The Eaton / MTL Instruments MTL4041B is a single-channel repeater power supply that energizes conventional 2- or 3-wire 4/20mA transmitters and smart transmitters installed in hazardous areas, then repeats the current signal in a separate safe-area circuit. The unit supports bi-directional digital communication signals superimposed on the 4/20mA loop, enabling interrogation from operator stations and hand-held communicators. It also accommodates hazardous-area current sources, vortex meters, and turbine meters.
## Technical Specifications
The MTL4041B delivers a minimum of 15V at 20mA to the transmitter and line, with maximum open-circuit voltage of 28V. Input and output signal range spans 4 to 20mA, with over-/under-range capability from 1.0mA to 21.5mA. Digital signal bandwidth extends from 10Hz to 8kHz. Transfer accuracy at 20°C is better than 20µA, with temperature drift less than 1µA/°C. Response time settles within 200µA of final value in 20ms.
For conventional transmitters, safe-area circuit load resistance is 0 to 650Ω; for smart transmitters, 250Ω ±10%. Safe-area output resistance exceeds 1MΩ. Ripple is limited to less than 50µA peak-to-peak up to 80kHz. The supply requires 65mA at 24V dc, 75mA at 20V dc, or 50mA at 35V dc with 20mA signal. Power dissipation reaches 1.2W at 24V with 20mA signal and 1.4W at 35V. Isolation between safe- and hazardous-area circuits is 250V ac.
## Key Features
• Line Fault Detection (LFD) repeats open-circuit or short-circuit currents to the safe-area control system
• Non-energy storing apparatus design (≤1.2V, ≤0.1A, ≤20µJ, ≤25mW) allows direct connection to any intrinsically safe loop with open-circuit voltage ≤28V
• Green LED power indicator
• Compact 16mm module width; 0.24 lbs weight
• Glass-fibre reinforced polyester base with transparent high-strength polycarbonate lid
• Fully floating DC supply for hazardous-area installations
## Typical Applications
• Energizing 2- or 3-wire 4/20mA transmitters in Zone 0, IIC, T4–6 or Div. 1, Group A hazardous locations
• Smart transmitter interrogation systems
• Vortex and turbine meter signal conversion
• Current source isolation in intrinsically safe circuits
## Compatibility & Integration
The MTL4041B is part of the MTL4000 series, now discontinued; the MTL4500 series is the manufacturer’s recommended replacement for new installations.
