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Category: Electrical Tables

UL Fuse Classification

Posted on by Brandy McNeil
Ul Class Fuse Overload Characteristics Interrupting Rating, Amperes AC Voltage Rating Available Ampere Ratings Ferraz-Shawmut Part Number
L TIME-DELAY 200,000 600 200 – 6000
601 – 4000
200 – 2000 		A4BQ
A4BT
A4BQ
RK1*** TIME-DELAY 200,000 250
600 		1/10 – 600 A2D-R
A6D-R
FAST-ACTING 200,000 250
600 		1 – 600 A2K-R
A6K-R
RK5 TIME-DELAY 200,000 250
600 		1/10 – 600 TR-R
A2D-R
TRS-R
A6D-R
A6DR IDSR
T FAST-ACTING 200,000 300
600 		1 – 1200
1 – 1200 		A3T
A6T
J TIME-DELAY 200,000 600 1 – 600 AJT
FAST-ACTING 200,000 600 1 – 600 A4J
CC TIME-DELAY 200,000 600 1/10 – 30
1/4 – 30 		ATQR
ATDR
FAST-ACTING 200,000 600 1/10 ATMR
CD TIME-DELAY 200,000 600 35 – 60 ATDR
G TIME-DELAY 100,000 480 1/2 – 60 AG
K5 FAST-ACTING 50,000 250
600 		1 – 600 OT
OTS
H Renewable Fuses Fast-Acting 10,000 250
600 		1 – 600 RF
RFS

Temperature Conversion Table

Posted on by Brandy McNeil
C° F° C° F° C° F° C° F°
0 32
1 33.8 26 78.8 51 123.8 76 168.8
2 35.6 27 80.6 52 125.6 77 170.6
3 37.4 28 82.4 53 127.4 78 172.4
4 39.2 29 84.2 54 129.2 79 174.2
5 41 30 86 55 131 80 176
6 42.8 31 87.8 56 132.8 81 177.8
7 44.6 32 89.6 57 134.6 82 179.6
8 46.4 33 91.4 58 136.4 83 181.4
9 48.2 34 93.2 59 138.2 84 183.2
10 50 35 95 60 140 85 185
11 51.8 36 96.8 61 141.8 86 186.8
12 53.6 37 98.6 62 143.6 87 188.6
13 55.4 38 100.4 63 145.4 88 190.4
14 57.2 39 102.2 64 147.2 89 192.2
15 59 40 104 65 149 90 194
16 60.8 41 105.8 66 150.8 91 195.8
17 62.6 42 107.6 67 152.6 92 197.6
18 64.4 43 109.4 68 154.4 93 199.4
19 66.2 44 111.2 69 156.2 94 201.2
20 68 45 113 70 158 95 203
21 69.8 46 114.8 71 159.8 96 204.8
22 71.6 47 116.6 72 161.6 97 206.6
23 73.4 48 118.4 73 163.4 98 208.4
24 75.2 49 120.2 74 165.2 99 210.2
25 77 50 122 75 167 100 212

Specific Resistance

Posted on by Brandy McNeil

The Specific Resistance (K) of a material is the resistance offered by a
wire of this material which is one foot long with a diameter of one MIL.

The resistance of a wire is directly proportional to the specific
resistance of the material.

Material “K” Material “K”
Brass 43.0 Aluminum 17.0
Constantan 295 Monel 253
Copper 10.8 Nichrome 600
German Silver 18 % 200 Nickel 947
Gold 14.7 Tantalum 93.3
Iron (Pure) 60.0 Tin 69.0
Magnesium 276 Tungsten 34.0
Manganin 265 Silver 9.7
“K” = Specific Resistance

