PRODUCT TRAINING MANUAL
for
ELECTRICAL PRODUCTS
designed for
$5.95
TABLE OF CONTENTS
Electrical
Page
Electrical System Course Outline . . . . . . . . . . . .1
Electrical System Overview . . . . . . . . . . . . . . . . .2
Electrical Training . . . . . . . . . . . . . . . . . . . . .3-18
Seal-A-Crimp Terminals . . . . . . . . . . . . . . . .19-20
Wire and Cable . . . . . . . . . . . . . . . . . . . . . . . . . .21
Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
Self-Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . .23
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
ELECTRICAL SYSTEMS
COURSE OUTLINE
PURPOSE:
To understand the basics of electricity and how they apply to daily electrical repairs.
OBJECTIVES: To be able to:
• Demonstrate basic knowledge of voltage, amperage, and resistance.
• Identify common electrical failures and their causes.
• Exhibit skills for making proper electrical connections.
Cut
Skive
Connect
Protect
Identify
Attach
• Identify terminal styles.
I. Electrical System Overview
II. Understanding Electrical Systems
A. OHM’s Law Explained
B. Voltage, Amperage, Resistance
C. Three types of circuits
D. Testing voltage drop.
III. Solderless Terminals
A. Design and Features
B. Barrel Styles and Lengths
C. Tongue Configurations, Tool Crimp Location and Color Coating.
D. Performance
E. Crimping, Testing, and Checking
IV. Seal-A-Crimp Terminals
A. Heavy Duty Heat Shrink Butt Connectors
B. Heat Shrink Terminals and Splices
C. Simple Installation
V. Wire and Battery Cable
VI. Terminology
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
1
I. OVERVIEW OF THE ELECTRICAL SYSTEM
Imperial has recognized that over 75% of all truck problems can be directly related to the electrical
system. The problem is not always related to the batteries, starters and alternators, but rather the
connections and the connectors. Too much resistance in the connectors that provide electrical current
to and from electrical devices such as batteries, starters, alternators, headlamps, horns, stop/turn/tail
lights and other electrical devices are an underlying cause for their failure. A known fact is that a one
volt drop at the starter can decrease its life expectancy as much as 50%. (Generally 3/10ths of a volt is
the maximum allowable voltage drop).
When replacing a major component, like a starter or alternator, especially if this vehicle has had
multiple electrical repairs, take a few extra moments to look at and perform the necessary inspection of
the electrical connectors, cables and wires. Excessive resistance at the battery or starter terminal
connections require cleaning or replacement of the connections. Failure to correct these high
resistance areas will cause components to work harder under less voltage and it will fail
prematurely.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
2
II. UNDERSTANDING ELECTRICAL SYSTEMS
A.) OHM’S LAW EXPLAINED
“The amount of current flowing in a circuit made up of pure resistances is directly proportional to
the electromotive forces impressed on the circuit and inversely proportional to the total resistance of
the circuit.”
Don’t let that quote scare you. It is not as scholarly as it sounds.
Now, before going further, make sure you understand two
things. What composes a circuit and what voltage, current,
and resistance are.
In simpler terms, Ohm’s Law means:
1. A steady increase in voltage, in a circuit with constant
resistance, produces a constant linear rise in current.
2. A steady increase in resistance, in a circuit with constant
voltage, produces a progressively (not a straight-line if
graphed) weaker current.
Ohm’s law is a set of formulas used in electronics to calculate an unknown amount of current, voltage,
or resistance. It was named after the German physicist George Simon Ohm. Knowledge of the law is
often underestimated by beginners. Unless you know this basic fundamental building block of electronics, you will never have a strong understanding of this field.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
3
B.) VOLTAGE, AMPERAGE, RESISTANCE
Ohm’s Law is a formulation of the relationship of voltage, current, and resistance, expressed as:
E=IxR
-orI= E
R=E
R
I
WHERE:
E is the Voltage measured in volts
I is the Current measured in amperes
R is the resistance measured in Ohms
THEREFORE:
Volts = Amps x Ohms
Ohms Law is used to calculate a missing value in a circuit.
