MTL5514D Eaton Crouse-Hinds Isolator Digital Input
Product Introduction
The Eaton MTL5514D isolator connects a switch or proximity detector from a hazardous location to a safe-area control system. This device belongs to the MTL5500 series and offers one input channel. It operates from a 20-35 Vdc supply and draws only 29 mA at 24 Vdc. The unit delivers two single-pole relay outputs with changeover contacts. Moreover, it includes user-selectable line fault detection (LFD) and phase reversal capability.
Key Technical Specifications
The MTL5514D provides a sensor voltage of 7-9 Vdc from a 1kΩ ±10% source. Its output closes when the input exceeds 2.1 mA (input circuit below 2kΩ). Conversely, the output opens when the input drops below 1.2 mA (input circuit above 10kΩ). Hysteresis is 200µA (650Ω nominal). Response time is 10 ms maximum.
For the relay contacts (Zone 2 safe area), the rating is 35V, 2A, 100VA. Galvanic isolation reaches 250V rms (highlighted in red if needed, but shown here in bold) between safe-area circuits and the power supply. Power dissipation is only 0.7W at 24V.
The unit complies with IEC/EN61326 for EMC and meets IEC61508 for SIL2 and SIL3 safety integrity. It carries IECEx/ATEX approval for Zone 0 hazardous areas.
Mechanical and Environmental Data
This isolator measures 109.8 mm in length, 118.8 mm in height, and 15.8 mm in width. It weighs just 150 g. The ambient operating temperature ranges from -20°C to 60°C. Storage temperature spans -40°C to 80°C. Humidity tolerance is 5-95% relative humidity (non-condensing).
Installation Guidelines
Mount the Eaton MTL5514D on a standard 35 mm DIN rail (T-section). Use crimp ferrules for electrical connections. The terminal accepts conductors up to 2.5 mm² (stranded or single-core). Set the line fault detection via switches on the side of the unit. The green LED indicates power, the yellow LED shows status, and the red LED lights for LFD.
For installation in hazardous locations, follow local codes and the device’s IECEx/ATEX certification. Ensure the power supply remains within 20-35 Vdc. Phase reversal is selectable to match sensor wiring.
Packaging List
1 x MTL5514D isolator unit
1 x Product label (pre-installed)
2 x Side-mounted configuration switches (integral)
No mounting screws required (DIN rail clip included)
Note: Certificates and warranty are not included in the package.
Shipping
We ship worldwide via FedEx, UPS, or DHL.
Frequently Asked Questions (FAQ)
1. What type of input sensor works with the MTL5514D?
It works with mechanical switches, NAMUR proximity detectors, and other dry contact devices. The input threshold is 2.1 mA for ON and 1.2 mA for OFF.
2. Can this isolator be used in a SIL3 loop?
Yes, the MTL5514D is certified for SIL2 and SIL3 according to IEC61508. It suits safety instrumented systems (SIS).
3. How do I enable line fault detection (LFD)?
Use the two small switches on the side of the unit. LFD monitors for open or short circuits in the field wiring. A red LED will indicate a fault.
4. What is the maximum relay switching frequency?
The datasheet specifies a response time of 10 ms. Therefore, the relay can switch up to approximately 50 Hz, but check your load for derating.
5. Does the unit require an external power supply?
Yes, you must connect a 20-35 Vdc power source. Current consumption is 29 mA at 24 Vdc. The unit does not loop-power from the input.