Full Load Current: Three Phase AC Motors

Posted on by Brandy McNeil
Motor Horsepower Motor Ampere Size Breaker Size Starter Heater Ampere Size Wire Size Conduit
1 230V
460 V 		4.2
2.1 		15
15 		00
00 		4.830
2.415 		12
12 		3/4″
3/4″
1-1/2 230V
460V 		6.0
3.0 		15
15 		00
00 		6.900
3.450 		12
12 		3/4″
3/4″
2 230V
460V 		6.8
3.4 		15
15 		0
00 		7.820
3.910 		12
12 		3/4″
3/4″
3 230V
460V 		9.6
4.8 		15
15 		0
0 		11.040
5.520 		12
12 		3/4″
3/4″
5 230V
460V 		15.2
7.6 		15
15 		1
0 		17.480
8.740 		12
12 		3/4″
3/4″
7-1/2 230V
460V 		22
11 		40
30 		1
1 		25.300
12.650 		10
12 		3/4″
3/4″
10 230V
460V 		28
14 		50
30 		2
1 		32.200
16.100 		10
12 		3/4″
3/4″
15 230V
460V 		42
21 		70
40 		2
2 		48.300
24.150 		6
10 		1″
3/4″
20 230V
460V 		54
27 		100
50 		3
2 		62.100
31.050 		6
10 		1″
3/4″
25 230V
460V 		68
34 		100
50 		3
2 		78.200
39.100 		4
8 		1-1/2″
1″
  1. 1. Overcurrent device may have to be increased due to starting current and
    load conditions. See NEC 430-52, Table 430-152. Wire based on 75°C
    terminations and insulation.
  2. 2. Overload heater must be based on motor nameplate and sized per NEC
    430-32.
  3. 3. Conduit size based on Rigid metal conduit with some spare capacity. For
    minimum size and other conduit types, see NEC Appendix C, or UGLY’S pages
    102-122.

Approximate Full Load Amperes

Posted on by Brandy McNeil
MOTOR R. P. M.
Horse Power VOLTS 3800 1800 1200 900
1/2 230 1.72 2.15 2.38
460 .86 1.08 1.19
3/4 230 2.46 2.93 3.26
460 1.23 1.46 1.63
1 230 2.80 3.56 3.76 4.30
460 1.40 1.78 1.88 2.15
1 1/2 230 4.36 4.86 5.28 5.60
460 2.18 2.43 2.64 2.80
2 230 5.60 6.40 6.84 7.90
460 2.80 3.20 3.42 3.95
3 230 8.34 9.40 .20 11.40
460 4.17 4.70 5.12 5.70
5 230 13.50 14.40 15.80 15.90
460 6.76 7.21 7.91 7.92
7 1/2 230 19.50 21.50 21.80 23.00
460 9.79 10.70 10.90 11.50
10 230 25.40 26.80 28.00 30.50
460 12.70 13.40 24.00 15.20
15 230 36.40 39.20 41.40 44.50
460 18.20 19.60 20.70 22.20
20 230 50.40 51.20 52.80 54.90
460 25.20 25.60 26.40 27.40
25 230 60.80 64.80 65.60 67.30
460 30.40 32.40 32.80 33.70
30 230 73.70 75.60 78.80 81.80
460 36.80 37.80 39.40 40.90
40 230 96.40 101.00 102.00 105.00
460 48.20 50.50 50.60 52.50
50 230 120.00 124.00 126.00 130.00
460 60.00 62.00 63.00 65.00
60 230 143.00 149.00 150.00 154.00
460 71.50 74.50 75.00 77.00
75 230 179.00 183.00 184.00 193.00
460 89.60 91.50 92.00 96.50
100 230 231.00 236.00 239.00 252.00
460 115.00 118.00 120.00 126.00
125 230 292.00 293.00 298.00 305.00
460 146.00 147.00 149.00 153.00
150 230 343.00 348.00 350.00 365.00
460 171.00 174.00 175.00 183.00
200 230 458.00 452.00 460.00 482.00
460 229.00 226.00 230.00 241.00

