0315402 JOHNSON BRACKET

Required Equipment
The following is a list of equipment required to test and calibrate temperature contactors.* 6V-7070 Multimeter or Equivalent A multimeter is used to verify the actuation and deactuation settings. This is done by checking for continuity between two terminals inside the contactor.* Heat Bath A heat bath is used to maintain a constant elevated temperature with the temperature probe submersed into a silicone heating fluid. This allows for the calibration of the actuation and deactuation settings. It must be temperature controlled and meet the following specifications:a. Capable of obtaining a temperature of 150° C (302° F) or have at least a 20° C (40° F) higher temperature capacity than the specified set point.b. Maintain the temperature within 1° C ( 2° F) maximum temperature difference.c. Must be equipped with a thermometer or digital display temperature read-out accurate to within 0.5° C ( 1° F).d. Circulate the heating fluid to maintain a uniform temperature.e. Must have a minimum bath capacity of 0.5 L (31.25 cu in). Also requires a working depth large enough to fully immerse the temperature probe.f. Must be compatible with silicone fluids.g. Can be a portable self-contained unit. The heat baths listed in Chart B meet the specified requirements and can be purchased from:Cole-Parmer Instruments Co.
7425 North Oakpark Ave.
Niles, IL, 60714 U.S.A.
Phone (800) 323-4340
Fax: (708) 647-9660
* Heat Bath Fluid The heat bath fluid must be able to obtain and maintain the required contactor actuation and deactuation temperatures. For the temperatures required for the calibration procedure, silicone fluid must be used. Silicone fluid has a temperature range between 10° C (50° F) and 230° C (446° F). Silicone fluid can be purchased from Cole-Parmer by ordering G-01294-40. The fluid comes in a 3.8 Liter (1 gal) container.
Use extreme caution around heat baths with high temperature fluids. High temperature fluids can cause severe burns.
Calibration Procedure
Use the following procedure to test and calibrate the temperature contactors.1. If connected, disconnect the contactor from the power supply. Mark the terminal location and disconnect the three wires from terminals 1, 2, and 4.
High voltage electrical shock is possible. The contactor must be disconnected from the power supply and the wires disconnected from terminals 1, 2, and 4. Failure to follow this recommendation can result in serious bodily injury.
2. Locate and record the part number of the temperature contactor in Chart A. This will determine the actuation and deactuation temperatures. If the temperature contactor is used in extreme ambient temperatures there will be a scale deviation from the required actuation and deactuation temperatures. Refer to the "Calculating Scale Correction for Severe Temperature Applications" section in this Special Instruction.
Temperature Contactor
(1) Housing cover. (2) Housing cover screws. (3) Temperature probe. (4) Capillary tube.3. Loosen housing cover screws (2) and remove housing cover (1).4. Fill the heat bath unit with silicone fluid and heat it to approximately 5° C (10° F) below the actuation temperature setting. Do not immerse the temperature probe at this time.
Nomenclature Of Internal Parts
(5). Lock screw. (6) Range spindle. (7) Range scale. (8) Differential spindle. (9) Differential scale.5. Loosen lock screw (5).6. Adjust range spindle (6) to a setting above the desired actuation setting determined in Step 2. Determine the setting by using range scale (7).7. Adjust the differential spindle (8) to the approximate mechanical differential temperature using differential scale (9). Mechanical differential temperature is the difference between the actuation and deactuation temperature settings.
Temperature Control Function For Actuation And Deactuation (specifically shown for 7C-3888 Contactor)
Adjusting Temperature and Differential Settings On The Temperature Contactor
This example shows the temperature set at 66° C with an 8° C differential setting. This results in a deactuation temperature of 58° C and actuation temperature of 66° C. (Refer to "Temperature Control Function For Actuation And Deactuation" illustration.)8. Fully immerse temperature probe (3) in the silicone fluid. Increase the heat bath temperature to the specified actuation temperature.9. When the actuation temperature has stabilized, very slowly turn range spindle (6) counterclockwise until the contact actuates. This will be accompanied by an audible "click".
When Contact Actuates, Terminals 1 And 4 Will Have Continuity10. Use a 6V-7070 Multimeter, or equivalent, to verify the actuation of the contactor. Check for continuity between terminals 1 and 4. If there is no continuity, the contactor has not actuated; continue to adjust the range spindle until there is continuity between terminals 1 and 4.11. Slowly decrease the heat bath temperature until the contact deactuates. Again, this will be accompanied by an audible "click".
When Contact Deactuates, Terminals 1 And 2 Will Have Continuity12. Verify the deactuation of the contactor by checking for continuity between terminals 1 and 2. If there is no continuity, the contactor has not deactuated; continue to decrease the temperature until it does. Record this deactuation temperature.13. Again, slowly increase the heat bath temperature until the contact actuates. This gives an accurate indication of the actual setting. If the actuation setting is not correct (too high or too low), adjust range spindle (6) until the required actuation setting is reached.14. Once the actuation setting is established, the deactuation setting can be slightly raised or lowered by adjusting differential spindle (8). Adjusting differential spindle (8) will generally not affect the actuation setting, but it is advisable to recheck it after any adjustments.15. Continue to adjust differential spindle (8) until the deactuation setting is established.16. Tighten lock screw (5) when both