Siemens Building Technology 243-0018 Signal Selector

The Siemens Building Technology 243-0018 Signal Selector is a high-performance, dual-input pneumatic logic device designed to compare two proportional air signals and transmit the higher value to downstream controllers or final control elements. As the direct replacement for RCC-1108, this highest pressure signal selector is essential for optimizing pneumatic control systems that require precise demand-based logic, such as multi-zone cooling applications using direct-acting thermostats. Built with a rugged glass-filled nylon housing and a flexible neoprene-fabric diaphragm, it supports a maximum operating pressure of 30 psi and an ambient temperature range up to 140°F. The 243-0018 features an air capacity of 130 scim at a 2 psi differential with zero air consumption, ensuring maximum efficiency without signal loss. Field installation is streamlined via standard 1/4-inch barbed connectors and the included versatile mounting bracket.

• Pneumatic Logic Integration: Seamlessly compares two high-capacity air signals to ensure the most demanding zone dictates system response.
• Drop-in Compatibility: Engineering-matched to replace legacy RCC-1108 units without requiring extensive manifold rework.
• Efficient Performance: No-bleed design eliminates continuous air consumption, maintaining system integrity and reducing compressor load.
• Versatile Mounting: Lightweight 4 oz. construction allows for in-line support by polyethylene tubing or fixed attachment using the included bracket.

Common Questions

Can the 243-0018 handle more than two input signals?
This specific model is a dual-input selector. For applications requiring the comparison of three or more pneumatic signals, you should integrate the 243-0019 or daisy-chain multiple 243-0018 selectors in a cascading configuration.

Is this selector compatible with 1/4-inch poly tubing?
Yes, the device is equipped with integrated barbed fittings specifically designed for standard 1/4-inch (6.4 mm) O.D. polyethylene tubing frequently used in HVAC pneumatic controls.

Does this unit require manual calibration?
The Siemens 243-0018 is a non-adjustable logic relay. It operates purely on pressure differentials between the two input ports, selecting the highest signal pressure automatically without the need for field adjustments.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.