In this simple circuit there is a current of 12 amps (12A) and a resistive load of 1 Ohm (1Ω). Using the
first formula from above we determine the Voltage:
E = 12 x 1 : E = 12 Volts (12V)
If we knew a battery was supplying 12 volts of pressure (voltage), and there was a resistive load of 1
Ohm placed in series, the current would be:
I = 12/1 : 1 I = 12 Amps (12A)
If we knew the battery was supplying 12 V and the current being generated as 12A, then the Resistance
would be:
R = 12/12 : R=1Ω
NOTE: Remember a battery is not measured in amperage. The battery supplies
the pressure that creates the flow (current) in a given circuit.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
4
An easy way to remember the formulas is by using this diagram.
To determine a missing value, cover it with your finger. The horizontal line in the middle means to
divide the two remaining values. The “X” in the bottom section of the circle means to multiply the
remaining values.
• If you are calculating voltage, cover it and you have I x R left (E = I x R).
• If you are calculating amperage, cover it, and you have E ÷ R left (R = E ÷ R).
• If your are calculating resistance, cover it, and you have E ÷ I left (R = E ÷ I).
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
5
C.) THREE TYPES OF CIRCUITS
Circuits
Circuits
❏ Series Circuits
❏ Parallel Circuits
- Two or more resistant values
- One path of electricity
- Current will be the same throughout
- Voltage drop will be different if resistant
values are different
- @ of E drop = Source E
- Two or more resistant values
- More than one path flow
- Current throughout each branch will be different
if the resistance is different
- No voltage drop
Example: Old style Christmas lights. If one light burns
out, you have to search the entire string to find the
problem bulb.
Example: New style Christmas lights. If one burns out,
the other bulbs still work.
Circuits
❏ Series Parallel
- Represents a combination of both
• Examples:
- dashboard lights
- some fuel sending units
Example: Combination of the two styles. Having a
dimmer switch on the light system.
THE DIFFERENCE BETWEEN SHORT CIRCUITS AND OPEN CIRCUITS
LOAD
SOURCE
A
B
C
D
GROUND
The schematic above shows a simple electrical circuit. The power comes from a source (the battery),
passes through the “hot” wire (from A to B), through the load (a light bulb, motor, etc.), and then to
ground (C and D).
A SHORT occurs when an inadvertent connection is made to ground, along the hot wire or within the
load, bypassing all or part of the load.
An OPEN circuit occurs if a break exists anywhere along the length of the circuit (from A to D) that
interrupts current flow.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
6
D.) TESTING VOLTAGE DROP
LET IMPERIAL SHOW YOU HOW TO REDUCE
REPLACEMENT OF THESE ITEMS
Imperial has recognized that over 75% of all truck problems can be directly related to the electrical system.
The problem is not always related to the batteries, starters and alternators, but rather the connections and the
connectors. Too much resistance in the connectors that provide electrical current to and from electrical devices
such as batteries, starters, alternators, headlamps, horns, stop/turn/tail lights and other electrical devices are an
underlying cause for their failure. A known fact is that a one volt drop at the starter can decrease its life
expectancy as much as 50%. (Generally 3/10ths of a volt is the maximum allowable voltage drop).
Typical Voltage Drop Test
Typical voltage drop test, please refer to your shop
manual for specific applications
Excessive resistance at the battery or starter terminal connections require cleaning and/or replacement of the
connections. Failure to correct this high resistance area will cause the starter to work harder under less voltage
(fail prematurely); the alternator will try to recharge the battery (it has to put out more to overcome resistance);
therefore, the battery will be discharged, which will in turn accelerate this problem area. Imperial has put together a simple 6 step approach to reduce potential problems in this area:
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
7
SIX STEP APPROACH
Cut
Cut the wire or cable clean and square at the ends. This needs to be done to insure proper
connection at the terminal, and equally important not to break any strands in the wire or cable
that will increase resistance.
