Watlow F4T Install & Troubleshooting • 14 • Chapter 2 Install and Wire
Input Connections (cont.)
Thermistor FM [M, L] A - [M, T] AAA - A _ _ _
S1
R1
• >20 MΩ input impedance
• 0 to 40kΩ, 0 to 20kΩ, 0 to 10kΩ, 0 to 5kΩ
• 2.252kΩ and 10kΩ base at 77°F (25°C)
• Drive current is 109 μA as a constant current source
• User-selectable curves for Alpha Technics, BetaTHERM and YSI
• User-scaling support for Steinhart-Hart coefcients
Thermistor
Curve Setting
Base R
@ 25 ºC
Alpha
Technics
Beta
Therm
YSI
Curve A 2.252K Curve A 2.2K3A 004
Curve B 10K Curve A 10K3A 016
Curve C 10K Curve C 10K4A 006
Custom
Use Steinhart-Hart equation coefficients (A, B and
C) from thermistor manufacturer corresponding to
the terms of the Steinhart-Hart equation:
1 / T = A + Bln(R) + C (ln(R))
3
Thermistor (High Density) FMHA - PAAA - A _ _ _
S1
R1
S2
R2
S3
R3
S4
R4
• >20 MΩ input impedance
• 0 to 40kΩ, 0 to 20kΩ, 0 to 10kΩ, 0 to 5kΩ
• 2.252kΩ and 10kΩ base at 77°F (25°C)
• Drive current is 109 μA as a constant current source
• User-selectable curves for Alpha Technics, BetaTHERM and YSI
• User-scaling support for Steinhart-Hart coefcients
Thermistor
Curve Setting
Base R
@ 25 ºC
Alpha
Technics
Beta
Therm
YSI
Curve A 2.252K Curve A 2.2K3A 004
Curve B 10K Curve A 10K3A 016
Curve C 10K Curve C 10K4A 006
Custom
Use Steinhart-Hart equation coefficients (A, B and
C) from thermistor manufacturer corresponding to
the terms of the Steinhart-Hart equation:
1 / T = A + Bln(R) + C (ln(R))
3
Anderson-Bolds ~ 216-360-9800