User`s manual

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), 500Ω minimum load resistance, 1KΩ 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 20KΩ

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 20KΩ

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.