Mistrigger

Two opposing SSRs (Nos 1 and 4 or 2 and 3) could still mistrigger simultaneously due to dv/dt or high-voltage transients; therefore, resistors R1 through R4 are inserted to limit the resultant surge current.

Pedestrians, motorcycles, birds, or debris are not a threat to mistrigger the system .

High peak harmonic currents may cause automatic relay protection devices to mistrigger.

While periodically operatin test switch reduce R2 (increasing ramp) until specified value is reached without mistrigger.

The 10K resistors and the 0.001μF disc capacitors in the input circuit of each timer IC prevent a possible mistrigger on positive pulse edges.

Any electrical noise present in the system will ride up these sloping sides, and interfere with the detection threshold in the receiving device, causing a mistrigger of the detection process, and subsequent errors.