Cartridge & Insertion Heaters
CEM/Rod Cartridge Heaters | Cartridge Immersion Heaters | Split Sheath Insertion Heaters | High Temperature Insertion Heaters | Bolt Heaters
"CEM ROD" CARTRIDGE HEATERS Go Back
CEMROD

Heater life is a function of several variables: operating temperature, heater fit, control, heat absorptivity characteristics of material being processed, watt density, contamination, etc.

Immersion Heaters
Immersion Heaters are intended to be used in liquids at all times. The heated portion must always be immersed. Sheath must be free of grease or foreign material for adequate thermal conductivity. Protect terminals from contaminants.

Fit Tolerances
The hole into which a cartridge heater is inserted, should be reamed to the nominal diameter of the heater.

CEM/ROD
Cartridge Heaters are .002" — .005" undersize. If close hole tolerances are not maintained, operating life of the heater will be reduced. The heated area of the cartridge can not extend beyond the hole. See watt density graphs.

Spacing
As a general rule it is not recommended to space heaters in a die or platen any closer to each other than the diameter of the heater.

Contamination
Contamination consists of any foreign matter such as plastic, oil, grease, dirt, or water entering through the terminal end and will shorten heater life.

Proper Care and Maintenance
  1. Heaters should be stored in a dry area, especially during periods of high humidity.
  2. Protect leads from abuse and abrasion.
  3. Maintain temperature control and accessories in good working condition to avoid over temperature operating conditions.
  4. All cartridge heaters (especially of swaged design) have hygroscopic tendencies, and can accumulate moisture in shipping and storage. Low heater insulation (less than 1 meg ohm) can be baked in an oven for several hours or started at low voltage to eliminate moisture.
Removal
Removal of heaters from one die or platen to another is not recommended.

Testing lnformatlons
Quality control standards on CEMROD Heaters include the following inspection procedures:
  1. Continuity test.
  2. Voltage breakdown test (Hypot) in accordance with N.E.M.A. standards.
  3. inspection of physical size.
  4. Resistance test.
How To Order
  1. When ordering Cartridge Heaters specify:
    1. Overall Length
    2. Heated Area
    3. Nominal Diameter
    4. Lead Length
    5. Voltage & Wattage
      Diameter and length are determined by the space available and your requirements for even heat distribution. The standard leads are internaly connected.
  2. Determine:
    calculation watt density
    Example: a 3/8" diameter by 3" long overall (with standard 3/8" cold end) rated at 300 watts
    calculation
  1. Determine: Fit maximum inside diameter of hole — minimum OD of sheath
    Example:
    a 3/8" Cartridge Heater in a .375± .001 reamed hole would have a .006 fit
    .376 .370 = .006 Check the required temperature against the watt density and fit indicated on the graph above.
  2. To extend heater life:
    1. Decrease the watt density by:
      1. increasing the diameter
      2. increasing heated length
      3. increasing the number of units used
      4. reducing the wattage, allowing for longer heat-up time
    2. Use a tighter fit.
    3. Consult factory or representative for alternative design recommendation.