WhatsApp: +86 16626708626
Email: 
Phone: +86 16626708626Description
Key Technical Specifications
| Parameter | Value |
|---|---|
| Model | MTL5517 |
| Manufacturer | Eaton / MTL |
| Product family | MTL5500 Intrinsic Safety Interface Range |
| Function | Galvanically isolated interface for hazardous-area switches and proximity detectors |
| Number of channels | 2 |
| Input signal type | Digital input, NAMUR-compatible proximity detectors or mechanical switches |
| Sensor supply | 7 to 9 V DC from 1 kΩ ±10% |
| Output energized threshold | Input current greater than 2.1 mA, input circuit resistance less than 2 kΩ |
| Output de-energized threshold | Input current less than 1.2 mA, input circuit resistance greater than 10 kΩ |
| Hysteresis | 200 µA nominal, equivalent to 650 Ω |
| Relay outputs | Two single-pole relays with normally open contacts |
| LFD output | One single-pole relay with normally open contact |
| Response time | 10 ms maximum |
| Safe-area relay contact rating | 250 V AC, 2 A, power factor greater than 0.7; 40 V DC, 2 A resistive load |
| Zone 2 relay contact rating | 35 V, 2 A, 100 VA |
| Supply voltage | 20 to 35 V DC |
| Current consumption | 35 mA maximum at 24 V DC |
| Power dissipation | 0.84 W at 24 V DC |
| Galvanic isolation | 250 V rms between safe-area circuits and power supply |
| Intrinsic-safety output per channel | Uo = 10.5 V; Io = 14 mA; Po = 37 mW; Um = 253 V rms or DC |
| Phase reversal | Selectable by side-mounted DIL switch |
| Line fault detection | Selectable by side-mounted DIL switch |
| LED indicators | Green power; yellow channel status; red line fault detection |
| Operating temperature | −20 to +60°C |
| Storage temperature | −40 to +80°C |
| Relative humidity | 5% to 95%, non-condensing |
| Mounting | T-section 35 mm DIN rail |
| Functional safety | SIL2 and SIL3 capable per IEC 61508 |
| Certifications | ATEX, IECEx, CSA, FM |
The Eaton MTL5517 is intended for switches and NAMUR proximity detectors located in Zone 0, IIC, T6 hazardous areas. Certified proximity detectors can be used in Zone 0, IIC, T4–T6 locations.
Product Introduction
The Eaton MTL5517 is a two-channel intrinsic-safety isolator for mechanical switches and NAMUR proximity detectors in hazardous areas. It supplies 7–9 V DC to each field sensor, isolates the hazardous-area circuit, and drives two safe-area relay outputs for connection to a PLC, DCS, or alarm system.
It includes selectable phase reversal and line fault detection. The LFD relay and red front-panel LEDs identify open- or short-circuit field-wiring faults, while yellow LEDs show the status of each output channel. Its SIL2/SIL3 capability makes it suitable for both general digital-input service and selected safety-related applications.
MTL5517
MTL5517
Troubleshooting Quick Reference
| Symptom | Possible Cause | Relevance to this Part | Quick Check Method | Recommendation |
|---|---|---|---|---|
| Green power LED off | 24 V DC supply loss, blown fuse, or incorrect polarity | ✅ High | Measure 20–35 V DC at the module supply terminals; inspect DIN-rail seating and fuse | Restore supply or correct wiring before replacing the MTL5517 |
| One channel always open | Open field loop, failed NAMUR sensor, or wiring fault | ✅ High | Measure loop current or resistance at the field terminals; compare with the 1.2 mA / 2.1 mA thresholds | Repair field wiring or replace the sensor first |
| One channel always closed | Shorted field wiring, failed sensor, or incorrect phase setting | ✅ High | Disconnect field wiring and measure loop resistance; check phase-reversal DIL switch | Correct field wiring or phase-reversal setting |
| Red LFD LED on | Open or short circuit in the field loop | ✅ High | With LFD enabled, measure loop resistance and current; check terminal tightness | Locate and repair the field-loop fault |
| LFD relay does not operate | LFD disabled by DIL switch or LFD wiring issue | ✅ Medium | Confirm LFD switch position and verify LFD relay wiring to the PLC/alarm circuit | Enable LFD and correct the LFD output wiring |
| PLC input does not change | Relay output wiring, PLC input card, or logic configuration issue | ❌ Low | Measure voltage across the relay output terminals while commanding the field device | Verify PLC input wiring and logic before replacing the isolator |
| Intermittent status | Loose terminal, damaged sensor cable, or vibration-induced contact issue | ✅ Medium | Re-torque terminals and inspect cable, glands, and sensor cable continuity | Re-terminate wiring and replace damaged cable or sensor |
❗ Do not assume the Eaton MTL5517 is faulty because an LFD alarm appears. In practice, a loose terminal, damaged NAMUR cable, or failed proximity detector causes most LFD events. Check the field loop first.
If the fault remains after checking supply voltage, DIL-switch settings, field wiring, and sensor condition, contact technical support with photos of the module, wiring, and PLC diagnostic data.
Frequently Asked Questions
Can I use the Eaton MTL5517 with a mechanical switch?
Yes. It accepts both mechanical switches and NAMUR-compatible proximity detectors. For a simple dry contact, wire it according to the MTL5517 installation manual and verify the resulting loop current against the module’s switching thresholds.
What type of proximity detector does it support?
It supports NAMUR-style proximity detectors conforming to EN 60947-5-6. The module supplies 7–9 V DC through a 1 kΩ source resistance and interprets changes in loop current as ON/OFF status.
Can I use it in a Zone 0 hazardous area?
Yes. The field-side circuit is intrinsically safe and supports switches in Zone 0, IIC, T6 locations. Certified NAMUR proximity detectors can be used in Zone 0, IIC, T4–T6 locations. The module itself mounts in the safe area.
Does the MTL5517 detect both open and short circuits?
Yes. When line fault detection is enabled, it detects open- and short-circuit conditions in the field loop and signals the fault through a dedicated LFD relay and red LEDs.
Can I reverse the logic without changing PLC programming?
Yes. The phase-reversal DIL switch on the side of the module inverts the output logic. This is useful when replacing an older module or matching an existing PLC logic convention.
Can I hot-swap the MTL5517?
To be honest, this is not a module to pull live without a plan. Although the MTL5500 housing is designed for DIN-rail installation, isolate the relevant loop and follow your plant’s live-work procedure. Removing it under power can disrupt the field circuit and may cause an unexpected PLC input change.
Why is New Surplus less expensive than factory-new stock?
New Surplus means genuine Eaton/MTL inventory manufactured earlier but not installed or commissioned. We inspect, document, and functionally verify each unit before shipment. It is not used, repaired, or refurbished stock unless clearly stated on the product page.