Skive
Skive the insulation off the wire or cable so only the insulation is removed. Be careful not
to cut into the individual strands as this will reduce the wire or cable diameter, and increase
resistance.
Connect
When making the connection (crimping, soldering, etc.), make sure the components are
clean from dirt, oil, and other contaminants. This will minimize the amount of voltage drop
through the connection. If crimping terminals, use the proper tool to insure the connection
is crimped evenly and securely.
Protect
It is important to use the proper type of protection on the terminal. This will insure the
connection will not corrode, which will impede current flow. Any connection outside of the
cab should be protected with one or more of the following: heat shrink tubing, sealing
compound, electrical tape, split loom, and fittings.
Identify
Use different wire colors, wire markers, or cable ties when making repairs for proper
identification on different electrical circuits. This will make the job easier if you or others
need to inspect the repair somewhere down the road.
Attach
To prevent the wire or cable from vibration and the problems resulting from vibrations
(opens and shorts) use frame clips, cable ties, and tube clamps to minimize the vibration and
provide the greatest longevity.
By following this simple six step process, you will reduce the failure and downtime that is
associated with electrical failures.
Avoid these common errors in electrical wiring!
• Twisting the tool to “cut” the insulation will add .05 ohms of resistance
• Cutting/nicking the wire will add .05 ohms of resistance per wire
• Stretching the wire will add .05 ohms of resistance
• Using your fingers to twist the wire strands will add .05 ohms of resistance
• Using your mouth to bite the insulation off will add .10 ohms of resistance
• Poor crimp (with air gaps) will add .05 ohms of resistance
Your goal should be zero ohms of resistance.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
8
III. SOLDERLESS TERMINALS
A.) DESIGN AND FEATURES OF SOLDERLESS TERMINALS
A. The quality of the base material must be evaluated. The material (metal) is either copper or brass depending on the product.
1. Base metals are purchased, inspected, and received to Military specifications.
2. Products use the guidelines of Mil-T-7928, set by the United States Federal Government.
B. Where preinsulated parts are used (ones with insulation), you must insure it is of a good quality. Mil specifications, as well
as U.L., covers this material.
C. Barrel Serration/Dimples
When quality solderless terminals are stamped, the inside of the barrel is scored with serrations or dimples.
Serrations “V” or Dimples
1. When the crimp is made and the metal terminal barrel is drastically deformed, the tin plating on the inside of the barrel is
fractured at the serrations, thus causing bare copper to contact between the wire and the terminal barrel. This greatly
enhances electrical conductivity.
2. If properly designed, the serrations or dimples have angled grooves, that during the crimping operation will bite into the
wire which greatly increases the mechanical integrity of the crimp.
Some manufacturers save money and time by not putting these serrations in their parts.
D. A quality solderless terminal has features built into the barrel that insures a quality crimp.
1. The non-insulated part will have a chamfer at the wire insertion end so the individual strands will not bump against the end
of the metal.
“Beveled” Chamfer
2. When you have an insulated part, the insulation should have a funnel entry. This acts as a slide for the wires to enter the
barrel smoothly.
These are two basic styles of insulated barrels. Both have a funnel feature.
Plain Insulation
Insulation W/Support Sleeve
Nylon Sleeve
Tin Plated Brass Sleeve
PHONE: 1-800-558-2808
Plastic Insulation Sleeve
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
9
Butted Seam
B. DIFFERENT BARREL STYLES
Transition or Throat
A. The barrel is the part of the terminal that is crimped around the wire.
Barrel
Tongue (Style Varies)
B. These are the five basic forms.
Metal Sleeve
2. Brazed Seam
1. Butted Seam
3. Insulation Only
4. Extra Metal Support Sleeve
#1 is the least expensive barrel type.
#2 is the same as #1 except the seam is brazed (welded closed). This allows for crimping from any direction without the
barrel opening up, and provides greater tensile strength.
#3 adds insulation protection to the barrel area. In wire sizes 22-10 AWG this insulation material is PVC (polyvinyl
chloride). This barrel style can be made from extruded or molded PVC, as well as molded or extruded nylon.
