F E ꢀ T ꢁ ꢂ E S
S P E C ꢃ F ꢃ C ꢀ T ꢃ O ꢄ S
• Terminals suitable for soldering
or bolt connection
Material
270 Series
Coating: Lead free vitreous
enamel. Very large models (750
watts and up) are supplied in
Silicone Ceramic. Also available
in low-cost Centohm coating;
Consult factory.
Core: Tubular ceramic.
Terminals: Solder coated radial
lug. RoHS solder composition is
96% Sn, 3.5% Ag, 0.5% Cu
Derating: Linearly from 100% @
+25°C to 0% @ +350°C.
Electrical
• High wattage applications
• Rugged lead free vitreous enam-
el coating
• Flame resistant coating
• All-welded construction
• RoHS compliant available
• “Fast on” option – see terminal
538, page 37
Vitreous Enamel Power
C
D
See page 36
for mounting
hardware
L
Dimensions (in. / mm)
Core
Code
Standard
Voltage Terminal
Series Wattage
Ohms
L
D
C
L12
L25
L50
L100
L175
L225
L500
L1000
12
25
50
100
175
225
500
1000
0.1-51K
1.75 / 44.4
2.0 / 50.8
4.0 / 101.6
6.5 / 165.1
8.5 / 215.9
10.5 / 266.7
12.0 / 304.8
20.0 / 508.0
0.313 / 7.94
0.562 / 14.3
0.562 / 14.3
0.750 / 19.1
1.125 / 28.6
1.125 / 28.6
2.50 / 63.5
2.50 / 63.5
0.188 / 4.76
0.313 / 7.94
0.313 / 7.94
0.50 / 12.7
0.75 / 19.1
0.75 / 19.1
1.75 / 44.5
1.75 / 44.5
D
K
K
M
P
P
S
S
565
625
57
40
40
40
46
46
45
45
Tolerance:
±5% 1Ω and over (J)
±10% under 1Ω (K)
Power rating: Based on 25°C free
air rating.
0.15-100K
0.38-260K
0.23-101K
0.13-101K
0.16-129K
0.38-218K
0.69-392K
1625
2845
3595
4595
4970
8900
Overload: 10 times rated wattage
for 5 seconds.
Temperature coefficient:
1 to 20Ω: ±400 ppm/°C.
Above 20Ω: ±260 ppm/°C
Dielectric withstanding voltage:
1000 VAC: 12 to 100 watt rating.
3000 VAC: 175 to 225 watt rat-
ing (Measured from terminal to
mounting bracket)
Non-Inductive versions available; Other sizes available; Also available in low cost Centohm or Silicone coating; Consult Ohmite.
* Maximum Voltage is based on Ohm’s Law [V=√P*R] as limited by the resistance value of specified product
Select 270 Type fixed resistors for applications requiring wattage ratings from 12 to 1000 watts.
The 270 Type resistors are equipped with lug terminals suitable for soldering or sturdy bolt con-
nection. When secure mounting is required, the hollow core of these resistors permit fastening with
spring-type brackets, thru bolts or thru bolts with slotted-steel brackets.
Suitable for rugged applications, the 270 Type resistors feature all-welded construction and
durable lead free vitreous enamel coating. Mounting brackets not included with resistors.
To calculate max. amps: use the
formula √P/R
Power limitations for high resis-
tance values: When resistance
exceeds the resistance values
listed, derate the Power Rating by
25% to improve reliability:
m a d e - t o - o r d e r p a r t S
o r d e r i n g i n f o
Non-inductive
Blank = Standard
N = Non-inductive
Core Diameter
See “Core and
Terminal Selection”
Non-inductive
F = Fast on Blank = Standard
RoHS
RoHS Compliant
(optional)
N = Non-inductive Compliant
No power
derating
necessary
for ratings
higher than
100W.
Power Resistance
� ꢀ ꢁ ꢂ ꢂ ꢃ ꢁ ꢄ ꢅ ꢁ ꢃ ꢆ ꢁ ꢁ ꢇ ꢈ
L
2 5 J 1 0 0 E
rating
12W
value
3,900Ω
Coating
Wattage
Ohms
Tolerance
5%
K = 10%
Series
Wattage Tolerance Ohms
270 = Vitreous
470 = Silicone Ceramic
R500 = 0.500 Ω
J =
J
=
5%
1R0 = 1 Ω
1R00 = 1 Ω
Coating
Terminal Type
K = 10% 250 = 250 Ω
25W
50W
100W
12,000Ω
35,000Ω
75,000Ω
250R = 250 Ω
1K00 = 1,000 Ω
25K0 = 25,000 Ω
25K5 = 25,500 Ω
Blank = Vitreous
C = Centohm
S = Silicone
See “Resistor Terminals
for Tubular Cores”
1K0 = 1,000 Ω
25K = 25,000 Ω
See website for
custom core and
terminal info
25K5 = 25,500 Ω
S ta n d a r d p a r t n u m b e r S f o r 2 7 0 S e r i e S
Wattage
Wattage
Ohmic
Ohmic
value
180
270
330
390
470
560
1000
1200
1500
2200
2700
4700
10000
18000
22000
51000
value
0.51
1
12 Watt
12 Watt
Part ꢄo.
Part ꢄo.
L12J180E
L12J270E
L12J330E
L12J390E
L12J470E
L12J560E
L12J1K0E
L12J1K2E
L12J1K5E
L12J2K2E
L12J2K7E
L12J4K7E
L12J10KE
L12J18KE
L12J22KE
L12J51KE
L12JKR51E
L12J1R0E
L12J3R3E
L12J4R7E
L12J10RE
L12J12RE
L12J15RE
L12J22RE
L12J27RE
L12J33RE
L12J47RE
L12J68RE
L12J82RE
L12J100E
L12J150E
Prefix
Prefix
Suffix
Suffix
3.3
4.7
10
12
15
22
27
33
47
68
82
100
150
1
2
3
4
5
–––1R0E
–––2R0E
–––3R0E
–––4R0E
–––5R0E
2,500 –––2K5E
3,000 –––3K0E
3,500 –––3K5E
4,000 –––4K0E
5,000 –––5K0E
6,000 –––6K0E
7,500 –––7K5E
10,000 –––10KE
12,000 –––12KE
15,000 –––15KE
20,000 –––20KE
25,000 –––25KE
30,000 –––30KE
10 –––10RE
15 –––15RE
25 –––25RE
50 –––50RE
75 –––75RE
100 –––100E
125 –––125E
150 –––150E
200 –––200E
250 –––250E
500 –––500E
750 –––750E
800 –––800E
1,000 –––1K0E
1,500 –––1K5E
2,000 –––2K0E
35,000 –––35KE
= Standard values; check availability using the worldwide
40,000 –––40KE
50,000 –––50KE
60,000 –––60KE
inventory search at www.ohmite.com
Red outlined values supplied in Silicone-Ceramic coatings
instead of vitreous enamel.
75,000 –––75KE
100,000 –––100KE
150,000 –––150KE
200,000 –––200KE
250,000 –––250KE
34
Ohmite Mfg. Co.
1-866-9-OHMITE • Int’l 1-847-258-0300 • Fax 1-847-574-7522 • www.ohmite.com • info@ohmite.com