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Chromalox 3901 User’s Manual
15
Section 5
Specifications
Alarm Output
Repeatability
+/- 1
°
F or 1
°
C
Reset
Differential
5
°
F or 3
°
C, nominal
Alarm Relay
Normally-open, normally-energized, SPST, latching
relay (contacts open on alarm & when no power is
applied to controller - failsafe)
Rating at 120 or 240 Vac (resistive load):
20 amps, 150,000 operations
15 amps, 200,000 operations
5 amps, 800,000 operations
Mechanical life, 10 million operations
Input
Specifications
Type J
Thermocouple
0 to 999
°
F, 0 to 500
°
C
Type K
Thermocouple
0 to 1999
°
F, 0 to 1100
°
C
Input Loop
Resistance
Up to 150 ohms
Cold Junction
Compensation
Automatic, typically less than 0.1
°
F per 1
°
F over
ambient 50 to 120
°
F
Indications
Open Sensor
Indications
Red LED lamp for J thermocouple input, “1”
illuminates for K thermocouple input Upscale burnout,
alarm indication, contacts open
Accuracy of
Indication
+/- 0.5% of span over mid-80% of scale
Resolution
1
°
F or 1
°
C
Repeatability
1
°
F or 1
°
C
Alarm Output
Red “ALARM” LED