This is how to troubleshoot where turning the key to the Test position does not put the smoke detector inside the duct enclosure into alarm, which will likely be due to the coil is missing.
The D344-RT Remote test/indicator plate includes a test coil and wiring harness. Selecting the test position energizes the coil, which simulates placing a magnet beside the smoke head. The test coil must be properly installed in order for the test function to work.
Figure 1 Remote Test/Indicator Plate
The steps below from the D344-RT installation manual provide steps for installing the test coil into the duct housing. Follow these steps to either install or confirm proper installation of the test coil.
1. Test Coil Installation
1 ― Test coil.
2 ― Rotate the test coil counterclockwise to align screw with mounting plate.
2. Mounting screw installation
1 ― Test coil mounting screw
3. Wiring harness connection
1 ― Connector with one wire
2 ― Connector with three wires