Molded
Extruded
#4 provides insulation as well as an insulation grip. The insulation is made of nylon, and has a secondary metal sleeve
added. This metal support sleeve is crimped around the wire insulation providing a strain relief, so the wire does not
vibrate, loosen, fray, or break.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
10
C. VARIOUS TONGUE CONFIGURATIONS
The “tongue” is the end of the part that attaches to other components (switch, stud, transformer, etc.). These tongue
configurations are varied, some of them are:
Quick Disconnects
Flanged Spades
Rings
Spades
Snap Spades
Flag Rings
Hooks
Multi Studs
WHAT DOES THE COLOR OF THE INSULATION MEAN?
A. The colors (red, blue, and yellow) are used to tell you the wire range that can be used in the part. This is an industry
standard color coding.
Example: Blue = 16 or 14 AWG wire
The colors repeat over and over, and are an industry
standard, i.e.... Yellow = 26-24
Red = 22-18
Blue = 16-14
Yellow = 12-10
Red = 8 AWG
Blue = 6 AWG
Yellow = 4 AWG
B. Remember there are different kinds of barrels. With this in mind you will note that different shades of color are used for
different barrel styles. Also, PVC and nylon take the color differently. In the 16-14 AWG range (blue), for example, the
PVC barrels will be dark blue. When using the lighter blue parts, the secondary sleeve will be crimped in addition to the
wire barrel crimp. The actual shape or color has nothing, per se, to do with quality of the insulation.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
11
D. ELECTRICAL PERFORMANCE VS. MECHANICAL PERFORMANCE
The Crimp Area
A. If you crimp real hard you can get a good mechanical performance, but if you crimp too easy, of course, the part
won’t hold.
B. However, if you crimp too hard you can extrude (stretch) the wire in the crimp area so it is thinner than the wire. This
causes resistance and a poor electrical connection.
Causing potential failure
mode or future break or
fracture point.
Wire is deformed
or compressed beyond
normal yield point.
Excessive
crimp depth.
Single strand wire.
Excessive
bell mouth.
Terminal wire braid.
So the hard crimp which might give a good mechanical performance may cause electrical problems. As shown in the chart
below, the perfect crimp is a compromise between good mechanical and electrical connection.
C
B
Increasing Mechanical Strength
And Electrical Performance
A
Increasing Crimping Force
Point A gives the best Mechanical Connection, Point B gives the best
Electrical. The optimum is in between at Point C.
WHAT CAN CAUSE A BAD ELECTRICAL CRIMP
A. Loose crimp (not crimped hard enough).
B. Over crimped (elongated and weakened strands).
C. Void or air space in the crimp area.
Void
End View of Barrel
Before Crimp
PHONE: 1-800-558-2808
Under-Crimped Part
Showing Void
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
12
E. THE CRIMPED JOINT
1. Importance of Proper Crimping
Once the correct terminal is selected, proper attachment to the wire is critical. One indication of the importance of
proper crimping is evident in a study for the Space Shuttle program that traced 28% of all defects to improperly assembled
wiring and connections.
Mechanical as well as electrical connections are important - The end result of a properly crimped joint is a reliable
mechanical and electrical connection.
The mechanical connection is the crimping of the terminal to the conductor. The desired result is sufficient force on the
outside of the barrel to tightly form it around the conductor. It must be secure enough so that it will not vibrate loose or be
pulled off through normal use.
Just as important are the electrical characteristics. The major concern is the amount of electrical resistance caused by the
mechanical joint. This electrical resistance will determine the crimped joint’s ability to conduct current. If you buy a
quality product, you will find that in many cases the mass of the metal barrel after crimping actually aids the conduction.
The extra mass allows for little or no resistance over the crimp - as long as the crimp is made properly.
2. Operation
To achieve a positive relationship between the mechanical and electrical connection in the crimped joint, the following
conditions are required:
1. The terminal must be of sufficient cross section size and conductive material that is as good as an electrical conductor
as the wire.
