Tutorial Wire

8/14/2019 Tutorial Wire

1/18

Email Home Page

Search

Web www.bcae1.com

www.bcot1.com

Wire

As you already know, wire comes in many different

styles and sizes. The information on this page will cover

many of the design parameters that you must consider

when choosing wire. The most important consideration

is the amount of current that will be carried by the

wire. The wire's size is indicated by gauge. The most

common wire sizes used in car audio range between

4awg and 22awg. The larger the awg (American Wire

Gauge) number, the smaller the wire size.

Resistance:

We already discussed resistance. Now you need to

realize that all wire has resistance. This is the reason

that wire has current limitations. If you remember the

formulas from Ohm's law, you will remember P=I^2*R. The power dissipated in wire will be

in the form of heat.

For Those Who Refuse to Fuse:Now let's see what will happen if excess current is passed through a small conductor. We

will assume that some imaginary piece of wire (we don't want to destroy a real piece of

wire) has 0.01 ohms of resistance (e.g. a 15 foot long piece of 8 gauge wire) and that

wire is connected directly to the positive terminal of the battery (without a fuse...

assuming that you've read the Fuses page, you know that that's a very bad situation).

Now let's say that the other end of the wire is allowed to touch to the chassis of the

vehicle (which, in most vehicles, is connected to the negative terminal of the battery).

The two battery terminals are essentially shorted together by the wire (through the

chassis). In this situation, a very significant amount of current will flow through the piece

www.alibaba.com

Choose From 1M+ Verified Suppliers. Contact Directly & Get Live Quotes!

Copper Wire

E http://www.bcae1.com/w

18 06/08/2013 0


2/18

of wire.

If we wanted to calculate the current flow through the wire, we would use the Ohm's law

formula I=E/R. If we use the ideal automotive battery, which is rated at 12 volts, and

divide it by the resistance of the wire which is approximately .01 ohms, we get a current

of 1200 amps.

I = E/RI = 12/0.01I = 1200 amps

Then plug the current into the formula P=I^2*R. We get:

P = I2*R

P = (1200*1200)*0.01P = 14,400 Watts

This shows that the wire would dissipate 14,400 watts of heat which would melt the

wire's insulation and more than likely ignite everything that comes in contact with the

wire (fuel lines, other wires, carpet, plastic, insulation). In comparison, the largest

burner on your electric stove will not put out that much heat on high!

When this happens, all you can do is stand back and hope that the wire burns open (to

break the circuit -- like the correct fuse would have done). Don't think you could pull the

wire loose with your hands (it's over 1000F when this occurs). It's unlikely that you

could get to a pair of wire cutters before the carpet and plastic panels were burning on

their own. The best that you can hope for is to be able to pull off of the road and get out

of the vehicle before you're seriously injured or killed.

This can also happen if the wire is fused improperly. For example, if the fuse was a 150

amp fuse (often included with fuse holders that accept 4-8g wire), the wire would likely

burn before the fuse blew. If you tap off of a larger wire with a smaller wire (commonly

done to power crossovers and other signal processors/accessories) and the fuseprotecting the large wire was rated significantly higher than the current capacity of the

smaller wire, you would again have a fire hazard.

Note:

We could have also used the formula P = E2/R.

P = E2/R

P = 122/.01

P = 14,400 Watts

Safety:Any time that a tap is made off of a power source (battery, fuse block, distribution

block...), you MUSTput a fuse inline as close to the source as possible. Another thing to

keep in mind is that you must insert a fuse inline anytime that the wire size is reduced,

such as a tap off of the main power wire for an amplifier, head unit, equalizer... The fuse

must be rated to open (blow) well before the wire starts to overheat. A secondary but

very important consideration is environment. Is the temperature going to be extreme,

hot or cold? Is there anything like oil, grease or solvents that will come in contact with

the wire's insulation? All of these things have to be considered when selecting the wire if

you want to build a reliable, well designed system.


18 06/08/2013 0


3/18

Resistance in Speaker Wire:

Many people are told that they need to use very large speaker wire to prevent a

noticeable loss in output. For most situations, 16g speaker wire is absolutely fine. In the

following calculator, you can see just how little loss you'll have with a given wire size.

