Ohmite 200, 270, 400, 470 Application Information

Ohmite Mfg. Co. 1600 Golf Rd., Suite 850, Rolling Meadows, IL 60008 • Tel. 1-866-9-OHMITE • Fax [phone] • www.ohmite.com • [e-mail]

Application Notes

Core and Terminal Selection for Type 200, 270, 400 and 470 Tubular Resistors

VITREOUS ENAMEL COATED OHMICONE® SILICONE COATED

Free Air
Wattage

Rating Length

3* 0.438” (11.1mm) 0.210” (5.25mm) 0.130” (3.17mm) AA 0.13 3.48K 48, 58

5.25* 0.625” (15.9mm) 0.250” (6.35mm) 0.135” (3.43mm) CA 0.19 7.06K 48, 58

6.5 1.0” (25.4mm) 0.250” (6.35mm) 0.125” (3.18mm) CA 0.10 2.30K 27.3K 57

8* 1.0” (25.4mm) 0.313” (7.95mm) 0.188” (4.76mm) D 0.10 2.16K 17.1K 48, 57
12* 1.75” (44.5mm) 0.313” (7.95mm) 0.188” (4.76mm) D 0.10 6.52K 51.6K 48, 57

11 1.0” (25.4mm) 0.438” (11.1mm) 0.250” (6.35mm) H 0.10 3.02K 28.2K 57
15 1.5” (38.1mm) 0.10 6.03K 56.4K 40
20* 2.0” (50.8mm) 0.11 10.1K 94.0K 48-40
26 3.0” (76.2mm) 0.21 18.1K 169.0K 40

25* 2.0” (50.8mm) 0.563” (14.3mm) 0.313” (7.95mm) K 0.15 12.9K 100.0K 40
35 3.0” (76.2mm) 0.26 23.2K 180.0K
50* 4.0” (101.6mm) 0.38 33.5K 260.0K
60 5.0” (127.0mm) 0.50 43.8K 340.0K
75* 6.0” (152.4mm) 0.61 54.1K 420.0K

24 1.5” (38.1mm) 0.750” (19.1mm) 0.50” (12.7mm) M 0.10 9.49K 12.2K 40
30 2.0” (50.8mm) 0.10 16.4K 21.1K
45 3.0” (76.2mm) 0.10 30.2K 38.8K
51 3.5” (88.9mm) 0.11 37.1K 47.6K
61 4.0” (101.6mm) 0.13 44.0K 56.5K
65 4.5” (114.3mm) 0.15 50.9K 65.3K
76 5.0” (127.0mm) 0.17 57.8K 74.2K
90 6.0” (152.4mm) 0.21 71.6K 91.9K
100* 6.5” (165.1mm) 0.23 78.5K 101.0K

52 3.0” (76.2mm) 1.0” (25.4mm) 0.625” (15.9mm) N 0.11 25.3K 40
70 4.0” (101.6mm) 0.17 37.2K
85 5.0” (127.0mm) 0.22 49.1K
105 6.0” (152.4mm) 0.27 61.0K
112 6.5” (165.1mm) 0.30 67.1K
120 7.0” (177.8mm) 0.33 72.9K
140 8.0” (203.2mm) 0.38 84.8K
176 10.0” (254.0mm) 0.49 109.0K

40 2.0” (50.8mm) 1.125” (28.6mm) 0.75” (19.1mm) P 0.10 9.63K 46
80 4.0” (101.6mm) 0.10 37.7K
95 5.0” (127.0mm) 0.10 51.7K
121 6.0” (152.4mm) 0.10 65.7K
130 6.5” (165.1mm) 0.10 72.7K
160 8.0” (203.2mm) 0.12 93.7K
175* 8.5” (215.9mm) 0.13 101.0K
225* 10.5” (266.7mm) 0.16 129.0K
235 11.25” (285.8mm) 0.18 139.0K
251 12.0” (304.8mm) 0.19 150.0K

150 5.0” (127.0mm) 1.5” (38.1mm) 1.125” (28.6mm) Q 0.10 34.2K 45

220 8.5” (215.9mm) 1.625” (41.3mm) 1.125” (28.6mm) R 0.18 75.0K 45
275 10.5” (266.7mm) 0.23 96.6K
300 11.75” (298.5mm) 0.26 110.0K

250 6.0” (152.4mm) 2.5” (63.5mm) 1.75” (44.5mm) S 0.15 6.11K 45
500 12.0” (304.8mm) 0.38 15.4K
750 15.0” (381.0mm) 0.50 20.0K

1000 20.0” (508.0mm) 0.69 27.7K

*These core sizes are used for the standard items. See the listing of the resistance
values under Types 200, 210 and 270

**See Application Note “Resistor Terminals for Tubular Cores,” page 35.

Nominal Core Dimensions

Outside

Diameter

Inside

Diameter

Code

Core

Dia.