Common Conversion Factors

Posted on by Brandy McNeil
Multiply: By: To Obtain:
Acres 43560 Square Feet
Acres 1.562 x 10-3 Square Miles
Acre-Feet 43560 Cubic Feet
Amperes per sq cm 6.452 Amperes per sq in.
Amperes per sq in. 0.1550 Amperes per sq cm.
Ampere-Turns 1.257 Gilberts
Ampere-Turns per cm 2.540 Ampere-Turns per in.
Ampere-Turns per in. 0.3937 Ampere-Turns per cm.
Atmospheres 76.0 Cm of mercury
Atmospheres 29.92 Inches of mercury
Atmospheres 33.90 Feet of Water
Atmospheres 14.70 Pounds per sq in.
British thermal units 252.0 Calories
British thermal units 778.2 Foot-Pounds
British thermal units 3.960 x 10-4 Horsepower-Hours
British thermal units 0.2520 Kilogram-calories
British thermal units 107.6 Kilogram-meters
British thermal units 2.931 x 10-4 Kilowatt-hours
British thermal units 1055 Watt-seconds
Btu per hour 2.931 x 10-2 Kilowatts
Btu per minute 2.359 x 10-2 Horsepower
Btu. per minute 1.759 x 10-2 Kilowatts
Bushels 1.244 Cubic Feet
Centimeters 0.3937 Inches
Circular mils 5.067 x 10-6 Square centimeters
Circular mils 0.7854 x 10-6 Square inches
Circular mils 0.7854 Square mils
Cords 128 Cubic Feet
Cubic Centimeters 6.102 x 10-6 Cubic Inches
Cubic feet 0.02832 Cubic meters
Cubic feet 7.481 Gallons
Cubic feet 28.32 Liters
Cubic Inches 16.39 Cubic centimeters
Cubic meters 35.31 Cubic feet
Cubic meters 1.308 Cubic yards
Cubic yards 0.7646 Cubic meters
Degrees [angle] 0.01745 Radians
Dynes 2.248 x 10-6 Pounds
Ergs 1 Dyne-centimeters
Ergs 7.37 x 10-6 Foot-pounds
Ergs 10-7 Joules
Farads 106 Microfarads
Fathoms 6 Feet
Feet 30.48 Centimeters
Feet of Water .08826 Inches of mercury
Feet of Water 304.8 Kg per square meter
Feet of Water 62.43 Pounds per square ft.
Feet of Water 0.4335 Pounds per square in.
Foot-pounds 1.285 x 10-2 British thermal units
Foot-pounds 5.050 x 10-7 Horsepower-hours
Foot-pounds 1.356 Joules
Foot-pounds 0.1383 Kilogram-meters
Foot-pounds 3.766 x 10-7 Kilowatt-hours
Gallons 0.1337 Cubic Feet
Gallons 231 Cubic Inches
Gallons 3.785 x 10-3 Cubic Meters
Gallons 3.785 Liters
Gallons per minute 2.228 x 10-3 Cubic Feet per second
Gausses 6.452 Lines per square in.
Gilberts 0.7958 Ampere-turns
Henries 103 Millihenries
Horsepower 42.41 Btu per min
Horsepower 2544 Btu per hour
Horsepower 550 Foot-pounds per sec
Horsepower 33000 Foot-pounds per min
Horsepower 1.014 Horsepower (metric)
Horsepower 10.70 Kg calories per min
Horsepower 0.7457 Kilowatts
Horsepower (boiler) 33520 Btu per hour
Horsepower – hours 2544 British thermal units
Horsepower – hours 1.98 x 106 Foot-pounds
Horsepower – hours 2.737 x 105 Kilogram-meters
Horsepower – hours 0.7457 Kilowatt-hours
Inches 2.540 Centimeters
Inches of mercury 1.133 Feet of water
Inches of mercury 70.73 Pounds per square ft.
Inches of mercury 0.4912 Pounds per square in.
Inches of water 25.40 Kg per square meter
Inches of water 0.5781 Ounces per square in.
Inches of water 5.204 Pounds per square ft.
