WATLOW Series 942 User's Manual
47
Appendix
Specifications
Secondary Output (Heat, Cool or None)
• Solid state relay, Form A 0.5A @ 24VAC min., 264VAC maximum, opto-
isolated, zero cross switching. Off state impedance is 20K
Ω
minimum for
942A-X
B
XX-X0000 units, and infinite impedance for 942A-X
K
XX-X000 units.
• Electromechanical relay, Form A, 6A @ 120/240VAC, 6A @ 28VDC,
1/8 hp. @ 120VAC, 125VA @ 120VAC. Off state impedance is 20K
Ω
min.
• Switched DC, Open collector, 500
Ω
minimum load resistance, 1K
Ω
load,
9mA minimum, 22mA maximum, non-isolated.
Auxiliary Outputs
• Electromechanical relay, Form A (N.O.) or B (N.C.), 6A @ 28VDC, 1/8 hp.
@ 120VAC, 125VA @ 120VAC. Off state impedance is 20K
Ω
minimum.
• Latching or non-latching.
• Process or deviation.
• Separate high and low values.
• Alarm silencing (inhibit) on power up for Alarm 1.
Retransmit Output
• 4-20mA into a 600
Ω
maximum load, non-isolated. Retransmit of process
or set point. User selectable range.
• 0-5VDC into a 10K
Ω
minimum load, non-isolated. Retransmit of process
or set point. User selectable range.
Accuracy
• Calibration Accuracy and Sensor Conformity:
±
0.1% of span,
±
1 LSD,
77
°
F
±
5
°
F (25
°
C
±
3
°
C) ambient & 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.
Communications
• Serial data communications.
• RS-422A or RS-423A (RS-232C compatible) or EIA-485, user selectable.
• ANSI X3.28 protocol, or XON/XOFF protocol.
• Isolated.
• Data logging.
• #6 compression type screw terminals.
Agency Approvals
• UL and CSA pending.
Terminals
• #6 compression type screw terminals.
Power
• 120/10%, -15%, 50/60Hz,
±
5%.
• 16VA maximum.
• Data retention upon power failure via nonvolatile memory.
Operating Environment
• 32 to 149
°
F/0 to 65
°
C.
• 0 to 90% RH, non-condensing.
Dimensions
• Height:
3.8 in
97 mm
• Width:
3.8 in
97 mm
• Overall depth:
7.0 in
178 mm
• Behind panel depth:
6.0 in
153 mm
• Weight:
2.5 lb max.
0.4 kg