Critical Resistance Limiting Factors

for

Min.

Ohms

For

Ohms

Over

Limits controlled by free air

watts and max. possible ohms

Limit Watts

and Working

Limit wattage

free air watts

volts to 500V

winding space

terminal edges

Limits controlled by

free air watts and

working volts to 500V

per inch of winding

space between
terminal edges

Maximum Diameter Over
Coating: The overall diameter

Voltage to

to 78% of

and working

per inch of

between

Max.

Possible

Ohms

Standard

Terminal**

of a finished resistor includes

Tolerance on Nominal Core Dimensions

Length Tolerance

0.438 (11.113mm) to 4.00 (101.60mm) ±0.031 (0.794mm)
Over 4.00 (101.60mm) to 6.50 (165.10mm) ±0.047 (1.191mm)
Over 6.50 (165.10mm) to 11.25 (285.575mm) +0.063 (1.588mm) / -0.094 (2.381mm)
Over 11.25 (285.575mm) to 20.0 (0.508mm) ±0.125 (3.175mm)

Tolerances do not include effect of longitudinal camber.

I.D. Tolerance

To 0.500 (12.700mm) ±0.016 (0.397mm)
Over 0.500 (12.700mm) to 1.125 (28.575mm) ±0.031 (0.794mm)
Over 1.125 (28.575mm) to 1.750 (44.450mm) ±0.063 (1.588mm)

the build-up due to wire diame­ter, coating and terminal mate­rial. This results in a possible
maximum increase in diameter
of 0.188 (4.763mm) for low
resistance, 1.125 (28.575mm)
O.D. core resistors and larger;

0.156 (3.969mm) for resistors
with smaller diameter cores.
On all high resistance units the
increase is generally less than

0.125 (3.175mm).

Other Core Sizes: Many other
specials are available includ­ing cores with special inside
diameter listed at right.

Critical Resistance Limiting Factors

Min.

Ohms

0.1 8.0K 155 15.8K

0.1 15.0K 281 34.0K

21.6K 375 45.4K

0.1 9.87K 281 42.8K

50.0K 775 50.4K

0.1 7.18K 281 35.3K

21.1K 563 70.5K

44.0K 938 118.0K

110.0K 1690 212.0K

0.1 35.2K 938 151.0K

81.6K 1690 272.0K

119.0K 2440 393.0K

170.0K 3190 340.0K

207.0K 3940 420.0K

0.1 11.1K 516 73.6K

26.6K 893 127.0K

59.8K 1640 234.0K

80.0K 2020 288.0K

93.6K 2390 341.0K

118.0K 2770 395.0K

130.0K 3140 448.0K

168.0K 3890 555.0K

182.0K 4270 609.0K

0.1 49.2K 1600 305.0K

78.9K 2350 448.0K

113.0K 3100 591.0K

141.0K 3850 734.0K

159.0K 4220 805.0K

176.0K 4600 877.0K

204.0K 5350 1.02M

267.0K 6850 1.31M

0.1 6.66K 516 89.3K

51.0K 2020 328.0K

80.8K 2770 450.0K

102.0K 3520 572.0K

116.0K 3890 633.0K

158.0K 5020 816.0K

166.0K 5390 877.0K

211.0K 6890 1.12M

237.0K 7460 1.21M

257.0K 8030 1.31M

0.1 44.4K 2580 433.0K

0.1 123.0K 5210 351.0K

164.0K 6710 452.0K

195.0K 7650 516.0K

0.1 35.0K 2960 86.3K

111.0K 7460 218.0K

125.0K 9680 283.0K

180.0K 13400 392.0K

Cores with
Non-standard I.D. (or O.D.)

O.D. I.D. Code

0.313” 0.219” DA
(7.938mm) (5.556mm)

0.438” 0.313” HA
(11.113mm) (7.938mm)

0.563” 0.391” KA
(14.288mm) (9.922mm)

0.625” 0.453” LA
(15.875mm) (11.509mm)

0.750” 0.547” MA
(19.050mm) (13.891mm)

0.938” 0.563” UA
(23.813mm) (14.288mm)

1.125” 0.875” PA
(28.575mm) (22.225mm)

For

Ohms

Over

Limit

Working

Voltage to

Max.