Joules 9.478 x 10-4 British thermal units
Joules 0.2388 Calories
Joules 107 Ergs
Joules 0.7376 Foot-Pounds
Joules 2.778 x 10-7 Kilowatt-hours
Joules 0.1020 Kilogram-meters
Joules 1 Watt-seconds
Kilograms 2.205 Pounds
Kilogram-calories 3.968 British thermal units
Kilogram meters 7.233 Foot-pounds
Kg per square meter 3.281 x 10-3 Feet of water
Kg per square meter 0.2048 Pounds per square ft.
Kg per square meter 1.422 x 10-3 Pounds per square in.
Kilolines 103 Maxwells
Kilometers 3.281 Feet
Kilometers 0.6214 Miles
Kilowatts 56.87 Btu per min
Kilowatts 737.6 Foot-pounds per second
Kilowatts 1.341 Horsepower
Kilowatts-hours 3.415 British thermal units
Kilowatts-hours 2.655 x 106 Foot-pounds
Knots 1.152 Miles
Liters 0.03531 Cubic Feet
Liters 61.02 Cubic Inches
Liters 0.2642 Gallons
Log Ne or in N 0.4343 Log10N
Log N 2.303 Loge N or in N
Lumens per square ft. 1 Footcandles
Maxwells 10-3 Kilolines
Megalines 106 Maxwells
Megaohms 106 Ohms
Meters 3.281 Feet
Meters 39.37 Inches
Meter-kilograms 7.233 Pound-feet
Microfarads 10-6 Farads
Microhms 10-6 Ohms
Microhms per cm cube 0.3937 Microhms per in cube
Microhms per cm cube 6.015 Ohms per mil foot
Miles 5280 Feet
Miles 1.609 Kilometers
Miner’s Inches 1.5 Cubic feet per min.
Ohms 10-6 Megohms
Ohms 106 Microhms
Ohms per mil foot 0.1662 Microhms per cm cube
Ohms per mil foot 0.06524 Microhms per in. cube
Poundals 0.03108 Pounds
Pounds 32.17 Poundals
Pound-feet 0.1383 Meter-kilograms
Pounds of water 0.01602 Cubic Feet
Pounds of water 0.1198 Gallons
Pounds per cubic foot 16.02 Kg per cubic meter
Pounds per cubic foot 5.787 x 10-4 Pounds per cubic in.
Pounds per cubic inch 27.68 Grams per cubic cm.
Pounds per cubic inch 2.768 x 10-4 Kg per cubic meter
Pounds per cubic inch 1.728 Pounds per cubic ft.
Pounds per square foot 0.01602 Feet of Water
Pounds per square foot 4.882 Kg per square meter
Pounds per square foot 6.944 x 10-3 Pounds per sq. in.
Pounds per square inch 2.307 Feet of Water
Pounds per square inch 2.036 Inches of Mercury
Pounds per square inch 703.1 Kg per square meter
Radians 57.30 Degrees
Square centimeters 1.973 x 105 Circular mils
Square Feet 2.296 x 10-5 Acres
Square Feet 0.09290 Square meters
Square inches 1.273 x 106 Circular mils
Square inches 6.452 Square centimeters
Square Kilometers 0.3861 Square miles
Square meters 10.76 Square feet
Square miles 640 Acres
Square miles 2.590 Square kilometers
Square Millimeters 1.973 x 103 Circular mils
Square mils 1.273 Circular mils
Tons (long) 2240 Pounds
Tons (metric) 2205 Pounds
Tons (short) 2000 Pounds
Watts 0.05686 Btu per minute
Watts 107 Ergs per sec
Watts 44.26 Foot-pounds per in
Watts 1.341 x 10-3 Horsepower
Watts 14.34 Calories per min
Watts-hours 3.412 British thermal units
Watts-hours 2655 Footpounds
Watts-hours 1.341 x 10-3 Horsepower-hours
Watts-hours 0.8605 Kilogram-calories
Watts-hours 376.1 Kilogram-meters
Webers 108 Maxwells

