Input/output unit with isolator, 55000-847IMC
The Context Plus XP95 input/output unit provides two voltage-free, single pole, change-over relay outputs, a single monitored switch input and an unmonitored, non-polarised opto-coupled input.
Compliant with EN54-17 & 18 (2005), the Input/Output Unit supervises one or more normally-open switches connected to a single pair of cables.
It is set to return an analogue value of 4 in the event of an open or short-circuit fault and 16 during normal operation. The status of the inputs is reported by means of two input bits. The change-over contacts are operated by an output bit.
The Input/Output unit is fitted with a bi-directional short-circuit isolator and will be unaffected by loop short-circuits on either loop input or output.
The unit operates at 17-28V DC with protocol voltage pulses of 5-9V. No electrical supply greater than 50V AC rms or 75V DC should be connected to any terminal.
Designed for indoor use only it includes four LEDs, two red and two yellow, which are visible through the front cover of the enclosure. One red LED is illuminated to indicate that the relay is set. The second red LED is illuminated to indicate that the switch input is closed. One yellow LED is illuminated whenever a fault condition (open or short circuit) has been detected. The other LED is illuminated whenever the built-in isolator has sensed a short-circuit loop fault.
The enclosure is moulded from white self-extinguishing polycarbonate.
Minimum loop operating voltage in normal conditions: 17V DC
Maximum loop operating voltage: 28V DC
Max. current consumption at 24V DC no protocol Switch-on surge, max 150ms: 3.5mA Quiescent, 20kW EOL fitted: 1.25mA
Switch input closed ‘switch closed’ LED on: 2.5mA
Switch input closed (LED disabled): 1.5mA Any other condition (max 2 LEDs on): 3.5mA Relay operated: 2mA
Switch input monitoring voltage (open-circuit condition): 9–11V DC
Maximum cable resistance: 50W
Maximum voltage: 35V DC
Relay output contact rating at 30V AC or DC (inductive or resistive): 1A
Relay output wetting current at 10mV DC: 10µA
On resistance 0.2W
Maximum continuous current: 1A Maximum switching current: 3A Maximum load: 20 Context Plus detectors Operating temperature: –20°C to +70°C Humidity (no condensation) : 0–95% RH Shock, vibration and impact: to GEI 1-052 IP rating: 54
Radiated and conducted RF emissions to: BS EN 50081-–1 & 2
Radiated and conducted RF immunity to: BS EN 50130–4
Dimensions of Input/Output Unit (surface mount):
150 x 90 x 48mm; Weight: 240g