Short Circuit Isolator | FLM-325 | BOSCH

• Automatic verification of data line for short circuit
• Contacts are rated to 1 A at 30 VDC
• Can be placed at any location on SLC loop
• 256 devices at maximum per loop for Class A (Style 7)
• Yellow LED provides data line status

The FLM‐325‐ISO Short Circuit Isolator isolates a shorted section on a specific polling circuit from the
rest of the system to minimize the loss of devices. It fits into a standard 4-inch square or double‐gang
electrical back box.

Basic Operation
If a short condition occurs, the two adjacent isolators activate and their respective LED turns on. This action prevents the entire polling circuit from becoming disabled. Upon removal of the shorted condition, the isolators automatically return to the normal operating state.

Start-up Delay
When power is applied or after a short is removed, detectors and devices cannot begin communicating
with the fire panel until they are sufficiently charged. Because the isolator must first charge the devices that are connected down the polling circuit, a start-up delay of approximately 30 s occurs when a full circuit of devices or detectors is connected to a single isolator without an optional loop circuit return
(Class B, Style 4). During charging, the LED remains on.

Status display
In case of a short circuit the isolator activates and the yellow LED turns on.

Certifications and approvals

Compatibility Information
The following products are compatible with the FLM‐325‐ISO Short Circuit Isolator:

Class A, Style 7 Wiring
The isolator can be located between any devices on the SLC loop. In the event of a short circuit on the SLC loop, the two adjacent isolators (closest isolators to the left and right of the shorted section) will activate and their respective LED indicators will be turned on.

All devices between the active short circuit isolators will be disconnected from the loop. This will prevent entire loop failure. After removal of the short circuit condition, the isolator goes back to normal and the fire panel restores the entire loop to normal operating state.

Class B, Style 4 Wiring
The isolator can be located between any devices on the SLC loop. In the event of a short circuit on SLC loop, an isolator closest to the shorted section will activate and the LED will be turned on. All the devices beyond the shorted section will be disconnected. After removal of the short circuit condition, the isolator will automatically restore the entire loop to the normal operating state.

Parts included

Technical specifications

Electrical

Mechanics

Environmental Conditions