Nema Locking Blade Configurations

Posted on by Brandy McNeil
Wiring Voltage 15 AMPERE 20 AMPERE 30 AMPERE
Receptacle Plug Receptacle Plug Receptacle Plug
2-Pole 2-Wire
125V L1 L1-15R
L1-15R 		L1-15P
L1-15P
250V L2 L2-20R
L2-20R 		L2-20P
L2-20P
277V AC L3 Reserved For Future Configurations
600V L4 Reserved For Future Configurations
2-Pole 3-Wire Grounding
125V L5 L5-15R
L5-15R 		L5-15P
L5-15P 		L5-20R
L5-20R 		L5-20P
L5-20P 		L5-30R
L5-30R 		L5-30P
L5-30P
250V L6 L6-15R
L6-15R 		L6-15P
L6-15P 		L6-20R
L6-20R 		L6-20P
L6-20P 		L6-30R
L6-30R 		L6-30P
L6-30P
277V AC L7 L7-15R
L7-15R 		L7-15P
L7-15P 		L7-20R
L7-20R 		L7-20P
L7-20P 		L7-30R
L7-30R 		L7-30P
L7-30P
347V AC L24 L24-20R
L24-20R 		L24-20P
L24-20P
480V AC L8 L8-20R
L8-20R 		L8-20P
L8-20P 		L8-30R
L8-30R 		L8-30P
L8-30P
600V AC L9 L9-20R
L9-20R 		L9-20P
L9-20P 		L9-30R
L9-30R 		L9-30P
L9-30P
3-Pole 3-Wire
125/250V L10 L10-20R
L10-20R 		L10-20P
L10-20P 		L10-30PR width=
L10-30R 		L10-30P
L10-30P
3Ø 250V L11 L11-15R
L11-15R 		L11-15P
L11-15P 		L11-20R
L11-20R 		L11-20P
L11-20P 		L11-30R
L11-30R 		L11-30P
L1-30P
3Ø 480V L12 L12-20R
L12-20R 		L12-20P
L12-20P 		L12-30R
L12-30R 		L12-30P
L12-30P
3Ø 600V L13 L13-30R
L13-30R
L13-30P
3-Pole 40Wire Grounding
125/250V L14 L14-20R
L14-20R 		L14-20P
L14-20P 		L14-30R
L14-30R 		L14-30P
L14-30P
3Ø 250V L15 L15-20R
L15-20R 		L15-20P
L15-20P 		L15-30R
L15-30R 		L15-30P
L15-30P
3Ø 480V L16 L16-20R
L16-20R 		L16-20P
L16-20P 		L16-30R
L16-30R 		L16-30P
L16-30P
3Ø 600V L17 L17-30R
L17-30R 		L17-30P
L17-30P
4-Pole 4-Wire
3ØY 120/208V L18 L18-20R
L18-20R 		L18-20P
L18-20P 		L18-30R
L18-30R 		L18-30P
L18-30P
3ØY 277/480V L19 L19-20R
L19-20R 		L19-20P
L19-20P 		L19-30R
L19-30R 		L19-30P
L19-30P
3ØY 347/600V L20 L20-20R
L20-20R 		L20-20P
L20-20P 		L20-30R
L20-30R 		L20-30P
L20-30P
4-Pole 5-Wire Grounding
3ØY 120/208V L21 L21-20R
L21-20R 		L21-20P
L21-20P 		L21-30R
L21-30R 		L21-30P
L21-30P
3ØY 277/480V L22 L22-20R
L22-20R 		L22-20P
L22-20P 		L22-30R
L22-30R 		L22-30P
L22-30P
3ØY 347/600v L23 L23-20R
L23-20R 		L23-20p
L23-20P 		L23-30R
L23-30R 		L23-30P
L23-30P

