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NoFossil Control System Components

A complete installation will in most cases require more than the controller itself. Due to connector space limitations, some sensor channels are grouped on a single connector and require a breakout box. Controlling high voltage loads requires an external relay box. The diagram to the right shows an NFCS system with typical components.


A standard NFCS has two sensor panels, each supporting eight sensors. Of those, four can be plugged directly into the NFCS, and four are plugged into a breakout box. The breakout box is connected with standard Category 5 network cable, and may be up to 100 feet from the NFCS controller.

The NFCS supports semiconductor sensors that can measure temperatures from -30 to +100 C (-22 to +212 F) as well as thermistors and type K thermocouples. Semiconductor and thermistors sensors can be plugged into any sensor connector, but thermocouples require an external interface box mounted at the thermocouple location. The box supports two thermocouples.

In the example shown, the first sensor interface has the analog output option which allows variable speed control of circulator pumps and fans. The output connector goes to a breakout box, and each variable speed load requires a variable speed control box mounted near the load. The system at right has two circulators and two fans with variable speed control.

Discrete Inputs

These inputs detect switch closures such as aquastats, relay contacts, and mechanical thermostats. Each connector can detect four individual devices.

Discrete Outputs

Discrete outputs can drive 12Vdc relay coils, LEDs, or other DC loads up to 200ma. Each connector supports four channels, and typically will be connected to a remote relay enclosure. In the system at the right, the relay box controls two circulators and two valves.

In this photo, two sensors are connected directly to the controller and two are connected to a sensor breakout box. A relay box is connected (via blue cable) to a discrete output connector. Ethernet and power cables are also visible.