminations performed at a motor housing require that the conductors be joined, or spliced, to the leads from the motor. They are still classified as terminations because they are also direct connections to a piece of electrical equipment and a stopping point for the conductors.
There are two (2) basic types of terminators: thermal terminators and mechanical terminators. Thermal terminators require heat to fasten them to the ends of conductors, and mechanical terminators require mechanical pressure.
There are three (3) factors that determine what type of terminator is used in a specific application: (1) the size of the conductor; (2) the metal the conductor is made of; and (3) the requirements of the electrical equipment at which the termination is to be made. Table 2 shows a typical supplier’s ring terminator chart showing the AWG wire sizes and stud size for various applications.
Table 2 – Ring Terminal Sizes
WireRange(AWG) / Stud Size / Carton
Quantity / Cat. No.
22-18 / 6 / 100 / 83-6111
8 / 100 / 83-6121
16-14 / 8 / 100 / 83-6161
10 / 100 / 83-6171
10 / 1000 / 84-6171
12-10 / 8 / 50 / 83-6211
10 / 50 / 83-6221
1/4 / 50 / 83-6231
Ring terminals, shown in Figure 8, are typically the best choice unless the terminal screw is captive. In that case, use flanged spade connectors. Figure 9 shows typical wire terminators.
Use butt connectors for applications where the equipment is supplied with wire leads instead of terminals. Step-down butt connectors let you connect heavy supply wires to lighter leads. To simplify servicing, it can be a good idea to make the connection with blade or snap connectors instead of butt connectors. Three-way connectors are useful for tapping into an existing circuit.
Figure 8 - Ring and Spade Terminals
Figure 9 - Typical Wire and Cable Terminators
For larger cable sizes and voltage ratings (5kV and up) the proper cable termination kit must be used for the particular cable being terminated. A list of cable types and the appropriate kit to use are listed in Table 3. When using any termination procedure and kit, several steps are necessary. These steps are:
- Gathering the required tools for termination of the specific cable
- Determining the amount of insulation cutback required
- Installing the lug, if used
- Abrading and cleaning the end of the cable
- Applying stress relief material (SRM) to the cable
- Grounding the cable insulation
- Applying sealant to the end of the cable
- Positioning and shrinking the HV tube
- Trimming the HV tube
- Applying skirt(s) for outdoor termination
Not all of these steps are require for all types on terminations and cable sizes. Proper performance of these steps is described in detail in section 2.0 of this system description.
Table 3 - Cable Termination Kits
Kit / Voltage / ConductorSize / Max./Min. Insulation Diameter / Max. Jacket Diameter
(inches) / (mm) / (inches) / (mm)
HVT-80-G(SG) / 5 kV / #4-#1 AWG / 0.35 – 0.60 / 9 - 15 / 0.95 / 24
HVT-81-G(SG) / 1/0-250 kcmil / 0.60 – 0.95 / 15 - 24 / 1.20 / 30
HVT-82-G(SG) / 300-500 kcmil / 0.80 – 1.25 / 20 - 32 / 1.50 / 38
HVT-83-G(SG) / 600-1750 kcmil / 1.10 – 1.75 / 28 - 44 / 2.10 / 53
HVT-84-G(SG) / 1500-2500 kcmil / 1.60 – 2.45 / 41 - 62 / 2.75 / 70
HVT-80-G(SG) / 8 kV / #6-#2 AWG / 0.35 – 0.60 / 9 - 15 / 0.95 / 24
HVT-81-G(SG) / #1-4/0 AWG / 0.60 – 0.95 / 15 - 24 / 1.20 / 30
HVT-82-G(SG) / 250-500 kcmil / 0.80 – 1.25 / 20 - 32 / 1.50 / 38
HVT-83-G(SG) / 600-1750 kcmil / 1.10 – 1.75 / 28 - 44 / 2.10 / 53
HVT-84-G(SG) / 2000-2500 kcmil / 1.60 – 2.45 / 41 - 62 / 2.75 / 70
HVT-151-G(SG) / 15 kV / #4-1/0 AWG / 0.60 – 0.95 / 15 - 24 / 1.20 / 30
HVT-152-G(SG) / 2/0-350 kcmil / 0.80 – 1.25 / 20 - 32 / 1.50 / 38
HVT-153-G(SG) / 400-1000 kcmil / 1.10 – 1.65 / 28 - 42 / 2.10 / 53
HVT-154-G(SG) / 1250-2500 kcmil / 1.60 – 2.45 / 41 - 62 / 2.75 / 70
HVT-252-G(SG) / 25 kV / #2-250 AWG / 0.80 – 1.25 / 20 - 32 / 1.50 / 38
HVT-253-G(SG) / 300-750 kcmil / 1.10 – 1.65 / 28 - 42 / 2.10 / 53
HVT-254-G(SG) / 1000-1750 kcmil / 1.60 – 2.45 / 41 - 62 / 2.75 / 70
HVT-255-G(SG) / 2000-2500 kcmil / 2.05 – 3.30 / 52 - 84 / 3.45 / 88
HVT-352-G(SG) / 35 kV / #1-1/0 AWG / 0.80 – 1.25 / 20 - 32 / 1.50 / 38
HVT-353-G(SG) / 2/0-500 kcmil / 1.10 – 1.65 / 28 - 42 / 2.10 / 53
HVT-354-G(SG) / 750-1750 kcmil / 1.60 – 2.45 / 41 - 62 / 2.75 / 70
HVT-355-G(SG) / 2000-2500 kcmil / 2.05 – 3.30 / 52 - 84 / 3.45 / 88
1.3Equipment Connections and Interface