Kidde uses a single wire surrounded embedded in ceramic beads coated with eutectic salts which melt and become conductive at a certain temperature. Fenwal uses two wires embedded in a material which becomes conductive when heated. Both systems basically short to their iconel tubing when heated to create the signal: However Fenwal has a backup circuit. Both will still function when severed, however they will not test.
Jonathan was here 7/14/2021
what is the difference of fenwal and kidde fire detection?
Kidde uses a single wire surrounded embedded in ceramic beads coated with eutectic salts which melt and become conductive at a certain temperature. Fenwal uses two wires embedded in a material which becomes conductive when heated. Both systems basically short to their iconel tubing when heated to create the signal: However Fenwal has a backup circuit. Both will still function when severed, however they will not test.