Possible

Ohms

Ohmite Mfg. Co. 1600 Golf Rd., Suite 850, Rolling Meadows, IL 60008 • Tel. 1-866-9-OHMITE • Fax [phone] • www.ohmite.com • [e-mail]

Application Notes

Core and Terminal Selection for Type 210 and 410 Tubular Resistors

VITREOUS ENAMEL COATED

Free Air
Wattage

Rating Length

3* 0.438” (11.1mm) 0.210” (5.25mm) 0.130” (3.17mm) AA 48, 58

5.25* 0.625” (15.9mm) 0.250” (6.35mm) 0.135” (3.43mm) CA 48, 58

6.5 1.0” (25.4mm) 0.250” (6.35mm) 0.125” (3.18mm) CA 57

8* 1.0” (25.4mm) 0.313” (7.95mm) 0.188” (4.76mm) D 48, 57
12* 1.75” (44.5mm) 0.313” (7.95mm) 0.188” (4.76mm) D 48, 57 0.95 4.47K 10.0K

11 1.0” (25.4mm) 0.438” (11.1mm) 0.250” (6.35mm) H 57
15 1.5” (38.1mm) 40 0.44 4.14K 11.8K
20* 2.0” (50.8mm) 48-40 0.73 6.90K 19.7K
26 3.0” (76.2mm) 40 1.30 12.4K 35.5K

25* 2.0” (50.8mm) 0.563” (14.3mm) 0.313” (7.95mm) K 40 0.24 8.88K 25.0K
35 3.0” (76.2mm) 0.43 16.0K 45.6K
50* 4.0” (101.6mm) 0.62 23.1K 100.0K
60 5.0” (127.0mm) 0.81 30.2K 86.2K
75* 6.0” (152.4mm) 1.00 37.3K 100.0K

24 1.5” (38.1mm) 0.750” (19.1mm) 0.50” (12.7mm) M 40 0.24 6.16K 8.73K
30 2.0” (50.8mm) 0.42 10.7K 15.1K
45 3.0” (76.2mm) 0.77 19.6K 27.8K
51 3.5” (88.9mm) 0.95 24.1K 34.1K
61 4.0” (101.6mm) 1.10 28.6K 40.5K
65 4.5” (114.3mm) 1.30 33.0K 46.8K
76 5.0” (127.0mm) 1.50 37.5K 53.2K
90 6.0” (152.4mm) 1.80 46.5K 65.9K
100* 6.5” (165.1mm) 1.00 50.9K 100.0K

52 3.0” (76.2mm) 1.0” (25.4mm) 0.625” (15.9mm) N 40 0.18 25.3K
70 4.0” (101.6mm) 0.26 37.2K
85 5.0” (127.0mm) 0.34 49.1K
105 6.0” (152.4mm) 0.42 61.0K
112 6.5” (165.1mm) 0.47 67.0K
120 7.0” (177.8mm) 0.51 72.9K
140 8.0” (203.2mm) 0.59 84.8K
176 10.0” (254.0mm) 0.75 109.0K

40 2.0” (50.8mm) 1.125” (28.6mm) 0.75” (19.1mm) P 46 0.10 9.57K
80 4.0” (101.6mm) 0.25 37.4K
95 5.0” (127.0mm) 0.34 51.3K
121 6.0” (152.4mm) 0.44 65.2K
130 6.5” (165.1mm) 0.48 72.2K
160 8.0” (203.2mm) 0.62 93.0K
175* 8.5” (215.9mm) 0.67 100.0K
225* 10.5” (266.7mm) 0.86 100.0K
235 11.25” (285.8mm) 0.93 138.0K
251 12.0” (304.8mm) 1.00 148.0K

150 5.0” (127.0mm) 1.5” (38.1mm) 1.125” (28.6mm) Q 45 0.41 29.4K

220 8.5” (215.9mm) 1.625” (41.3mm) 1.125” (28.6mm) R 45 0.91 64.6K
275 10.5” (266.7mm) 1.20 83.2K
300 11.75” (298.5mm) 1.30 94.8K

250 6.0” (152.4mm) 2.5” (63.5mm) 1.75” (44.5mm) S 45 0.61 6.11K
500 12.0” (304.8mm) 1.50 15.4K
750 15.0” (381.0mm) 2.00 20.0K

1000 20.0” (508.0mm) 2.80 27.7K

*These core sizes are used for the standard items. See the listing of the resistance
values under Types 200, 210 and 270

**See Application Note “Resistor Terminals for Tubular Cores,” page 35.

Nominal Core Dimensions

Outside

Diameter

Inside

Diameter

Code

for

Core

Dia.

Std.

Term.**

Min.

Ohms

Critical Resistance

For Ohms

Over

Limiting Factors

Limit Watts and

Working Voltage to

These core sizes not available as adjustable resistors

10W; 316V 12W; 345V

These core sizes not available as adjustable resistors

Limit wattage to

78% of free air

watts and working

volts to 500V per

inch of winding

space between
terminal edges

Limits controlled by

free air watts and

working volts to 500V

per inch of winding

space between
terminal edges

OHMICONE®

SILICONE COATED

Critical Resistance

Limiting Factors

Limit Watts and

Working Voltage to

Limits controlled by

free air watts and

working volts to 500V

per inch of winding

space between
terminal edges

Max.

Possible

Ohms

Ohmite Mfg. Co. 1600 Golf Rd., Suite 850, Rolling Meadows, IL 60008 • Tel. 1-866-9-OHMITE • Fax [phone] • www.ohmite.com • [e-mail]