The IQ331BI isolator base protects the bus in the event of a short-circuit fault. When a fault occurs, the isolator base nearest the short-circuit acts quickly to cut off the affected section, allowing other devices on the bus to continue operating normally. Once the fault is cleared, the isolated section automatically reconnects. The isolator base requires no coding and does not occupy an address in the loop.

Key Features:

• Fast activation response
• LED indicates isolation condition
• Protection against overload conditions
• Minimizes disruption from short circuits
• Stable communication with high noise immunity
• Up to 20 detectors can be installed between isolating bases
• Suitable for smoke, heat, and multi-sensor detectors
• Automatic restoration once short circuit is cleared
• Should be used with Loop Stabilizer
• Applus certified

Key Specs:

• Operating Voltage: 20–28V
• Static Current: <85µA | Isolation Current: <9mA
• Isolation Voltage: Less than 14V
• Indicator: Yellow — on during isolation, off during monitoring
• Operating Temperature: -10°C to +55°C
• Relative Humidity: ≤95%, non-condensing
• Terminal Wiring Capacity: 0.2mm²–2.5mm²
• External Dimensions: Ø100 x 31.4mm

Note: The description text refers to the product as “IQ311BI,” but the document title and spec table both use “IQ331BI” — I’ve used IQ331BI throughout to match the filename and header, but worth confirming the correct model number with your source.