The Yokogawa UT152-VN is a critical safety interface device. It is not just a signal converter but a certified safety barrier that protects industrial plants by ensuring signals to and from hazardous areas are energy-limited, thus preventing the risk of fire or explosion.<br />
<br />
Technical Parameters / Specifications
Category Parameter Specification
General Model UT152-VN
Type Single-channel Intrinsically Safe Isolator (Rectifier Type)
Mounting DIN rail mount inside a Yokogawa UTSX Series housing
Input (Field Side - Hazardous Area) Signal 4 to 20 mA DC (2-wire transmitter)
Input Resistance 85 Ω (internal burden)
Maximum Open Voltage (Ui) 28 V DC (Energy-limited for safety)
Maximum Short Current (Ii) 93 mA (Energy-limited for safety)
Output (System Side - Safe Area) Signal 4 to 20 mA DC
Load Resistance 0 to 750 Ω
Power Supply 20.4 to 31.2 V DC (Supplied to the UTSX housing)
Performance Accuracy ±0.1% of span
Temperature Drift ±0.015% of span per °C
Response Time < 150 ms
Isolation 1500 V AC between Input-Output-Power
Safety Approvals Intrinsic Safety Typically approved under ATEX, IECEx, NEPSI, and other international standards for intrinsic safety. (Note: Specific approval codes depend on the certification body and must be verified for the specific unit.)
Hazardous Area Rating The approved entity parameters (Ui, Ii, Pi, etc.) define the safe installation conditions for the field device.
Environment Operating Temperature -20°C to +60°C
Storage Temperature -40°C to +80°C
Humidity 10 to 90% RH (non-condensing)
Function and Application
Function:
Power Provision: Supplies loop power to a 2-wire intrinsically safe field transmitter (e.g., pressure, temperature, flow transmitter).
Signal Conditioning: Receives the 4-20mA signal from the transmitter, isolates it, and reproduces a precise, noise-free 4-20mA output signal for the control system.
Safety Barrier: Limits the voltage (Ui) and current (Ii) available in the hazardous area to levels that cannot cause an ignition.