These basically similar units both enable a safe-area load to be controlled by a proximity detector or switch located in a hazardous area, the MTL3011 having a relay output for general use, and the MTL3012 a floating solid-state on/off switch compatible with logic circuits. In both units a built-in phase-reverse control allows an alarm condition (output open) to be signalled for either state of the sensor. A line-fault detection feature opens the output in the event of short or open-circuit lines: intended for use primarily with proximity detectors,it can also be used with switches made to resemble them electrically by adding two resistors, or disabled by a link if not required. MTL3011 SWITCH PROXIMITY DETECTOR RELAYS
SPECIFICATION
See also 'Common specification' Number of channels
One, fully floating
Location of switch
Zone 0, IIC, T6 hazardous area
Div 1, Group A, hazardous location Location of proximity detector
Zone 0, IIC, T4–6 if suitably certified
Div 1, Group A, hazardous location
Voltage applied to sensor
7.7 to 9.0V dc from 1kΩ
Input/output characteristics
Output closed if >2.1mA* (<2kΩ) in sensor circuit
Output open if <1.2mA* (>10kΩ) in sensor circuit
Hysteresis: 200µA (650Ω) nominal
*NAMUR and DIN 19234 standards for proximity detectors Phase reverse facility MTL3011 SWITCH PROXIMITY DETECTOR RELAYS Operation reversed by switch on top of unit
Power supply failure protection
Output circuit opens if supply fails Brokenorted lines protection
By built-in line-fault detection feature (LFD)
Output open if input current <100µA (broken line)
Output open if input current >6.5mA (shorted lines)
Note: to prevent false triggering of LFD, switch-type
sensors must be fitted with resistors as shown or LFD be
disabled by linking terminals 7 and 8
Output characteristics, MTL3011
Response time: 1ms typical
Contact rating: 200V, 0.5A, 10VA (ac); 200V, 0.5A, 10W (dc)
(USA: 60V) individual maxima, resistive loads
Contact life expectancy: 0.75 x 106 operations at max. load
Note: reactive loads must be adequately suppressed to protect the light-duty contacts in this unit
Output characteristics, MTL3012
Operating frequency: typically dc to 2kHz
Maximum off-state voltage: 35V
Maximum off-state leakage current: 10µA
Maximum on-state voltage drop: 1+ (0.13 x current in mA) V
Maximum on-state current: 50mA
Note: the solid-state output is Zener-diode protected
against inductive loads LED indicator
ON when output circuit is closed
Power requirement
25mA typical at 24V
35mA maximum at 20 to 35V
Power dissipation within unit
0.6W typical at 24V
1.3W maximum at 35V MTL3011 SWITCH PROXIMITY DETECTOR RELAYS
orted lines protection