2. The surfaces of the wire and terminal that will be pressed into contact in the crimp must be clean and free of heavy,
non-conductive films such as oxides, sulfides, and similar substances.
Some reasons for failure of crimped joints to meet minimum tensile requirements include nicked wires, nicked or
ruptured strands, strand turn back at crimp joint, and ruptured wires outside of the crimped terminal. To avoid these
problems, use the correct size wire for the barrel, prepare your wire carefully, and use the proper matching tool.
3. Electrical Resistance
The electrical resistance across the crimp is compared to the resistance of an equal length of wire, and expressed as
relative resistance for a particular wire size.
Relative resistance of the crimp to the wire:
RC
RW
RC = Resistance over Crimp
RW = Resistance of Wire
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
13
Relative resistance values of less than 1.0 denote a crimped joint with less resistance than the wire. Values more than 1.0
indicate greater resistance than the wire. Usually it is easier to measure the voltage drop across the crimped joint. Many
specifications state the requirements in terms of voltage drop at a specified current. Voltage drop is the more commonly
used term in the industry. If the resistance value is desired it may be calculated from Ohms Law:
R (ohms) = E (volts)
I (amps)
Crimp voltage drop and resistance values are quite small and are expressed in terms of millivolts (.001 volts) and
milliohms (.001 ohms).
The resistance increase or millivolt drop will indicate a poor crimp joint and could be caused by several factors:
1. The presence of air pockets or voids in the crimped joint will cause a higher resistance.
2. These same voids cause higher resistance and will cause a temperature rise which in turn increases the corrosion rate
and further increases the resistance.
3. A crimped joint that has been over crimped and the conductor (wire) elongated out of shape could cut the circular area
of the conductor and cause a greater resistance at this weakened point.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
14
FACTS ABOUT CRIMPED JOINTS
A finely stranded wire (large number of small diameter strands) usually improves crimped joint performance. A wire
composed of a few strands of a larger size will tend to act as a solid wire in the crimp. Some stranded wire crimp
configurations are not satisfactory for solid wire. More deformation must be imposed in order to form wire and barrel into
a solid mass. On the other hand, finer strands will more readily fill the inside contour of the crimp shape and more evenly
distribute strand formation.
Brazed barrel terminals usually give higher tensile test than the non-brazed (for specific values, tensile tests must be
performed on each part).
WHAT GIVES QUALITY TO A SOLDERLESS TERMINAL
A. Quality is something that must be measured by some set of criteria. There are four major agencies that give test criteria
for solderless terminals. They are:
1. U.L. (Underwriters Laboratories)
2. CSA (Canadian Standard Association)
3. NEMA (National Electronic Manufacturers Association)
4. Federal Government Spec - Mil-T-7928
B. In all the above standards, specific reference is made to the following areas:
1. Copper or brass quality specifications.
2. Tin plating specs to kind and thickness.
3. Smoothness of edges and lack of burrs.
4. Firmness of fit between metal and insulation.
5. There is a series of tests to be performed on the crimp area after the crimp was made:
• Tensile test
• Dielectric withstand
• Salt spray
• Vibration
• Heat rise
The most widely used field test for testing the quality of the crimp is the pull test or tensile test.
The two most widely used measurements are the U.L. and Military Tensile values. Note that the Military is higher
than the U.L.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
15
QUALITY CHECKS BEFORE CRIMPING
Checking the Wire
Check the stranded wire to see if any strands have loosened and expanded to be larger than the wire and the insulation
together. If this has occurred, retwist the wires to the size they were before they were stripped. Be sure that the stranded
wire is within the outside diameter of the insulation after you have retwisted them.
ACCEPT
REJECT
Expanded
Strands
Loose Wire
Wire Within
Outside Diameter
Outside
Wire
Diameter
Exceeds
Outside
Diameter
Check to see if a stripping tool or machine has cut or nicked any of the wires.
