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Cimco Electronics, Inc.
P.O. Box 1338
McMurray, PA 15317 USA
Phone: 724.941.8001
Fax: 724.941.8002
Email: cimco@cimcoelectronics.com

 

 

 
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 Cimco Electronics Inc BBB Business Review

Background Information

Topics

Hall Effect
  • Hall Effect “noise” is generated when magnetic materials are in a magnetic field and a current passes through the magnetic material simultaneously.
  • Cimco's position: Hall-Effect noise, as related to temperature measurement errors, is negligible with Type E Thermocouples.
  • Do not use Type K Thermocouples.

K-Factor
  • Harmonics are generated by distortions in current or voltage wave-forms.
  • These harmonics increase Hall Effect noise and temperature in transformer windings.
  • Cimco's Position: K-Factor harmonics do not influence the accuracy of Type E.
  • Thermocouples and the instrument will indicate actual temperature of the windings.

Impulse Test
  • K-Factor and Hall Effect noise are very high during impulse test and can create a false high temperature signal which could cause the trip relay to change state and "trip" the transformer.
  • Cimco instruments, with Cimco's Type E thermocouples, will operate properly during impulse test.
  • Actual tests were conducted.
  • Contact Cimco Electronics, Inc. at cimco@cimcoelectronics.com for advice with electrical insulation on the thermocouples.

High Current
  • Hall-Effects and Eddy-Losses increase as winding currents increase.
  • Winding temperature will increase with increased losses caused by Hall-Effects and Eddy-Losses.
  • Hall-Effect and Eddy Current influences on temperature are accurately sensed by the Type E thermocouples and displayed on Cimco's control panel.

Radio Frequencies
  • Radio frequencies can induce noise, which become signals, into sensors containing magnetic materials.
  • False trip signals can de-energize the transformer.
  • Noise signals from radio frequencies do not influence Cimco's instrument.
  • Low-quality insulation on input power leads can cause malfunctions on electronic equipment.
  • Actual tests were conducted.
Shielding and Filtering
  • Well designed transformer coil shielding can limit noise to manageable levels.
  • VERY HIGH COST!
  • Shielding can create unexpected problems.
  • Use shielded sensors with caution.
  • Sensor leads in steel conduit are acceptable.
  • Cimco offers "special" insulated thermocouples for unusual noise and voltage applications.
  • Signal inputs are filtered to 75 dB.
  • Model A21 uses two carbon steel boxes for very high-level protection against magnetic and high voltage fields.

If more information is needed please email cimco@cimcoelectronics.com.
Thank you.

 

© Cimco Electronics, Inc. 2005


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