Keep in mind that 1 dB is generally the minimum difference you'll be able to hear. If the

loss is less than 1dB, you'll never hear it. This calculator was originally written when

amplifiers were rarely capable of producing more than approximately 1000w into 2 ohms.

It's recently been re-written to indicate when the wire needs to be larger to prevent it

from overheating. As with any calculators on the site, email me to let me know if you finda problem with a calculator or to recommend improvements. This calculator was modified

due to concerns of a visitor to the site.

Click HERE to make this applet fill this window.

Loss of Power Output:

Since amplifiers are relatively inefficient and can draw significant amounts of current, it's

necessary to use the proper wire size. The following demo shows how much voltage and

power is lost with a given wire size. Notice that there is loss in the ground wires also. All

of the voltage lost across all of the conductors are added together to give the total loss.

That's subtracted from the battery (charging system) voltage. What's left is what the

amplifier sees. Notice that the loss is not constant. It's proportional to the power output

of the amplifier. At zero volume, there is virtually no current draw and no loss of voltage

(battery_voltage=amplifier_voltage). When the amplifier is at or near full power, the


18 06/08/2013 0


4/18

drop in voltage is much more significant. Length is in feet. 'Gauge' is American Wire

Gauge.


Quick Reference

This table shows the amount of current flow which will cause a 1/2 volt drop in a 15 foot

run of cable. Many people consider 1/2 volt to be the maximum acceptable voltage loss in

a system's main power wire. The 'total amp power' is the total maximum unclipped RMS

power output of all of the amplifiers combined. It is based on 60% efficiency (for class

AB amplifiers) and a battery voltage of 13.8 volts.

For all of the calculators and tables on this page, unless otherwise noted, 'max power'

is the RMS power output when the amplifier is on the threshold of clipping.

Wire Gauge Current FlowMax Total Amp Power

Class AB (60% eff)

Max Total Amp Power

Class D (75% eff)

0 awg 330 amps 2731 watts 3414 watts




18 06/08/2013 0


5/18













Wire GaugeRecommended

Maximum Fuse Size

00 awg 400 amps

0 awg 325 amps

1 awg 250 amps

2 awg 200 amps

4 awg 125 amps

6 awg 80 amps

8 awg 50 amps

10 awg 30 amps

12 awg 20 amps

14 awg 15 amps

16 awg 7.5 amps

These are the recommended maximumfuse ratings for the corresponding wire size. Using a smaller fuse

than what's recommended here will be perfectly safe.

Please note that the recommended fuse ratings are roughly based on 300 circular mils

(explained at the bottom of the page) of copper per amp of current. Others may suggest

slightly different fuses for a given wire size but these should be generally recognized as

safe in most all situations.

For a printable version of this quick reference section, click HERE and print the page that

opens in a new tab. To make the page fit on a single sheet, use the print preview option

in your browser and select 'shrink to fit' then print the page. Printing to one page is

simpler with Firefox or Internet Explorer.


18 06/08/2013 0


6/18

Maximum Power for a Given Wire Size:

If you have a power wire in your vehicle and want to know how much power you can run

on it, use the following calculator. If you don't know if you have class A/B or class D

amplifiers, leave the efficiency at 50%.


Wire and Fuse Selection:

The following calculator will give basic wire and fuse sizes for the main power wire and

for each individual amplifier. Select the class of operation for each amplifier and enter

the power output at the right of the amplifier. If you have less that 4 amplifiers, enter

zero in the fields that are not needed. Keep in mid that these are just suggestions. If your

amplifiers don't have internal or on-board fuses, use the manufacturers suggested fuse

in the distribution block. The fuse sizes given are to protect the vehicle from fire not

necessarily to protect the amplifier.


18 06/08/2013 0


7/18


Power Wire Calculator

Enter the total power output of all of your amplifiers, length of the power wire, wire

gauge you intend to use, battery (charging system) voltage and amplifier efficiency

below.

It will calculate the total voltage drop you can expect in your main power wire at full

power output.

