Ohmite Mfg. Co. 1600 Golf Rd., Suite 850, Rolling Meadows, IL 60008 Tel. 1-866-9-OHMITE Fax 1-847-574-7522 www.ohmite.com info@ohmite.com
Ohmite Mfg. Co. 1600 Golf Rd., Suite 850, Rolling Meadows, IL 60008 Tel. 1-866-9-OHMITE Fax 1-847-574-7522 www.ohmite.com info@ohmite.com
Metalohm Series
Wirewound Resistors
0.5"
A
B
C
ø0.195"
D
0.75"
term. style 276 (sq. collar, G3923)
278 (oval collar, G3860)
1.5" max.
0.250"
ø0.068"
±0.005
23/16" max.
term. style 277
1.5" max.
term. style 279
0.437" dia.
ø0.089"
1" max.
term. style 211
term. style 252
5/16"
1.25" max.
ø0.171"
term. style 297
1.25" max.
term. style 298
wire wire
FEATURES
Flameproof and inorganic
Higher power rating due to heat
sink capacity
All welded construction
Nonhygroscopic
High surge construction
SPECIFICATIONS
Electrical
Wattage: Based on a 275°C “U”
characteristic derating curve
Temperature coefficient:
18 ohm: 0 ±90ppm/°C
8 < 18 ohm: 0 ±50ppm/°C
<8 ohm: 0 ±180ppm/°C
(TC for some watt/ohm combina-
tions may be lower)
Dielectric strength: Terminal to
case, depends on terminal style
(1500V min.)
Creepage: term. style 277: 1.2”
term. styles 278/276: 0.4”/0.7
term. styles 211/252/279: 0.15”
Termination Wires
Stranded, available in any insu-
lation rated 125°C or higher
(may require term. style 297).
Custom cut/stripped lengths
Can be potted or pre-soldered to
terminal styles 211 or 252
Quick connect (fully or partially
insulated), ring or spade termina-
tions available
Dielectric Sleeves
Steatite construction
Style 276 meets UL/NEMA
2500V RMS for one minute
requirement
Available as terminal styles 276,
277, 278, 297
Watts Dimensions (inches)
Style w/o heat sink w/ heat sink* A B C D Ohmic range**
20/45M 20 45 1 17/16 17/8 3/4 0.05-6K
40/70M 40 70 29/16 3 37/16 3/4 1.0-25K
HV40-70M 40 70 29/16 3 37/16 7/8 1.0-25K
50/100M 50 100 311/16 41/8 49/16 3/4 1.5-47.5K
60/115M 60 115 59/16 6 67/16 3/4 2.5-81K
*Based on a 12”x12”x1/8” aluminum heat sink, using a thermal compound, in a 25°C ambient
**Standard winding ranges only listed, other values available; contact factory.
DIELECTRIC STRENGTH
Terminal Type 211 252, 279 276 278 277 297 298
Style Dielectric Strength
20/45M 1500 N/A N/A N/A N/A 2500V 2500V
40/70M 1500 1500 2500 2500 N/A 2500V 2500V
HV40/70M N/A N/A N/A N/A 4250 N/A N/A
50/100M 1500 1500 2500 2500 N/A 2500V 2500V
60/115M 1500 1500 2500 2500 N/A 2500V 2500V
OPTIONS
Noninductive versions (Aryton-
Perry windings)
Terminal sleeves to increase
dielectric strength and maximize
creepage distance
Variety of terminal choices
Potted or soldered wire leads
including quick connect, ring,
spade terminals
Tapped models ORDERING INFORMATION

Style
Ohms
1R000 = 1.000
10R5K = 10,500
Terminal Type
A = 211
B = 252
C = 279
D = 276
Non-inductive
(optional)
Tolerance
K = 10%
J = 5%
H = 3%
G= 2%
F = 1%
RoHS Compliant
E = 277
F = 278
G = 297
H = 298
30