5005 ContextPlus Brochure 270411_Context plus final singles 10/05/2011 08:53 Page 29
Context
INPUT/OUTPUT UNIT WITH ISOLATOR Plus
Input/output unit with isolator, 55000-847IMC
The Context Plus XP95 input/output unit provides two VdS
voltage-free, single pole, change-over relay outputs, a 010ah
0832 G201032
single monitored switch input and an unmonitored,
non-polarised opto-coupled input.
FEATURES
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
Part Number 55000-847IMC 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.
ELECTRICAL CONSIDERATIONS
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.
Technical Data
Minimum loop operating voltage in normal Relay output contact rating at 30V AC or DC
conditions: 17V DC (inductive or resistive): 1A
Maximum loop operating voltage: 28V DC Relay output wetting current at 10mV DC: 10µA
Max. current consumption at 24V DC no protocol On resistance 0.2Ω
Switch-on surge, max 150ms: 3.5mA Maximum continuous current: 1A
Quiescent, 20kΩ EOL fitted: 1.25mA Maximum switching current: 3A
Switch input closed ‘switch closed’ LED on: 2.5mA Maximum load: 20 Context Plus detectors
Switch input closed (LED disabled): 1.5mA Operating temperature: –20°C to +70°C
Any other condition (max 2 LEDs on): 3.5mA Humidity (no condensation) : 0–95% RH
Relay operated: 2mA Shock, vibration and impact: to GEI 1-052
Switch input monitoring voltage (open-circuit IP rating: 54
condition): 9–11V DC Radiated and conducted RF emissions to:
Maximum cable resistance: 50Ω BS EN 50081-–1 & 2
Opto-coupled input Radiated and conducted RF immunity to:
Maximum voltage: 35V DC BS EN 50130–4
Impedance: 10kΩ Dimensions of Input/Output Unit (surface mount):
150 x 90 x 48mm; Weight: 240g
Also available:
Three Channel Input/Output Unit, order code 55000-588
Provides three voltage-free, single pole, change-over VdS
relay outputs and three monitored switch inputs.
010ah 0832 G201052
Supervises one or more normally-open switches on each
of the three inputs. Capable of switching up to 30V at 1A on each of the three
outputs
Mains Switching Input/Output Unit, order code 55000-875
Provides a voltage-free, single pole change-over relay output and a
monitored switch input. Supervises one or more normally-open
switches connected to a single pair of cables. Capable of switching 010ag 0832
250V AC at up to 5A
Output Unit, order code 55000-849
Provides a voltage-free single pole, change-over relay VdS
output. It is a simplified version of the Input/Output
unit without circuitry for monitoring inputs. Capable 010ah 0832 G201032
of switching up to 30V at 1A
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