Question 2

Question: In what way the noise immunity of detectors SPD 3.0 connected to the AC loop of a Fire Control Panel “Gamma-132” should be increased?

Answer: The connecting of SPD-3.0 should be carried out according to the scheme . A resistor R_term ought to be placed at the end of the loop, not on the Control panel itself. The introduction of a capacitor С connected parallel to R_term allows decreasing the switch velocity of the AC loop. Moreover it is worth while to provide the earth of the common wire of an electronic block of the Control panel “Gamma-132”, for that the lower lead of a terminal “Fault – open collector” located on the left side of a block should be connected through a resistor (resistance 1 KΩ) with an earth terminal of the Control panel located on the rear wall of a case on the right side. The control panel itself must be connected to the ground mat with the resistance ≤ 4 Ω.