Product Overview
DWYER INSTRUMENTS, INC. | dwyer-inst.com96
Single Pressure Switches /
Single Pressure Transmitters
PRESSURE
WATER PUMP PRESSURE SWITCH
Simple, Reliable, Adjustable Set Point and Deadband
2-17/64[57.6]
3-3/8
[85.5]
3-45/64 [94]
2-9/16 [65]
SPECIFICATIONS
Service: Compatible liquids and gases.
Wetted Materials: Silicone, steel, and SS.
Temperature Limits: 140°F (60°C).
Pressure Limits: See model chart.
Enclosure Rating: General purpose.
Repeatability: ±5 psig (±0.3 bar).
Switch Type: DPST snap action (see model chart).
Electrical Ratings: 20 A @ 120 VAC, 12 A @ 240 VAC, 9.6 A @ 240 VAC (3
phase), 8.6 A @ 32 VDC, 3.1 A @ 120 VDC, 1.6 A @ 240 VDC.
Electrical Connections: Screw terminal.
Conduit Connection: 7/8˝ hole for 1/2˝ conduit hub (2 places).
Process Connection: 1/4˝ female NPT.
Mounting Orientation: Switch can be installed in any position.
Set Point Adjustment: Internal screws.
Weight: 0.75 lb (0.34 kg).
Deadband: See model chart.
SPECIFICATIONS
Service: Compatible liquids and gases.
Wetted Parts: 316L SS.
Accuracy: ±.20% FS (includes non-linearity, hysteresis and non-repeatability).
Temperature Limits: -40 to 260°F (-40 to 125°C) 10 to 90% RH, non-condensing.
Pressure Limits: See table.
Compensated Temperature Range: 20 to 180°F (-7 to 80°C).
Thermal Effect: Zero and span shift: ±2.0% FS/100°F.
Power Requirements: 9-30 VDC.
Output Signal: 4-20 mA, 2-wire.
Zero and Span Adjustment: ±0.5 mA, non-interactive.
Response Time: ≤ 10 ms.
Loop Resistance: 800 Ω.
Electrical Connections: 1/2˝ conduit tting and strain relief with 15 ft (4.5 m)
cable.
Process Connection: 2˝ or 1-1/2˝ sanitary clamp tting male NPT.
Clamping Effect: Zero and span shift: ±0.15% FS for ranges up to 30 psi; ±0.25%
FS for ranges >30 psi.
Weight: 8 oz (227 g).
SANITARY PRESSURE TRANSMITTER
No Liquid Fill Diaphragm, Sanitary Clamp Fitting
1.743
[44]
2.272
[58]
2.516
[64]
1/2 NPT
SERIES CXA | MERCOID
®
BY DWYER
SERIES 681
The Series CXA Water Pump Pressure Switch has been proven reliable for
controlling automatic water systems. These switches are very popular for use on
water well pumps and pumping systems. The set point and dead-band are both easily
adjustable via screws inside the cover. For ease of installation, the switches come with
a 1/4˝ female NPT process connection and can be mounted in any orientation. The
series CXA’s simple design makes it a great switch for an installer at any skill level.
FEATURES/BENEFITS
• The set point and deadband are both easily adjustable reducing time to install and
operation
• Mounting in any position and feature simple makes a reliable switch that can be
installed by any skill level
APPLICATIONS
• Electric water pumps
• Water system applications
• Well pumps
• Pumping systems
The Series 681 Sanitary Pressure Transmitter is designed to meet 3A standards
for applications in food, dairy, beverage and pharmaceutical processing, liquid level
control, and sanitary pipelines. The unit is fully sealed to withstand high pressure wash-
down in Clean-in-Place (CIP) and Sterilize-in-Place (SIP) installations. The Series 681
is designed with a unique, no liquid ll diaphragm and a sanitary clamp pressure tting
for easy installation with negligible clamping effect. A conduit tting, shielded cable
with vent tube and sealed screws for zero and span adjustment combine to make the
Series 681 completely watertight.
FEATURES/BENEFITS
• Fully sealed to withstand Clean-in-Place and Sterilize-in-Place installations supports
regulatory conditions for sanitary processes
• Sanitary clamp tting makes for easy installation
APPLICATIONS
• Sanitary process applications
• Food and beverage processing
• Water processing
• Dairy processing
• Pharmaceutical processing
MODEL CHART
Model Range Overpressure Sanitary Clamp Connection
681-02
681-12
681-42
681-52
681-62
0 to 1 psi
0 to 2 psi
0 to 15 psi
0 to 30 psi
0 to 60 psi
50 psi
100 psi
150 psi
150 psi
180 psi
2˝
2˝
2˝
2˝
2˝
OPTIONS
Use order code: Description
NISTCAL-PT1 NIST traceable calibration certicate for pressure transmitters
MODEL CHART
Model Switch Type Range psig (bar) Approx. Adjustable Deadband psig (bar) Max. Pressure psig (bar)
CXA-S1
CXA-S2
CXA-S3
CXA-R1
CXA-R2
CXA-R3
NC
NC
NC
NO
NO
NO
15 to 80 (1.0 to 5.5)
30 to 100 (2.1 to 6.9)
35 to 150 (2.4 to 10.3)
15 to 80 (1.0 to 5.5)
30 to 100 (2.1 to 6.9)
35 to 150 (2.4 to 10.3)
15 to 30 (1.0 to 2.1)
20 to 35 (1.4 to 2.4)
30 to 40 (2.1 to 2.8)
15 to 30 (1.0 to 2.1)
20 to 35 (1.4 to 2.4)
30 to 40 (2.1 to 2.8)
129 (8.9)
179 (12.3)
204 (14.1)
129 (8.9)
179 (12.3)
204 (14.1)
Pressure_2021.indb 96 7/15/20 8:20 AM