Note: Class A/B amplifiers (most amplifiers) are generally 50-60% efficient at full

power. Class D amplifiers are about 70-80% efficient at full power. Both are much less

efficient at less than full power.

Notice how the current draw increases as the efficiency decreases (and vice versa).

To calculate for

wire sizes 00,

Input


18 06/08/2013 0


8/18

000 and

0000...

00 = -1

000 = -2

0000 = -3

Wire Gauge? 4 (AWG)

Length of Wire? 15 Feet

Total Amplifier Power? 500 Watts

Amplifier Efficiency? 60 %

Charging System Voltage? 13.8 Volts

Calculate Clear

Output

Resistance/foot: 0 Ohms

Total Resistance: 0 Ohms

Voltage Drop: 0 Volts

Current Flow: 0 Amps

Circular Mils: 0

Power Drawn From Charging System: 0 Watts

Notes:If there was a warning of too few circular mils in the calculator above, the wire that

you've chosen may have problems with overheating at full power. You will get this

warning when you punch in the numbers for something like a short piece of 8g wire to

go between the distribution block and the amplifier. Some people use a single strand

of 8g wire to make the connection between the dblock and an 800 or 1000 watt amp.

Even though the voltage drop in that short piece of wire may not be significant, the

power dissipation may be sufficient to soften/melt the insulation. The value of 300

circular mils per amp of current is somewhat arbitrary and may lead to some

arguments but it is a safe value.

Many people find this page when searching for wire current carrying capacity for AC

circuits. The voltage drop given by this calculator is for one conductor (such as thepower wire from the battery to an amplifier). For 2 conductors (such as are used for

120 volt equipment) the voltage drop would be twice the values given by the

calculator.

Oxygen Free Copper:< RANT >

As you have probably noticed, wire designated as OFC wire usually has a clear insulation

and the wire is bright and shiny underneath the transparent insulator. Well... It is nice

and shiny for a while but after a short time (actually from the time it is drawn), it starts


18 06/08/2013 0


9/18

to oxidize (unless the wire is kept in an oxygen free atmosphere). When copper oxidizes,

it becomes a less effective conductor. This means that, in time, the wire's current

carrying capabilities will become significantly reduced. The problem is made worse by

having many very small conductors. This creates even more surface area which makes

the oxidation process even more efficient. In my opinion, if you are designing a system of

any type for long term use, I think the better choice is a 'tinned' copper wire (often sold

as marine grade wire or boat wire). In this type of wire, the copper is plated with tin or

similar conductor (maybe a lead/tin or bismuth/tin alloy) which will not oxidize as

quickly and never as completely as the bare copper. As a side note, this has nothing to dowith the copper being 'oxygen free'. It has everything to do with the fact that the wire is

unprotected (untinned) and is finely stranded. I used OFC wire in this example because

most OFC has many fine unprotected strands.< /RANT >

Tech Tip

Wire Connections and Resistance:

Whenever making connections, make sure that they are tight. If you're making crimp

connections, try to pull the wire out of the connector. If you can pull the wire out of the

connector, it wasn't crimped good enough. If you are inserting the wire into a terminal

block, tighten the screw down tight. If there is a bad connection and a sufficient amount

of current flow through the junction (wire to terminal block), the block will heat up and

possibly do irreparable damage to the terminal block or the printed circuit board (if the

terminal block is on your amp).

Calculating Resistance and Cross Sectional Area

Calculating Resistance:

At some point in time, you may need to determine the resistance in a length of wire but

you may not have a reference book available. This section will help you to calculateresistance for different wire sizes and lengths. To make quick calculations with an easy

reference I use 10g wire as the starting point. It's resistance is approximately 1 ohm per

thousand feet of wire length which makes it easy to remember. For non critical

calculations, I round it to 1 ohm/1000 ft or 0.001 ohms/foot of wire. If you have a 15

foot run of 10g wire and want to determine the resistance in that run of wire (like the

calculator does above), you simply multiply the resistance per foot by the length of the

wire.

