These firestat duct fan and limit switches are installed in air ducts to shut down heating, air conditioning and ventilation equipment when air temperature exceeds a pre-set limit.

Our CEMCO Firestat switch division commonly are installed in apartment complexes or equipment that require several units.

At Senasys, price and lead time is quantity based and units are made to order. To get the best possible price and lead time we recommend sending in a request for quote with your estimated annual usage to our inside sales team for quantities greater than 100.

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The Duct High Temperature Switches feature a helix bimetal element that senses rapid increases in duct temperature, such as those caused by fire. The high temperature limit then operates an SPST switch that opens with a rise in temperature. A manual reset button reactivates the temperature limit after the high-temperature condition has cleared. These duct high temperature limits are indispensable in specialized HVAC applications and Building Automation Systems. For more information about where duct fan and limit control are used, click here to visit our application notes.

Firestat Limit Controls CatalogRFQ firestat duct limit controls


Adjustable Temperature Duct Limit Switch

The adjustable temperature duct limit switch features a helix bi-metal element that senses rapid increases in temperature.The duct limit switch operates a single pole, single throw (SPST) switch that opens when temperature rises. The adjustable duct limit switch can be set by the operator to sense 100°F to 250°F. (read more)

Adjustable Temperature Duct Limit SwitchPurchase firestat adjustable temperature duct limit switch

Fixed Temperature Duct Limit Switch

The TC Firestat limit switches are available as a fixed temperature option. The fixed duct limit switch offers the same benefits as our other duct limit switches, but comes preset at the required temperature. Our standard fixed temperatures include, 125°F, 165°F or 200°F. (read more)

Fixed Temperature Duct Limit SwitchPurchase firestat duct limit controls
Duct Fan Controls

Senasys is currently working on the R&D for other duct control possibilities. Our current product offering for the TC Series only opens on temperature rise. We are looking at other possibilities such as close on temperature rise and a DPDT switch, which will open and close two sets of contacts on temperature rise.
Duct Fan Control