POWEROHM Resistors Type CR Case Resistors Catalog Page

Type CR Case Resistors - 100 to 400 Watts

APPLICATION

Powerohm's Type CR Case Resistors can be used in any
AC or DC power circuit. Units are most commonly used for
light-duty braking of variable frequency drives, space heating
and any other low wattage load applications.

The Type CR resistors are suitable for intermittent and
continuous duty applications requiring relatively high resis­tance and low wattage. The compact size of this unit makes
it ideal for an installation where space is a premium. This
unit can withstand extreme shock, qualifying it for nearly
any high vibration application.

BASIC CONSTRUCTION

Powerohm's Type CR resistors are manufactured with
quality components for superior performance and increased
life expectancy. Our case resistors feature a nickel­chromium wire helically wound, then placed inside a ce­ramic fixture and inserted into a corrosion resistant alumi­num case. Each coil end is terminated to high temperature
wire leads and encapsulated with a ceramic potting mate­rial. The result is a resistor element electrically isolated, but
thermally bound to the outer case to allow the element heat
to transfer to the metallic case and efficiently cool. The units
are supplied with wire leads, and the case is machined to
include two mounting holes for easy installation.

Our ceramic insulating cores are manufactured in-house to
maintain total control over production and quality standards.
Powerohm is the only domestic resistor manufacturer with
this added advantage.

OPTIONS

Type CR Case Resistor

ELECTRICAL CHARACTERISTICS

VOLTAGE INSULATION: A standard Type CR resistor is

insulated for up to 1000 volts maximum.

RESISTANCE TOLERANCE: + 10% for all units; as low as
+ 3% if required.

COEFFICIENT OF RESISTIVITY: Resistance values will
increase as the element temperature rises. Expect an
approximate increase of 5% in resistance after the unit
reaches an operating temperature of 375ºC above ambient.
Contact the factory for more specific information if needed.

AMBIENT TEMPERATURE: Standard ratings are based on
maximum ambient temperatures of 40ºC. Derate wattage
rating 90% for 50ºC ambient, 80% for 80ºC ambient and 70%
for 100ºC ambient.

EFFECTS OF ALTITUDE: The published electrical ratings
are applicable for altitudes of 6000 feet or less. Contact the
factory for deration factors above 6000 feet.

CUSTOM SIZES: Type CR resistors are normally available
in (5) standard sizes with values between 100 to 400 watts
per assembly. The overall size of the case determines the
wattage rating and can be varied to meet specific ratings if
necessary. Also, these units can be custom wound to any
resistance value as long as it remains within the resistance
ranges listed in the table on the following page.

CUSTOM LEADS: The standard lead length can be varied
and the ends can be furnished with ring or fork terminals and
male or female disconnects.

POWEROHM

Ω

RESISTORS, INC.

CUSTOM DESIGNS

Powerohm offers a complete selection of standard size
units. Numerous variations are available for almost any
application. Please contact the factory if there are special
service requirements, such as overloads, high peak cur­rents, high ambient temperatures, etc.

5713 13th Street

Katy, Texas 77493

Phone: [phone], Fax: [phone]

Please visit our website at www.powerohm.com

Type CR Electrical Ratings & Dimensions

SPECIFY PART NUMBERS AS FOLLOWS: CR __ - __ - __

Wattage

Resistance Required

For special lead lengths,
add "L" and the lead length
in inches.

RATINGS: The continuous current ratings are based on a 375ºC temperature rise. The resistance values are measured
at 25ºC and have a + 10% tolerance.

For example, the part number for a 100 watt, 20
ohm unit with standard 18 inch leads is CR100-

20. The catalog number for the same resistor
with a custom lead length of 36 inches is
CR100-20-L36.

ELECTRICAL RATINGS & DIMENSIONS OF STANDARD SIZE CASE RESISTORS

DIMENSIONS IN INCHES

1-1/2

1-1/2

3

3

3/4

3/4

1-1/2

1-1/2

5-1/2

8-1/2

5-1/2

8-1/2

3/4

3/4

1-1/2

1-1/2

WATTAGE

100

150

200

300

RESISTANCE

RANGE (OHMS)

5 - 500

10 - 750

20 - 1000

30 - 1500

A B C D E

6

9

6

9

400

40 - 2000

TOP VIEW

E

B

C

(2) 7/32 DIA.

D

A

FRONT VIEW

12

3

1-1/2

ALUMINUM CASE

11-1/2

(2) 18 IN. HIGH TEMP

SILICONE LEADS

1-1/2

A

24 HOUR EMERGENCY SERVICE [phone]