Resistance = .001*15 Resistance = .015 ohms

Different Wire Gauges:

The previous calculation is great if you're using 10g wire but what if you have a different

wire gauge. Although wire resistance can be calculated using a logarithmic scale, I'm

going to keep it simple here and use a simple multiplier. For each single digit change in

the gauge, the resistance changes by a factor of ~1.26. This means that an 11g wire

would have a resistance of approximately 1.26 ohms per thousand feet of wire

(remember that we're using 10g wire as a reference and it has a resistance of 1 ohm per

thousand feet). A 9g wire would have a resistance of ~.79 ohms per thousand feet (1

ohm/1.26). You can easily step through the wire sizes by continuing to multiply each

consecutive value by 1.26. If you have to calculate the resistance of a wire with a

significantly larger or smaller gauge (like 4g power wire), you can use the following


18 06/08/2013 0


10/18

formula:

For 4g wire:Resistance = 1/1.26^(difference between 4g and 10g) Resistance = 1/1.26^6 Resistance = 1/4 ohms per1000 feet of wire Resistance = .25 ohms per 1000 feet of wire (or 0.00025 ohms per foot)

Or for 16g wire:Resistance = 1*1.26^(difference between 16g and 10g) Resistance = 1*1.26^6 Resistance = 1*4 ohms per1000 feet of wire Resistance = 4 ohms per 1000 feet of wire (or 0.004 ohms per foot)

Or for 20g wire:Resistance = 1*1.26^(difference between 20g and 10g) Resistance = 1*1.26^10 Resistance = 1*10 ohms per1000 feet of wire Resistance = 10 ohms per 1000 feet of wire (or 0.01 ohms per foot)

To determine the voltage drop at the current that you expect to pass through the wire,

you can use the Ohm's Law formula V=I*R. Vis the voltage drop across the piece of wire.

Iis the current flow through the wire. Ris the resistance of the length of wire. If you

have 15 feet of 4g power wire and your amplifier will draw 150 amps max...

Voltage Drop = current flow * (length of wire in feet * resistance per foot) Voltage Drop = 150 * (15*.00025)Voltage Drop = 150 *.00375 ohms Voltage Drop = .563 volts at 150 amps of current

Calculating Wire Diameter and Area:

Here in the US, we use the AWG (American Wire Gauge), circular mils and square mils. In

most other parts of the world, they use mm2. I'll try to touch on each of these.

Solid Wire Diameter:

This section will address the diameter of solid wire. Stranded wire has air spaces

between conductors and different combinations of different gauge strands will result in

different overall diameters. Keep in mind that, in the following description, we are talking

about the area of the wire in a circular shape. This means that the total cross sectional

area is doubled when the diameter is increased by a factor of 1.414.

OK... For a reference that's relatively easy to remember, lets use 10g wire again. It's

~0.1" in diameter. If we go up in wire size 6 sizes again (to 4g), the diameter is going to

be double the 10g wire. The multiplier is ~1.123 per gauge.

Diameter = .1*1.123^(difference between 4g and 10g) Diameter = .1*1.123^6 Diameter = .1*2.005 Diameter =approximately 0.2" in diameter


f 18 06/08/2013 0


11/18

This image shows the relative difference between

10g and 4g wires (not actual size). You can easily

see that doubling the diameter quadruples the cross

sectional area.

Until now we've only discussed the diameter of the wire. The cross sectional area of

round wire is the one-half of the diameter (the radius) squared then multiplied by Pi

(r2*3.14). For some conductors like buss bars and circuit boards, you won't have a wire

gauge or diameter to use to see how much current a conductor can handle. Circular mils,

square mils and mm2allow us to express the cross sectional area and therefore calculate

the resistance for the conductor. It has another advantage over simply stating the

diameter of a conductor in that it doesn't matter if the wire is stranded or solid. If a cross

sectional area is given in in circular mils, square mils and mm2, spaces between

conductors are no longer a factor.

Circular Mils:

One 'mil' is one thousandth of an inch. A wire with a cross sectional area of 1 circular milhas a diameter of .001". If we need to calculate the circular mils for a 10g wire, we

simply square the diameter in mils. Since the 10g wire has an approximate diameter of

.1" or 100 mils, we square 100 and get 10,000 circular mils. 10g wire actually has a cross

sectional area of 10,384 circular mils but for car audio appliciations, 10,000 circular mils

will be close enough and easy to remember.