If you see a nicked wire, you must cut and restrip the wire before crimping to be sure that the amount of current that can
be carried is not reduced.
ACCEPT
REJECT
Improper Stripping
“nicked” Strands
Proper Stripping
Undamaged Strands
Improper Stripping
Cut Strands
Checking the Insulation
1. Check the insulation to ensure that there has been a nice clean cut.
2. Wires with damaged insulation should not be used.
ACCEPT
REJECT
Insulation
Wiskers
Insulation
Thickness
Damage
1/2 Of Insulation
Thickness
Or Greater
Damage
Less Than 1/2
Of Insulation
Thickness
Split
Cut
Burned
Or Charred
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
16
HAND CRIMPING INSTRUCTIONS
Insure the tool is designed to crimp the size wire and specific terminal you want to use.
Check the wire’s insulation thickness and then adjust the hand tool’s crimp pressure on the insulation sleeve to the correct
setting, using the appropriate method for that specific hand tool.
Strip the wire.
Place the terminal in the tool. Select the proper crimp station.
Insert the wire.
Squeeze the handle.
Check the finished crimp to see that the wire’s insulation is held firmly by the insulation support barrel, the wires are
visible, and a bell mouth is present.
Insure that your hand tools are calibrated regularly.
Easy as . . .
PHONE: 1-800-558-2808
1
Select the correct splice size for the wire gauge. Strip the
wires 0.3" (7.6mm) from the end and insert into the crimp
barrel.
2
Making sure the wire end is properly seated, make the crimp
connection using a tool designed for insulated splices.
3
Apply heat directly to the splice, working from the
center out to the edges, using a hot air gun or other heat
source, until the tubing recovers and the adhesive flows.
Allow to cool before inspecting splice and checking
integrity.
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
17
Mechanical
The tensile test or pull test is a means of evaluating the mechanical properties of the crimped connection. The chart
below shows the UL and Government Specifications (MIL-T-7982) for various wire sizes. The tensile strength is shown in
pounds and indicates the minimum acceptable force to break or separate terminal from the conductor.
When the crimp is made, there must be enough pressure applied so that the oxides that may build up on the stripped
conductor and the tin plating on the inside of the terminal barrel are broken down and there is good metal-to-metal contact.
If this situation does not occur, resistance can again build in the connectors.
Dielectric Testing (The term “dielectric” refers to an insulator)
Some terminals are covered with insulation so that electrical contact can be made only where it is desirable. The crimp
is made through (on) this insulation which is compressed and extruded due to the pressure of the crimping dies. Obviously,
not all insulation materials can withstand this treatment and even with the strongest materials, the crimp must be correctly
designed so as not to rupture the insulation.
Dielectric tests are made on insulated terminals after crimping to determine that the crimp process is not rupturing the
insulation or thinning it out so it will not withstand impressed voltages. The test is made by impressing a voltage between
the wire to which the terminal is crimped and conductive materials contacting the terminal insulation.
The voltage is gradually increased until the requirements are reached or until a breakdown occurs which means the
insulation breaks. Depending on the use and the specifying agency, dielectric withstanding requirements normally range
from 1500 to 8000 volts, resulting in a 300 to 600 volt rating.
Wire
Size
Tensile
Strength
Pounds UL
Tensile
Strength
Pounds UL
Quick
Disconnects
Tensile
Strength
Pounds
MIL-T-7928
26
24
22
20
18
16
14
12
10
8
6
4
2
1
1/0
2/0
3/0
4/0
250MCM
300MCM
350MCM
3
5
8
13
20
30
50
70
80
90
100
140
180
200
250
300
350
450
500
550
600
—
—
8
13
20
30
50
70
80
—
—
—
—
—
—
—
—
—
—
—
—
7
10
15
19
38
50
70
110
150
225
300
400
550
650
700
750
825
875
1000
1120
1125
TESTING
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
18
IV. SEAL-A-CRIMP HEAT SHRINK
A. HEAVY DUTY HEAT SHRINK BUTT CONNECTORS
Waterproof Adhesive Seal
Heavy Duty Seal-A-Crimp butt connectors give a long-lasting, moisture-proof connections that
withstand water, salt, condensation, corrosion and heat, all of which cause serious problems for
conventional, unsealed splices.