Nema Straight Blade Configurations

Posted on by Brandy McNeil

NEMA Configurations for general-purpose nonlocking Plugs and Receptacles

Voltage 15 Ampere 20 Ampere 30 Ampere 50 Ampere 60 Ampere
Receptacle Plug Receptacle Plug Receptacle Plug Receptacle Plug Receptacle Plug
2 Pole 2 Wire
125V 1
1-15R
1-15P
250V 2
2-15P
2-20R
2-20P
2-30R
2-30P
277V AC 3 Reserved For Future Configurations
600V 4 Reserved For Future Configurations
2 Pole 3 Wire Grounding
125V 5
5-15R
5-15P
5-20R
5-20P
5-30R
5-30P
5-50R
5-50P
250V 6
6-15R
6-15P
6-20R
6-20P
6-30R
6-30P
6-50R
6-50P
277V AC 7
7-15R
7-15P
7-20R
7-20P
7-30R
7-30P
7-50R
7-50P
347V AC 24
24-15R
24-15P
24-20R
24-20P
24-30R
24-30P
24-50R
24-50P
480V AC 8 Reserved For Future Configurations
600V 9 Reserved For Future Configurations
3 Pole 3 Wire
125/250V 10
10-20R
10-20P
10-30R
10-30P
10-50R
10-50P
3Ø 250V 11
11-15R
11-15P
11-20R
11-20P
11-30R
11-30P
11-50R
11-50P
3Ø 480V 12 Reserved For Future Configurations
3Ø 600V 13 Reserved For Future Configurations
3 pole 4 Wire Grounding
125/250V 14
14-15R
14-15P
14-20R
14-20P
14-30R
14-30P
14-50R
14-50P
14-60R
14-60P
3Ø 250V 15
15-15R
15-15P
15-20R
15-20P
15-30R
15-30P
15-50R
15-50P
15-60R
15-60P
3Ø 480V 16 Reserved For Future Configurations
3Ø 600V 17 Reserved For Future Configurations
4 Pole 4 Wire
3ØY
120/208V 		18
18-15R
18-15P
18-20R
18-20P
18-30R
18-30P
18-50R
18-50P
18-60R
18-60P
3ØY
277/480V 		19 Reserved For Future Configurations
3ØY
347/600V 		20 Reserved For Future Configurations
4 Pole 5 Wire Grounding
3ØY
120/208V 		21 Reserved For Future Configurations
3ØY
277/480V 		22 Reserved For Future Configurations
3ØY
347/600V 		23 Reserved For Future Configurations

Conduit Fill Table

Posted on by Brandy McNeil
Trade Size Wire Size (THWN, THHN) Conductor Size AWG/kcmil
14 12 10 8 6 4 3 2 1 1/0 2/0 3/0 4/0 250 300 350 400 500 600 700 750
1/2
EMT		 12 9 5 3 2 1 1 1 1 1

IMC		 14 10 6 3 2 1 1 1 1 1 1

GRC		 13 9 6 3 2 1 1 1 1 1
3/4
EMT		 22 16 10 6 4 2 1 1 1 1 1 1 1

IMC		 24 17 11 6 4 3 2 1 1 1 1 1 1
GRC 22 16 10 6 4 2 1 1 1 1 1 1 1
1 EMT 35 26 16 9 7 4 3 3 1 1 1 1 1 1 1 1
IMC 39 29 18 10 7 4 4 3 2 1 1 1 1 1 1 1 1
GRC 36 26 17 9 7 4 3 3 1 1 1 1 1 1 1 1 1
1 1/4 EMT 61 45 28 16 12 7 6 5 4 3 2 1 1 1 1 1 1 1 1 1
IMC 68 49 31 18 13 8 6 5 4 3 2 1 1 1 1 1 1 1 1 1 1
GRC 63 46 29 16 12 7 6 5 4 3 2 1 1 1 1 1 1 1 1 1
1 1/2 EMT 84 61 38 22 16 10 8 7 5 4 3 2 1 1 1 1 1 1 1 1 1
IMC 91 67 42 24 17 10 9 7 5 4 4 3 3 2 1 1 1 1 1 1 1
GRC 85 62 39 22 16 10 8 7 5 4 3 3 2 1 1 1 1 1 1 1 1
2 EMT 138 101 63 36 26 16 13 11 8 7 6 5 4 3 2 1 1 1 1 1 1
IMC 149 109 68 39 38 17 15 12 9 8 6 5 4 3 3 2 2 1 1 1 1
GRC 140 102 64 37 27 16 14 11 8 7 6 5 4 3 3 2 2 1 1 1 1
2 1/2 EMT 241 176 111 64 46 28 24 20 15 12 10 8 7 6 5 4 4 3 2 2 1

