Dwyer CX User Manual

Series CX Compressor Pressure Switch

Specifications - Installation and Operating Instructions

Bulletin IN-525

INSTALLATION/MOUNTING

The switch can be pipe mounted in any position. Do not twist the case when installing. Use a wrench on the pressure connection flats.

WIRING

All wiring must conform to the National Electrical Code and local regulations. Do not install the control to handle loads in excess of electrical rating shown in specifications or as indicated on instructions inside control cover.

WIRING DIAGRAM

SPECIFICATIONS

Service: Air and non-combustible compatible gases. Wetted Materials: NBR (Nitrile-Butadiene) rubber diaphragm,

steel connection (CX-1), aluminum alloy connection (CX-4).

Temperature Limits: 140°F (60°C). Pressure Limits: See model chart. Enclosure Rating: General purpose. Repeatability: ±5 psig (±0.3 bar). Switch Type: 2 each SPST snap action, normally closed (NC). Electrical Ratings: 20A @ 120 VAC, 12A @ 240 VAC, 9.6A @

240 VAC (3 phase), 8.6A @ 32 VDC, 3.1A @ 120 VDC, 1.6A @ 240 VDC. 1.5 HP @ 120 VAC, 2 HP @ 240 VAC, 3 HP @ 240 VAC (3 phase), 0.25 HP @ 32/120/240 VDC.

Electrical Connections: Screw terminal. Conduit Connection: 7/8˝ hole for 1/2˝ conduit hub (2 places). Process Connection: 1/4˝ female NPT (CX-4: 4 places). Mounting Orientation: Switch can be installed in any position. Setpoint Adjustment: Internal screws. Weight: CX-1: 0.78 lb (0.35 kg); CX-4: 1.03 lb (0.47 kg). Deadband: See model chart. Agency Approval: CE, UL pending.

MODELS

Model

Number

CX-11 CX-12 CX-13 CX-41 CX-42 CX-43

Range

psig (bar)

25-100 (1.7-6.9) 35-150 (2.4-10.3) 50-175 (3.4-12.1)

Approx. Adjustable

Deadband psig (bar)

20-30 (1.4-2.1) 30-40 (2.1-2.8) 35-55 (2.4-3.8) 20-30 (1.4-2.1) 30-40 (2.1-2.8) 35-55 (2.4-3.8)

Max. Pressure

psig (bar)

129 (8.9) 179 (12.3) 204 (14.1)

CAUTION: No lubrication or periodic servicing is required. Mount the control securely. Never exceed the electrical rating for the switch. Use the control only with compatible medias.

MAINTENANCE

Upon final installation of the Series CX Low Cost Pressure Switch, no routine maintenance is required. A periodic check of the system calibration is recommended. The Series CX is not field serviceable and should be returned if repair is needed (field repair should not be attempted and may void warranty). Be sure to include a brief description of the problem plus any relevant application notes. Contact customer service to receive a return good authorization number before shipping.

MERCOID DIVISION

DWYER INSTRUMENTS, INC. P.O. BOX 258 • MICHIGAN CITY, INDIANA 46361 U.S.A.

Phone: 219/879-8000 www.dwyer-inst.com Fax: 219/872-9057 e-mail: info@dwyer-inst.com

Number of Ports

1 1 1 4 4 4

CX-1

CX-4

The Series CX Compressor Pressure Switches are designed with a 20 amp normally closed SPST switch for direct control of pumps and motors. The set point and deadband are both easily adjustable via screw terminals inside the cover. For ease of installation, the switches come with a 1/4˝ female NPT process connection or the optional 4-port connection block on the CX-4 models. Besides making installation easier, one of the other ports can be used to install a pressure gage. Plus, these switches can be mounted in any orientation.

These units can be found regulating tank pressure on small air compressors. The CX series switches come with an unloader valve, which prevents compressors from starting under load. They also come with an auto/off disconnect lever for manually cutting off the load. When the lever is in the off position, there is a test button inside the housing that can be pushed to turn on the load.

.236

[Ø6.00]

[Ø6.35]

Ø.250

3-35/64

[90]

CX-1

3-45/64

2-17/64

[57.6]

Ø.236

[Ø6.00]

[94]

3-3/8

[85.5]

Ø.250

[Ø6.35]

3-35/64

[90]

3-45/64

[94]

2-17/64

[57.5]

CX-4

3-45/64

[94]

1-27/64

[36]

TURN CLOCKWISE TO INCREASE BOTH CUT-OUT

ND CUT-IN

PRESSURE

MOTOR

LINE

POWER SUPPLY

TURN CLOCKWISE TO INCREASE CUT-OUT PRESSURE WITHOUT AFFECTING CUT-IN