Isolating Base, XPERT Style, 45681-284IMC

The Context Plus XPERT Style Isolating Base is designed to detect and isolate short-circuit faults on loops and spurs.

The base is loop-powered, polarity sensitive and accepts an XPERT card to set the address of the associated device.

During a short-circuit condition, the integral yellow LED remains illuminated while the detector associated with the base stays active. Power and signals to the affected section are restored automatically when the fault is cleared.

Under normal operating conditions, the base allows power and signals to pass to the next device. If a short circuit or abnormally low impedance is detected, the base isolates the negative supply in the direction of the fault.

The catalogue states that up to 20 devices may be installed between isolating bases, provided their total switch-on surge current does not exceed 20mA.

Key Features:

• Detects and isolates short-circuit faults on loops and spurs.
• Loop-powered operation.
• Accepts an XPERT card for device addressing.
• Associated detector remains active during a short circuit.
• Automatic restoration after the fault is cleared.
• Yellow LED isolation indicator.
• Supports up to 20 devices between isolating bases, subject to surge-current limits.

Technical Specifications:

• Product number: 45681-284IMC.
• Maximum loop operating voltage: 28V DC plus 9V protocol pulses.
• Minimum normal loop operating voltage: 17V DC.
• Power-up time: greater than 10ms.
• Current consumption at 18V: 23µA.
• Current consumption at 28V: 43µA.
• Current consumption at 18V with adjacent sector isolated: 4mA.
• Maximum continuous non-isolating line current: 1A.
• Transition-to-isolation current: 3A.
• On resistance: less than 0.2Ω.
• Operating temperature: -20°C to +60°C.
• Storage temperature: -30°C to +80°C.
• Relative humidity: 0 to 95%, non-condensing and non-icing.
• Dimensions: 100mm diameter × 24mm high.
• Weight: 100g.
• Materials: White polycarbonate moulding and nickel-plated stainless steel.