Series-CX

Supported Applications

The Dwyer Series CX Compressor Pressure Switches are designed for the direct control of pumps and motors, specifically regulating tank pressure on small air compressors. These units manage systems handling air and non-combustible compatible gases.

Operating Conditions & Performance

The series operates within a temperature limit of 140°F (60°C) with a repeatability of ±5 psig (±0.3 bar). Pressure ranges vary by model, covering spans from 25-100 psig (1.7-6.9 bar), 35-150 psig (2.4-10.3 bar), and 50-175 psig (3.4-12.1 bar). Maximum pressure limits correspond to the selected range, reaching up to 204 psig (14.1) for higher-range models.

Electrical ratings support direct motor control with capacities including:

• 20A @ 120 VAC
• 12A @ 240 VAC
• 9.6A @ 240 VAC (3 phase)
• 8.6A @ 32 VDC, 3.1A @ 120 VDC, and 1.6A @ 240 VDC
• Horsepower ratings of 1.5 HP @ 120 VAC, 2 HP @ 240 VAC, 3 HP @ 240 VAC (3 phase), and 0.25 HP @ 32/120/240 VDC

The switches feature a General purpose enclosure rating.

Configuration Options

The Series CX offers configurable port configurations, wetted materials, and adjustment features to accommodate specific installation needs:

• Housing & Ports: Models are available with 1 or 4 ports. The standard configuration includes a 1/4" female NPT process connection (CX-1 series), while the CX-4 models feature an optional 4-port connection block, allowing one port to be used for installing a pressure gage.
• Wetted Materials: Construction utilizes an NBR (Nitrile-Butadiene) rubber diaphragm. Connections are steel on CX-1 models and aluminum alloy on CX-4 models.
• Switch Type & Adjustment: The series includes 2 each SPST snap action, normally closed (NC) switches. Set point and deadband are adjustable via internal screws accessible through the cover.
• Features: Units include an unloader valve to prevent compressors from starting under load and an auto/off disconnect lever for manually cutting off the load. A test button inside the housing allows turning on the load when the lever is in the off position.
• Mounting & Connections: The switch can be installed in any orientation without twisting the case. Electrical connections are made via screw terminals, with a 7/8" hole for 1/2" conduit hub (2 places).

Key Product Differences

The series is divided into two primary model families based on port count and connection material:

• CX-1 Series (CX-11, CX-12, CX-13): Features 1 port with a steel process connection. Dimensions are approximately 3-45/64" width x 3-3/8" height x 2-17/64" depth.
• CX-4 Series (CX-41, CX-42, CX-43): Features 4 ports with an aluminum alloy process connection. Dimensions are approximately 3-45/64" width x 3-45/64" height x 2-17/64" depth.

All models share the same pressure ranges and deadband specifications within their respective range categories (e.g., CX-11 and CX-41 both cover 25-100 psig with a 20-30 psig adjustable deadband). Agency approvals include CE, with UL pending.