MTL4511 Switch/Proximity Detector Interface – 1-Channel
Product Introduction
The MTL4511 from MTL (now Eaton) is a 1-channel interface for switch or proximity detector inputs. You can place the switch or sensor in Zone 0, IIC, T6 hazardous areas or Div. 1, Group A locations. This unit applies 7 to 9V dc voltage to the sensor through a 1kΩ ±10% source. This value is critical for proper NAMUR operation.
This device follows the BS EN60947-5-6:2001 standard for NAMUR proximity detectors. The output relay changes state based on the input current. Additionally, you can enable line fault detection (LFD) to monitor for open or short circuits in the field wiring.
Technical Specifications
Input Characteristics
Number of channels: 1
Sensor voltage: 7 to 9V dc from 1kΩ ±10%
Turn-on threshold: > 2.1mA (input circuit < 2kΩ)
Turn-off threshold: < 1.2mA (input circuit > 10kΩ)
Hysteresis: 200µA (650Ω) nominal
Line Fault Detection (LFD)
Open-circuit alarm ON: Iin < 50µA
Open-circuit alarm OFF: Iin > 250µA
Short-circuit alarm ON: Rin < 100Ω
Short-circuit alarm OFF: Rin > 360Ω
External resistors required for contact inputs:
Output Characteristics
Output type: Single-pole relay with changeover contacts
Response time: 10ms maximum (one of the fastest in its class)
Contact rating (safe area / Zone 2): 10W, 0.5A, 35V dc
Power and Safety
Max current consumption: 25mA at 24V dc
Power dissipation: 0.6W at 24V dc
Safety parameters (per channel):
Uo = 10.5V
Io = 14mA
Po = 37mW
Um = 253V rms or dc
LED Indicators and User Interface
The MTL4511 provides three LED indicators for easy diagnostics.
Green LED: Power is present
Yellow LED: Output relay is energized (channel active)
Red LED: Line fault detected (when LFD is enabled)
You select the LFD function using switches located on the side of the unit. When a line fault occurs, the red LED turns on, and the output relay de-energizes automatically.
Mechanical and Environmental Information
Operating Conditions
Ambient temperature: -20°C to +60°C
Storage temperature: -40°C to +80°C
Humidity: 5% to 95% non-condensing
Mounting
This unit mounts on a standard DIN rail. It requires no external calibration. Ensure adequate clearance for heat dissipation.
Frequently Asked Questions (FAQ)
1. Can the MTL4511 work with a mechanical switch instead of a NAMUR sensor?
Yes. You can connect a dry contact switch. However, when using line fault detection (LFD), you must add the recommended series and parallel resistors. Without LFD, no resistors are needed.
2. What happens to the output relay during a line fault?
The MTL4511 de-energizes the output relay when a line fault (open or short circuit) is detected. The red LED also turns on. This behavior is fixed and cannot be changed.
3. Is the MTL4511 suitable for Zone 2 output circuits?
Yes. The relay contacts are rated for Zone 2 hazardous areas at 10W, 0.5A, 35V dc. For safe-area installations, the same rating applies.
4. How fast does the MTL4511 respond to a sensor change?
The response time is 10ms maximum. This includes the time from input change to relay contact switching.
5. Can I use the MTL4511 with a 3-wire proximity sensor?
No. The MTL4511 is designed only for 2-wire NAMUR proximity detectors (BS EN60947-5-6:2001). For 3-wire sensors, consider a different MTL model.