The inner wall of a heat shrinkable Heavy Duty Seal-A-Crimp sleeve is lined with a special hotmelt adhesive which is inert at room temperature, permitting wires to be inserted easily into the butt
connector. As the sleeve is heated, the adhesive melts and flows under pressure from the tubing.
This action fills any existing voids and creates a seal which repels moisture incursion, even during
pressure cycling, and stands up to some of the most rigorous tests that can be applied to high
performance splices.
Features and Benefits
• Wall thickness is significantly thicker than the polyolefin or nylon products, providing
excellent durability.
• Shrinks fast! Up to 40% faster than polyolefin and nylon products, saving installation costs
and dramatically reducing the potential to wire jacket damage.
• Excellent chemical properties Seal-A-Crimp will keep on working even when immersed in
the following chemicals: Antifreeze, brake fluid, gasoline, motor oil, trichloroethylene, diesel
fuel, salt, water and battery acid.
• Minimum shrink temperature 90 degree C.
B. HEAT SHRINK TERMINALS AND SPLICES
Features and Benefits
• A totally environmental sealed terminal connection.
• Simply crimp and heat. A special heat shrink tubing is utilized with an adhesive inner liner
that melts and adheres as the tubing shrinks, providing a complete environmental seal.
• This dual-wall, heat seal terminal is specifically suited for those applications which require
“environment proof” connections.
• The construction of this unique terminal begins with a funnel entry terminal made of pure
electrolytic (EPT) copper and is plated to resist corrosion.
• Seal-A-Crimp splices and terminals are color coded for easy identifications of wire
gauge sizes.
• Available in many different sizes and styles.
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
19
C. SIMPLE INSTALLATION
Heavy Duty Seal-A-Crimp and Seal-A-Crimp connectors are best to be installed using a barrel
and wire double crimping tool (Imperial offers a ratchet hand crimping tool of this type).
The ratcheting tool insures fifty pounds of equal and exact crimping pressure on electrical terminals
that Underwriters Laboratory recommends. Heavy Duty Seal-A-Crimp and Seal-A-Crimp
connectors are color coded for easy identification of wire gauge sizes. The ultra clear insulation
allows for visual inspection of the finished splice.
RATCHET HAND TOOL
Imperial part number 71498
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
20
V. IMPERIAL CROSS-LINK WIRE and COLOR-CODED
BATTERY CABLE
Cross-linked polyethylene insulation provides better durability and outstanding heat resistance. When
vulcanized, it provides a thermosetting insulation and is superior to thermoplastic because it will not
melt when exposed to heat. Cross-link remains flexible in -700F. temperatures and is noted superior to
any other primary wire in pinch, abrasion, and heat aging test.
Superior resistance to elements, abrasion, and where temperature extremes are
encountered.
Complies with SAE specification J1128.
Temperature range: -400C to +1050C.
Voltage range: 50 volts maximum.
Lock-Out Item: Thermoplastic Primary Wire
Imperial is recommending Color-Coded Battery Cable to match the color coded terminals. Battery
Cable is OEM standard. The battery cable meets or exceeds the standards established by the SAE.
Battery cable is insulated with PVC which is flame-retardant, resistant to fuel, oil, acid, and salt. The
wire is 100% copper. Three reasons we recommend using color coded battery cable:
Easy and fast identification of the wire gauge.
The color coding machines the wire to the terminal for less errors.
The color stripe helps you measure the length of your cable.
Lock-Out Item: Standard Black Battery Cable
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
21
VI. TERMINOLOGY
Crimping Tool
A device with built-in aids to ensure ease of use that’s designed with a stop that prevents it from crushing the terminal by
over crimping. Designed so that it cannot be opened until it has been completely closed to prevent under crimping. It has a
part number that corresponds to the types of terminals with which it can be used to ensure that the terminal used with a
certain tool is the correct one.