IMC		 211 154 97 56 40 25 21 17 13 11 9 7 6 5 4 4 3 3 2 1 1

GRC		 200 146 92 53 38 23 20 17 12 10 8 7 6 5 4 3 3 2 1 1 1
3
EMT		 364 266 167 96 69 43 36 30 22 19 16 13 11 9 7 6 6 5 4 3 3

IMC		 362 238 150 86 62 38 32 27 20 17 14 12 9 8 7 6 5 4 3 3 3

GRC		 309 225 142 82 59 36 31 26 19 16 13 11 9 7 6 5 5 4 3 3 3
3 1/2
EMT		 476 347 219 126 91 56 47 40 29 25 20 17 14 11 10 9 8 6 5 4 4

IMC		 436 318 200 115 83 51 43 36 27 23 19 16 13 10 9 8 7 6 5 4 4

GRC		 412 301 189 109 79 48 41 34 25 21 18 15 12 10 8 7 7 5 4 4 4
4
EMT		 608 443 279 161 116 71 60 51 37 32 26 22 18 15 13 11 10 8 7 6 5

IMC		 562 410 258 149 107 66 56 47 35 29 24 20 17 13 12 10 9 7 6 5 5

GRC		 531 387 244 140 101 62 53 44 33 27 23 19 16 13 11 10 8 7 6 5 5

Above information referenced from tables C1, C4, and C8 of the 1996 NEC.

Direct Current Motor Full Load Current

Posted on by Brandy McNeil
HP 90V 120V 180V 240V 500V 550V
1/4 4.0 3.1 2.0 1.6
1/3 5.2 4.1 2.6 2.0
1/2 6.8 5.4 3.4 2.7
3/4 9.6 7.6 4.8 3.8
1 12.2 9.5 6.1 4.7
1/2 13.2 8.3 6.6
2 17 10.8 8.5
3 25 16 12.2
5 40 27 20
7/2 58 29 13.6 12.2
10 76 38 18 16
15 55 27 24
20 72 34 31
25 89 43 38
30 106 51 46
40 140 67 61
50 173 83 75
60 206 99 90
75 255 123 111
100 341 164 148
125 425 205 185
150 506 246 222
200 675 330 294

Allowable Ampacities Insulated Conductors

Posted on by Brandy McNeil

Table 310-16 1996 N.E.C.

60°C 75°C 90°C 60°C 75°C 90°C
AWG THW THW
TW THWN TW THWN
MCM UF USE THHN UF USE THHN
COPPER ALUMINUM
18 14*
16 18*
14 20* 20* 25*
12 25* 25* 30* 20* 20* 25*
10 30* 35* 40* 25* 30* 35*
8 40 50 55 30 40 45
6 55 65 75 40 50 60
4 70 85 95 55 65 75
3 85 100 110 65 75 85
2 95 115 130 75 90 100
1 110 130 150 85 100 115
1/0 125 150 170 100 120 135
2/0 145 175 195 115 135 150
3/0 165 200 225 130 155 175
4/0 195 230 260 150 180 205
250 215 255 290 170 205 230
300 240 285 320 190 230 255
350 260 310 350 210 250 280
400 280 335 380 225 270 305
500 320 380 430 260 310 350
600 355 420 475 285 340 385
700 385 460 520 310 375 420
750 400 475 535 320 385 435

* Unless otherwise specifically permitted elsewhere in the National
Electrical Code Book, the overcurrent protection for conductor types marked
with an asterisk shall not exceed 15 amperes for No. 14, 20 amperes for No.
12 & 30 amperes for No. 10 copper; or 15 amperes for No. 12 & 25 amperes
for No. 10 aluminum & copper-clad aluminum after any correction factors for
ambient temperature & number of conductors has been applied.