Note:

Various wire tables list slightly different values for circular mils and the diameter of the different wire sizes. The values here are a

rough average of the various tables I've found.

Circular Mil Foot:

A circular mil foot is a piece of wire with a cross sectional area of 1 circular mil and alength of 1 foot. To calculate the resistance for a length of wire, there are a couple of

things you need to know. The first, cross sectional area in circular mils, has been

discussed. The second, the length, is known (15 feet in this example). And the Third is

the Specific Resistivity for the conductor. The Specific Resistivity is the value of

resistance for a circular mil foot of wire. For copper, the SR is 10.37. To determine the

resistance for a 15 foot long piece of 10g wire we can use the following formula:

Resistance = SR*(length of wire/cross sectional area in circular mils)Resistance = 10.37*(15 feet/10384 circular mils)Resistance = 0.015 ohms for a 15 foot length


f 18 06/08/2013 0


12/18

For 4g wire:

Resistance = SR*(length of wire/cross sectional area in circular mils)Resistance = 10.37*(15 feet/41534 circular mils) (4g wire has 41534 circular mils)Resistance = 0.00375 ohms for a 15 foot length

As you can see, we got the same resistance for the 15 foot long piece of 10g wire as

before (with an entirely different method). If you were using a different type of wire like

silver, gold or aluminum, the specific resistance would be different. You should also know

that the SR used here is for copper at or near room temperature (~70F).

Square Mils:

Square Mils are similar to circular mils in that their outer dimensions are again 1 mil but

this time we're talking about the area of a square instead of a circle. This makes a square

mil slightly larger than a circular mil. The conversion factor to convert from one to the

other is:

1 circular mil = .7854 square mils

Circular Mils? 10380 Click to Convert Square Mils: 0

or

1 square mil = 1.273 circular mils

Square Mils? 8151 Click to Convert Circular Mils: 0

This diagram should help you

understand the difference between a

circular and a square mil.

Square Millimeters:

In Europe and other parts of the world, they use a somewhat less confusing system to

express wire cross sectional area. They express it in square millimeters(mm2). For square

conductors, it is simply the height times the width of the conductor in millimeters. For

round conductors, it's the radius (half the diameter) of the conductor squared then


f 18 06/08/2013 0


13/18

multiplied by Pi.

For example a 10g conductor with a diameter of ~2.6mm:Area of the conductor = radius of conductor squared*PiArea of the conductor = R2*3.14Area of the conductor = 1.32*3.14Area of the conductor = 1.69*3.14Area of the conductor = 5.3 mm2

To calculate for

wire sizes 00,

000 and

0000...

00 = -1

000 = -2

0000 = -3

Input

Wire Gauge? 10 (AWG)

Calculate Area Clear

Output

Circular Mils: 0

Radiusof Round Wire: 0 Inches

Radiusof Round Wire: 0 mm

Cross Sectional Area: 0 mm

The following diagram shows the relationship between a piece of solid round wire and a

piece of square copper stock with the same area (and therefore the same resistance for a

given length).

Square Millimeters to Circular Mils:

To convert from mm2to circular mils, multiply by 1973.

For 10g wire:5.3 mm * 1973 = 10457 circular mils

Square Millimeters?

5.26Click to Convert

Circular Mils:

0


f 18 06/08/2013 0


14/18

The answer we got (10457) is a little off from the actual value of 10384 circular mils for

10g wire but that's because we didn't have enough significant digits for the area of the

wire. If we'd used the more accurate value of 5.26, we'd have been closer to the actual

cross sectional area. Either value is close enough for this tutorial and anything related to

car audio.

Solid Wire Table:The values in the first table are based on a value of 10,000 circular mils for 10g wire. I

skewed the values slightly so you could see how the diameter and cross sectional area of

one wire relates to the others. Remember that 10g wire is the reference. The second

table is more accurate. The values on either table would be good enough for calculations

in car audio applications.

