Fire Alarm Systems FLM‑I 420‑S Short Circuit Isolator
FLM‑I 420‑S Short Circuit Isolator
▶ Rotary switch for automatic and manual address setting
▶ Preservation of LSN loop functions in the event of a
▶ Power supply via LSN
▶ Three free screw terminals
The Short Circuit Isolator isolates alarm zones in which a short circuit has occurred. This means the functionality of the remainder of the network remains preserved.
Functions
Features of improved LSN
The interface modules in the 420 series offer all the features of improved LSN technology:
System Overview
CL 0 | 1 | 9 | 0 | 1 | 9 0 | 1 |
| 2 | 8 |
| 2 | 8 | 2 |
|
| 76 | 5 | 4 3 | 76 5 | 4 3 |
| LSN |
|
|
|
|
|
b1+ | a- | b2+ | N/A | N/A | N/A | |
Description | Connector |
b1+ / | LSN |
N/A (3 x) | free terminals, e.g. for looping through ext. auxiliary volt- |
| age and for shielding |
•Flexible network structures including T‑tapping without additional elements
•Up to 254
•Unshielded cable can be used
Address switch (rotary switch)
The address of the Short Circuit Isolator is set using the rotary switches.
The following settings are possible:
0 0 0 | Loop/stub in LSN mode improved version with automatic |
| addressing |
0 0 1 - 254
| with manual addressing |
CL 0 0 | Loop/stub in classic LSN mode |
Configuration
The Short Circuit Isolator isolates alarm zones in which a short circuit has occurred. The following illustrations show typical configurations of the isolator module.