Page 19 of 91
Rev. 4.20
3.1.5 Check of SHI short circuits at power supply line
Connect the positive clip +24; to the loop
Set the tester at 50Vdc and measure the voltage between shielded and the negative (of the battery or the clip –
24): THERE MUST NOT BE VOLTAGE!!!
A possible reading of voltage may occur in the case of short circuit in one ore more detectors or between the
shielded clip means that a short circuit, inside a few detectors, between shielded clip and the clip R and the
terminal R and common terminal (common clip of base nr. 2 or nr. 3).
FURTHER CHECK FOR SHORT CIRCUITS ON THE LOOP LINE AND POWERED UP SYSTEM:
Connect the negative cable of the loop to the clip –24; all leds must flash.
Connect a 1K
Ω
- 5Watt resistance bloop and +24.
The un-flashing leds suggest a problem on the detector.
IF THE LEDS ARE STILL NOT FLASHING; CHECK FOR SHORT CIRCUITS ALONG THE LINE.
Warning: the presence of isolators along the line cuts off the check verification, so to have final proof for the
proper functioning, one may “Jeri Wire” the relay by bridging it to the jumper terminal.