Solid Wire Dimensions and Resistance

Skewed for clarity

A.W.G. Ohms per foot Circular MilsDiameter

(inches)

4/0 0.00004961 201585.18 0.4490

3/0 0.00006250 159998.40 0.4000

2/0 0.00007875 126990.92 0.3564

0 0.00009921 100792.84 0.3175

1 0.00012500 79999.40 0.2828

2 0.00015749 63495.62 0.2520

3 0.00019843 50396.55 0.2245

4 0.00025000 39999.80 0.2000

5 0.00031498 31747.89 0.1782

6 0.00039685 25198.34 0.1587

7 0.00050000 19999.95 0.1414

8 0.00062996 15873.98 0.1260

9 0.00079370 12599.20 0.1122

10 0.00100000 10000.00 0.1000

11 0.00125992 7937.01 0.0891

12 0.00158740 6299.62 0.0794

13 0.00200000 5000.01 0.0707

14 0.00251983 3968.52 0.0630

15 0.00317479 3149.82 0.0561

16 0.00399998 2500.01 0.0500

17 0.00503965 1984.26 0.0445

18 0.00634956 1574.91 0.0397

19 0.00799994 1250.01 0.0354

20 0.01007928 992.13 0.0315

21 0.01269909 787.46 0.0281

22 0.01599984 625.01 0.0250

Solid Wire Dimensions and Resistance

More Accurate

A.W.G. Ohms per foot Circular MilsDiameter

(inches)

4/0 0.00004955 209322.28 0.4575

3/0 0.00006242 166139.20 0.4076

2/0 0.00007865 131864.77 0.3631

0 0.00009909 104661.14 0.3235

1 0.00012485 83069.60 0.2882

2 0.00015730 65932.39 0.2568

3 0.00019818 52330.57 0.2288

4 0.00024969 41534.80 0.2038

5 0.00031460 32966.19 0.1816

6 0.00039636 26165.28 0.1618

7 0.00049939 20767.40 0.1441

8 0.00062919 16483.10 0.1284

9 0.00079273 13082.64 0.1144

10 0.00099878 10383.70 0.1019

11 0.00125838 8241.55 0.0908

12 0.00158546 6541.32 0.0809

13 0.00199755 5191.85 0.0721

14 0.00251676 4120.77 0.0642

15 0.00317092 3270.66 0.0572

16 0.00399511 2595.93 0.0510

17 0.00503352 2060.39 0.0454

18 0.00634184 1635.33 0.0404

19 0.00799022 1297.96 0.0360

20 0.01006704 1030.19 0.0321

21 0.01268368 817.67 0.0286

22 0.01598043 648.98 0.0255


f 18 06/08/2013 0


15/18

23 0.02015852 496.07 0.0223

24 0.02539812 393.73 0.0198

25 0.03199960 312.50 0.0177

26 0.04031694 248.03 0.0157

27 0.05079611 196.87 0.0140

28 0.06399904 156.25 0.0125

29 0.08063367 124.02 0.011130 0.10159197 98.43 0.0099

31 0.12799776 78.13 0.0088

32 0.16126694 62.01 0.0079

33 0.20318344 49.22 0.0070

34 0.25599488 39.06 0.0063

35 0.32253307 31.00 0.0056

36 0.40636586 24.61 0.0050

37 0.51198848 19.53 0.0044

38 0.64506453 15.50 0.003939 0.81272970 12.30 0.0035

40 1.02397440 9.77 0.0031

23 0.02013408 515.10 0.0227

24 0.02536735 408.83 0.0202

25 0.03196086 324.49 0.0180

26 0.04026816 257.55 0.0160

27 0.05073471 204.42 0.0143

28 0.06392172 162.25 0.0127

29 0.08053632 128.77 0.011330 0.10146941 102.21 0.0101

31 0.12784345 81.12 0.0090

32 0.16107265 64.39 0.0080

33 0.20293882 51.10 0.0071

34 0.25568689 40.56 0.0064

35 0.32214530 32.19 0.0057

36 0.40587764 25.55 0.0051

37 0.51137379 20.28 0.0045

38 0.64429060 16.10 0.004039 0.81175529 12.78 0.0036

40 1.02274758 10.14 0.0032

The Following calculator will allow you to enter whole and fractional wire gauges

(fractional wire gauges are used for magnet wire) between 0000 and 46 gauge. It also

allows direct current input instead of having it calculated like the calculator above. After

all of the material we just covered, it should be self-explanatory. Due to different

rounding on the spreadsheet and the calculator, the values will differ slightly between

the calculator and the table above.