Dielectric Test
This is a test to ensure the crimping procedure did not puncture or destroy the insulation material on the terminal.
Flash
An abnormal protrusion on the wire barrel (either insulation material or metal) that indicates that your crimping tool is
either misaligned or worn and thus should not be used.
Gas Tight Seal
The result of all the wires and the terminal being compressed so tightly that air cannot get through. This contributes to
an excellent crimp because it ensures that oxidation (which will cause a decrease in electrical efficiency) does not take
place. This also adds to reliability because it ensures that an intermittent condition (sometimes working, sometimes not)
caused by a loose crimp, does not occur.
Hand Crimping
An easy mechanical means of joining terminals to wires. It’s an important way of ensuring quality control of harness
materials by replacing terminals that are found to be defective. It’s a necessary skill to know, especially in cases of short
production runs.
Harness
A bundle of prepared wires and terminals that have been formed as an assembly so that they are ready to be attached to
the various electronic components and allow them to function as a whole.
Mechanical Strength
To insure how strong the connection is or how much the wire and terminal must be squeezed to get a gas tight seal, it’s
important to crimp the wires tight enough to keep them from slipping out of the connector, but not so tight as to crush the
wires in the terminal, causing them to break off. The connection is weakened if the wires are cut or nicked.
Pull Test
Machine method of determining mechanical strength. Done by testing how much force it takes to pull the wire out of
the crimp.
Tensile Test
A pull test to determine the mechanical strength of the crimped wire. There are specific values set for each wire size.
Terminal
A convenient, reliable device that is used to attach a wire or cable to an electrical component. Two main types include
the open barrel and the closed barrel. Parts of the terminal are:
• Insulation barrel - Where the wire’s insulation will be crimped or supported so that it is firmly gripped.
• Wire barrel - Where the bare wire will be crimped.
• Contact area - Where the terminal will be attached to the equipment.
Voltage Drop Test
A test of the electrical integrity of the crimp.
Wire
Generally, there are two types, solid wire (which is a single strand of material) and the more commonly used stranded
wire (several wires twisted together to act as one).
Wire Size
Wires have varying sizes or gauges that carry different amounts of electrical current with each wire used for a separate
purpose. The size is called out with a number, such as 8 to 10, followed by the letters AWG (American Wire Gauge).
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
22
ELECTRICAL SYSTEMS
SELF-EVALUATION
Directions: Answer the following questions by circling True or False.
True False 1. 75% of all breakdowns are caused by electrical failure.
True False 2. Nicked or uneven strands of wire cause a reduced amount of current that can be
carried in a wire.
True False 3. Stripping insulation with a knife will ensure a clean and even cut.
True False 4. Twisting the wires with your fingers will ensure an even fit and clean connection.
True False 5. Cable ties and tube clamps minimize vibration and prevent opens and shorts in
the system.
True False 6. Heat from a flame is the best source when installing shrink tubing to protect an
electrical connection.
True False 7. Double crimping an electrical terminal is best to ensure a good electrical contact and
a secure mechanical connection.
True False 8. Proper protection of an electrical connection will ensure that moisture will not corrode
the wire and cause additional resistance in the system.
True False 9. Ohm's Law is E (voltage) = I (current) x R (resistance)
Directions: Circle the best answer.
10. The colors (red, blue, and yellow) are used to tell you
A. The different styles of electrical connectors.
B. The wire range that can be used in the part.
C. The size fuse that must be used in the system.
D. The color of wire that should be used.
11. Electricity is the:
A. Current flow of ionic particles.
B. Mass movement of electrons around a conductor.
C. Relative resistance values of less than 6.24 billion.
D. All of the above
Answers: 1.) True, 2.) True, 3.) False, 4.) False, 5.) True, 6.) False, 7.) True, 8.) True, 9.) True, 10.) B, 11.) B
PHONE: 1-800-558-2808
FAX: 1-800-553-8769
WEB: www.imperialsupplies.com
23