Specifications – Watlow Series 945 High/Low Limit Control User Manual
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WATLOW Series 945 High/Low Limit User's Manual
Specifications
Control Mode
• High/Low limit.
• RS-422A,RS423A, or EIA-485 data communications available.
Operator Interface
• Membrane front panel.
• Dual, four digit 0.56" LED displays.
• MODE, UP, DOWN, and ALARM CLEAR keys.
Input
• Thermocouple, RTD, and electrical process input.
• Automatic cold junction compensation for thermocouple.
• RTD input 2 or 3 wire, platinum, 100 ohm @ 0
°
C software selectable, JIS
curve #3916 (0.003916
Ω
/
Ω
/
°
C) or DIN curve #3850 (0.003850
Ω
/
Ω
/
°
C).
• Sensor break protection de-energizes control outputs to protect the system.
• Grounded or ungrounded sensors.
•
°
F,
°
C, or process variable units are user selectable.
• Operating ranges user selectable.
J t/c:
32
to
1382
°
F
or
0
to
750
°
C
K t/c:
-328
to
2282
°
F
or
-200
to
1250
°
C
T t/c:
-328
to
662
°
F
or
-200
to
350
°
C
N t/c:
32
to
2282
°
F
or
0
to
1250
°
C
C t/c:
797
to
4200
°
F
or
425
to
2315
°
C
PT2
32
to
2543
°
F
or
0
to
1395
°
C
1
°
RTD:
-328
to
1112
°
F
or
-200
to
600
°
C
0.1
°
RTD:
-99.9
to
392.0
°
F
or
-99.9
to
200.00
°
C
0-5VDC:
-500
to 3500 units
4-20mA:
-500
to 3500 units
Sonalert, Alarm 1, Output 1
• Switched DC (Open Collector), 500
Ω
minimum load resistance, 1K
Ω
load,
9mA minimum, 22mA maximum, non-isolated. Energized in alarm state.
Alarm 2, Output 2
• Electromechanical relay, Form A or B, 6A @ 115/230VAC, 6A @ 28VDC,
1/8 hp, @ 115 VAC, 125VA @ 115VAC. Off state impedance is 20K
Ω
minimum.
Alarm 2, Output 3
• Electromechanical relay, Form A or B, 6A @ 115/230VAC, 6A @ 28VDC,
1/8 hp @ 115VAC, 125VA @ 115VAC. Off state impedance is 20K
Ω
minimum.
Accuracy
• Calibration Accuracy and Sensor Conformity:
±
0.1% of span,
±
1 LSD,
77
°
F
±
5
°
F (25
°
C
±
3
°
C) ambient and rated line voltage
±
10%.
• Accuracy Span: 1000
°
F or 540
°
C minimum.
• Temperature Stability: 0.1
°
F/
°
F (0.1
°
C/
°
C) change in ambient.
• Voltage Stability:
±
0.01% of span /% of rated line voltage.
Terminals
• #6 compression type screw terminals.