JC-A1A Datasheet, PDF (7/13 Pages) List of Unclassifed Manufacturers – ENGINEERING DATA SHEET

3. Calculation of coil temperature rise when R initial and R final are known:
Delta T = (234.5 + T₁) (R₂/R₁ - 1)
Delta T = Temperature rise (°C)
T₁ = Initial temperature (°C)
R₁ = Initial resistance (Ohms)
R₂ = Final resistance (Ohms)
R₂ = K₂R₁
Temperature can also be found by making the R₂/R₁ ratio = the
coefficient of correction graph in Fig. 2, and then finding the corresponding temperature.
TEMPERATURE CORRECTION CHART FOR RESISTANCE
Fig. 2
EXAMPLE:
Catalog indicates coil resistance of 290 ohm at 25°C. What is the value at 125°C?
From the chart: 290 x 1.39 = 403.31 Ohms.
Date of issue: 6/00
- 16 -
Page 2 of 2