To calculate for

wire sizes 00,

000 and

0000...

00 = - 1

000 = - 2

0000 = - 3

Input

Wire Gauge? 4 (AWG)

Length of Wire? 15 Feet

Current Flow? 150 Max Amps

Calculate Voltage Drop Clear

Output

Resistance/foot: 0 Ohms

Total Resistance: 0 Ohms

Circular Mils: 0

Voltage Drop: 0 Volts

Cir Mils/Amp: 0


f 18 06/08/2013 0


16/18

If you need to know how many 8 gauge wires are equal to 1

4 gauge wire(s),

press this Button .

The answer is: 0

Wire Insulation Types

Definitions

PVC:

PVC is short for PolyVinyl Chloride. Different formulations make the material soft and

suitable for wire insulation or hard and suitable for water and drain pipe.

Thermoplastic:

A thermoplastic is a plastic that can be softened by heat which allows it to be easily

formed. Different types of thermoplastics are PVC, Polyethylene and Polypropylene.

Latex:A light colored fluid produced by various plants and used to make latex rubber products.

Common Wire Designations

The following designations will help you understand the properties of thhn and other

wire types. Keep in mind that these are general properties. There will be exceptions to

these rules. Before you use any wire in a critical situation, consult the datasheet from

the wire's manufacturer.

T Thermoplastic insulator (generally PVC)

HDry location - household/building wire (generally the first 'H' if there are 2 Hs)

High temperature (second H if there are 2 Hs)

N Nylon outer insulator (protects against abrasion)

SSilicone rubber (if used at beginning of designation) Generally used in high temp

applications.


f 18 06/08/2013 0


17/18

Switchboard wire (if used at end of designation)

B Braided

W Wet locations

R Rubber (non specific)

RU Latex rubber

A Asbestos

F Fixture Wiring

Specific Wire Designations (individual conductors)

THHNHightemperature (90C 194F max.) thermoplastic for use in dry locations like building

wiring with a nylon outer insulator.

THWN Standard temperature (75C 167F) thermoplastic for use in wet or dry locations with anylon outer coating.

RW Moisture resistant rubber

R Rubber

RH Rubber moderate temperature (75C 167F)

RHH Rubber high temperature (90C 194F)

TBS Thermoplastic insulator with braided cover (generally used for switchboard applications)

RUH Heat resistant latex rubber

You should remember:

Wire has resistance and therefore will have a voltage drop across the length of it

any time current is flowing through it.

You May Be Interested in My Other Sites

All Sorts of Stuff:This site was started for pages/information that didn't fit well on my other sites. It includes topics from backing up

computer files to small engine repair to 3D graphics software to basic information on diabetes.

Basic Macro Photography:

This site introduces you to macro photography. Macro photography is nothing more than the photography of small

objects. It can take quite a while to understand the limitations associated with this type of photography. Without help,

people will struggle to get good images. Understanding what's possible and what's not possible makes the task much

easier. If you need to photograph relatively small objects (6" in height/width down to a few thousandths of an inch), this

site will help.

Air Rifle Links and Demos:

If you're interested in air rifles, this site will introduce you to the types of rifles available and many of the things you'll

need to know to shoot accurately. It also touches on field target competition. There are links to some of the better sites


f 18 06/08/2013 0


18/18

and forums as well as a collection of interactive demos.

Basic Computer Operation:

This site helps anyone new to computers and anyone with a basic understanding of computers with a desire to learn

more about the internal components of a computer. If you have a computer that you'd like to upgrade but don't know

where to start, this is a good site for you.

Basic Go-Kart Mechanics:

This site is for those who want to begin racing karts but don't fully understand how the various parts work. It's mostly

interactive demos that show how the various parts of the kart work.

Click HEREto visit a friend's new car audio tech site.

calculator


Documents

Tutorial Wire