MTL5511
SWITCH/ PROXIMITY
DETECTOR INTERFACE
1-channel, with line fault detection
The MTL5511 enables a safe-area load to be controlled by a switch or
proximity detector located in a hazardous-area. When chosen, open
or short circuit conditions in the field wiring are detected by the linefault-detect
(LFD) facility and also indicated on the top of the module.
Phase reversal for the channel is chosen by a switch on the side of the
module and output is provided by changeover relay contacts.
SPECIFICATION
See also common specification
Number of channels
One
Location of switches
Zone 0, IIC, T6 hazardous area
Div. 1, Group A hazardous location
Location of proximity detector
Zone 0, IIC, T4–6 hazardous area if suitably certified
Div. 1, Group A hazardous location
Hazardous-area inputs
Inputs conforming to BS EN60947–5–6:2001 standards for
proximity detectors (NAMUR)
Voltage applied to sensor
7 to 9V dc from 1kΩ ±10%
Input/output characteristics
Normal phase
Outputs closed if input > 2.1mA (< 2kΩ in input circuit)
Outputs open if input < 1.2mA (> 10kΩ in input circuit)
Hysteresis: 200µA (650Ω) nominal
Line fault detection (LFD)
User-selectable via switches on the side of the unit. A line fault is
indicated by an LED. The channel output relay is de-energised if an
input line fault is detected.
Open-circuit alarm on if Iin < 50µA
Open-circuit alarm off if Iin > 250µA
Short-circuit alarm on if Rin < 100Ω
Short-circuit alarm off if Rin > 360Ω
Note: Resistors must be fitted when using the LFD facility with a contact input
500Ω to 1kΩ in series with switch
20kΩ to 25kΩ in parallel with switch
Safe-area output
Single pole relay with changeover contacts
Note: reactive loads must be adequately suppressed